© 2009 Microchip Technology Inc. DS21974B-page 1
TC1313
Features
Dual-Output Regulator (500 mA Buck Regulator
and 300 mA Low-Dropout Regulator (LDO))
Total Device Quiescent Current = 57 µA (Typical)
Independent Shutdown for Buck and LDO
Outputs
Both Outputs Internally Compensated
Synchronous Buck Regulator:
- Over 90% Typical Efficiency
- 2.0 MHz Fixed-Frequency PWM
(Heavy Load)
- Low Output Noise
- Automatic PWM-to-PFM mode transition
- Adjustable (0.8V to 4.5V) and Standard
Fixed-Output Voltages (0.8V, 1.2V, 1.5V,
1.8V, 2.5V, 3.3V)
Low-Dropout Regulator:
- Low-Dropout Voltage = 137 mV Typical @
200 mA
- Standard Fixed-Output Voltages
(1.5V, 1.8V, 2.5V, 3.3V)
Small 10-pin 3x3 DFN or MSOP Package Options
Operating Junction Temperature Range:
- -40°C to +125°C
Undervoltage Lockout (UVLO)
Output Short Circuit Protection
Overtemperature Protection
Applications
Cellular Phones
Portable Computers
USB-Powered Devices
Handheld Medical Instruments
Organizers and PDAs
Description
The TC1313 device combines a 500 mA synchronous
buck regulator and 300 mA Low-Dropout Regulator
(LDO) to provide a highly integrated solution for
devices that require multiple supply voltages. The
unique combination of an integrated buck switching
regulator and low-dropout linear regulator provides the
lowest system cost for dual-output voltage applications
that require one lower processor core voltage and one
higher bias voltage.
The 500 mA synchronous buck regulator switches at a
fixed frequency of 2.0 MHz when the load is heavy,
providing a low-noise, small-size solution. When the
load on the buck output is reduced to light levels, it
changes operation to a Pulse Frequency Modulation
(PFM) mode to minimize quiescent current draw from
the battery. No intervention is necessary for smooth
transition from one mode to another.
The LDO provides a 300 mA auxiliary output that
requires a single 1 µF ceramic output capacitor,
minimizing board area and cost. The typical dropout
voltage for the LDO output is 137 mV for a 200 mA
load.
The TC1313 device is available in either the 10-pin DFN
or MSOP package.
Additional protection features include: UVLO,
overtemperature and overcurrent protection on both
outputs.
For a complete listing of TC1313 standard parts,
consult your Microchip representative.
Package Type
10-Lead DFN *
10-Lead MSOP
1
2
6
8
7
9
10
5
4
3
SHDN2
VIN2
VOUT2
AGND
PGND
LX
VIN1
SHDN1
VFB1/VOUT1
NC
VOUT2
VIN2
NC
LX
VIN1
1
2
3
4
10
9
8
7SHDN1
PGND
SHDN2
EP
11
56VFB1/VOUT1
AGND
* Includes Exposed Thermal Pad (EP); see Ta b l e 3 - 1 .
500 mA Synchronous Buck Regulator,
+ 300 mA LDO
TC1313
DS21974B-page 2 © 2009 Microchip Technology Inc.
Functional Block Diagram
Synchronous Buck Regulator
NDRV
PDRV
PGND
VIN1
LX
Driver
PGND
Control
VOUT1/VFB1
VIN2
SHDN1
VREF
LDO
VOUT2
AGND
AGND
PGND
Undervoltage Lockout UVLO
UVLO
SHDN2
VREF (UVLO)
© 2009 Microchip Technology Inc. DS21974B-page 3
TC1313
Typical Application Circuits
10-Lead DFN
4.7 µF
Input
Voltage
4.7 µH
4.7 µF 2.1V @
F 3.3V @
4.5V to 5.5V
Adjustable-Output Application
121 k
200 k4.99 k
33 pF
1
2
6
8
7
9
10
54
3SHDN2
VIN2
VOUT2
AGND
PGND
LX
VIN1
SHDN1 VOUT1
NC
4.7 µF
4.7 µH
4.7 µF 1.5V @ 500 mA
F 2.5V @ 300 mA
2.7V to 4.2V
TC1313
VOUT1
VOUT2
VIN
VOUT1
VOUT2
1.0 µF
*Optional
Capacitor
VIN2 300 mA
500 mA
Note: Connect DFN package exposed pad to AGND.
10-Lead MSOP
Fixed-Output Application
TC1313
Note
VOUT2
VIN2
NC
LX
8
2
7
1
9
10
6
3
SHDN1
PGND
SHDN2
EP
11
45
VOUT1
AGND
VIN1
TC1313
DS21974B-page 4 © 2009 Microchip Technology Inc.
NOTES:
© 2009 Microchip Technology Inc. DS21974B-page 5
TC1313
1.0 ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings †
VIN - AGND ......................................................................6.0V
All Other I/O ...............................(AGND - 0.3V) to (VIN + 0.3V)
LX to PGND...............................................-0.3V to (VIN + 0.3V)
PGND to AGND .................................................. -0.3V to +0.3V
Output Short Circuit Current ................................ Continuous
Power Dissipation (Note 7) .......................... Internally Limited
Storage temperature .....................................-65°C to +150°C
Ambient Temp. with Power Applied ................-40°C to +85°C
Operating Junction Temperature...................-40°C to +125°C
ESD protection on all pins (HBM) ....................................... 3kV
† Notice: Stresses above those listed under “Maximum
Ratings” may cause permanent damage to the device. This is
a stress rating only and functional operation of the device at
those or any other conditions above those indicated in the
operational listings of this specification is not implied.
Exposure to maximum rating conditions for extended periods
may affect device reliability.
DC CHARACTERISTICS
Electrical Characteristics: VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
= 4.7 µH, VOUT1 (ADJ) = 1.8V,
IOUT1 = 100 ma, IOUT2 = 0.1 mA TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C.
Parameters Sym Min Typ Max Units Conditions
Input/Output C haracteristics
Input Voltage VIN 2.7 5.5 VNote 1, Note 2, Note 8
Maximum Output Current IOUT1_MAX 500 —— mANote 1
Maximum Output Current IOUT2_MAX 300 —— mANote 1
Shutdown Current
Combined VIN1 and VIN2 Current
IIN_SHDN 0.05 1 µA SHDN1 =SHDN2=GND
Operating IQIQ—57100 µA SHDN1 =SHDN2=V
IN2
IOUT1 =0mA, I
OUT2 =0mA
Synchronous Buck IQ 38 µA SHDN1 = VIN, SHDN2 = GND
LDO IQ 44 µA SHDN1 = GND, SHDN2 = VIN2
Shutdown/UVLO/Thermal Shutdown Characteristics
SHDN1,SHDN2,
Logic Input Voltage Low
VIL ——15 %VIN VIN1 =V
IN2 = 2.7V to 5.5V
SHDN1,SHDN2,
Logic Input Voltage High
VIH 45 ——%V
IN VIN1 =V
IN2 = 2.7V to 5.5V
SHDN1,SHDN2,
Input Leakage Current
IIN -1.0 ±0.01 1.0 µA VIN1 =V
IN2 = 2.7V to 5.5V
SHDNX =GND
SHDNY=V
IN
Thermal Shutdown TSHD 165 °C Note 6, Note 7
Thermal Shutdown Hysteresis TSHD-HYS —10 °C
Undervoltage Lockout
(VOUT1 and VOUT2)
UVLO 2.4 2.55 2.7 VV
IN1 Falling
Undervoltage Lockout Hysteresis UVLO-HYS 200 mV
Note 1: The Minimum VIN has to meet two conditions: VIN 2.7V and VIN VRX + VDROPOUT, VRX = VR1 or VR2.
2: VRX is the regulator output voltage setting.
3: TCVOUT2 = ((VOUT2max – VOUT2min) * 106)/(VOUT2 * DT).
4: Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested
over a load range from 0.1 mA to the maximum specified output current.
5: Dropout voltage is defined as the input-to-output voltage differential at which the output voltage drops 2% below its
nominal value measured at a 1V differential.
6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction
temperature and the thermal resistance from junction to air. (i.e. TA, TJ, θJA). Exceeding the maximum allowable power
dissipation causes the device to initiate thermal shutdown.
7: The integrated MOSFET switches have an integral diode from the LX pin to VIN, and from LX to PGND. In cases where
these diodes are forward-biased, the package power dissipation limits must be adhered to. Thermal protection is not
able to limit the junction temperature for these cases.
8: VIN1 and VIN2 are supplied by the same input source.
TC1313
DS21974B-page 6 © 2009 Microchip Technology Inc.
Synchronous Buck Regulator (VOUT1)
Adjustable Output Voltage Range VOUT1 0.8 4.5 V
Adjustable Reference Feedback
Voltage (VFB1)
VFB1 0.78 0.8 0.82 V
Feedback Input Bias Current
(IFB1)
IVFB1 —-1.5 nA
Output Voltage Tolerance Fixed
(VOUT1)
VOUT1 -2.5 ±0.3 +2.5 %Note 2
Line Regulation (VOUT1)V
LINE-REG 0.2 %/V VIN = VR+1V to 5.5V,
ILOAD = 100 mA
Load Regulation (VOUT1)V
LOAD-REG —0.2 %V
IN =V
R+1.5V, I
LOAD = 100 mA to
500 mA (Note 1)
Dropout Voltage VOUT1 VIN – VOUT1 280 mV IOUT1 = 500 mA, VOUT1 =3.3V
(Note 5)
Internal Oscillator Frequency FOSC 1.6 2.0 2.4 MHz
Start Up Time TSS —0.5 msT
R = 10% to 90%
RDSon P-Channel RDSon-P 450 mΩIP = 100 mA
RDSon N-Channel RDSon-N 450 mΩIN = 100 mA
LX Pin Leakage Current ILX -1.0 ±0.01 1.0 μA SHDN = 0V, VIN = 5.5V, LX = 0V,
LX = 5.5V
Positive Current Limit Threshold +ILX(MAX) 700 mA
LDO Output (VOUT2)
Output Voltage Tolerance (VOUT2)V
OUT2 -2.5 ±0.3 +2.5 %Note 2
Temperature Coefficient TCVOUT 25 ppm/°C Note 3
Line Regulation ΔVOUT2/
ΔVIN
-0.2 ±0.02 +0.2 %/V (VR+1V) VIN 5.5V
Load Regulation, VOUT2 2.5V ΔVOUT2/
IOUT2
-0.75 0.1 +0.75 %I
OUT2 = 0.1 mA to 300 mA (Note 4)
Load Regulation, VOUT2 < 2.5V ΔVOUT2/
IOUT2
-0.90 0.1 +0.90 %I
OUT2 = 0.1 mA to 300 mA (Note 4)
Dropout Voltage VOUT2 > 2.5V VIN – VOUT2 137 300 mV IOUT2 = 200 mA (Note 5)
IOUT2 = 300 mA
205 500
Power Supply Rejection Ratio PSRR 62 dB f = 100 Hz, IOUT1 = IOUT2 = 50 mA,
CIN = 0 µF
Output Noise eN 1.8 µV/(Hz)½f = 1 kHz, IOUT2 =50mA,
SHDN1 =GND
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics: VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
= 4.7 µH, VOUT1 (ADJ) = 1.8V,
IOUT1 = 100 ma, IOUT2 = 0.1 mA TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C.
Parameters Sym Min Typ Max Units Conditions
Note 1: The Minimum VIN has to meet two conditions: VIN 2.7V and VIN VRX + VDROPOUT, VRX = VR1 or VR2.
2: VRX is the regulator output voltage setting.
3: TCVOUT2 = ((VOUT2max – VOUT2min) * 106)/(VOUT2 * DT).
4: Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested
over a load range from 0.1 mA to the maximum specified output current.
5: Dropout voltage is defined as the input-to-output voltage differential at which the output voltage drops 2% below its
nominal value measured at a 1V differential.
6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction
temperature and the thermal resistance from junction to air. (i.e. TA, TJ, θJA). Exceeding the maximum allowable power
dissipation causes the device to initiate thermal shutdown.
7: The integrated MOSFET switches have an integral diode from the LX pin to VIN, and from LX to PGND. In cases where
these diodes are forward-biased, the package power dissipation limits must be adhered to. Thermal protection is not
able to limit the junction temperature for these cases.
8: VIN1 and VIN2 are supplied by the same input source.
© 2009 Microchip Technology Inc. DS21974B-page 7
TC1313
TEMPERATURE SPECIFICATIONS
Output Short Circuit Current
(Average)
IOUTsc2 240 mA RLOAD2 1Ω
Wake-Up Time
(From SHDN2 mode), (VOUT2)
tWK —31100µsI
OUT1 = IOUT2 = 50 mA
Settling Time
(From SHDN2 mode), (VOUT2)
tS 100 µs IOUT1 = IOUT2 = 50 mA
Electrical Specifications: Unless otherwise indicated, all limits are specified for: VIN = +2.7V to +5.5V
Parameters Sym Min Typ Max Units Conditions
Temperature Ranges
Operating Junction Temperature Range TJ-40 +125 °C Steady state
Storage Temperature Range TA-65 +150 °C
Maximum Junction Temperature TJ +150 °C Transient
Thermal Package Resistances
Thermal Resistance, 10L-DFN θJA 41 °C/W Typical 4-layer board with Internal
Ground Plane and 2 Vias in Thermal
Pad
Thermal Resistance, 10L-MSOP θJA 113 °C/W Typical 4-layer board with Internal
Ground Plane
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics: VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
= 4.7 µH, VOUT1 (ADJ) = 1.8V,
IOUT1 = 100 ma, IOUT2 = 0.1 mA TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C.
Parameters Sym Min Typ Max Units Conditions
Note 1: The Minimum VIN has to meet two conditions: VIN 2.7V and VIN VRX + VDROPOUT, VRX = VR1 or VR2.
2: VRX is the regulator output voltage setting.
3: TCVOUT2 = ((VOUT2max – VOUT2min) * 106)/(VOUT2 * DT).
4: Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested
over a load range from 0.1 mA to the maximum specified output current.
5: Dropout voltage is defined as the input-to-output voltage differential at which the output voltage drops 2% below its
nominal value measured at a 1V differential.
6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction
temperature and the thermal resistance from junction to air. (i.e. TA, TJ, θJA). Exceeding the maximum allowable power
dissipation causes the device to initiate thermal shutdown.
7: The integrated MOSFET switches have an integral diode from the LX pin to VIN, and from LX to PGND. In cases where
these diodes are forward-biased, the package power dissipation limits must be adhered to. Thermal protection is not
able to limit the junction temperature for these cases.
8: VIN1 and VIN2 are supplied by the same input source.
TC1313
DS21974B-page 8 © 2009 Microchip Technology Inc.
2.0 TYPICAL PERFORMANCE CURVES
Note: Unless otherwise indicated, VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
=4.H,
VOUT1 (ADJ) = 1.8V, TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C. TA= +25°C. Adjustable or fixed-
output voltage options can be used to generate the Typical Performance Characteristics.
FIGURE 2-1: IQ Switcher and LDO
Current vs. Ambient Temperature.
FIGURE 2-2: IQ Switcher Current vs.
Ambient Temperature.
FIGURE 2-3: IQ LDO Current vs. Ambient
Temperature.
FIGURE 2-4: VOUT1 Output Efficiency vs.
Input Voltage (VOUT1 = 1.2V).
FIGURE 2-5: VOUT1 Output Efficiency vs.
IOUT1 (VOUT1 = 1.2V).
FIGURE 2-6: VOUT1 Output Efficiency vs.
Input Voltage (VOUT1 = 1.8V).
Note: The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
52
54
56
58
60
62
64
66
-40 -25 -10 5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
IQ Switcher and LDO (µA)
VIN = 5.5V
VIN = 4.2V
VIN = 3.6V
SHDN1 = VIN2
SHDN2 = VIN2
30
32
34
36
38
40
-40 -25 -10 5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
IQ Switcher (µA)
VIN = 5.5V
VIN = 4.2V
VIN = 3.6V
SHDN1 = VIN2
SHDN2 = AGND
36
38
40
42
44
46
48
50
-40 -25 -10 5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
IQ LDO (µA)
VIN = 5.5V
VIN = 4.2V
VIN = 3.6V
SHDN1 = AGND
SHDN2 = VIN2
50
55
60
65
70
75
80
85
90
95
100
2.7 3.05 3.4 3.75 4.1 4.45 4.8 5.15 5.5
Input Voltage (V)
VOUT1 Efficiency (%)
IOUT1 = 100 mA
IOUT1 = 250 mA
IOUT1 = 500 mA
SHDN1 = VIN2
SHDN2 = AGND
70
75
80
85
90
95
100
0.005 0.104 0.203 0.302 0.401 0.5
IOUT1 (A)
VOUT1 Efficiency(%)
VIN1 = 3.0V
VIN1 = 4.2V VIN1 = 3.6V
SHDN1 = VIN2
SHDN2 = AGND
60
65
70
75
80
85
90
95
100
2.7 3.05 3.4 3.75 4.1 4.45 4.8 5.15 5.5
Input Voltage (V)
VOUT1 Efficiency(% )
IOUT1 = 100 mA
IOUT1 = 250 mA
IOUT1 = 500 mA
SHDN1 = VIN2
SHDN2 = AGND
© 2009 Microchip Technology Inc. DS21974B-page 9
TC1313
Note: Unless otherwise indicated, VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
=4.H,
VOUT1 (ADJ) = 1.8V, TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C. TA= +25°C. Adjustable or fixed-
output voltage options can be used to generate the Typical Performance Characteristics.
FIGURE 2-7: VOUT1 Output Efficiency vs.
IOUT1 (VOUT1 = 1.8V).
FIGURE 2-8: VOUT1 Output Efficiency vs.
Input Voltage (VOUT1 = 3.3V).
FIGURE 2-9: VOUT1 Output Efficiency vs.
IOUT1 (VOUT1 = 3.3V).
FIGURE 2-10: VOUT1 vs. IOUT1
(VOUT1 = 1.2V).
FIGURE 2-11: VOUT1 vs. IOUT1
(VOUT1 = 1.8V).
FIGURE 2-12: VOUT1 vs. IOUT1
(VOUT1 = 3.3V).
75
80
85
90
95
100
0.005 0.104 0.203 0.302 0.401 0.5
IOUT1 (A)
VOUT1 Efficiency(%)
SHDN1 = VIN2
SHDN2 = AGND
VIN = 3.0V
VIN = 4.2V
VIN = 3.6V
80
84
88
92
96
100
3.60 3.92 4.23 4.55 4.87 5.18 5.50
Input Voltage (V)
VOUT1 Efficiency (%)
IOUT1 = 100 mA
IOUT1 = 250 mA
IOUT1 = 500 mA
SHDN1 = VIN2
SHDN2 = AGND
60
65
70
75
80
85
90
95
100
0.005 0.104 0.203 0.302 0.401 0.5
IOUT1 (A)
VOUT1 Efficiency (%)
VIN1 = 5.5V
SHDN1 = VIN2
SHDN2 = AGND
VIN1 = 4.2V
VIN1 = 3.6V
1.19
1.194
1.198
1.202
1.206
1.21
0.005 0.104 0.203 0.302 0.401 0.5
IOUT1 (A)
VOUT1 (V)
SHDN1 = VIN2
SHDN2 = AGND
VIN1 = 3.6V
1.79
1.795
1.8
1.805
1.81
1.815
1.82
0.005 0.104 0.203 0.302 0.401 0.5
IOUT1 (A)
VOUT1 (V)
SHDN1 = VIN2
SHDN2 = AGND
VIN1 = 3.6V
3.2
3.24
3.28
3.32
3.36
3.4
0.005 0.104 0.203 0.302 0.401 0.5
IOUT1 (A)
VOUT1 (V)
SHDN1 = VIN2
SHDN2 = AGND
VIN1 = 4.2V
TC1313
DS21974B-page 10 © 2009 Microchip Technology Inc.
Note: Unless otherwise indicated, VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
=4.H,
VOUT1 (ADJ) = 1.8V, TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C. TA= +25°C. Adjustable or fixed-
output voltage options can be used to generate the Typical Performance Characteristics.
FIGURE 2-13: VOUT1 Switching Frequency
vs. Input Voltage.
FIGURE 2-14: VOUT1 Switching Frequency
vs. Ambient Temperature.
FIGURE 2-15: VOUT1 Adjustable Fee dback
Voltage vs. Ambient Temp erature.
FIGURE 2-16: VOUT1 Switch Resistance
vs. Input Voltage.
FIGURE 2-17: VOUT1 Switch Resistance
vs. Ambient Temperature.
FIGURE 2-18: VOUT1 Dropout Voltage vs.
Ambient Temperature.
1.90
1.95
2.00
2.05
2.10
2.15
2.20
2.73.13.53.94.34.75.15.5
Input Voltage (V)
VOUT1 Frequency (MHz)
SHDN1 = VIN2
SHDN2 = AGND
1.90
1.92
1.94
1.96
1.98
2.00
-40
-25
-10
5
20
35
50
65
80
95
110
125
Ambient T emp erature C)
VOUT1 Frequency (MHz)
SHDN1 = VIN2
SHDN2 = AGND
0.790
0.795
0.800
0.805
0.810
0.815
0.820
-40
-25
-10
5
20
35
50
65
80
95
110
125
Ambient Temperature (°C)
VOUT1 FB Voltage (V)
SHDN1 = VIN2
SHDN2 = AGND
VIN1 = 3.6V
0.40
0.45
0.50
0.55
0.60
0.65
3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5
Input Voltage (V)
VOUT1 Switch Resistance (:)
SHDN1 = VIN2
SHDN2 = AGND
VIN1 = 3.6V
N-Channel
P-Channel
0.40
0.45
0.50
0.55
0.60
0.65
0.70
-40 -25 -10 5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
Buck Regulator Switch
Resistance (:)
VIN1 = 3.6V
N-Channel
P-Channel
SHDN1 = VIN2
SHDN2 = AGND
0.1
0.15
0.2
0.25
0.3
0.35
0.4
-40
-25
-10
5
20
35
50
65
80
95
110
125
Ambient Temperature (°C)
VOUT1 Dropout Voltage (V)
SHDN1 = VIN2
SHDN2 = AGND
VOUT1
= 3.3
V
IOUT1
= 500 mA
© 2009 Microchip Technology Inc. DS21974B-page 11
TC1313
Note: Unless otherwise indicated, VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
=4.H,
VOUT1 (ADJ) = 1.8V, TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C. TA= +25°C. Adjustable or fixed-
output voltage options can be used to generate the Typical Performance Characteristics.
FIGURE 2-19: VOUT1 and VOUT2 Heavy
Load Switching Waveforms vs. Time.
FIGURE 2-20: VOUT1 and VOUT2 Light
Load Switching Waveforms vs. Time.
FIGURE 2-21: VOUT2 Output Voltage vs.
Input Voltage (VOUT2 = 1.5V).
FIGURE 2-22: VOUT2 Output Voltage vs.
Input Voltage (VOUT2 = 1.8V).
FIGURE 2-23: VOUT2 Output Voltage vs.
Input Voltage (VOUT2 = 2.5V).
FIGURE 2-24: VOUT2 Output Voltage vs.
Input Voltage (VOUT2 = 3.3V).
1.482
1.484
1.486
1.488
1.49
1.492
2.7 3.05 3.4 3.75 4.1 4.45 4.8 5.15 5.5
Input Voltage (V)
VOUT2 Output Voltage(V)
TA
= - 40°C
TA
= + 25°C
TA
= + 85°C
IOUT2 = 150 mA
SHDN1 = AGND
SHDN2 = VIN2
1.792
1.794
1.796
1.798
1.800
1.802
2.7 3.05 3.4 3.75 4.1 4.45 4.8 5.15 5.5
Input Voltage (V)
VOUT2 Output Voltage (V )
TA
= - 40°C
TA
= + 25°C
TA
= + 85°C
IOUT2 = 150 mA SHDN1 = AGND
SHDN2 = VIN2
2.496
2.498
2.500
2.502
2.504
2.506
2.508
3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5
Input Voltage (V)
VOUT2 Output Voltage (V )
TA
= - 40°C
TA
= + 25°C
TA
= + 85°C
IOUT2 = 150 mA SHDN1 = AGND
SHDN2 = VIN2
3.292
3.293
3.294
3.295
3.296
3.297
3.298
3.60 3.92 4.23 4.55 4.87 5.18 5.50
Input Voltage (V)
VOUT2 Output Voltage (V)
TA
= - 40°C
TA
= + 25°C
TA
= + 85°C
IOUT2 = 150 mA SHDN1 = AGND
SHDN2 = VIN2
TC1313
DS21974B-page 12 © 2009 Microchip Technology Inc.
Note: Unless otherwise indicated, VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
=4.H,
VOUT1 (ADJ) = 1.8V, TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C. TA= +25°C. Adjustable or fixed-
output voltage options can be used to generate the Typical Performance Characteristics.
FIGURE 2-25: VOUT2 Dropout Voltage vs.
Ambient Temperature (VOUT2 = 2.5V).
FIGURE 2-26: VOUT2 Dropout Voltage vs.
Ambient Temperature (VOUT2 = 3.3V).
FIGURE 2-27: VOUT2 Line Regulation vs.
Ambient Temperature.
FIGURE 2-28: VOUT2 Load Regulation vs.
Ambient Temperature.
FIGURE 2-29: VOUT2 Power Su pply Ripp le
Rejection vs. Frequency.
FIGURE 2-30: VOUT2 Noise vs. Frequency.
0.05
0.10
0.15
0.20
0.25
0.30
-40
-25
-10
5
20
35
50
65
80
95
110
125
Ambient Temperature (°C)
VOUT2 Dropout Voltage (V)
IOUT2 = 200 mA
IOUT2 = 300 mA
SHDN1 = AGND
SHDN2 = VIN2
0.0
0.1
0.2
0.3
-40 -25 -10 5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
VOUT2 Dropout Voltage (V)
IOUT2 = 200 mA
SHDN1 = AGND
SHDN2 = VIN2
IOUT2 = 300 mA
-0.035
-0.030
-0.025
-0.020
-0.015
-0.010
-0.005
0.000
0.005
-40 -25 -10 5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
VOUT2 Line Regulation (%/V)
VOUT2
= 3.3V
IOUT2 = 100 µA
SHDN1 = AGND
SHDN2 = VIN2
VOUT2
= 2.5V
VOUT2
= 1.5V
-0.4
-0.3
-0.2
-0.1
0.0
0.1
-40
-25
-10
5
20
35
50
65
80
95
110
125
Ambient Temperature (°C)
VOUT2 Load Regulation (%)
VOUT2
= 3.3V
VIN2 = 3.6V SHDN1 = AGND
SHDN2 = VIN2
VOUT2
= 2.6V
VOUT2
= 1.5V
-80
-70
-60
-50
-40
-30
-20
-10
0
0.01 0.1 1 10 100 1000
Frequency (kHz)
VOUT2 PSRR (dB)
SHDN1 = GND
VOUT2 = 1.5V
IOUT2 = 30 mA
CIN = 0 µF
COUT2 = 1.0 µF
COUT2 = 4.7 µF
0.01
0.1
1
10
0.01 0.1 1 10 100 1000 10000
Frequency (kHz)
VOUT2 Noise (µV/Hz)
SHDN1 = AGND
SHDN2 = VIN2
VIN = 3.6V
VOUT2 = 2.5V
IOUT2 = 50 mA
© 2009 Microchip Technology Inc. DS21974B-page 13
TC1313
Note: Unless otherwise indicated, VIN1 = VIN2 = SHDN1,2 = 3.6V, COUT1 =C
IN = 4.7 µF, COUT2 =1µF, L
=4.H,
VOUT1 (ADJ) = 1.8V, TA= +25°C. Boldface specifications apply over the TA range of -40°C to +85°C. TA= +25°C. Adjustable or fixed-
output voltage options can be used to generate the Typical Performance Characteristics.
FIGURE 2-31: VOUT1 Load S tep Respo nse
vs. Time.
FIGURE 2-32: VOUT2 Load S tep Respo nse
vs. Time.
FIGURE 2-33: VOUT1 and VOUT2 Line Step
Response vs. Time.
FIGURE 2-34: VOUT1 and VOUT2 Startup
Waveforms.
FIGURE 2-35: VOUT1 and VOUT2 Shut down
Waveforms.
TC1313
DS21974B-page 14 © 2009 Microchip Technology Inc.
NOTES:
© 2009 Microchip Technology Inc. DS21974B-page 15
TC1313
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1: PIN FUNCTION TABLE
3.1 LDO Shutdown Input Pin (SHDN2)
SHDN2 is a logic-level input used to turn the LDO
regulator on and off. A logic-high (> 45% of VIN) will
enable the regulator output. A logic-low (< 15% of VIN)
will ensure that the output is turned off.
3.2 LDO Input Voltage Pin (VIN2)
VIN2 is a LDO power-input supply pin. Connect
variable-input voltage source to VIN2. Connect VIN1 and
VIN2 together with board traces as short as possible.
VIN2 provides the input voltage for the LDO regulator.
An additional capacitor can be added to lower the LDO
regulator input ripple voltage.
3.3 LDO Output Voltage Pin (VOUT2)
VOUT2 is a regulated LDO output voltage pin. Connect
a 1 µF or larger capacitor to VOUT2 and AGND for proper
operation.
3.4 No Connect Pin (NC)
No connection.
3.5 Analog Ground Pin (AGND)
AGND is the analog ground connection. Tie AGND to the
analog portion of the ground plane (AGND). See the
physical layout information in Section 5.0 “Application
Circuits/Issues” for grounding recommendations.
3.6 Buck Regulator Output Sense Pin
(VFB/VOUT1)
For VOUT1 adjustable-output voltage options, connect
the center of the output voltage divider to the VFB pin.
For fixed-output voltage options, connect the output of
the buck regulator to this pin (VOUT1).
3.7 Buck Regulator Shutdown Input
Pin (SHDN1)
SHDN1 is a logic-level input used to turn the buck
regulator on and off. A logic-high (> 45% of VIN) will
enable the regulator output. A logic-low (< 15% of VIN)
will ensure that the output is turned off.
3.8 Buck Regulator Input Voltage Pin
(VIN1)
VIN1 is the buck regulator power-input supply pin.
Connect a variable-input voltage source to VIN1.
Connect VIN1 and VIN2 together with board traces as
short as possible.
3.9 Buck Inductor Output Pin (LX)
Connect LX directly to the buck inductor. This pin
carries large signal-level current; all connections
should be made as short as possible.
3.10 Power Ground Pin (PGND)
Connect all large-signal level ground returns to PGND.
These large-signal level ground traces should have a
small loop area and length to prevent coupling of
switching noise to sensitive traces. Please see the
physical layout information supplied in Section 5.0
“Application Circuits/Issues” for grounding
recommendations.
3.11 Exposed Pad (EP)
For the DFN package, connect the EP to AGND with
vias into the AGND plane.
Pin DFN MSOP Function
1 SHDN2 SHDN2 Active Low Shutdown Input for LDO Output Pin
2V
IN2 VIN2 Analog Input Supply Voltage Pin
3V
OUT2 VOUT2 LDO Output Voltage Pin
4 NC NC No Connect
5A
GND AGND Analog Ground Pin
6V
FB / VOUT1 VFB / VOUT1 Buck Feedback Voltage (Adjustable Version)/Buck Output Voltage (Fixed
Version) Pin
7 SHDN1 SHDN1 Active Low Shutdown Input for Buck Regulator Output Pin
8V
IN1 VIN1 Buck Regulator Input Voltage Pin
9L
XLXBuck Inductor Output Pin
10 PGND PGND Power Ground Pin
11 EP Exposed Pad. It is a thermal path to remove heat from the device. Electri-
cally, this pad is at ground potential and should be connected to AGND.
TC1313
DS21974B-page 16 © 2009 Microchip Technology Inc.
NOTES:
© 2009 Microchip Technology Inc. DS21974B-page 17
TC1313
4.0 DETAILED DESCRIPTION
4.1 Device Overview
The TC1313 combines a 500 mA synchronous buck
regulator with a 300 mA LDO. This unique combination
provides a small, low-cost solution for applications that
require two or more voltage rails. The buck regulator
can deliver high-output current over a wide range of
input-to-output voltage ratios while maintaining high
efficiency. This is typically used for the lower-voltage,
higher-current processor core. The LDO is a minimal
parts-count solution (single-output capacitor), providing
a regulated voltage for an auxiliary rail. The typical LDO
dropout voltage (137 mV @ 200 mA) allows the use of
very low input-to-output LDO differential voltages,
minimizing the power loss internal to the LDO pass
transistor. Integrated features include independent
shutdown inputs, UVLO, overcurrent and
overtemperature shutdown.
4.2 Synchronous Buck Regulator
The synchronous buck regulator is capable of supply-
ing a 500 mA continuous output current over a wide
range of input and output voltages. The output voltage
range is from 0.8V (min) to 4.5V (max). The regulator
operates in three different modes and automatically
selects the most efficient mode of operation. During
heavy load conditions, the TC1313 buck converter
operates at a high, fixed frequency (2.0 MHz) using
current mode control. This minimizes output ripple and
noise (less than 8 mV peak-to-peak ripple) while main-
taining high efficiency (typically > 90%). For standby or
light-load applications, the buck regulator will automat-
ically switch to a power-saving Pulse Frequency
Modulation (PFM) mode. This minimizes the quiescent
current draw on the battery while keeping the buck
output voltage in regulation. The typical buck PFM
mode current is 38 µA. The buck regulator is capable of
operating at 100% duty cycle, minimizing the voltage
drop from input to output for wide-input, battery-
powered applications. For fixed-output voltage applica-
tions, the feedback divider and control loop compensa-
tion components are integrated, eliminating the need
for external components. The buck regulator output is
protected against overcurrent, short circuit and over-
temperature. While shut down, the synchronous buck
N-channel and P-channel switches are off, so the LX
pin is in a high-impedance state (this allows for
connecting a source on the output of the buck regulator
as long as its voltage does not exceed the input
voltage).
4.2.1 FIXED-FREQUENCY PWM MODE
While operating in Pulse Width Modulation (PWM)
mode, the TC1313 buck regulator switches at a fixed
2.0 MHz frequency. The PWM mode is suited for higher
load current operation, maintaining low output noise
and high conversion efficiency. PFM to PWM mode
transition is initiated for any of the following conditions.
Continuous inductor current is sensed
Inductor peak current exceeds 100 mA
The buck regulator output voltage has dropped
out of regulation (step load has occurred)
The typical PFM-to-PWM threshold is 80 mA.
4.2.2 PFM MODE
PFM mode is entered when the output load on the buck
regulator is very light. Once detected, the converter
enters the PFM mode automatically and begins to skip
pulses to minimize unnecessary quiescent current
draw by reducing the number of switching cycles per
second. The typical quiescent current for the switching
regulator is less than 38 µA. The transition from PWM
to PFM mode occurs when discontinuous inductor
current is sensed, or the peak inductor current is less
than 60 mA (typ.). The typical PWM to PFM mode
threshold is 30 mA. For low input-to-output differential
voltages, the PWM to PFM mode threshold can be low
due to the lack of ripple current. It is recommended that
VIN1 be one volt greater than VOUT1 for PWM to PFM
transitions.
4.3 Low-Dropout Regulator (LDO)
The LDO output is a 300 mA low-dropout linear
regulator that provides a regulated output voltage with
a single 1 µF external capacitor. The output voltage is
available in fixed options only, ranging from 1.5V to
3.3V. The LDO is stable using ceramic output
capacitors that inherently provide lower output noise
and reduce the size and cost of the regulator solution.
The quiescent current consumed by the LDO output is
typically less than 43.7 µA, with a typical dropout
voltage of 137 mV at 200 mA. The LDO output is
protected against overcurrent and overtemperature.
While operating in Dropout mode, the LDO quiescent
current will increase, minimizing the necessary voltage
differential needed for the LDO output to maintain
regulation. The LDO output is protected against over-
current and overtemperature.
4.4 Soft Start
Both outputs of the TC1313 are controlled during
startup. Less than 1% of VOUT1 or VOUT2 overshoot is
observed during start-up from VIN rising above the
UVLO voltage; or SHDN1 or SHDN2 being enabled.
TC1313
DS21974B-page 18 © 2009 Microchip Technology Inc.
4.5 Overtemperature Protection
The TC1313 has an integrated overtemperature
protection circuit that monitors the device junction
temperature and shuts the device off if the junction
temperature exceeds the typical 165°C threshold. If the
overtemperature threshold is reached, the soft start is
reset so that, once the junction temperature cools to
approximately 155°C, the device will automatically
restart.
© 2009 Microchip Technology Inc. DS21974B-page 19
TC1313
5.0 APPLICATION CIRCUITS/
ISSUES
5.1 Typical Applications
The TC1313 500 mA buck regulator + 300 mA LDO
operates over a wide input-voltage range (2.7V to 5.5V)
and is ideal for single-cell Li-Ion battery-powered
applications, USB-powered applications, three-cell
NiMH or NiCd applications and 3V to 5V regulated
input applications. The 10-pin MSOP and 3x3 DFN
packages provide a small footprint with minimal exter-
nal components.
5.2 Fixed-Output Application
A typical VOUT1 fixed-output voltage application is
shown in “Typical Application Circuits”. A 4.7 µF
VIN1 ceramic input capacitor, 4.7 µF VOUT1 ceramic
capacitor, 1.0 µF ceramic VOUT2 capacitor and 4.7 µH
inductor make up the entire external component
solution for this dual-output application. No external
dividers or compensation components are necessary.
For this application, the input-voltage range is 2.7V to
4.2V, VOUT1 = 1.5V at 500 mA, while VOUT2 =2.5V at
300 mA.
5.3 Adjustable-Output Application
A typical VOUT1 adjustable-output application is also
shown in “Typical Application Circuits”. For this
application, the buck regulator output voltage is adjust-
able by using two external resistors as a voltage
divider. For adjustable-output voltages, it is recom-
mended that the top resistor divider value be 200 kΩ.
The bottom resistor divider can be calculated using the
following formula:
EQUATION 5-1:
Example:
For adjustable output applications, an additional R-C
compensation is necessary for the buck regulator
control loop stability. Recommended values are:
An additional VIN2 capacitor can be added to reduce
high-frequency noise on the LDO input-voltage pin
(VIN2). This additional capacitor (1 µF) is not necessary
for typical applications.
5.4 Input and Output Capacitor
Selection
As with all buck-derived dc-dc switching regulators, the
input current is pulled from the source in pulses. This
places a burden on the TC1313 input filter capacitor. In
most applications, a minimum of 4.7 µF is
recommended on VIN1 (buck regulator input-voltage
pin). In applications that have high source impedance,
or have long leads (10 inches) connecting to the input
source, additional capacitance should be used. The
capacitor type can be electrolytic (aluminum, tantalum,
POSCAP, OSCON) or ceramic. For most portable
electronic applications, ceramic capacitors are
preferred due to their small size and low cost.
For applications that require very low noise on the LDO
output, an additional capacitor (typically 1 µF) can be
added to the VIN2 pin (LDO input voltage pin).
Low ESR electrolytic or ceramic can be used for the
buck regulator output capacitor. Again, ceramic is
recommended because of its physical attributes and
cost. For most applications, a 4.7 µF is recommended.
Refer to Tabl e 5 -1 for recommended values. Larger
capacitors (up to 22 µF) can be used. There are some
advantages in load step performance when using
larger value capacitors. Ceramic materials, X7R and
X5R, have low temperature coefficients and are well
within the acceptable ESR range required.
TABLE 5-1: TC1313 RECOMMENDED
CAPACITOR VALUES
RTOP =200kΩ
VOUT1 =2.1V
VFB =0.8V
RBOT =200kΩ x (0.8V/(2.1V – 0.8V))
RBOT =123kΩ (Standard Value = 121 kΩ)
RCOMP =4.99kΩ
CCOMP =33pF
RBOT RTOP VFB
VOUT1VFB
--------------------------------
⎝⎠
⎛⎞
×=
C (VIN1)C (V
IN2)C
OUT1 COUT2
Min 4.7 µF none 4.7 µF 1 µF
Max none none 22 µF 10 µF
TC1313
DS21974B-page 20 © 2009 Microchip Technology Inc.
5.5 Inductor Selection
For most applications, a 4.7 µH inductor is
recommended to minimize noise. There are many
different magnetic core materials and package options
to select from. That decision is based on size, cost and
acceptable radiated energy levels. Toroid and shielded
ferrite pot cores will have low radiated energy but tend
to be larger and more expensive. With a typical
2.0 MHz switching frequency, the inductor ripple
current can be calculated based on the following
formulas.
EQUATION 5-2:
Duty cycle represents the percentage of switch-on
time.
EQUATION 5-3:
The inductor ac ripple current can be calculated using
the following relationship:
EQUATION 5-4:
Solving for ΔIL= yields:
EQUATION 5-5:
When considering inductor ratings, the maximum DC
current rating of the inductor should be at least equal to
the maximum buck regulator load current (IOUT1), plus
one half of the peak-to-peak inductor ripple current (1/
2*ΔIL). The inductor DC resistance can add to the
buck converter I2R losses. A rating of less than 200 mΩ
is recommended. Overall efficiency will be improved by
using lower DC resistance inductors.
TABLE 5-2: TC1313 RECOMMENDED
INDUCTOR VALUES
5.6 Thermal Calculations
5.6.1 BUCK REGULATOR OUTPUT
(VOUT1)
The TC1313 is available in two different 10-pin
packages (MSOP and 3x3 DFN). By calculating the
power dissipation and applying the package thermal
resistance, (θJA), the junction temperature is estimated.
The maximum continuous junction temperature rating
for the TC1313 is +125°C.
To quickly estimate the internal power dissipation for
the switching buck regulator, an empirical calculation
using measured efficiency can be used. Given the
measured efficiency (Section 2.0 “Typical Perfor-
mance Curves”), the internal power dissipation is
estimated below.
EQUATION 5-6:
The first term is equal to the input power (definition of
efficiency, POUT/PIN = Efficiency). The second term is
equal to the delivered power. The difference is internal
power dissipation. This estimate assumes that most of
the power lost is internal to the TC1313. There is some
percentage of power lost in the buck inductor, with very
little loss in the input and output capacitors.
DutyCycle VOUT
VIN
-------------=
TON DutyCycle 1
FSW
----------
×=
Where:
FSW = Switching Frequency
VLLΔIL
Δt
--------
×=
Where:
VL= voltage across the inductor
(VIN – VOUT)
Δt = on-time of P-channel MOSFET
ΔILVL
L
------ Δt×=
Part
Number Value
(µH)
DCR
Ω
(max)
MAX
IDC (A) Size
WxLxH (mm)
Coiltronics®
SD10 2.2 0.091 1.35 5.2, 5.2, 1.0 max.
SD10 3.3 0.108 1.24 5.2, 5.2, 1.0 max.
SD10 4.7 0.154 1.04 5.2, 5.2, 1.0 max.
Coiltronics
SD12 2.2 0.075 1.80 5.2, 5.2, 1.2 max.
SD12 3.3 0.104 1.42 5.2, 5.2, 1.2 max.
SD12 4.7 0.118 1.29 5.2, 5.2, 1.2 max.
Sumida Corporation®
CMD411 2.2 0.116 0.950 4.4, 5.8, 1.2 max.
CMD411 3.3 0.174 0.770 4.4, 5.8, 1.2 max.
CMD411 4.7 0.216 0.750 4.4, 5.8, 1.2 max.
Coilcraft®
1008PS 4.7 0.35 1.0 3.8, 3.8, 2.74 max.
1812PS 4.7 0.11 1.15 5.9, 5.0, 3.81 max.
VOUT1IOUT1
×
Efficiency
-------------------------------------
⎝⎠
⎛⎞
VOUT1IOUT1
×()PDissipation
=
© 2009 Microchip Technology Inc. DS21974B-page 21
TC1313
For example, for a 3.6V input, 1.8V output with a load
of 400 mA, the efficiency taken from Figure 2-7 is
approximately 84%. The internal power dissipation is
approximately 137 mW.
5.6.2 LDO OUTPUT (VOUT2)
The internal power dissipation within the TC1313 LDO
is a function of input voltage, output voltage and output
current. The following equation can be used to
calculate the internal power dissipation for the LDO.
EQUATION 5-7:
The maximum power dissipation capability for a
package can be calculated given the junction-to-
ambient thermal resistance and the maximum ambient
temperature for the application. The following equation
can be used to determine the package’s maximum
internal power dissipation.
5.6.3 LDO POWER DISSIPATION
EXAMPLE
5.7 PCB Layout Information
Some basic design guidelines should be used when
physically placing the TC1313 on a Printed Circuit
Board (PCB). The TC1313 has two ground pins,
identified as AGND (analog ground) and PGND (power
ground). By separating grounds, it is possible to
minimize the switching frequency noise on the LDO
output. The first priority, while placing external
components on the board, is the input capacitor (CIN1).
Wiring should be short and wide; the input current for
the TC1313 can be as high as 800 mA. The next
priority would be the buck regulator output capacitor
(COUT1) and inductor (L1). All three of these
components are placed near their respective pins to
minimize trace length. The CIN1 and COUT1 capacitor
returns are connected closely together at the PGND
plane. The LDO optional input capacitor (CIN2) and
LDO output capacitor COUT2 are returned to the AGND
plane. The analog ground plane and power ground
plane are connected at one point (shown near L1). All
other signals (SHDN1, SHDN2, feedback in the
adjustable output case) should be referenced to AGND
and have the AGND plane underneath them.
FIGURE 5-1: Component Placement,
Fixed-Output 10-Pin MSOP.
There will be some difference in layout for the 10-pin
DFN package due to the thermal pad. A typical fixed-
output DFN layout is shown below. For the DFN layout,
the VIN1 to VIN2 connection is routed on the bottom of
the board around the TC1313 thermal pad.
FIGURE 5-2: Component Placement,
Fixed-Output 10-Pin DFN.
Input Voltage
VIN =5V ±10%
LDO Output Voltage and Current
VOUT =3.3V
IOUT = 300 mA
Internal Power Dissipation
PLDO(MAX) =(V
IN(MAX) – VOUT2(MIN)) x IOUT2(MAX)
PLDO = (5.5V) – (0.975 x 3.3V))
x 300 mA
PLDO = 684.8 mW
PLDO VIN MAX()
VOUT2MIN()
()IOUT2MAX()
×=
Where:
PLDO = LDO Pass device internal power
dissipation
VIN(MAX) = Maximum input voltage
VOUT(MIN) = LDO minimum output voltage
TC1313
1
2
6
8
7
9
10
5
4
3
+VOUT1
PGND
+VIN1
AGND
AGND
+VOUT2
COUT1
CIN2
COUT2
CIN1
PGND Plane
AGND Plane
L1
AGND to PGND
+VIN2
* CIN2 Optional
- Via
1
2
6
8
7
9
10
5
4
3
+VOUT1
PGND
+VIN1
AGND
AGND
+VOUT2
COUT1
CIN2
COUT2
CIN1
PGND Plane
AGND Plane
L1
AGND to PGND
PGND
* CIN2 Optional
+VIN2
TC1313
- Via
TC1313
DS21974B-page 22 © 2009 Microchip Technology Inc.
5.8 Design Example
VOUT1 = 2.0V @ 500 mA
VOUT2 = 3.3V @ 300 mA
VIN =5V ±10%
L=4.7µH
Calculate PWM mode inductor ripple current
Nominal Duty
Cycle = 2.0V/5.0V = 40%
P-channel
Switch-on time = 0.40 x 1/(2 MHz) = 200 ns
VL=(V
IN-VOUT1)=3V
ΔIL=(V
L/L) x TON =128mA
Peak inductor current:
IL(PK) =I
OUT1+1/2ΔIL= 564 mA
Switcher power loss:
Use efficiency estimate for 1.8V from Figure 2-7
Efficiency = 84%, PDISS1 =190mW
Resistor Divider:
RTOP =200kΩ
RBOT =133kΩ
LDO Output:
PDISS2 =(V
IN(MAX)
VOUT2(MIN))xI
OUT2(MAX)
PDISS2 = (5.5V – (0.975) x 3.3V) x 300 mA
PDISS2 =684.8mW
Tota l
Dissipation = 190 mW + 685 mW = 875 mW
Junction Temp Rise and Maximum Ambient
Operating Temperature Calculations
10-Pin MSOP (4-Layer Board with internal Planes)
RθJA =113°C/Watt
Junction Temp.
Rise = 875 mW x 113° C/Watt = 98.9°C
Max. Ambient
Temperature = 125°C - 98.9°C
Max. Ambient
Temperature = 26.1°C
10-Pin DFN
RθJA = 41° C/Watt (4-Layer Board with
internal planes and 2 vias)
Junction Temp.
Rise = 875 mW x 41° C/Watt = 35.9°C
Max. Ambient
Temperature = 125°C - 35.9°C
Max. Ambient
Temperature = 89.1°C
This is above the +85°C max. ambient temperature.
© 2009 Microchip Technology Inc. DS21974B-page 23
TC1313
6.0 PACKAGING INFORMATION
6.1 Package Marking Information
Second letter represents VOUT1 configuration: Third letter represents VOUT2 configuration:
Fourth letter represents +50 mV Increments:
10-Lead MSOP Example:
51H0
0527
256
Example:
51H0E
527256
10-Lead DFN
XXXX
YYWW
NNN
— 5 = TC1313
— 1 = 1.375V VOUT1
— H = 2.6V VOUT2
— 0 = Default
XXXXXX
YWWNNN
Code VOUT1 Code VOUT1 Code VOUT1
A3.3VJ2.4VS1.5V
B3.2VK2.3VT1.4V
C 3.1V L 2.2V U 1.3V
D 3.0V M 2.1V V 1.2V
E 2.9V N 2.0V W 1.1V
F 2.8V O 1.9V X 1.0V
G2.7VP1.8VY0.9V
H 2.6V Q 1.7V Z Adj
I 2.5V R 1.6V 1 1.375V
Code VOUT2 Code VOUT2 Code VOUT2
A3.3VJ2.4VS1.5V
B3.2VK2.3VT
C 3.1V L 2.2V U
D 3.0V M 2.1V V
E 2.9V N 2.0V W
F 2.8V O 1.9V X
G2.7VP1.8VY
H 2.6V Q 1.7V Z
I 2.5V R 1.6V
Code Code
0 Default 2 +50 mV to V2
1 +50 mV to V1 3 +50 mV to V1
and V2
Legend: XX...X Customer-specific information
Y Year code (last digit of calendar year)
YY Year code (last 2 digits of calendar year)
WW Week code (week of January 1 is week ‘01’)
NNN Alphanumeric traceability code
Pb-free JEDEC designator for Matte Tin (Sn)
*This package is Pb-free. The Pb-free JEDEC designator ( )
can be found on the outer packaging for this package.
Note: In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
3
e
3
e
TC1313
DS21974B-page 24 © 2009 Microchip Technology Inc.
 !"#$
%
  !"#$%!&'(!%&! %(%")%%%"
 *&&# "%( %" 
+ *  ) !%"
 & "%,-.
/01 / & %#%! ))%!%% 
,21 $& '! !)%!%%'$$&%!  
% 2%& %!%*") '  %*$%%"%
%%133)))&&3*
4% 55,,
& 5&% 6 67 8
6!&($ 6 
% ./0
79% :  
%"$$    .
0%%* + ,2
75% +/0
,# ""5%   +. :
7;"% , +/0
,# "";"% ,  .: .
0%%;"% ( : . +
0%%5% 5 +  .
0%%%,# "" <  = =
D
N
NOTE 1 12
E
b
e
N
L
E2
NOTE 1
1
2
D2
K
EXPOSED
PAD
BOTTOM VIEW
TOP VIEW
A3 A1
A
NOTE 2
  ) 0>+/
© 2009 Microchip Technology Inc. DS21974B-page 25
TC1313
&' ()*#'($
%
  !"#$%!&'(!%&! %(%")%%%"
 &  ","%!"&"$ %!  "$ %!   %#".&& "
+ & "%,-.
/01 / & %#%! ))%!%% 
,21 $& '! !)%!%%'$$&%!  
% 2%& %!%*") '  %*$%%"%
%%133)))&&3*
4% 55,,
& 5&% 6 67 8
6!&($ 6 
% ./0
79% = = 
""**  . :. .
%"$$   = .
7;"% , /0
""*;"% , +/0
75% +/0
2%5% 5  > :
2%% 5 .,2
2% I? = :?
5"* : = +
5";"% ( . = ++
D
E
E1
N
NOTE 1
12
b
e
A
A1
A2 c
L
L1
φ
  ) 0/
TC1313
DS21974B-page 26 © 2009 Microchip Technology Inc.
NOTES:
© 2009 Microchip Technology Inc. DS21974B-page 23
TC1313
APPENDIX A: REVISION HISTORY
Revision B (January 2009)
The following is the list of modifications:
1. Added the new DFN package information.
Revision A (November 2005)
Original Release of this Document.
TC1313
DS21974B-page 24 © 2009 Microchip Technology Inc.
NOTES:
© 2009 Microchip Technology Inc. DS21974B-page 25
TC1313
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
Device: TC1313: PWM/LDO combo.
Options Code VOUT1 Code VOUT2 Code +50 mV
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
1
3.3V
3.2V
3.1V
3.0V
2.9V
2.8V
2.7V
2.6V
2.5V
2.4V
2.3V
2.2V
2.1V
2.0V
1.9V
1.8V
1.7V
1.6V
1.5V
1.4V
1.3V
1.2V
1.1V
1.0V
0.9V
Adjustable
1.375V
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
1
3.3V
3.2V
3.1V
3.0V
2.9V
2.8V
2.7V
2.6V
2.5V
2.4V
2.3V
2.2V
2.1V
2.0V
1.9V
1.8V
1.7V
1.6V
1.5V
0
1
2
3
Default
V1 + 50 mV
V2 + 50 mV
V1 and V2
+ 50 mV
* Contact Factory for Alternate Output Voltage and Reset
Voltage Configurations.
Temperature
Range:
E = -40°C to +85°C
Package: MF = Dual Flat, No Lead (3x3 mm body), 10-lead
UN = Plastic Micro Small Outline (MSOP), 10-lead
Tube or
Tape and Reel:
Blank = Tube
TR = Tape and Reel
Examples:
a) TC1313-1H0EMF: 1.375V, 2.6V, Default,
10LD DFN pkg.
b) TC1313-1H0EUN: 1.375V, 2.6V, Default,
10LD MSOP pkg.
c) TC1313-1P0EMF: 1.375V, 1.8V, Default,
10LD DFN pkg.
d) TC1313-1P0EUN: 1.375V, 1.8V, Default,
10LD MSOP pkg.
e) TC1313-DG0EMF: 3.0V, 2.7V, Default,
10LD DFN pkg.
f) TC1313-RD1EMF: 1.65V, 3.0V,
10LD DFN pkg.
g) TC1313-ZS0EUN: Adj., 1.5V, Default,
10LD MSOP pkg.
h) TC1313-1H0EMFTR: 1.375V, 2.6V, Default,
10LD DFN pkg
Tape and Reel.
i) TC1313-1H0EUNTR: 1.375V, 2.6V, Default,
10LD MSOP pkg
Tape and Reel.
j) TC1313-1P0EMFTR: 1.375V, 1.8V, Default,
10LD DFN pkg
Tape and Reel.
k) TC1313-1P0EUNTR: 1.375V, 1.8V, Default,
10LD MSOP pkg
Tape and Reel.
l) TC1313-DG0EMFTR: 3.0V, 2.7V, Default,
10LD DFN pkg
Tape and Reel.
m) TC1313-RD1EMFTR: 1.65V, 3.0V,
10LD DFN pkg
Tape and Reel.
n) TC1313-ZS0EUNTR: Adj., 1.5V, Default,
10LD MSOP pkg
Tape and Reel.
PART NO. X
VOUT1
TC1313
X
VOUT2
X
+50 mV
Increments
X
Temp
Range
XX
Package
XX
Tube
or
Tape &
Reel
TC1313
DS21974B-page 26 © 2009 Microchip Technology Inc.
NOTES:
© 2009 Microchip Technology Inc. DS21974B-page 27
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION,
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR
FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip
devices in life support and/or safety applications is entirely at
the buyer’s risk, and the buyer agrees to defend, indemnify and
hold harmless Microchip from any and all damages, claims,
suits, or expenses resulting from such use. No licenses are
conveyed, implicitly or otherwise, under any Microchip
intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, Accuron,
dsPIC, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro,
PICSTART, rfPIC, SmartShunt and UNI/O are registered
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
FilterLab, Linear Active Thermistor, MXDEV, MXLAB,
SEEVAL, SmartSensor and The Embedded Control Solutions
Company are registered trademarks of Microchip Technology
Incorporated in the U.S.A.
Analog-for-the-Digital Age, Application Maestro, CodeGuard,
dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, In-Circuit Serial
Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB
Certified logo, MPLIB, MPLINK, mTouch, PICkit, PICDEM,
PICDEM.net, PICtail, PIC32 logo, PowerCal, PowerInfo,
PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Total
Endurance, WiperLock and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2009, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
Note the following details of the code protection feature on Microchip devices:
Microchip products meet the specification contained in their particular Microchip Data Sheet.
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
Microchip is willing to work with the customer who is concerned about the integrity of their code.
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Microchip received ISO/TS-16949:200 2 certif ication for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in Calif ornia
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperi pherals, nonvola tile memo ry and
analog product s. In addition, Microchip s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
DS21974B-page 28 © 2009 Microchip Technology Inc.
AMERICAS
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://support.microchip.com
Web Address:
www.microchip.com
Atlanta
Duluth, GA
Tel: 678-957-9614
Fax: 678-957-1455
Boston
Westborough, MA
Tel: 774-760-0087
Fax: 774-760-0088
Chicago
Itasca, IL
Tel: 630-285-0071
Fax: 630-285-0075
Dallas
Addison, TX
Tel: 972-818-7423
Fax: 972-818-2924
Detroit
Farmington Hills, MI
Tel: 248-538-2250
Fax: 248-538-2260
Kokomo
Kokomo, IN
Tel: 765-864-8360
Fax: 765-864-8387
Los Angeles
Mission Viejo, CA
Tel: 949-462-9523
Fax: 949-462-9608
Santa Clara
Santa Clara, CA
Tel: 408-961-6444
Fax: 408-961-6445
Toronto
Mississauga, Ontario,
Canada
Tel: 905-673-0699
Fax: 905-673-6509
ASIA/PACIFIC
Asia Pacific Office
Suites 3707-14, 37th Floor
Tower 6, The Gateway
Harbour City, Kowloon
Hong Kong
Tel: 852-2401-1200
Fax: 852-2401-3431
Australia - Sydney
Tel: 61-2-9868-6733
Fax: 61-2-9868-6755
China - Beijing
Tel: 86-10-8528-2100
Fax: 86-10-8528-2104
China - Chengdu
Tel: 86-28-8665-5511
Fax: 86-28-8665-7889
China - Hong Kong SAR
Tel: 852-2401-1200
Fax: 852-2401-3431
China - Nanjing
Tel: 86-25-8473-2460
Fax: 86-25-8473-2470
China - Qingdao
Tel: 86-532-8502-7355
Fax: 86-532-8502-7205
China - Shanghai
Tel: 86-21-5407-5533
Fax: 86-21-5407-5066
China - Shenyang
Tel: 86-24-2334-2829
Fax: 86-24-2334-2393
China - Shenzhen
Tel: 86-755-8203-2660
Fax: 86-755-8203-1760
China - Wuhan
Tel: 86-27-5980-5300
Fax: 86-27-5980-5118
China - Xiamen
Tel: 86-592-2388138
Fax: 86-592-238813S0
China - Xian
Tel: 86-29-8833-7252
Fax: 86-29-8833-7256
China - Zhuhai
Tel: 86-756-3210040
Fax: 86-756-3210049
ASIA/PACIFIC
India - Bangalore
Tel: 91-80-4182-8400
Fax: 91-80-4182-8422
India - New Delhi
Tel: 91-11-4160-8631
Fax: 91-11-4160-8632
India - Pune
Tel: 91-20-2566-1512
Fax: 91-20-2566-1513
Japan - Yokohama
Tel: 81-45-471- 6166
Fax: 81-45-471-6122
Korea - Daegu
Tel: 82-53-744-4301
Fax: 82-53-744-4302
Korea - Seoul
Tel: 82-2-554-7200
Fax: 82-2-558-5932 or
82-2-558-5934
Malaysia - Kuala Lumpur
Tel: 60-3-6201-9857
Fax: 60-3-6201-9859
Malaysia - Penang
Tel: 60-4-227-8870
Fax: 60-4-227-4068
Philippines - Manila
Tel: 63-2-634-9065
Fax: 63-2-634-9069
Singapore
Tel: 65-6334-8870
Fax: 65-6334-8850
Taiwan - Hsin Chu
Tel: 886-3-572-9526
Fax: 886-3-572-6459
Taiwan - Kaohsiung
Tel: 886-7-536-4818
Fax: 886-7-536-4803
Taiwan - Taipei
Tel: 886-2-2500-6610
Fax: 886-2-2508-0102
Thailand - Bangkok
Tel: 66-2-694-1351
Fax: 66-2-694-1350
EUROPE
Austria - Wels
Tel: 43-7242-2244-39
Fax: 43-7242-2244-393
Denmark - Copenhagen
Tel: 45-4450-2828
Fax: 45-4485-2829
France - Paris
Tel: 33-1-69-53-63-20
Fax: 33-1-69-30-90-79
Germany - Munich
Tel: 49-89-627-144-0
Fax: 49-89-627-144-44
Italy - Milan
Tel: 39-0331-742611
Fax: 39-0331-466781
Netherlands - Drunen
Tel: 31-416-690399
Fax: 31-416-690340
Spain - Madrid
Tel: 34-91-708-08-90
Fax: 34-91-708-08-91
UK - Wokingham
Tel: 44-118-921-5869
Fax: 44-118-921-5820
WORLDWIDE SALES AND SERVICE
01/02/08