TPS54231
www.ti.com .............................................................................................................................................................................................. SLUS851–OCTOBER 2008
RECOMMENDED OPERATING CONDITIONS
over operating free-air temperature range (unless otherwise noted)
MIN
3.5
TYP
MAX UNIT
Operating Input Voltage on (VIN pin)
Operating junction temperature, TJ
28
V
–40
150
°C
ELECTRICAL CHARACTERISTICS
TJ = –40°C to 150°C, VIN = 3.5V to 28V (unless otherwise noted)
DESCRIPTION
TEST CONDITIONS
MIN
TYP
MAX UNIT
SUPPLY VOLTAGE (VIN PIN)
Internal undervoltage lockout threshold
Shutdown supply current
Operating – non switching supply current
ENABLE AND UVLO (EN PIN)
Enable threshold
Rising and Falling
3.5
4
V
EN = 0V, VIN = 12V, –40°C to 85°C
VSENSE = 0.85 V
1
µA
µA
75
110
Rising and Falling
1.25
-1
1.35
V
Input current
Enable threshold – 50 mV
Enable threshold + 50 mV
µA
µA
Input current
-4
VOLTAGE REFERENCE
Voltage reference
0.772
0.8 0.828
V
HIGH-SIDE MOSFET
On resistance
BOOT-PH = 3 V, VIN = 3.5 V
BOOT-PH = 6 V, VIN = 12 V
115
80
200
150
mΩ
ERROR AMPLIFIER
Error amplifier transconductance (gm)
Error amplifier DC gain(1)
–2 µA < I(COMP) < 2 µA, V(COMP) = 1 V
VSENSE = 0.8 V
92
800
2.7
±7
µmhos
V/V
Error amplifier unity gain bandwidth(1)
Error amplifier source/sink current
Switch current to COMP transconductance
SWITCHING FREQUENCY
TPS54231 Switching Frequency
Minimum controllable on time
Maximum controllable duty ratio(1)
PULSE SKIPPING ECO-MODE™
Pulse skipping Eco-mode™ switch current threshold
CURRENT LIMIT
5 pF capacitance from COMP to GND pins
V(COMP) = 1 V, 100 mV overdrive
VIN = 12 V
MHz
µA
9
A/V
VIN = 12V
400
90
570
105
93
740
130
kHz
ns
VIN = 12V, 25°C
BOOT-PH = 6 V
%
100
3.5
mA
A
Current limit threshold
VIN = 12 V
2.3
THERMAL SHUTDOWN
Thermal Shutdown
165
°C
SLOW START (SS PIN)
Charge current
V(SS) = 0.4 V
V(SS) = 0.4 V
2
µA
SS to VSENSE matching
10
mV
(1) Specified by design
Copyright © 2008, Texas Instruments Incorporated
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