Datasheet
SS3
AGND
EN1
SS1
DGND
SW1
IN1
IS1
IN3
OUT3
FB1
FB2
FB3
EN3
EN2
SS2
DGND
SW2
IN2
IS2
TPS75003-EP
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SGLS311A –DECEMBER 2006– REVISED MARCH 2011
PIN FUNCTIONS
PIN
DESCRIPTION
NAME RHL
Ground connection for BUCK1 and BUCK2 converters. Pins 6 and 15 should be connected to the back side
DGND 6, 15, PAD
exposed pad by a short metal trace as shown in the PCB Layout section of this data sheet.
AGND 18 Ground connection for LDO
IN1 13 Input supply to BUCK1
IN2 8 Input supply to BUCK2
IN3 20 Input supply to LDO
Driving the enable pin (ENx) high turns on BUCK1 regulator. Driving this pin low puts it into shutdown mode,
EN1 17
reducing operating current. The enable pin does not trigger on fast negative going transients.
EN2 4 Same as EN1 but for BUCK2 controller
EN3 3 Same as EN1 but for LDO
Connecting a capacitor between this pin and ground increases start-up time of the BUCK1 regulator by slowing
SS1 16 the ramp-up of current limit. This high-impedance pin is noise-sensitive; careful layout is important. See the
Typical Characteristics, Applications, and PCB Layout sections for details.
SS2 5 Same as SS1 but for BUCK2 regulator.
Connecting a capacitor from this pin to ground slows the start-up time of the LDO reference, therby slowing
SS3 19
output voltage ramp-up. See the Applications section for details.
Current sense input for BUCK1 regulator. The voltage difference between this pin and IN1 is compared to an
IS1 12 internal reference to set current limit. For a robust output start-up ramp, careful layout and bypassing are
required. See the Applications section for details.
IS2 9 Same as IS1, but compared to IN2 and used for BUCK2 controller
SW1 14 Gate drive pin for external BUCK1 P-channel MOSFET
SW2 7 Same as SW1, but for BUCK2 controller
FB1 11 Feedback pin. Used to set the output voltage of BUCK1 regulator
FB2 10 Same as FB1, but for BUCK2 controller
FB3 2 Same as FB1, but for LDO
Regulated LDO output. A small ceramic capacitor (≥ 2.2 μF) is needed from this pin to ground to ensure
OUT3 1
stability.
Copyright © 2006–2011, Texas Instruments Incorporated 7
Product Folder Link(s): TPS75003-EP