Preliminary
RT9264
High Frequency, High Efficiency, Step-up DC/DC Converter
General Description
The RT9264 is a compact, high efficient, step-up
DC/DC converter with current mode PWM control
loop, providing stable and high efficient operations
without external compensation.
The RT9264 suitable for 1 to 4 battery cells as well
as USB power applications providing up to 400mA
output current. The high switching rate minimized
the size of external components.
A 300mA LDO is included in RT9264 to provide a
secondary low noise output as well as an output
current stop in the shutdown mode. RT9264 is
provided in SOP-8 packages.
Features
400mA High Supply Capability
90% Efficiency
Switching Rate higher Than 1.4MHz
Providing Flexibility for Using Internal and
External Power Switches
Built-in 300mA LDO, also for the Zero-Output-
Current Shutdown Mode
Boost DC-DC Integrating LDO for Up-Down
Regulation
8-Pin SOP Package
Applications
Portable Instrument
ADSL Modem
USB Devices
Ordering Information
RT9264
Package type
S : SOP-8
Operating temperature range
C: Commercial standard
Pin Configurations
Part Number
RT9264CS
(Plastic SOP-8)
GND
1
EXT
2
LFB
3
LDOO
4
Pin Configurations
TOP VIEW
8
7
6
5
CE
LX
VDD
FB
Typical Application Circuit
V
IN
L1
2.2碌H
D1
1N5819
C2
1碌F
+
R2
22K
47碌F
VDD
CE
R1
36K
3.3V
V
OUT1
RT9264
EXT
LX
2.5V
V
OUT2
C3
10碌F
+
R4
42K
R3
22K
L DO O
LFB
GND
FB
C1
47碌F
Fig. 1 RT9264 Typical Application for Portable Instruments
DS9264-00 December 2001
www.richtek-ic.com.tw
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