Diodes AP3591 User Manual
Ap3591, Description, Features
AP3591
Document number: DS36906 Rev.
1 - 2
1 of 18
March 2014
© Diodes Incorporated
AP3591
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A Product Line of
Diodes Incorporated
SINGLE PHASE SYNCHRONOUS BUCK CONTROLLER
Description
The AP3591 is a synchronous adaptive on-time buck controller
providing high efficiency, excellent transient response and high DC
output accuracy for low voltage regulation in notebook application.
The constant-on-time PWM control scheme handles wide input/output
voltage ratios with ease and features small external component count
and fast transient response.
The operation mode is selectable by EN voltage. A Diode Emulation
Mode (DEM) is activated for increasing efficiency at light loads, while
PWM mode is activated only for low noise operation. The AP3591
also integrates internal Soft-start, UVLO, OVP, OTP, and
programmable OCP to protect the circuit. A Power Good signal is
employed to monitor the output voltage.
The AP3591 is available in U-QFN3535-14 package.
Features
Fixed
Frequency
Constant
On-time
Control;
Resistor
Programmable Frequency Adjustable from 100kHz to 700kHz
Good Stability Independent of the Output Capacitor ESR
Quick Load Step Response
Input Voltage Range: 4.5V to 26V
Output Voltage Range: 0.75V to 5.5V
CCM/DEM Mode Selection
Integrated Bootstrap Diode
Resistor Programmable Current Limit by Low-side R
DS_ON
Sense
Integrated Negative Over Current Limit
Integrated OVP/UVP and Over Thermal Shutdown Function
Power Good Indicator
Internal Soft-start
Integrate Output Discharge (Soft-stop)
Safe Start-up into Pre-biased Loads
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
(Top View)
U-QFN3535-14
Applications
Notebook Computer, AIO PC
Low-voltage Distribute Power
I/O Supplies
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. Seer more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-
free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
VOUT
VDD
FB
PGOOD
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LGATE
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TON
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UGATE
PHASE
CS
VDDP
Pin 1 Mark
EP
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14
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