L6928_07 Datasheet, PDF (1/16 Pages) STMicroelectronics – High efficiency monolithic synchronous step down regulator

L6928
High efficiency monolithic synchronous step down regulator
Features
■ 2V to 5.5V battery input range
■ High efficiency: up to 95%
■ Internal synchronous switch
■ No external schottky required
■ Extremely low quiescent current
■ 1µA max shutdown supply current
■ 800mA max output current
■ Adjustable output voltage from 0.6V
■ Low drop-out operation: up to 100% duty cycle
■ Selectable low noise/low consumption mode at
light load
■ Power good signal
■ ±1% output voltage accuracy
■ Current-mode control
■ 1.4MHz switching frequency
■ Externally synchronizable
from 1MHz to 2MHz
■ OVP
■ Short circuit protection
Applications
■ Battery-powered equipments
■ Portable instruments
■ Cellular phones
■ PDAs and hand held terminals
■ DSC
■ GPS
Figure 1. Application test circuit
MSOP8
VFQFPN8
Description
The device is dc-dc monolithic regulator
specifically designed to provide extremely high
efficiency.
L6928 supply voltage can be as low as 2V
allowing its use in single Li-ion cell supplied
applications. Output voltage can be selected by
an external divider down to 0.6V. Duty Cycle can
saturate to 100% allowing low drop-out operation.
The device is based on a 1.4MHz fixed-frequency,
current mode-architecture.
Low Consumption Mode operation can be
selected at light load conditions, allowing
switching losses to be reduced. L6928 is
externally synchronizable with a clock which
makes it useful in noise-sensitive applications.
Other features like Powergood, Overvoltage
protection, Shortcircuit protection and Thermal
Shutdown (150°C) are also present.
August 2007
V_IN=2V to 5.5V
C1
10µF
6.3V
SYNC
7
V_CC
6
RUN
1
2
COMP
D01IN1528
C2
220pF
L 4.7µH
5
LX
R3
500K
8
PGOOD
3
4
VFB
GND
Rev 5
R2
200K
R1
100K
V_OUT=1.8V
C4
10µF
6.3V
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