A Product Line of
Diodes Incorporated
AP3585
SINGLE PHASE SYNCHRONOUS BUCK PWM CONTROLLER
Description
The AP3585 is a synchronous-rectified buck controller specifically
designed to operate from 4.5V to 13.2V supply voltage and deliver
high-quality output voltage as low as 0.6V. This device operates at
fixed 300kHz frequency and provides an optimal level of integration to
reduce size and cost of the power supply.
Pin Assignments
(Top View)
BOOT
UGATE
1
2
3
4
8
7
6
5
PHASE
COMP/EN
FB
VCC
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.
This controller provides single feedback loop, voltage-mode control
with fast transient response. The error amplifier features a 10MHz
gain-bandwidth product and 6V/μs slew rate which enables high
converter bandwidth for fast transient performance.
Other features include internal soft-start, under voltage protection,
over current protection and shutdown function. With afore mentioned
functions, this part provides customers a compact, high efficiency,
well-protected and cost-effective solutions.
The AP3585 is available in SO-8 and SO-8EP packages.
GND
LGATE/OCSET
SO-8 (M Package)
(Top View)
1
2
3
4
8
BOOT
UGATE
GND
LGATE/OCSET
PHASE
COMP/EN
FB
VCC
Exposed
Pad
9
7
6
5
Features
Supply Voltage: 4.5V to 13.2V
V
IN
Input Range: 3V to 13.2V
0.6V to 82% of V
IN
Output Range
Internal Reference: 0.6V
Simple Single-loop Control
Voltage-mode PWM Control
Duty Cycle: 0% to 82%
Fast Transient Response
10MHz High-bandwidth Error Amplifier with 6V/μs Slew Rate
Fixed Oscillator Frequency: 300kHz
Lossless, Programmable Over Current Protection
(Uses Lower MOSFET R
DS(ON)
)
Start-up into Pre-biased Load
Built-in Thermal Shutdown
Built-in Soft-start
Over Current Protection
Over Voltage Protection
Under Voltage Protection
Integrated Boot Diode
Totally Lead-free & Fully RoHS Compliant (Note 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
SO-8EP (MP Package)
Applications
Subsystem Power Supplies
PCI, AGP, Graphics Cards, Digital TV
SSTL-2 and DDR/2/3 SDRAM Bus Termination Supply
Cable Modems, Set Top Boxes, and DSL Modems
Industrial Power Supplies and General Purpose Supplies
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.
AP3585
Document number: DS36790 Rev. 1 - 2
1 of 16
www.diodes.com
April 2014
© Diodes Incorporated
A Product Line of
Diodes Incorporated
AP3585
Typical Applications Circuit
VCC Supply
(5V to 12V)
R5
C5 1mF 2R2
V
IN
AP3585
5
7
VCC
COMP
/EN
BOOT
UGATE
PHASE
1
2
C4
0.1mF
C
IN1
10mF
Q1
NTD4963
L1 1mH
C
IN2
270mF
OFF
ON
Q3
2N7002
C2
15pF
C1
10nF
R3
10kW
8
V
OUT
6
LGATE
4
/OCSET
FB
GND
3
R
OCSET
Q2
NTD4965
C
OUT
1000mF
X
2
R1 1kW
R2
2kW
Pin Descriptions
Pin Number
SO-8
1
2
SO-8EP
1
2
Pin Name
BOOT
UGATE
Function
Bootstrap pin. Connect a bootstrap capacitor from this pin to PHASE for
creating a BOOT voltage suitable to drive a standard N-Channel MOSFET
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 turned off
Ground for the IC. All voltage levels are measured with respect to this pin.
Connect this pin directly to the low side MOSFET source and ground plane with
the lowest impedance. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation
Low-side Gate Driver Output and Over-Current Setting Input. This pin is the
gate driver for low-side MOSFET. It is also used to set the maximum inductor
current. Refer to the section in “Function Description” for detail
Bias supply pin. Provides a 4.5V to 13.2V bias supply for the chip from this pin.
The pin should be bypassed with a capacitor to GND
Feedback pin. This pin is the inverting input of the internal error amplifier. Use
FB pin, in combination with the COMP pin, to compensate the voltage control
feedback loop of the converter. A resistor divider from output to GND is used to
set the output voltage
Compensation and disable pin. This pin is the output of the Error Amplifier. Pull
COMP pin low will shut down the IC
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 has turned off
Exposed Pad as ground pin
3
3
GND
4
5
4
5
LGATE/OCSET
VCC
6
6
FB
7
8
–
7
8
9
COMP/EN
PHASE
Exposed Pad
AP3585
Document number: DS36790 Rev. 1 - 2
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Diodes Incorporated
AP3585
Functional Block Diagram
VCC
5
I
OCSET
(21.5mA typ)
Regulator
Sample
And
Hold
V
ROCSET
Power-On-Reset
1
BOOT
V
REF
3V
(0.6V Typ)
Sense Low Side
2
UGATE
8
PHASE
To LGATE
UVP
Comparator
Soft-Start
And
Fault Logic
-
+
2*V
ROCSET
0.4
+
-
IZCMP
+
-
V
CC
OVP
Comparator
inhibit
Gate
Control
4
LGATE/
OCSET
0.8
+
-
Soft Start
+
+
-
Error Amplifier
+
-
PWM
Comparator
Oscillator
V
REF
0.6V
6
FB
7
COMP/EN
0.3V +
-
Disable
3
GND
AP3585
Document number: DS36790 Rev. 1 - 2
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April 2014
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A Product Line of
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AP3585
Absolute Maximum Ratings
(Note 4)
Symbol
V
CC
V
BOOT-PHASE
V
UGATE
Parameter
Supply Input Voltage
BOOT to PHASE Voltage
DC
UGATE to PHASE Voltage
<200ns
DC
V
PHASE
PHASE to GND Voltage
<200ns
DC
V
LGATE
–
P
D
LGATE to GND Voltage
<200ns
Other Pin Voltage
SO-8
Power Dissipation
SO-8EP
SO-8
Thermal Resistance (Junction to Ambient)
SO-8EP
SO-8
Thermal Resistance (Junction to Case)
SO-8EP
Operating Junction Temperature
Storage Temperature
Lead Temperature (Soldering, 10 sec)
ESD (Human Body Model) (Note 5)
ESD (Machine Model) (Note 5)
-40 to +125
-65 to +150
+260
2000
200
22
ºC
ºC
ºC
V
V
70
22
ºC/W
1.43
115
ºC/W
-0.3 to 6
0.87
W
-5 to 30
-0.3 to V
CC
+0.3
-5 to V
CC
+5
V
V
Rating
-0.3 to 15
-0.3 to 15
-0.3 to V
BOOT-PHASE
+0.3
-5 to V
BOOT-PHASE
+5
-0.3 to 15
V
Unit
V
V
V
θ
JA
θ
JC
T
J
T
STG
T
LEAD
–
–
Notes:
4. Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Conditions” is not implied.
Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability.
5. Devices are ESD sensitive. Handling precaution is recommended.
Recommended Operating Conditions
Symbol
V
CC
T
A
Supply Input Voltage
Operating Ambient Temperature
Parameter
Min
4.5
-40
Max
13.2
+85
Unit
V
C
AP3585
Document number: DS36790 Rev. 1 - 2
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© Diodes Incorporated
A Product Line of
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AP3585
Electrical Characteristics
(V
CC
=12V, T
A
=+25ºC, unless otherwise specified.)
Symbol
SUPPLY INPUT
I
CC
I
CC_Q
V
IN
Supply Current
Quiescent Supply Current
Power Input Voltage
UGATE and LGATE Pins Open;
Switching
V
FB
=V
REF
+0.1V, No Switching
–
–
–
3.0
5
4
–
–
–
13.2
mA
mA
V
Parameter
Conditions
Min
Typ
Max
Unit
POWER ON RESET
V
POR
V
POR_HYS
OSCILLATOR
f
OSC
ΔV
OSC
Oscillator Frequency
Ramp Amplitude
–
–
270
–
300
1.4
330
–
kHz
V
P-P
V
CC
Rising Threshold
V
CC
Threshold Hysteresis
V
CC
Rising
–
4.0
–
4.2
500
4.4
–
V
mV
ERROR AMPLIFIER
G
DC_OL
G
BW
SR
–
–
–
Open Loop DC Gain
Gain-bandwidth Product
Slew Rate
Transconductance
Output Source Current
Output Sink Current
V
FB
<V
REF
V
FB
>V
REF
–
–
–
–
55
–
3
–
80
80
70
10
6
800
120
120
–
–
–
1100
–
–
dB
MHz
V/µs
µA/V
µA
µA
PWM CONTROLLER GATE DRIVERS
I
UG_SRC
I
UG_SNK
R
UGATE
I
LG_SRC
I
LG_SNK
R
LGATE
–
–
–
–
Upper Gate Source Current
Upper Gate Sink Current
Upper Gate Sink Resistance
Lower Gate Source Current
Lower Gate Sink Current
Lower Gate Sink Resistance
PHASE Falling to LGATE Rising
Delay
LGATE Falling to UGATE Rising
Delay
Minimum Duty Cycle
Maximum Duty Cycle
V
BOOT
-V
PHASE
=12V, V
BOOT
-V
UGATE
=6V
V
BOOT
-V
PHASE
=12V, V
BOOT
-V
UGATE
=6V
50mA Source Current
V
CC
-V
LGATE
=6V
V
LGATE
=6V
50mA Source Current
V
PHASE
<1.2V to V
LGATE
>1.2V
V
LGATE
<1.2V to (V
UGATE
-V
PHASE
)>1.2V
–
–
–
–
–
–
–
–
–
–
–
75
-1.0
1.5
2
-1
1.5
1
50
50
0
82
–
–
4
–
–
2
–
–
–
89
A
A
Ω
A
A
Ω
ns
ns
%
%
REFERENCE VOLTAGE
V
FB
I
FB
PROTECTION
V
FB_UVP
V
FB_OVP
I
OPS
V
OCP_MAX
t
SS
V
COMP/EN
T
OTSD
T
HYS
Under Voltage Protection
Over Voltage Protection
OC Current Source
Built-in Maximum OCP Voltage
Soft-start Interval
Enable Threshold
Thermal Shutdown
Thermal Shutdown Hysteresis
–
–
–
–
–
–
–
–
0.3
–
19.5
–
–
0.25
–
–
0.4
0.8
21.5
0.3
2
0.30
+160
+20
0.5
–
23.5
–
–
0.35
–
–
V
V
µA
V
ms
V
ºC
ºC
Feedback Voltage
Feedback Bias Current
V
FB
=5V
–
0.591
–
0.6
10
0.609
50
V
nA
AP3585
Document number: DS36790 Rev. 1 - 2
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April 2014
© Diodes Incorporated
