Vishay Siliconix
SiP12401
Document Number: 73193
S-71822-Rev. C, 03-Sep-07
www.vishay.com
1
Boost Controller For Double AA Cell or Li-Ion Battery
For White LED Application
FEATURES
• Voltage Mode Control with Internal
Frequency Compensation
• 1.8 V to 5.0 V Input Voltage Range
• PWM Control with 600 kHz Fixed
Switching Frequency
• Analog Control of LED Intensity
• Regulated Output Current
• Integrated UVLO and Soft-Start
• Logic Controlled Shutdown (< 1 µA)
• High Efficiency: Typical 80 %
• PowerPAK® MLP33-6 Package
APPLICATIONS
• White LED Backlighting
• LCD Bias Supplies
• Handheld Devices
• Digital Cameras
• Portable Applications
DESCRIPTION
SiP12401 is a boost controller IC for double cell NiMH or
Alkaline battery and Li Ion battery, which can drive white
LEDs connected in series to provide backlight in hand-held
devices. Series connection of the LEDs provides identical
LED currents resulting in uniform brightness and eliminating
the need for ballast resistors. For best efficiency
performance, the SiP12401 is designed to operate in PWM
mode with 600 kHz switching. The voltage-mode PWM
design is internally compensated, reducing the external
parts count. It accepts input voltages from 1.8 V to 5.0 V. The
LED current can be adjusted externally for its brightness
control. SiP12401 features low shutdown current of under
1 µA.
SiP12401 is available in a lead (Pb)-free 6-pin, PowerPAK
MLP33 package and is specified to operate over the
industrial temperature range of - 40 °C to 85 °C.
TYPICAL APPLICATION CIRCUIT
XSHD AGND
SiP12401
PGND
VIN
EXT
FB
1
3
4
6
2
5
22 µ H
XSHD
10 µF
VIN
4.7 µF
MBR0520
15 Ω
Si2302ADS
RoHS
COMPLIANT
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Document Number: 73193
S-71822-Rev. C, 03-Sep-07
Vishay Siliconix
SiP12401
Notes:
a. Derate 20 mW/°C above 70 °C.
b. Device Mounted with all leads soldered or welded to PC board.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation
of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
Notes:
a. Full = - 40 to 85 °C.
b. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum (- 40° to 85 °C).
c. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing.
ABSOLUTE MAXIMUM RATINGS (all voltages referenced to GND = 0 V)
Parameter Limit Unit
Input Voltage, VIN - 0.3 to 6
V
EXT Voltage - 0.3 to VIN + 0.5
XSHD Voltage - 0.3 to VIN + 0.5
FB Voltage - 0.3 to VIN + 0.5
Maximum Junction Temperature 150
°CStorage Temperature - 55 to 150
Operating Junction Temperature 125
Power DissipationaPowerPAK MLP33-6 (TA = 70 °C)a1100 mW
Thermal ResistancebPowerPAK MLP33-6 50 °C/W
RECOMMENDED OPERATING RANGE (all voltages referenced to GND = 0 V)
Parameter Limit Unit
Input Voltage, VIN 1.8 to 5
V
XSHD, EXT Voltage 0 V to VIN
LX Voltage 0 to VOUT + 0.5
FB Voltage 0 to 5
Operating Temperature Range - 40 to 85 °C
SPECIFICATIONSa
Parameter Symbol
Test Conditions Unless Specified
VIN = 3 V, TA = 25 °C
Tempa
Limits
Unit Minb TypcMaxb
Input Voltage VIN Full 1.8 5
V
UVLO VUVLO Full 1.65 1.77
UVLO Hysteresis VUVLOHYST 0.1
Feedback Voltage VFB
0.291 0.3 0.309
Full 0.282 0.318
Feedback Input Current IFB VFB = 0.3 V 1nA
Maximum PWM Duty Cycle MAXDTY 77 85 %
PWM Switching Frequency fOSC Full 425 600 775 kHz
Quiescent Current IQVFB = 0.4 V 200 300 µA
Stand-By Current ISTB XSHD = 0 V Full 1
XSHD Input High Level VXSHDH Full 1.2 V
XSHD Input Low Level VXSHDL Full 0.2
EXT High On Resistance REXTH IEXT = 10 mA 35 Ω
EXT Low On Resistance REXTL 30
Document Number: 73193
S-71822-Rev. C, 03-Sep-07
www.vishay.com
3
Vishay Siliconix
SiP12401
PIN CONFIGURATION AND TRUTH TABLE
PIN FUNCTIONS
XSHD (Pin 1)
XSHD is the logic controlled shutdown input pin. When
XSHD is low, the IC is shutdown and it’s quiescent current is
less than 1 µA. When XSHD is high, the IC is working in
normal operation.
VIN (Pin 2)
VIN is the pin connected to battery input voltage. The IC gets
its power supply from VIN.
FB (Pin 3)
FB is the feedback pin of the output voltage via resistor
divider. FB is about 0.3 V and its difference from 0.3 V
reference voltage is amplified by the error amplifier.
AGND (Pin 4)
AGND is the pin for ground of controlling circuit.
PGND (Pin 5)
PGND is the pin for ground of the internal power MOS driver.
EXT (Pin 6)
EXT is the output pin of internal driver. It’s connected to the
gate of external power MOSFET.
FB AGND
2
3
6
5
4
1
PowerPAK MLP33-6
Top View
V
IN
XSHD
PGND
EXT
ORDERING INFORMATION
Part Number Temperature Range Marking
SiP12401DMP-T1-E3 - 40 to 85 °C 2401
PIN DESCRIPTION
Pin Number Name Function
1 XSDH Logic Controlled Shutdown Input, XSHD = High: Normal Operation, XSHD = Low: Shutdown
2VIN Battery Input Voltage
3FB Output Voltage Feedback Pin
4 AGND Signal Ground
5 PGND Power Ground
6 EXT Drive Pin for External Power MOS
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Document Number: 73193
S-71822-Rev. C, 03-Sep-07
Vishay Siliconix
SiP12401
FUNCTIONAL BLOCK DIAGRAM
DETAILED OPERATION
SiP12401 is a 600 kHz boost controller IC, packaged in 6-pin
MLP33, for white LED applications. It features fixed
frequency voltage mode PWM control with internal frequency
compensation. With the low rDS(on) external power MOSFET,
this device maintains high efficiency over a wide range of
load current.
Soft-Start
During soft-start, the loop compensation guarantees the slow
increase of the output voltage and inrush current, so that no
large voltage overshoot and inrush current occur when the
soft-start is ended.
PWM operation
After soft-start, the device is working in PWM operation with
a fixed frequency of 600 kHz.
APPLICATION INFORMATION
White LED Brightness Control
The current of white LED can be adjusted by PWM signal on
the XSHD pin or by a variable dc voltage to control its
brightness, (see Figure 1.) As control voltage VCTRL
increases, the voltage drop on R2 increases and the voltage
drop on R1 decreases. Thus, the LED current decreases.
The selection of R2 and R3 will make the current from VCTRL
much smaller than LED current and much larger than the FB
pin bias current.
Compensation
Reference and Soft-Start Oscillator
Driver
-
+
PWM+
-
E/A
VIN
AGND
PGND
FB
XSHD
EXT
XSHD AGND
SiP12401
PGND
V
IN
EXT
FB
1
3
4
6
2
5
22 µ H
XSHD
10 µ F
V
IN
4.7 µ F
MBR0520
15 Ω
Si2302ADS
R3
3.9 kΩ
V
CTRL
R2
1 kΩ
I
LED
0.3 V
15 Ω
0.3 V
CTRL
15 Ω
R2
R3
-
Document Number: 73193
S-71822-Rev. C, 03-Sep-07
www.vishay.com
5
Vishay Siliconix
SiP12401
TYPICAL CHARACTERISTICS
Maximum PWM Duty Cycle vs. Temperature
Feedback Voltage vs. Temperature
80
81
82
83
84
85
-50-30-101030507090
Temperature (°C)
elcyC ytuD %
-4
-3
-2
-1
0
1
2
3
4
-50 -30 -10 10 30 50 70 90
)%(
y
car
uccA ega
t
l
oV
kc
ab
dee
F
VIN = 5 V
Temperature (°C)
VIN = 2 V
Supply Current vs. Temperature
Shutdown Threshold vs. Temperature
180
185
190
195
200
205
210
215
220
-50 -30 -10 10 30 50 70 90
)Am( tmerruC ylppuS
Temperature (°C)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
-50 -30 -10 10 30 50 70 90
Temperature (°C)
)V(
dl
o
hs
er
h
T
nw
o
d
tu
h
S
VIN = 5 V
VIN = 2 V
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Document Number: 73193
S-71822-Rev. C, 03-Sep-07
Vishay Siliconix
SiP12401
TYPICAL WAVEFORMS
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon
Technology and Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and
reliability data, see http://www.vishay.com/ppg?73193.
Figure 1. PWM Dimming Control
200 Hz 50 % Duty Cycle PWM Signal on XSHD Pin
1 ms/div
V
XSHD
2 V/div
V
OUT
2 V/div
V
FB
0.2 V/div
V
IN = 3.6 V
Four LEDs in series
Figure 3. Switching Waveforms: VIN, VOUT and VEXT
VIN = 3.6 V, L = 22 µH, COUT = 4.7 µF, Four LEDs in Series
1 µ s/div
V
IN
20 mV/div
ac coupled
V
OUT
50 mV/div
ac coupled
V
EXT
2 V/div
Document Number: 91000 www.vishay.com
Revision: 18-Jul-08 1
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