Diodes AP3583/A - Manual (Page 2)

Data Sheet
Single Phase Synchronous Buck PWM Controller With Reference Input AP3583/A
Dec. 2011 Rev. 1. 1 BCD Semiconductor Manufacturing Limited
2
Pin Configuration
MP Package
(PSOP-8)
1
2
3
4
8
7
6
5
Figure 2. Pin Configuration of AP3583/A (Top View)
Pin Description
Pin Number Pin Name Function
1 BOOT
Bootstrap pin. Connect a bootstrap capacitor (Typically from 0.1
to 0.47 µF) from this pin to PHASE pin to create a BOOT voltage
suitable to drive a standard N-Channel MOSFET
2 UGATE
Upper-gate drive pin. Connect this pin to the upper MOSFET gate
providing the gate drive. This pin is monitored by the adaptive
shoot-through protection circuitry to determine when the upper
MOSFET has been turned off
3 OPS
Over-current setting pin. Connecting a resistor (R
OCSET
) between
OPS and GND to set the over-current trigger point
4 LGATE
Lower-gate drive pin. Connect LGATE to the lower MOSFET
gate providing the gate drive for the lower MOSFET. This pin is
monitored by the adaptive shoot-through protection circuitry to
determine when the lower MOSFET has been turned off
5 VCC
Bias supply pin. Provides a 5V or 12V bias supply for the chip
from this pin. The pin should be bypassed with a capacitor to
GND
6 FB
Feedback pin. This pin is the inverting input of the internal error
amplifier. A resistor divider from output to GND is used to set the
output voltage
7 REFIN
External reference input pin. This pin receives a voltage with
range from 0.4V to 3.0V as the reference voltage at the
non-inverting input of the error amplifier. Pull this pin lower than
0.3V to disable the controller, and the V
UGATE
and V
LGATE
will go
low. Let this pin open for internal 0.6V reference use
8 PHASE
PHASE pin. This pin connects to the source of the upper
MOSFET and the drain of the lower MOSFET. This pin is also
monitored by the adaptive shoot-through protection circuitry to
determine when the upper MOSFET is turned off
9 GND
Exposed pad as ground pin. Represents the signal and power
ground for the IC. Tie this pin to ground island/plane through the
lowest impedance connection available