STEVAL-ISA078V1
High efficiency synchronous step-up regulator based on the L6926
Data brief
Features
■
2 V to 5.5 V battery input range
■
High efficiency: up to 95%
■
Extremely low quiescent current
■
1 µA max. shutdown supply current
■
800 mA max. output current
■
Adjustable output voltage from 0.6 V
■
Low dropout operation: up to 100% duty cycle
■
± 1% output voltage accuracy
■
600 MHz switching frequency externally
synchronizable up to 1.4 MHz
■
Short-circuit protection
■
RoHS compliant
The low MOSFET R
DS(on)
at high output current.
ensures high efficiency
Description
The STEVAL-ISA078V1 demonstration board is a
high efficiency monolithic synchronous step-down
regulator capable of delivering up to 800 mA of
continuous output current and of regulating the
output voltage from 0.6 V up to V
100% duty cycle operation capability.
The input voltage ranges from 2 V to 5.5 V.
The control loop architecture is based on a
constant frequency peak current mode, while high
efficiency at light loads is achieved by a low
consumption functionality.
The very low quiescent current (25 µA) and
shutdown current (0.2 µA) means that the device
is very suitable for supplying battery-powered
equipment like PDAs, hand-held terminals, DSCs
(digital still cameras) and cellular phones.
The switching frequency is internally set at 600
kHz, but the device can be externally
synchronized up to 1.4 MHz. An internal
reference voltage of 0.6 V (typ.) allows the device
to regulate a minimum output voltage of the same
low value.
thanks to the
IN
Additional beneficial features are: hysteretic
UVLO, OVP, constant current short-circuit
protection, Power Good and thermal shutdown.
The MSOP8 package allows significant space
savings on the board.
March 2012 Doc ID 022889 Rev 1 1/4
For further information contact your local STMicroelectronics sales office.
www.st.com
4
Circuit schematic STEVAL-ISA078V1
AM12057v1
VIN= 2 to 5.5V
V
IN
= 1.8V
C1
10µF
6.3V
R2
100kΩ
R4
100kΩ
R3
200kΩ
L1 6.8µH
C2
22µF
6.3V
C3
220pF
R1
10kΩ
LX
PGOOD
VFB
GNDCOMP
V
CC
RUN
SYNC
5
8
3
7
1
6
24
L6926
1 Circuit schematic
Figure 1. Circuit schematic
2/4 Doc ID 022889 Rev 1
STEVAL-ISA078V1 Revision history
2 Revision history
Table 1. Document revision history
Date Revision Changes
20-Mar-2012 1 Initial release.
Doc ID 022889 Rev 1 3/4
STEVAL-ISA078V1
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4/4 Doc ID 022889 Rev 1
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