AP1635 Datasheet, PDF (1/7 Pages) Diodes Incorporated – PWM/PFM DUAL MODE STEP-DOWN DC/DC CONVERTER

Features
• Input voltage range: 2.2V~5V (V_OUT type)
• Oscillator frequency: 700KHz (Typ.)
• Internal reference: 1.0V (Typ.)
• High efficiency: 93% (Typ.)
• Current limit and thermal shutdown protection
• Pb-Free Package: SOP-8L
AP1635
PWM/PFM DUAL MODE STEP-DOWN DC/DC
CONVERTER
General Description
The AP1635 series are multi-functional step-down DC/DC
converters with built-in speed, low ON resistance drivers. It is
capable to deliver more than 1.2A output current with external
coil, diode and capacitor.
Output voltage is set-up by the external resistors. (±2.5%
accuracy). The 700KHz AP1635 that can work out with small
value external components comes out more compact board.
The device switches to and works under PFM mode with light
loads. It keeps at high efficiency for both light loads and large
output current.
AP1635 can be soft-start with a proper capacitor connected
between CE/SS pin and ground. The stand-by current is less
than 6uA when CE/SS pin is at “LOW” status. The device is
forced to switch off as the voltage at that pin is lower than the
stipulated voltage.
Pin Assignments
FB ¹
CE/SS ²
SVcc ³
PVcc 4
( Top View )
AP1635
8 GND
7 GND
6 SW
5 _SW
Pin Descriptions
Pin
Name
FB
CE/SS
SVcc
PVcc
SW
GND
Pin
No.
Description
1 Feedback pin
Chip Enable/ Soft Start:
2 H: Enable
L: Disable
IC signal power supply pin, add a
3 20Ω resistor to PVcc and a 0.1µF
capacitor to GND.
4 IC power supply pin
Switch Pin. Connect external
5/6 inductor/diode here. Minimize trace
area at this pin to reduce EMI.
7/8 GND Pin
Applications
• Electronic Information Organizers
• Palmtops
• Cellular and portable phones
• Portable Audio Systems
• Various Multi-function Power Supplies
AP1635 Rev. 3
1 of 7
www.diodes.com
OCTOBER 2006
© Diodes Incorporated