TPS40090 Datasheet, PDF (1/24 Pages) Texas Instruments – HIGH FREQUENCY MULTIPHASE CONTROLLER

TPS40090
TPS40091
SLUS578A − OCTOBER 2003 − REVISED JUNE 2004
HIGHĆFREQUENCY,
MULTIPHASE CONTROLLER
FEATURES
DESCRIPTION
D Two-, Three-, or Four-Phase Operation
D 5-V to 15-V Operating Range
D Programmable Switching Frequency Up to
1-MHz/Phase
D Current Mode Control With Forced Current
Sharing⁽¹⁾
D 1% Internal 0.7-V Reference
D Resistive Divider Set Output Voltage
D True Remote Sensing Differential Amplifier
D Resistive or DCR Current Sensing
D Current Sense Fault Protection
D Programmable Load Line
D Compatible with UCC37222 Predictive Gate
Drive Technology Drivers
D 24-Pin Space-Saving TSSOP Package
D TPS40090: Binary Output
TPS40091: Tri−State Output
APPLICATIONS
D Internet Servers
D Network Equipment
D Telecommunications Equipment
D DC Power Distributed Systems
PW PACKAGE
(TOP VIEW)
CS1
1
CS2
2
CS3
3
CS4
4
CSCN
5
ILIM
6
DROOP
7
REF
8
COMP
9
FB
10
DIFFO
11
VOUT
12
24
EN/SYNC
23
VIN
22
BP5
21
PWM1
20
PWM2
19
PWM3
18
PWM4
17
GND
16
RT
15
SS
14
PGOOD
13
GNDS
(1) _{Patent pending}
Predictive Gate Drive is a trademark of Texas Instruments Incorporated.
The TPS4009x family are two-, three-, or
four-phase programmable synchronous buck
controllers, optimized for low-voltage, high-
current applications powered by a 5-V to 15-V
distributed supply. A multi-phase converter offers
several advantages over a single power stage
including lower current ripple on the input and
output capacitors, faster transient response to
load steps, improved power handling capabilities,
and higher system efficiency.
Each phase can be operated at a switching
frequency up to 1-MHz, resulting in an effective
ripple frequency of up to 4-MHz at the input and the
output in a four-phase application. A two phase
design operates 180 degrees out-of- phase, a
three-phase design operates 120 degrees out of
phase, and a four-phase design operates 90
degrees out of phase as shown in Figure 1.
The number of phases is programmed by con−
necting the de-activated phase PWM output to the
output of the internal 5-V LDO. In two-phase
operation the even phase outputs should be
de-activated.
The TPS4009x uses fixed frequency, peak current
mode control with forced phase current balancing.
When compared to voltage mode control, current
mode results in a simplified feedback network and
reduced input line sensitivity. Phase current is
sensed by using either current sense resistors
installed in series with output inductors or, for
improved efficiency, by using the DCR (direct
current resistance) of the filter inductors. The
latter method involves generation of a current
proportional signal with an R-C circuit (shown in
Figure 10.
The R-C values are selected by matching the time
constants of the R-C circuit and the inductor;
R-C = L/DCR. With either current sense method,
the current signal is amplified and superimposed
on the amplified voltage error signal to provide
current mode PWM control.
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  1999 − 2003, Texas Instruments Incorporated
www.ti.com
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