AP1520
PWM CONTROL 2A STEP-DOWN CONVERTER
Description Pin Assignments
AP1520 consists of step-down switching regulator with PWM control.
These devices include a reference voltage source, oscillation circuit, (Top View)
error amplifier and internal PMOS.
AP1520 provides low-ripple power, high efficiency and excellent
Vss
FB 1 8
transient characteristics. The PWM control circuit is able to vary the
duty ratio linearly from 0 up to 100%. This converter also contains an
Vss
2 7
EN
error amplifier circuit. An enable function, an over current protection
AP1520
and a short circuit protection are built inside, and when OCP or SCP
3 6 Output
OCSET
happens, the operation frequency will be reduced from 300kHz to
30kHz. Also, an internal compensation block is built in to minimum
4 5
external component count. VCC
Output
With the addition of an internal P-channel Power MOS, a coil,
capacitors, and a diode connected externally, these ICs can function
SO-8
as step-down switching regulators. They serve as ideal power supply
units for portable devices when coupled with the SO-8 package,
providing such outstanding features as low current consumption.
Applications
Since this converter can accommodate an input voltage up to 23V, it is
also suitable for the operation via an AC adapter.
PC Motherboard
LCD Monitor
Graphic Card
Features
DVD-Video Player
Input Voltage: 3.6V to 23V
Telecom Equipment
Output Voltage: 0.8V to V
CC
ADSL Modem
Duty Ratio: 0% to 100% PWM Control
Printer and Other Peripheral Equipment
Oscillation Frequency: 300kHz Typ
Microprocessor Core Supply
Current Limit, Enable Function
Networking Power Supply
Thermal Shutdown Function
Built-in Internal SW P-channel MOS
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free.Green Device (Note 3)
Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See
AP1520
Pin Descriptions
Pin Number Pin Name Description
Feedback pin
1 FB
Enable Input pin
H: Normal operation
(Step-down operation)
2 EN
L: Step-down operation stopped
(All circuits deactivated)
Add an external resistor to set max output current
3 OCSET
IC power supply pin
4 V
CC
Switch Pin. Connect external inductor/diode here. Minimize trace area at this pin to reduce EMI
5, 6 Output
GND Pin
7, 8 V
SS
Functional Block Diagram
Output
Oscillation Reference Voltage
Circuit Source with Soft Start
V
cc
+
PWM-Switched
FB
Control Circuit
-
Thermal
Shutdown
100uA
V Vss
EN
OCSET
EN
Absolute Maximum Ratings
Symbol Parameter Rating Unit
V V Pin Voltage V - 0.3 to V + 25 V
CC CC SS SS
FB Pin Voltage V
V V - 0.3 to V
FB SS CC
V EN Pin Voltage V - 0.3 to V + 0.3 V
EN SS IN
Output Pin Voltage V
V V - 0.3 to V + 0.3
OUT SS IN
P Power Dissipation Internally Limited mW
D
Operating Junction Temperature Range -20 to +125 C
T
OP
T Storage Temperature Range -65 to +150 C
ST
Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded
under any conditions.
2 of 9
AP1520 December 2017
Diodes Incorporated
www.diodes.com
Document number: DS31174 Rev. 6 - 2