Datasheet

TPS54311, TPS54312
TPS54313, TPS54314
TPS54315, TPS54316
SLVS416B FEBRUARY 2002 REVISED APRIL 2005
www.ti.com
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 1113 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 610 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 1416 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.