Document
A Product Line of Diodes Incorporated
AP3595
DUAL PHASE SYNCHRONOUS RECTIFIED BUCK CONTROLLER
Description
The AP3595 is a compact dual phase synchronous rectified buck controller specifically designed to deliver high quality output voltage. This device operates at adjustable operation frequency and is capable of delivering up to 60A output current. This controller integrates internal MOSFET drivers that support 12V+12V bootstrapped voltage for high efficiency power conversion. The bootstrap diode is built-in to simplify the circuit design and minimize external part count. The AP3595 features configurable gate driving voltage for maximum efficiency and optimal performance. The built-in bootstrap diode simplifies the circuit design and reduces external part count and PCB space. The output voltage is precisely regulated to the reference input that is dynamically adjustable by external voltage divider. Other features include adjustable soft start, adjustable operation frequency, and quick response to step-load transient. With aforementioned functions, the IC provides customers a compact, high efficiency, well-protected and cost-effective solution. This IC is available in U-QFN4040-24 package.
Pin Assignments
(Top View)
PHASE2 BOOT2
Pin 1 Mark
RSET
HG2
LG2
VID
24
REFIN VREF RT/EN IOFS COMP FB
23
22
21
20
19 18
VCC
1 2 3 4 5 6 7
FBRTN
17 PVCC
EP
16 15 14
LG1 PHASE1 HG1
13 BOOT1 8
EAP
9
SS
10
CSN
11
CSP
12
PSI
U-QFN4040-24 (FN Package)
Features
Operate with Single Supply Voltage Simple Single Loop Voltage Mode Control 12V+12V Bootstrapped Drivers with Internal Bootstrap Diode Adjustable Over Current Protection by DCR Current Sensing Adjustable Current Balancing by RDS(ON) Current Sensing Adjustable Operation Frequency from 50kHz to 1MHz Per Phase External Compensation Dynamic Output Voltage Adjustment Adjustable Soft Start U-QFN4040-24 Package RoHS Compliant and 100% Lead (Pb)-free Totally Lead-free & Fully RoHS Compliant (Note1 & 2) Halogen and Antimony Free. “Green” Device (Note 3)
Applications
Middle-High End GPU Core Power High End Desktop PC Memory Core Power Low Output Voltage, High Power Density DC-DC Converters Voltage Regulator Modules
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See http://www.diodes.com/quality/lead_free.html for 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.
AP3595
Document number: DS36749 Rev. 1 - 2
1 of 23 www.diodes.com
January 2014
© Diodes Incorporated
Free Datasheet http://www.datasheetlist.com/
A Product Line of Diodes Incorporated
AP3595 Typical Applications Circuit
VIN
18
PHASE2 PHASE1 VOUT
17 11 10 12 4 2
PVCC CSP
VCC BOOT1 HG1
13 14
CSN PSI IOFS VREF
PHASE1 15 LG1 16 BOOT2 22 HG2 21
VOUT
1 24
REFIN RSET SS EAP VID RT/EN
AP3595
PHASE2
20
FBRTN
9 8 23 3
LG2 19
FBRTN
7
FB COMP
6 5
GND
AP3595
Document number: DS36749 Rev. 1 - 2
2 of 23 www.diodes.com
January 2014
© Diodes Incorporated
Free Datasheet http://www.datasheetlist.com/
A Product Line of Diodes Incorporated
AP3595 Pin Descriptions
Pin Number 1 2 3 4 5 Pin Name REFIN VREF RT/EN IOFS COMP Function External Reference Input. This is the input pin of external reference voltage. Connect a voltage divider from VREF to REFIN and FBRTN to set the reference voltage Output for Reference Voltage. This is the output pin of high precision 2V reference voltage. Bypass this pin with a 1F ceramic capacitor to FBRTN Operation Frequency Setting. Connecting a resistor between this pin and GND to set the operation frequency. Pull this pin to ground to shut down the AP3595 Current Balance Adjustment. Connect a resistor from this pin to VREF or GND to adjust the current sharing Error Amplifier Output. This is the output of the error amplifier (EA) and the non-inverting input of the PWM comparators. Use this pin in combination with the FB pin to compensate the voltage control feedback loop of the converter Feedback Voltage. This pin is the inverting input to the error amplifier. Use this pin in combination with the COMP pin to compensate the voltage control feedback loop of the converter Feedback Return. Connect this pin to the ground where the output voltage is to be regulated Non-inverting Input of Error Amplifier. Connect a resistor from this pin to SS pin to set the droop slope Soft Start Output. Connect a capacitor to FBRTN to set the soft start interval Negative Input for Current Sensing Amplifier Positive Input for Current Sensing Amplifier Power Saving Mode. Connect this pin to VREF for always two phase operation. Short this pin to ground for always single phase operation Bootstrap Supply for the Floating Upper Gate Driver of Channel 1. Conne.