Preliminary
RT9262/A
High Efficiency, Low Supply Current, Step-up DC/DC Converter
General Description
The RT9262/A is a compact, high efficient, step-up
DC/DC converter with an adaptive current mode PWM
control loop, providing a stable and high efficient operation
over a wide range of load currents. It operates in both
continuous and discontinuous current modes in stable
waveforms without external compensation.
The low start-up input voltage below 1V makes
RT9262/A suitable for 1 to 4 battery cell applications
providing up to 400mA output current. The 550kHz high
switching rate minimized the size of external components.
Besides, the 17μA low quiescent current together with
high efficiency maintains long battery lifetime.
The 1.8V to 5V output voltage is set with 2 external
resistors. Both internal 2A switch and driver for driving
external power devices (NMOS or NPN) are provided.
A 300mA LDO is included in RT9262 to provide a
secondary low noise output as well as an output current
stop in the shutdown mode. Similarly, a 1.8V to 5V LDO
output voltage can be set with 2 external resistors. For
RT9262A, a low battery detector with 0.86V detection
voltage is included. RT9262/A are provided in SOP-8
packages.
Features
1.0V Low Start-up Input Voltage
High Supply Capability to Deliver 3.3V 100mA with
1V Input Voltage
17μA Quiescent (Switch-off) Supply Current
μ
90% Efficiency
550kHz Fixed Switching Rate
Providing Flexibility for Using Internal and External
Power Switches
Built-in 300mA LDO, also for the Zero-Output-
Current Shutdown Mode (RT9262)
Boost DC-DC Integrating LDO for Up-Down
Regulation (RT9262)
Built-in 0.86V Voltage Detector (RT9262A)
8-Pin SOP Package
RoHS Compliant and 100% Lead (Pb)-Free
Applications
PDA
Portable Instrument
Wireless Equipment
DSC
LCD Back Bias Circuit
RF-Tags
Ordering Information
RT9262/A
Package Type
S : SOP-8
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Include Low Battery Detector
Include LDO
Pin Configurations
(TOP VIEW)
GND
EXT
LFB
LDO O
2
3
4
8
7
6
5
EN
LX
VDD
FB
RT9262CS
Note :
RichTek Pb-free and Green products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
100%matte tin (Sn) plating.
GND
EXT
LBO
LBI
2
3
4
8
7
6
5
EN
LX
VDD
FB
RT9262ACS
SOP-8
DS9262/A-11 March 2007
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
