L6997 Datasheet, PDF (1/23 Pages) STMicroelectronics – STEP DOWN CONTROLLER FOR LOW VOLTAGE OPERATIONS

L6997
STEP DOWN CONTROLLER
FOR LOW VOLTAGE OPERATIONS
FEATURES
s FROM 3V TO 5.5V V_CC RANGE.
s MINIMUM OUTPUT VOLTAGE AS LOW AS
0.6V.
s 1V TO 28V INPUT VOLTAGE RANGE.
s CONSTANT ON TIME TOPOLOGY ALLOWS.
OPERATION WITH VERYLOW AND HIGH
DUTY CYCLES.
s VERY FAST LOAD TRANSIENTS.
s 0.6V, ±1% VREF.
s SELECTABLE SINKING MODE.
s LOSSLESS CURRENT LIMIT, AVAILABLE
ALSO IN SINKING MODE
s REMOTE SENSING.
s OVP,UVP LATCHED PROTECTIONS.
s 600µA TYP QUIESCENT CURRENT.
s POWER GOOD AND OVP SIGNALS.
s PULSE SKIPPING AT LIGTH LOADS.
s 94% EFFICIENCY FROM 3.3V TO 2.5V.
APPLICATIONS
s NETWORKING.
s DC/DC MODULES.
s DISTRIBUTED POWER.
s MOBILE APPLICATIONS.
s CHIP SET, CPU, DSP AND MEMORIES SUPPLY.
TSSOP20
ORDERING NUMBERS: L6997D
L6997DTR
DESCRIPTION
The device is a high efficient solution for networking
dc/dc modules and mobile application compatible
with 3.3V bus and 5V bus.
It's able to regulate an output voltage as low as 0.6V.
The constant on time topology assures fast load tran-
sient response. The embedded voltage feed-forward
provides nearly constant switching frequency opera-
tion.
An integrator can be introduced in the control loop to
reduce the static output voltage error.
The remote sensing improves the static and dynamic
regulation, recovering the wires voltage drop.
Pulse skipping technique reduces power consump-
tion at light loads. Drivers current capability allows
output currents in excess of 20A.
MINIMUM COMPONENT COUNT APPLICATION
3.3V
Rin2
Rin1
OSC
BOOT
HGATE
Rilim
PGOOD
PHASE
OVP
LGATE
L6997
ILIM
PGND
GND
GNDSENSE
Cin
Dboot
HS
Cboot
L
LS
DS
0.6V
Ro1
Ro2
Cout
SS
Css
SHDN
VSENSE
INT
VFB
Vref
Cvref
April 2003
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