Datasheet

TPS54521
www.ti.com SLVS981C –JUNE 2010–REVISED AUGUST 2013
ELECTRICAL CHARACTERISTICS (continued)
T
J
= –40°C to 125°C, VIN = 4.5V to 17V, PVIN = 1.6V to 17V (unless otherwise noted)
DESCRIPTION CONDITIONS MIN TYP MAX UNIT
THERMAL SHUTDOWN
Thermal shutdown 140 150 °C
Thermal shutdown hysteresis 5 °C
TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN)
Minimum switching frequency Rrt = 240 kΩ (1%) 160 200 240 kHz
Switching frequency Rrt = 100 kΩ (1%) 400 480 560 kHz
Maximum switching frequency Rrt = 53 kΩ (1%) 765 900 1035 kHz
Minimum pulse width 20 ns
RT/CLK high threshold 2 V
RT/CLK low threshold 0.8 V
RT/CLK falling edge to PH rising edge delay Measure at 500 kHz with RT resistor in series 62 ns
Switching frequency range (RT mode set point 200 900 kHz
and PLL mode)
PH (PH PIN)
Minimum on time Measured at 90% to 90% of PH, T
A
= 25°C, I
PH
= 97 135 ns
2A
Minimum off time BOOT-PH ≥ 3 V 0 ns
BOOT (BOOT PIN)
BOOT-PH UVLO 2.1 3 V
SLOW START AND TRACKING (SS/TR PIN)
SS charge current 2.3 μA
SS/TR to VSENSE matching V
(SS/TR)
= 0.4 V 29 60 mV
POWER GOOD (PWRGD PIN)
VSENSE falling (Fault) 91 % Vref
VSENSE rising (Good) 94 % Vref
VSENSE threshold
VSENSE rising (Fault) 109 % Vref
VSENSE falling (Good) 106 % Vref
Output high leakage VSENSE = V
ref
, V
(PWRGD)
= 5.5 V 30 100 nA
Output low I
(PWRGD)
= 2 mA 0.3 V
Minimum VIN for valid output V
(PWRGD)
< 0.5V at 100 μA 0.6 1 V
Minimum SS/TR voltage for PWRGD valid 1.2 1.4 V
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