ap3409 BCD Semiconductor Manufacturing Limited, ap3409 Datasheet - Page 2

• Manufacturer Part Number: ap3409
• Description: 3a, 4mhz High Efficiency Synchronous Buck Converter
• Manufacturer: BCD Semiconductor Manufacturing Limited

Pin Configuration
Pin Description
Jul. 2010 Rev. 1. 0
3A, 4MHz High Efficiency Synchronous Buck Converter
Number
Pin
3, 4
6, 7
10
1
2
5
8
9
Pin Name
SHDN/RT
COMP
PGND
PVDD
GND
VDD
SW
FB
SHDN/RT
Figure 2. Pin Configuration of AP3409 (Top View)
PGND
Oscillator resistor input. Connect a resistor to GND from this pin to set
the switching frequency. Forcing this pin to V
Signal ground. All small-signal ground, such as the compensation
components and the exposed pad should be connected to this pin, which
in turn connects to PGND at one point
Internal power switch output. Connect this pin with one terminal of the
inductor
Power ground. Connect this pin as close as possible to C
Power Input Supply. Decouple this pin to PGND with a capacitor
Signal input supply. Decouple this pin to GND with a capacitor. Normally
V
Feedback voltage. This pin is the inverting input of internal error
amplifier. It senses the converter output voltage through an external
resistor divider. The internal reference voltage is 0.8V, which determines
the output voltage through the resistor divider
Compensation input. This pin is the output of internal error amplifier.
Connect external compensation elements to this pin to stabilize the
control loop
GND
DD
SW
SW
is equal to V
1
2
4
5
3
(DFN-3×3-10)
DN Package
by Marking
Pin 1 Dot
Exposed Pad
Connected to
PVDD
PGND
2
Description
10
9
8
7
6
BCD Semiconductor Manufacturing Limited
COMP
PVDD
PVDD
FB
VDD
Preliminary Datasheet
DD
to shutdown the device
IN
and C
AP3409
OUT