Datasheet

TPS54310-EP
SLVS818 – APRIL 2008 ..................................................................................................................................................................................................... www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
T
J
= – 55 ° C to 125 ° C, VIN = 3 V to 6 V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
OSCILLATOR
SYNC ≤ 0.8 V, RT open 255 350 450
Internally set free-running frequency range kHz
SYNC ≥ 2.5 V, RT open 400 550 700
RT = 180 k Ω (1% resistor to AGND)
(4)
245 280 313
Externally set free-running frequency range RT = 100 k Ω (1% resistor to AGND) 450 500 550 kHz
RT = 68 k Ω (1% resistor to AGND) 650 700 775
High-level threshold voltage, SYNC 2.5 V
Low-level threshold voltage, SYNC 0.8 V
Pulse duration, SYNC
(5)
50
Frequency range, SYNC
(5)
330 700 kHz
Ramp valley
(4)
0.75 V
Ramp amplitude (peak-to-peak)
(4)
1 V
Minimum controllable on time 200 ns
Maximum duty cycle 90%
ERROR AMPLIFIER
Error amplifier open loop voltage gain 1 k Ω COMP to AGND
(5)
90 110 dB
Error amplifier unity gain bandwidth Parallel 10 k Ω , 160 pF COMP to AGND
(5)
3 5 MHz
Error amplifier common-mode input voltage range Powered by internal LDO
(5)
0 VBIAS V
I
IB
Input bias current, VSENSE VSENSE = V
ref
60 250 nA
V
O
Output voltage slew rate (symmetric), COMP 1.4 V/µs
PWM COMPARATOR
PWM comparator propagation delay time, PWM
10 mV overdrive
(5)
70 85 ns
comparator input to PH pin (excluding dead time)
SLOW-START/ENABLE
Enable threshold voltage, SS/ENA 0.82 1.20 1.45 V
Enable hysteresis voltage, SS/ENA
(4)
0.03 V
Falling edge deglitch, SS/ENA
(4)
2.5 µs
Internal slow-start time 2.2 3.35 4.1 ms
Charge current, SS/ENA SS/ENA = 0 V 2.5 5 8 µA
Discharge current, SS/ENA SS/ENA = 0.2 V, V
I
= 2.7 V 1.2 2.3 4 mA
POWER GOOD
Power good threshold voltage VSENSE falling 90 %V
ref
Power good hysteresis voltage
(4)
3 %V
ref
Power good falling edge deglitch
(4)
35 µs
Output saturation voltage, PWRGD I
(sink)
= 2.5 mA 0.18 0.30 V
Leakage current, PWRGD V
I
= 5.0 V 1 µA
CURRENT LIMIT
V
I
= 3 V, output shorted
(5)
4 6.5
Current limit trip point A
V
I
= 6 V, output shorted
(5)
4.5 7.5
Current limit leading edge blanking time
(4)
100 ns
Current limit total response time
(4)
200 ns
THERMAL SHUTDOWN
Thermal shutdown trip point
(4)
135 150 165 ° C
Thermal shutdown hysteresis
(4)
10 ° C
OUTPUT POWER MOSFETS
I
O
= 0.5 A, VI = 6 V
(6)
59 88
r
DS(on)
Power MOSFET switches m Ω
I
O
= 0.5 A, VI = 3 V
(6)
85 136
(4) Specified by design
(5) Specified by design for T
J
= -40 ° C to 125 ° C
(6) Matched MOSFETs, low side r
DS(on)
production tested, high side r
DS(on)
specified by design.
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