SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUAR Y 2002
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
features
DLow Dropout Voltage Regulator, 1.2-V
D150-mA Load Current Capability
DPower Okay (POK) Function
DLoad Independent, Low Ground
Current,150-µA
DCurrent Limiting
DThermal Shutdown
DLow Sleep State Current (Off Mode)
DFast Transient Response
DLow Variation Due to Load and Line
Regulation
DOutput Stable With Low ESR Capacitors
DTTL Logic Controlled Enable Input
applications
DProcessor Powerup Sequencing
DPalmtop Computers, Laptops, and
Notebooks
description
The SN105125 is a low dropout voltage regulator with an output tolerance of ±2% over the operating range. The
device is optimized for low noise applications and has a low quiescent current (enable <0.8 V). The device has
a low dropout voltage at full load (150 mA). The power okay function monitors the output voltage and indicates
when an error occurs in the system (active low). In the event of an output fault such as overcurrent, thermal
shutdown, or dropout, the power okay output is pulled low (open drain).
The SN105125 has a fast transient response recovery capability in the event of load transition from heavy load
to light load. The device also minimizes overshoot during this condition. During power down, the output
capacitor and load are de-energized through the internal active shutdown clamp, which is turned on when the
device is disabled.
The SN105125 requires a small output capacitor for stability with low ESR. An input capacitor is not required
unless the bulk ac capacitor is placed away from the device or the power supply is a battery. In this situation,
a 1-µF capacitor is recommended for the application. Low ESR ceramic capacitors may be used with the device
to reduce board space in power applications, a key concern in hand-held wireless devices.
Copyright 2002, Texas Instruments Incorporated
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
3
2
4
5
DBV PACKAGE
(TOP VIEW)
1
VI
GND
EN
VO
POK
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
2POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
functional block diagram
Enable/Disable
Control
Voltage
Reference
Thermal
Sensor
Undervoltage
Lockout
Error
Amplifier
Gate Drive Control
and
Current Amplifier
Active
Shutdown
Voltage Supervisor
With
Delay Timer
Power Okay
Control
Overcurrent
Detection and
Dropout Voltage
Detection
Fault
Fault
VI
EN
VO
POK
GND
Terminal Functions
TERMINAL
I/O
DESCRIPTION
NAME NO. I/O DESCRIPTION
EN 3 I Enable/shutdown input (active high)
GND 2 I Ground
POK 4 I Power okay indicator
VI1 I Input supply voltage
VO5 O Output voltage
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Main input voltage range, VI (see Notes 1 and 2) 0 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enable input voltage range, V(EN) (see Notes 1 and 2) 0 V – VI
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power okay output voltage range V(POK), (see Notes 1 and 2) 0 V – VI
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regulated output current limit, IO 400 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous power dissipation, PD, TA = 25°C 0.5 W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrostatic discharge susceptibility, V(HBMESD), (see Note 3) 2 kV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Junction temperature, TJ, 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, Tstg –55°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature (soldering, 10 sec) 260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†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 under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may af fect device reliability.
NOTES: 1. All voltage values are with respect to GND.
2. Absolute negative voltage on these terminals should not go below –0.5 V.
3. The human body model is a 100-pF capacitor discharged through a 1.5-kΩ resistor into each terminal. Devices are ESD sensitive.
Handling precautions are recommended.
recommended operating conditions
MIN TYP MAX UNIT
Main input voltage, VI (see Notes 1 and 2) 3 5.25 V
Enable input voltage, V(EN) (see Notes 1 and 2) 0 VIV
Power okay voltage, V(POK) (see Notes 1 and 2) 0 VIV
Operating ambient temperature, TA0 70 °C
NOTES: 1. All voltage values are with respect to GND.
2. Absolute negative voltage on these terminals should not go below –0.5 V.
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
4POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics, TA= 25°C, VI =5 V, V(EN) = VI, IO = 100 µA, CL = 1 µF(unless otherwise noted)
regulator VOPARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Output voltage IO = 25 mA 1.2 V
VO
Output voltage accuracy
IO = 0 –1% 1%
VO
Output voltage accuracy IO = 50 mA, TA = 0°C to 70°C (see Note 4) –2% 2%
IQQuiescent supply current V(EN) ≤ 0.8 V 1µA
I
Ground terminal current (see Note 5)
IO = 0 150
A
I(GND) Ground terminal current (see Note 5) IO = 150 mA 150 µA
ILOutput load current 150 mA
I(Limit) Output current limit VO = 0 160 300 mA
∆V(LNR) Line regulation VI = 3 V to 5.25 V 10 mV
∆V(LDR) Load regulation IO = 0.1 mA to150 mA, See Note 6 2% 3%
V V
Dropout voltage
IO = 100 µA 1
V
VI – VODropout voltage IO = 150 mA 1V
CLLoad capacitance ESR and capacitance tradeoffs 1µF
I(REV) Reverse output current on VIVI = GND, VO = regulated voltage 50 µA
NOTES: 4. Assured by design, not tested in production.
5. Ground terminal current is the regulator quiescent current drawn from the supply to support the load current.
6. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Devices are tested for load regulation
in the load range from 0.1 mA to 150 mA.
enable input
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
VIL Regulated shutdown VI = 3 V to 5.25 V regulated shutdown 0.8 V
VIH Regulated enabled VI = 3 V to 5.25 V regulated enabled 2 V
I
Enable input current
Shutdown, VIL ≤ 0.8 V 0.01
A
I(EN) Enable input current Enabled, VIH ≥ 2 V 0.01 µA
Resistance discharge V(EN) ≤ 0.8 V 500 Ω
thermal protection (see Note 4)
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
T(SD) Thermal shutdown 165 °C
T(SDHYS) Hysteresis 15 °C
NOTE 4: Assured by design, not tested in production.
power okay (see Note 7)
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
V(POKLO) Low threshold Output falls % of VO (power NOT okay) 85%
V(POKTH) High threshold Output reaches % of VO, starts delay timer (power okay) 90%
VOL VO out of regulation Fault condition, IOL = 100 µA 0.4 V
Ilkg Leakage current VI = 5 V 1µA
NOTE 7: Power okay is a function of the output voltage being 5% lower than the specified range. The function is a detection of one of the following:
over current, over temperature, or dropout.
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
switching characteristics (see Note 4),TA = 25°C, VI = 5 V, V(EN) = VI, IO = 100 µA, CL = 1 µF(unless
otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Power up overshoot Maximum voltage overshoot allowed on output during
powerup 1%
t(STEP) Output transient time limit T ime for output to return within specified regulation range 5µs
Output transient voltage limit V oltage that load step can affect the nominal output voltage 1%
I(SR) Load step current slew rate IL = 0.1 mA to 150 mA 10 mA/µs
trPower up rise time 50 µs
tfPower down fall time Discharge resistance = 500 Ω, VO < 1.08 V 60 µs
td(POK) Power okay delay time VI > V(POKTH) until POK↑2.5 ms
NOTE 4: Assured by design, not tested in production.
thermal resistance
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
RθJC Thermal impedance, junction-to-case 145 °C/W
RθJA Thermal impedance, junction-to-ambient 235 °C/W
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
6POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
V(POKTH)
VO
POK
td(POK)
90%
Figure 1. Power Okay Timing During Power Up
EN
VI
POK Delay 2.5 ms typ
85% min
90% max
VO
POK
Figure 2. Power Okay Delay Timing and Output Voltage Supervisory
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
VO
IL
Figure 3. Load Regulation, 50-mA Dynamic Load Step (VI = 3 V)
VO
IL
Figure 4. Load Regulation, 150-mA Dynamic Load Step (VI = 3 V)
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
8POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
VO
IL
Figure 5. Load Regulation, 50-mA Dynamic Load Step (VI = 5 V)
VO
IL
Figure 6. Load Regulation, 150-mA Dynamic Load Step (VI = 5 V)
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
9
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
VO
POK
EN
Figure 7. Power Okay Delay During Power Up Condition
VO
POK
Figure 8. Power Okay Delay During Power Down Condition
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
10 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
THERMAL INFORMATION
The SN105125 is designed to provide a continuous load current of 150 mA when the maximum power
dissipation of the package is not exceeded in the application. To determine the maximum power dissipation of
the package, use the junction-to-ambient thermal resistance of the device. The basic equation is as follows:
Maximum power dissipation (W)
PD(MAX) = (TJ(MAX) – TA) / RθJA (maximum power dissipation limit)
Where:
TJ(MAX) is the maximum junction temperature of the die (less than 150°C, minimum thermal shutdown)
TA is the operating ambient temperature
RθJA is the thermal resistance and is layout dependent
The recommended minimum footprint offers a RθJA of 235°C/W.
To determine the actual power dissipation of the regulator, use the following equation:
PD = (VI – VO) IO + VI I(GND) (Watts)
Power dissipation resulting from quiescent current is negligible. When the power dissipation is excessive, the
thermal protection circuit is triggered.
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
11
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
1
2
3
5
4
47 kΩ
Shutdown
Enable
VI
GND
EN
VO
POK
Optional: EN May
Be Connected to VI1 µF
1.2 V
SN105125
Figure 9. Typical Application Schematic
1
2
3
5
4
VI
GND
EN
VO
POK
1 µF
SN105125 10 kΩ
1 µF
VCC3_3 VCC1_2
Figure 10. Typical Application For Processor VID Code Power Sequencing Schematic
SN105125
150-mA LOW DROPOUT REGULATOR WITH POK
SLVS418 – JANUARY 2002
12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
MECHANICAL DATA
DBV (R-PDSO-G5) PLASTIC SMALL-OUTLINE
0,10
M
0,20
0,95
0°–8°
0,25
0,35
0,55
Gage Plane
0,15 NOM
4073253-4/F 10/00
2,60
3,00
0,50
0,30
1,50
1,70
45
31
2,80
3,00
0,95
1,45 0,05 MIN
Seating Plane
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion.
D. Falls within JEDEC MO-178
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Post Office Box 655303
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Copyright 2002, Texas Instruments Incorporated
