GM3326 Datasheet, PDF (1/7 Pages) Gamma Microelectronics Inc. – PWM,PWM/PFM SWITCHING STEP-UP & DOWN DC/DC CONVERTER CONTROLLER ICS

Description
GM3326 is step-up/down DC/DC converter controller ICs
with fast, and low ON resistance drivers built-in. A versatile
step-up/ down DC/DC converter can be realised by using
with large output current only 4 basic external components
- transistors, coils, diodes, and capacitors.
Output voltage is selectable in 0.1V steps within a 2.4V ~
6.0V ( ± 2.5% accuracy) range, and switching frequency is
set at or 300KHz.
GM3326 switches from PWM to PFM control during light
loads, and the series offers high efficiencies from light
loads through to large output currents.
Soft-start time is internally set to 10 msec, which offers
protection against rush currents when the power is
switched on and also against voltage overshoot.
During shutdown (CE pin = L), consumption current can be
reduced to as little as 0.5µA or less.
Features
Input Voltage Range : 2.0V ~ 10V
Output Voltage Range : 2.4V ~ 6.0V ( ± 2.5%
accuracy) (selectable in 0.1V steps)
Oscillation Frequency : 300KHz ( ± 15%
accuracy)
Output Current : more than 250mA (V_IN=2.4V,
V_OUT=3.3V)
Efficiency : 81% (typ) at 5.0V, 78% (typ) at 3.3V
Stand-By : ISTB = 0.5µA (max)
Output Voltage Internal Set-Up
SOT-25 Package
Application
Mobile phones
PDAs
Palmtop computers
TYPICAL APPLICATION CIRCUITS
Portable audio equipment
Various power supplies
V_OUT
3L colis SMTSPR5D5047C-220
Schottky ^{Youth coils YCDH57-220}
Pch MOSFET
MBRS140
L
FDN338P
V_IN
Nch MOSFET
FDN339AN
Schottky
MBRS140
+
C_L
68µF/ 10V
Chemi_con
PT- Series
V_OUT
EXT
V_DD
GM3326
CE
GND
+
C_IN
100µF/ 10V
Chemi_con
PT- Series
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