User guide

Data Sheet
1.2A, 1.4MHz High Efficiency Synchronous DC-DC Buck Converter AP3417B
Jan. 2013 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
2
1
2
34
5
EN
GND
SW
FB
VIN
Pin Configuration
K Package
(SOT-23-5)
Figure 2. Pin Configuration of AP3417B (Top View)
Pin Description
Pin Number Pin Name Function
1 EN
Control input pin. Forcing this pin above 1.5V enables the IC.
Forcing this pin below 0.4V shuts down the IC. When the IC is
in shutdown mode, all functions are disabled to decrease the
supply current below 1µA
2 GND Ground pin
3 SW
Power switch output pin. Inductor connection to drain of the
internal PFET and NFET switches
4 VIN
Supply input pin. Bypass to GND with a 4.7µF or greater
ceramic capacitor
5 FB
This is the feedback pin of the device. Connect this pin directly
to the output if the fixed output voltage version is used. For the
adjustable version, an external resistor divider is connected to
this pin