
LP38855
www.ti.com
SNVS461D –OCTOBER 2006–REVISED APRIL 2013
Operating Ratings(1)
VIN Supply Voltage (VOUT + VDO) to VBIAS
VBIAS Supply Voltage 3.0V to 5.5V
VEN Enable Input Voltage 0.0V to VBIAS
IOUT 0 mA to 1.5A
Junction Temperature Range(2) −40°C to +125°C
(1) Absolute maximum ratings indicate limits beyond which damage to the component may occur. Operating ratings indicate conditions for
which the device is intended to be functional, but do not ensure specific performance limits. For ensured specifications, see Electrical
Characteristics. Specifications do not apply when operating the device outside of its rated operating conditions.
(2) Device power dissipation must be de-rated based on device power dissipation (TD), ambient temperature (TA), and package junction to
ambient thermal resistance (θJA). Additional heat-sinking may be required to ensure that the device junction temperature (TJ) does not
exceed the maximum operating rating. See the Application Information section for details.
Electrical Characteristics
Unless otherwise specified: VIN = VOUT(NOM) + 1V, VBIAS = 3.0V, IOUT = 10 mA, CIN = COUT = 10 µF, CBIAS = 1µF, VEN = VBIAS.
Limits in standard type are for TJ= 25°C only; limits in boldface type apply over the junction temperature (TJ) range of -40°C
to +125°C. Minimum and Maximum limits are ensured through test, design, or statistical correlation. Typical values represent
the most likely parametric norm at TJ= 25°C, and are provided for reference purposes only.
Symbol Parameter Conditions Min Typ Max Units
VOUT(NOM) + 1V ≤VIN ≤VBIAS,-1.0 +1.0
3.0V ≤VBIAS ≤5.5V, 0
-3.0 +3.0
10 mA ≤IOUT ≤1.5A
VOUT Output Voltage Tolerance %
VOUT(NOM) + 1V ≤VIN ≤VBIAS,
3.0V ≤VBIAS ≤5.5V, -2.0 0 +2.0
10 mA ≤IOUT ≤1.5A,
0°C ≤TJ≤125°C
ΔVOUT/ΔVIN Line Regulation, VIN(1) VOUT(NOM) + 1V ≤VIN ≤VBIAS - 0.04 - %/V
ΔVOUT/ΔVBIAS Line Regulation, VBIAS(1) 3.0V ≤VBIAS ≤5.5V - 0.10 - %/V
ΔVOUT/ΔIOUT Output Voltage Load Regulation(2) 10 mA ≤IOUT ≤1.5A - 0.2 - %/A
165
VDO Dropout Voltage, VIN −VOUT(3) IOUT = 1.5A - 130 mV
180
LP38855-0.8 8.5
- 7.0
10 mA ≤IOUT ≤1.5A 9.0 mA
Ground Pin Current Drawn from VIN LP38855-1.2 12
IGND(IN) - 11
Supply 10 mA ≤IOUT ≤1.5A 15
10
VEN ≤0.5V - 1.0 µA
300
3.8
10 mA ≤IOUT ≤1.5A - 3.0 mA
4.5
Ground Pin Current Drawn from
IGND(BIAS) VBIAS Supply 170
VEN ≤0.5V - 100 µA
200
VBIAS rising until device is 2.20 2.70
UVLO Under-Voltage Lock-Out Threshold 2.45 V
functional 2.00 2.90
VBIAS falling from UVLO threshold 60 300
UVLO(HYS) Under-Voltage Lock-Out Hysteresis 150 mV
until device is non-functional 50 350
VIN = VOUT(NOM) + 1V,
ISC Output Short-Circuit Current - 4.5 - A
VBIAS = 3.0V, VOUT = 0.0V
(1) Output voltage line regulation is defined as the change in output voltage from nominal value resulting from a change in input voltage.
(2) Output voltage load regulation is defined as the change in output voltage from nominal value as the load current increases from no load
to full load.
(3) Dropout voltage is defined the as input to output voltage differential (VIN - VOUT) where the input voltage is low enough to cause the
output voltage to drop 2% from the nominal value.
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