Datasheet
TPS54311, TPS54312
TPS54313, TPS54314
TPS54315, TPS54316
SLVS416B − FEBRUARY 2002 − REVISED APRIL 2005
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5
PIN ASSIGNMENTS
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
AGND
VSENSE
NC
PWRGD
BOOT
PH
PH
PH
PH
PH
RT
FSEL
SS/ENA
VBIAS
VIN
VIN
VIN
PGND
PGND
PGND
PWP PACKAGE
(TOP VIEW)
NC − No internal connection
Terminal Functions
TERMINAL
DESCRIPTION
NAME NO.
DESCRIPTION
AGND 1 Analog ground. Return for compensation network/output divider, slow-start capacitor, VBIAS capacitor, RT resistor and
FSEL pin. Make PowerPAD connection to AGND.
BOOT 5 Bootstrap input. 0.022-µF to 0.1-µF low-ESR capacitor connected from BOOT to PH generates floating drive for the
high-side FET driver.
FSEL 19 Frequency select input. Provides logic input to select between two internally set switching frequencies.
NC 3 No connection
PGND 11−13 Power ground. High current return for the low-side driver and power MOSFET. Connect PGND with large copper areas to the
input and output supply returns, and negative terminals of the input and output capacitors.
PH 6−10 Phase input/output. Junction of the internal high and low-side power MOSFETs, and output inductor.
PWRGD 4 Power good open drain output. Hi-Z when VSENSE ≥ 90% V
ref
, otherwise PWRGD is low. Note that output is low when
SS/ENA is low or internal shutdown signal active.
RT 20 Frequency setting resistor input. Connect a resistor from RT to AGND to set the switching frequency, f
s
.
SS/ENA 18 Slow-start/enable input/output. Dual function pin which provides logic input to enable/disable device operation and capacitor
input to externally set the start-up time.
VBIAS 17 Internal bias regulator output. Supplies regulated voltage to internal circuitry. Bypass VBIAS pin to AGND pin with a high
quality, low ESR 0.1-µF to 1.0-µF ceramic capacitor.
VIN 14−16 Input supply for the power MOSFET switches and internal bias regulator. Bypass VIN pins to PGND pins close to device
package with a high quality, low ESR 1-µF to 10-µF ceramic capacitor.
VSENSE 2 Error amplifier inverting input. Connect directly to output voltage sense point.