AR2003FV
ACTIVE/SYNCHRONOUS RECTIFICATION CONTROLLER
Description
The AR2003FV is Active/Synchronous Rectification Controller,
providing output voltage from 4.5V to 21V. Using internal drain-to-
source voltage sensing, the AR2003FV is ideal for Fly-back, LLC-
resonant and other power supply architectures. It has SFB pin that
can eliminate the external feedback resistor when target output
voltage is 5V or 12V.
The small footprint of the AR2003FV makes it ideal for space
constrained applications.
Intelligent features of this IC are the Minimum Off Time (TOFF) and
Minimum on Time (TON), these features blank the noise generated
during the turn on and turn off instances of the power FET. Light load
detection for improved efficiency at light and no load is implemented.
Other features include Under Voltage Lock Out (UVLO), SYNC
feature for CCM operation and low turn off threshold voltage for
improved efficiency.
Pin Assignments
(Top View)
TON
2
AGND 3
TOFF/EN 4
SFB 5
OVS 6
NC 7
8
VS
9
VD
VD
NC
1
14 VCC
13 GND
12 DGATE
11 SYNC
10 GATE
V-DFN3535-14
Features
Primary-Side
or
Secondary-side
Active/Synchronous
Rectification, Optimized for Systems with Dynamic Voltage
Scaling Capabilities
Frequency of Operation up to 600kHz
Suitable for Discontinuous (DCM), Continuous (CCM) and
Critical (CrCM) Conduction Mode
Minimum On-time and Off-time to Blanking Turn-on/off
Oscillations
Light Load Detection and Sleep Mode
Drain Voltage Rating of 200V
Recommended Operating Voltage from 4.5V up to 21V
Low Component Count.
Low Under Voltage Lockout
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Applications
USB PD Adaptor
AC-DC Battery Charger
Fly-back Conversion
PC Power Supply
SMPS
Power Adaptors
Auxiliary Power Supplies
PoE Power Devices
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.
AR2003FV
Document number: DS37473 Rev. 3 - 2
1 of 15
www.diodes.com
December 2014
© Diodes Incorporated
AR2003FV
Pin Descriptions
Pin Number
1, 7
2
3
Pin Name
NC
TON
AGND
Not Connected
Minimum On-time Setting Pin
This is the ground reference for all internal comparators and thresholds.
Enable Pin/ Minimum Off-time
This pin combines the functions of setting the programmable minimum off-time as well as acting as the
enable pin. The device enters Under Voltage Lock Out (UVLO) mode when VCC falls below the UVLO
threshold. At this point the TOFF/EN pin is internally shorted to ground through a resistor. The internal
current source (used for setting TOFF) is powered down. Once the UVLO threshold is exceeded, the internal
resistance is removed and the current source is activated. If the voltage applied to the TOFF/EN pin exceeds
the VEN
ON
threshold then the device is in Active Mode. If the voltage drops below the VEN
OFF
threshold then
the device is in Sleep Mode.
Output pin of internal feedback resistor which is connected to VCC. It is sent to TL431 (or its compatible) to
drive the opto-coupler and provide feedback voltage to primary side controller to realize Secondary
Synchronous Rectification.
Output voltage (VCC) select pin, work together with SFB to select output voltage in 5V or 12V.
This is the connection to internal MOSFET Source. VS is also connected to GND.
This is a connection to the internal MOSFET Drain. The pin needs to be connected as closely as possible to
the transformer used in the application, to minimize the effects of parasitic inductance on the performance of
the device. The device requires that VD has a voltage greater than 1.5V and that the T
OFF
timer has expired
before the MOSFET is able to be activated. Once these conditions are met and the voltage internally sensed
on the VD pin is 150mV lower than the VS pin, the internal MOSFET is turned on and the T
ON
minimum on
time period is started. The MOSFET will remain on for at least the length of the minimum on time. The only
thing that can override this is if a pulse is detected on the SNYC pin. After the TON period, the MOSFET
remains on until the VD to VS voltage has reached to the V
THOFF
threshold, at which point the internal
MOSFET is turned off. As mentioned before, if the V
THOFF
threshold is reached before the TON period has
expired, the device will enter the Light Load Mode. Under this mode, the MOSFET will not be turned on the
next switching cycle. When the drain voltage has increased to 1.5V, the TOFF timer is triggered, during
which the MOSFET is prevented from turning on.
Connect GATE to the gate of the controlled MOSFET through a small series resistor using short PC board
tracks to achieve optimal switching performance. The GATE output can achieve >2-A peak source current
when High and >4-A peak sink current when Low into a large N-channel power MOSFET.
If a falling edge is sensed on this pin, the internal MOSFET is immediately turned off, irrespective of the
sensed drain to source voltage or the state of the TON timer. This characteristic allows the device to be
easily used in a Continuous Conduction Mode (CCM) system. The SYNC pin needs to be connected to a
suitable control signal on the primary side of the convertor, using a high voltage isolation cap, transformer or
other suitable means.
During Over Voltage Protection, DGATE will drive external MOSFET to pull down the output voltage so that
Primary side controller will start the Short Circuit Protection handling.
This is the reference potential for all internal comparators and thresholds.
VCC supplies all the internal circuitry of the device. A DC supply is required to be connected to this pin. It is
required that a 10µF or larger capacitor is placed between this pin and GND, as close to the pins as possible.
The device will not function until the V
CC
has risen above the UVLO threshold. The device can safely be
turned off by bringing V
CC
below the UVLO threshold (minus the UVLO threshold hysteresis). If V
CC
drops
below the UVLO threshold (minus UVLO threshold hysteresis), the MOSFET is turned off and the TOFF/EN
pin is internally connected to GND.
Function
4
TOFF/EN
5
6
8
SFB
OVS
VS
9, VD pad
VD
10
GATE
11
SYNC
12
13
DGATE
GND
14
VCC
AR2003FV
Document number: DS37473 Rev. 3 - 2
3 of 15
www.diodes.com
December 2014
© Diodes Incorporated
AR2003FV
Absolute Maximum Ratings
(Note 4)
Symbol
VCC
VD
VS
Input Voltage Range VCC
Input Voltage Range VD
Input Voltage Range VS
Parameter
Rating
-0.3 to 24
-1 to 200
-1 to 1
-0.3 to 6
-40 to +150
+ 260
-65 to +150
2
kV
Charged Device Model, JESD22-C101
Note 4:
These are stress ratings only. Operation outside the absolute maximum ratings may cause device failure.
Operation at the absolute maximum rating for extended periods may reduce device reliability.
Unit
V
V
V
V
°
C
°
C
°
C
TOFF/EN, TON, OVS, SYNC Input Voltage Range Other
T
J
T
L
T
ST
ESD
Operating Junction Temperature
Lead Temperature
Storage Temperature
Human Body Model, JESD22-A114
0.5
Package Thermal Data
(@T
A
= +25° unless otherwise specified)
C,
Symbol
P
D
R
θJA
R
θJC
Notes:
Parameter
Power Dissipation (Note 5)
Thermal Resistance, Junction to Ambient Air (Note 6)
Thermal Resistance, Junction to Case (Note 7)
Rating
0.67
36
21
Unit
W
°
C/W
°
C/W
5. Device mounted on FR-4 PCB, 2oz with minimum recommended pad layout.
6. Device mounted on 25mm x 25mm 2oz copper board.
7. Device mounted on 50mm x 50mm 2oz copper board.
Recommended Operating Conditions
Symbol
V
CC
V
DS
f
SW
T
J
R
TOFF
R
TON
C
VCC
TW
sync
Supply Voltage Range
Voltage Cross Drain and Source
Switching Frequency
Operating Junction Temperature Range
TOFF Resistor Value
TON Resistor Value
VCC Bypass Capacitor
Sync Pulse Width
Parameter
Min
4.5
-1
20
-40
85
8.25
10
20
Max
21
V
200
600
+125
200
100
–
–
kHz
°
C
kΩ
kΩ
μF
nS
Unit
AR2003FV
Document number: DS37473 Rev. 3 - 2
5 of 15
www.diodes.com
December 2014
© Diodes Incorporated
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