Datasheet

TPS54425
SLVSA84C –AUGUST 2010– REVISED JULY 2011 www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
over operating free-air temperature range, V
IN
= 12V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
CURRENT LIMIT
I
ocl
Current limit L
OUT
= 1.5 μH
(2)
, T
A
= -20ºC to 85ºC 4.7 5.4 7.5 A
THERMAL SHUTDOWN
Shutdown temperature
(2)
165
T
SDN
Thermal shutdown threshold °C
Hysteresis
(2)
30
ON-TIME TIMER CONTROL
T
ON
On time V
IN
= 12 V, V
O
= 1.05 V 145 ns
T
OFF(MIN)
Minimum off time T
A
= 25°C, V
FB
= 0.7 V 260 310 ns
SOFT START
I
SSC
SS charge current V
SS
= 0 V 1.4 2.0 2.6 μA
I
SSD
SS discharge current V
SS
= 0.5 V 0.1 0.2 mA
POWER GOOD
V
FB
rising (good) 85 90 95 %
V
THPG
PG threshold
V
FB
falling (fault) 85 %
I
PG
PG sink current PG = 0.5 V 2.5 5 mA
OUTPUT UNDERVOLTAGE AND OVERVOLTAGE PROTECTION
V
OVP
Output OVP trip threshold OVP detect 115 120 125 %
T
OVPDEL
Output OVP prop delay 10 μs
UVP detect 60 65 70 %
V
UVP
Output UVP trip threshold
Hysteresis 10 %
T
UVPDEL
Output UVP delay 0.25 ms
T
UVPEN
Output UVP enable delay Relative to soft-start time x 1.7
UVLO
Wake up V
REG5
voltage 3.5 3.8 4.1
V
UVLO
UVLO threshold V
Hysteresis V
REG5
voltage 0.23 0.35 0.47
(2) Not production tested.
4 Copyright © 2010–2011, Texas Instruments Incorporated