Preliminary
RT9261B
VFM Step-Up DC/DC Converter
General Description
The RT9261B Series are VFM Step-up DC/DC converter
ICs with ultra low supply current by CMOS process and
suitable for use with battery-powered instruments.
The RT9261B IC consists of an oscillator, a VFM control
circuit, a driver transistor (LX switch), a reference voltage
unit, an error amplifier, resistors for voltage detection, and
a LX switch protection circuit. A low ripple and high efficiency
step-up DC/DC converter can be constructed with the
RT9261B IC and only three external components.
The EN pin enables the circuit to set the standby supply
current at a maximum of 0.5μA.
Features
Minimal Number of External Components (Only an
Inductor, a Diode, and a Capacitor)
Ultra Low Input Current (6.5μA at Switch Off)
μ
Capable of Supplying 50mA Output Current with
Internal Switch
±
2% Output Voltage Accuracy
Low Ripple and Low Noise
Low Start-up Voltage, 0.8V at 1mA
80% Efficiency with Low Cost Inductor
+50 ppm/° C Low Temperature-Drift
SOT-89 and
SOT-23-5
Small Packages
RoHS Compliant and 100% Lead (Pb)-Free
Ordering Information
RT9261B-
Package Type
B : SOT-23-5
X : SOT-89
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Output Voltage
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
Applications
Power source for battery-powered equipment
Power source for cameras, camcorders, VCRs, PDAs,
pagers, electronic data banks, and hand-held
communication equipment
Power source for appliances, which require higher
voltage than that of batteries used in the appliances
Pin Configurations
(TOP VIEW)
EN
1
2
3
4
GND
5
LX
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.
NC
VOUT
SOT-23-5
Marking Information
For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area, otherwise visit our website for detail.
1
2
3
GND VOUT
(TAB)
LX
SOT-89
DS9261B-12 March 2007
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
