Datasheet


SLVS456C − OCTOBER 2003 − REVISED OCTOBER 2004
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4
ELECTRICAL CHARACTERISTICS
T
J
= –40°C to 125°C, VIN = 4.5 V to 20 V (unless otherwise noted)
PARAMETER
TEST CONDITIONS MIN TYP MAX UNIT
FEED− FORWARD MODULATOR (INTERNAL SIGNAL)
Modulator gain VIN = 12 V, T
J
= 25°C 8 V/V
Modulator gain variation −25% 25%
Minimum controllable ON time
(1)
180 ns
Maximum duty factor
(1)
VIN = 4.5 V 80% 86%
ERROR AMPLIFIER (VSENSE AND COMP PINS)
Error amplifier open loop voltage gain
(1)
60 80 dB
Error amplifier unity gain bandwidth
(1)
1.0 2.8 MHz
Input bias current, VSENSE pin 500 nA
COMP Output voltage slew rate (symmetric)
(1)
1.5 V/µs
ENABLE (ENA PIN)
Disable low level input voltage 0.5 V
Internal slow-start time (10% to 90%)
f
s
= 250 kHz, RT = ground
(1)
4.6
ms
Internal slow-start time (10% to 90%)
f
s
= 500 kHz, RT = Hi−Z
(1)
2.3
ms
Pullup current source 1.8 5 10 µA
Pulldown MOSFET II(ENA)=1 mA 0.1 V
POWER GOOD (PWRGD PIN)
Power good threshold Rising voltage 97%
Rising edge delay
(1)
fs = 250 kHz 4
ms
Rising edge delay
(1)
fs = 500 kHz 2
ms
Output saturation voltage I
sink
= 1 mA, VIN > 4.5 V 0.05 V
PWRGD
Output saturation voltage I
sink
= 100 µA, VIN = 0 V 0.76 V
PWRGD
Open drain leakage current Voltage on PWRGD = 6 V 3 µA
CURRENT LIMIT
Current limit VIN = 12 V 3.3 4.5 6.5 A
Current limit Hiccup Time
(1)
f
s
= 500 kHz 4.5 ms
THERMAL SHUTDOWN
Thermal shutdown trip point
(1)
165 _C
Thermal shutdown hysteresis
(1)
7 _C
LOW SIDE MOSFET DRIVER (LSG PIN)
Turn on rise time, (10%/90%)
(1)
VIN = 4.5 V, Capacitive load = 1000 pF 15 ns
Deadtime
(1)
VIN = 12 V 60 ns
Driver ON resistance
VIN = 4.5 V sink/source 7.5
Ω
Driver ON resistance
VIN = 12 V sink/source 5
Ω
OUTPUT POWER MOSFETS (PH PIN)
Phase node voltage when disabled DC conditions and no load, ENA = 0 V 0.5 V
Voltage drop, low side FET and diode
VIN = 4.5 V, Idc = 100 mA 1.13 1.42
V
Voltage drop, low side FET and diode
VIN = 12 V, Idc = 100 mA 1.08 1.38
V
r
DS(ON)
, high side power MOSFET switch
(2)
VIN = 4.5 V, BOOT−PH = 4.5 V, I
O
= 0.5 A 150 300
mΩ
r
DS(ON)
, high side power MOSFET switch
(2)
VIN = 12 V, BOOT−PH = 8 V, I
O
= 0.5 A 100 200
m
Ω
(1)
Ensured by design, not production tested.
(2)
Resistance from VIN to PH pins.