Datasheet


SLUS489 − OCTOBER 2001
4
www.ti.com
electrical characteristics over recommended operating junction temperature range,
T
A
= −40_C to 85_C for the TPS43000, RT = 75 kΩ (500 kHz), VIN = VP = 3.5 V, VOUT = 3.1 V, COMP/FB
pins shorted, BUCK-configured, T
A
= T
J
(unless otherwise noted)
soft-start
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
RT = 37.5 kΩ (1 MHz) 1.0 3.0 6.0
ms
Soft-start time
RT = 75 kΩ (500 kHz) 2.0 5.5 12.0
ms
Soft-start time
RT = 150 kΩ (250 kHz) 4.0 10.5 24.0
oscillator
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
RT = 37.5 kΩ (1 MHz), V
COMP
= 600 mV 0.90 1.00 1.10 MHz
Oscillator frequency
RT = 75 kΩ (500 kHz), V
COMP
= 600 mV 450 500 550 kHz
Oscillator frequency
RT = 150 kΩ (250 kHz), V
COMP
= 600 mV 225 250 280 kHz
SYNC/SD
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Synchronization threshold voltage 0.8 1.25 1.6 V
SYNC pulse width SYNC/SD = 2 V, COMP/FB=600 mV 100 50 ns
SYNC input current SYNC/SD = 1.6 V 0.5 1 µA
SYNC high to shutdown delay time Float COMP, V
FB
= 0 V 10 22 35 µs
Synchronous range Force COMP/FB to 600 mV 1.1 f
o
1.5 f
o
current limit
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Hiccup overcurrent threshold voltage Voltage measured from VIN to SWN 175 250 325 mV
Delay to termination of P-channel gate drive time Measured at PDRV 125 300 ns
BOOST configured hiccup overcurrent threshold
voltage
Voltage measured from SWN to GND,
BUCK grounded
175 250 325 mV
Delay to termination of N-channel gate drive time Measured at NDRV, BUCK grounded 150 300 ns
Consecutive overcurrent clock cycles before
shutdown
50 63 75
Clock cycles before restart 800 900 1000
CCS threshold voltage
Constant current source configured if
0.40 0.70 1.00 V
CCS pull-down current
Constant current source configured if
V
CCS
> 1 V
0.5 1.0 µA
CCS current threshold voltage Measured from VIN to SWN 85 150 225
BOOST-configured CCS current threshold voltage
Measured from SWN to GND,
BUCK grounded
85 150 225
mV