Datasheet

TPS54331
www.ti.com SLVS839D –JULY 2008– REVISED JANUARY 2012
PACKAGE DISSIPATION RATINGS
(1) (2) (3)
THERMAL IMPEDANCE PSEUDO THERMAL IMPEDANCE
PACKAGE
JUNCTION TO AMBIENT JUNCTION TO TOP
SOIC8 100°C/W 5°C/W
SOIC8 PowerPAD™ 50°C/W 5°C/W
(1) Maximum power dissipation may be limited by overcurrent protection
(2) Power rating at a specific ambient temperature T
A
should be determined with a junction temperature of 150°C. This is the point where
distortion starts to substantially increase. Thermal management of the PCB should strive to keep the junction temperature at or below
150°C for best performance and long-term reliability. See power dissipation estimate in application section of this data sheet for more
information.
(3) Test board conditions:
(a) 2 inches x 1.5 inches, 2 layers, thickness: 0.062 inch
(b) 2-ounce copper traces located on the top and bottom of the PCB
(c) 6 thermal vias located under the device package
RECOMMENDED OPERATING CONDITIONS
over operating free-air temperature range (unless otherwise noted)
MIN TYP MAX UNIT
Operating Input Voltage on (VIN pin) 3.5 28 V
Operating junction temperature, T
J
–40 150 °C
ELECTRICAL CHARACTERISTICS
T
J
= –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 Rising and Falling 3.5 V
Shutdown supply current EN = 0V, VIN = 12V, –40°C to 85°C 1 4 μA
Operating – non switching supply current VSENSE = 0.85 V 110 190 μA
ENABLE AND UVLO (EN PIN)
Enable threshold Rising and Falling 1.25 1.35 V
Input current Enable threshold – 50 mV -1 μA
Input current Enable threshold + 50 mV -4 μA
VOLTAGE REFERENCE
Voltage reference 0.772 0.8 0.828 V
HIGH-SIDE MOSFET
BOOT-PH = 3 V, VIN = 3.5 V 115 200 mΩ
On resistance
BOOT-PH = 6 V, VIN = 12 V 80 150
ERROR AMPLIFIER
Error amplifier transconductance (gm) –2 μA < I
(COMP)
< 2 μA, V
(COMP)
= 1 V 92 μmhos
Error amplifier DC gain
(1)
VSENSE = 0.8 V 800 V/V
Error amplifier unity gain bandwidth
(1)
5 pF capacitance from COMP to GND pins 2.7 MHz
Error amplifier source/sink current V
(COMP)
= 1 V, 100 mV overdrive ±7 μA
Switch current to COMP transconductance VIN = 12 V 12 A/V
SWITCHING FREQUENCY
Switching Frequency VIN = 12V, 25°C 456 570 684 kHz
Minimum controllable on time VIN = 12V, 25°C 105 130 ns
Maximum controllable duty ratio
(1)
BOOT-PH = 6 V 90% 93%
PULSE SKIPPING ECO-MODE™
Pulse skipping Eco-mode™ switch current threshold 160 mA
CURRENT LIMIT
Current limit threshold VIN = 12 V 3.5 5.8 A
(1) Specified by design
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