TPS54900 Datasheet, PDF (1/16 Pages) Texas Instruments – PROGRAMMABLE FOUR-CHANNEL STEP-DOWN DC/DC CONVERTER

TPS54900
(6,4 mm x 5,0 mm)
PROGRAMMABLE FOUR-CHANNEL STEP-DOWN
DC/DC CONVERTER
SLVS405 – OCTOBER 2001
FEATURES
D Four Independent 100-mA Channels
Programmable Over 4-Wire Serial Port
D Converter Regulation Range:
7.5 V to 13.1 V in 400-mV Steps, Plus
Unregulated Pass-Through Mode to Shunt VIN
to any Output
D Internally Compensated PWM Controller and
Integrated PMOS Power Switches
D Global and Per Channel Status Available
Through Serial Port
D External Synchronization of PWM With
System Clock
D Per Channel Current Limit and Global Thermal
Shutdown
D –40°C to 85°C Ambient Temperature Range
APPLICATIONS
D ADSL Central Office Line Drivers
D Software Line Card Provisioning
EFFICIENCY
vs
DRIVER SUPPLY VOLTAGE
100
100
Efficiency
80
90
60
80
Driver Current
40
70
20
60
0
7
9
11
13
15
Driver Supply Voltage – V
DESCRIPTION
The TPS54900 four-channel step-down converter uses
voltage mode PWM control to provide four
independently programmable output voltages. Each
regulated channel includes a high-side PMOSFET
switch with a typical r_DS(ON) of 0.8 Ω, which makes it
suitable for high efficiency, low current applications.
Commands sent to the TPS54900 over the four-wire
serial port programs the outputs independently or
globally to supply voltages from 7.5 V to 13.1 V in 0.4-V
increments. When the input voltage is desired at an
output, a bypass mode can be activated which fully
enhances the PMOSFET switch and disables the
switching circuitry of the selected channel.
The TPS54900 is an ideal companion device to power
THS7102 ADSL line drivers as a part of the AC5 central
office ADSL chipset. With the AC5 chipset controlling
the TPS54900 output voltages, significant power
savings are realized by reducing the excess supply
headroom on a per line basis.
LX0
LX1
GND
SFS
SDI
EN
FB0
FB1
TSSOP (PW) PACKAGE
(TOP VIEW)
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
LX3
LX2
VIN
SDO
SCLK
CBS
FB3
FB2
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright  2001, Texas Instruments Incorporated
www.ti.com
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