AP1509
150KHz, 2A PWM BUCK DC/DC CONVERTER
Description
Pin Assignments
The AP1509 series are monolithic IC designed for a step-
down DC/DC converter, and own the ability of driving a
2A load without additional transistor. It saves board space.
The external shutdown function can be controlled by logic
level and then come into standby mode. The internal
compensation makes feedback control having good line and
load regulation without external design. Regarding protected
function, thermal shutdown is to prevent over temperature
operating from damage, and current limit is against over
current operating of the output switch. If current limit function
occurs and VFB is down below 0.5V, the switching frequency
will be reduced. The AP1509 series operates at a switching
frequency of 150KHz thus allow smaller sized filter
components than what would be needed with lower frequency
switching regulators. Other features include a guaranteed
+4% tolerance on output voltage under specified input voltage
and output load conditions, and +15% on the oscillator
frequency. The output version included fixed 3.3V, 5V, 12V,
and an adjustable type. The chips are available in a standard
8-lead SOP-8 package.
(Top View)
VIN
GND
GND
GND
GND
8
7
6
5
1
2
3
4
Output
FB
AP1509
SOP-8L
SD
Features
Applications
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Simple High-Efficiency Step-Down Regulator
On-Card Switching Regulators
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Output Voltage: 3.3V, 5V, 12V and Adjustable Output
Version
Positive to Negative Converter
Adjustable Version Output Voltage Range, 1.23V to
18V+4%
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150KHz +15% Fixed Switching Frequency
Voltage Mode Non-Synchronous PWM Control
Thermal-Shutdown and Current-Limit Protection
ON/OFF Shutdown Control Input
Operating Voltage can be up to 22V
Output Load Current: 2A
SOP-8L Packages
Low Power Standby Mode
Built-in Switching Transistor On Chip
SOP-8L: Available in “Green” Molding Compound
(No Br, Sb)
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Lead Free Finish/ RoHS Compliant (Note 1)
Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/products/lead_free.html.
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www.diodes.com
June 2010
© Diodes Incorporated
AP1509
Document number: DS31016 Rev. 4 - 2