APR34150

APR34150
SECONDARY SIDE SYNCHRONOUS RECTIFICATION SWITCHER
Description
Pin Assignments
APR34150 is a secondary side Combo IC, which combines an NChannel MOSFET and a driver circuit designed for synchronous
rectification (SR) in DCM operation.
(Top View)
NEW PRODUCT
The N-Channel MOSFET has been optimized for low gate charge,
low RDS(ON), fast switching speed and body diode reverse recovery
performance.
DRISR
1
8
DRAIN
VDET
2
7
DRAIN
AREF
3
6
GND
VCC
4
5
GND
The synchronous rectification can effectively reduce the secondary
side rectifier power dissipation and provide high performance solution.
By sensing MOSFET drain-to-source voltage, APR34150 can output
ideal drive signal with less external components. It can provide high
performance solution for 5V output voltage application.
The APR34150 is available in SO-8 package.
SO-8
Applications
Features
• Synchronous Rectification for DCM Operation Flyback
• Eliminate Resonant Ring Interference
• Fast Detector of Supply Voltages
• Fewest External Components


•
•
Adapters/Chargers for Cell/Cordless Phones, ADSL Modems, MP3
and Other Portable Apparatus
Standby and Auxiliary Power Supplies
Totally Lead-free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
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.
Typical Applications Circuit
C21
+
C23
C22
+
R21
APR34150
R23
DRAIN
GND
DRAIN
GND
VDET
VCC
DRISR
AREF
RAREF
APR34150
Document number: DS37985 Rev. 2 - 2
R24
C24
CAREF
1 of 10
www.diodes.com
October 2015
© Diodes Incorporated
APR34150
NEW PRODUCT
Pin Descriptions
Pin Number
Pin Name
Function
1
DRISR
Synchronous rectification MOSFET drive
2
VDET
Synchronous rectification sense input, connected to DRAIN through a resistor
3
AREF
Program a voltage reference with a resistor from AREF to GND, to enable synchronous
rectification MOSFET drive signal
4
VCC
Power supply, connected with system output
5, 6
GND
Source pin of internal MOSFET, connected to Ground
7, 8
DRAIN
Drain pin of internal MOSFET
Functional Block Diagram
VCC
4
VREF
VDET
Integrator
(VDET-VCC)*tONP
IOVP
OVP
IAREF
tONPDET
AREF
DRISR
Counter
3
OSC
1
SRDRIVER
5, 6
DRAIN
GND
7, 8
2
VDET
APR34150
Document number: DS37985 Rev. 2 - 2
2 of 10
www.diodes.com
October 2015
© Diodes Incorporated
APR34150
Absolute Maximum Ratings (Note 4)
Symbol
NEW PRODUCT
VCC
Parameter
Supply Voltage
Rating
Unit
-0.3 to 7.5
V
VDET, VDRAIN
Voltage at VDET, DRAIN Pin
-2 to 50
V
VAREF, VDRISR
Voltage at AREF, DRISR Pin
-0.3 to 6
V
ID
Continuous Drain Current
15
A
IDM
Pulsed Drain Current
60
A
PD
Power Dissipation at TA=+25ºC
0.7
W
θJA
Thermal Resistance (Junction to Ambient)
(Note 5)
Thermal Resistance (Junction to Case)
(Note 5)
170
ºC/W
24
ºC/W
+150
ºC
-65 to +150
ºC
+300
ºC
θJC
TJ
Operating Junction Temperature
TSTG
Storage Temperature
TLEAD
Lead Temperature (Soldering, 10 sec)
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. FR-4 substrate PC board, 2oz copper, with 1 inch2 pad layout.
Recommended Operating Conditions
Symbol
Parameter
Min
Max
Unit
VCC
Supply Voltage
3.3
6
V
TA
Ambient Temperature
-40
+85
ºC
APR34150
Document number: DS37985 Rev. 2 - 2
3 of 10
www.diodes.com
October 2015
© Diodes Incorporated
APR34150
Electrical Characteristics
Symbol
(@TA = +25°C, VCC =5V, unless otherwise specified.)
Parameter
Conditions
Min
Typ
Max
Unit
Supply Voltage ( VCC Pin )
ISTARTUP
IOP
NEW PRODUCT
VSTARTUP
–
VOVP
IOVP
Startup Current
VCC=VSTARTUP-0.1V
–
100
150
μA
Operating Current
VDET pin floating
VCC=VTRIGGER+20mV
40
100
150
μA
Startup Voltage
–
–
3.1
–
V
UVLO
–
–
2.8
–
V
Overshoot Voltage for Discharge
–
5.7
5.8
5.9
V
Overshoot Current for Discharge
VCC=VOVP+0.1V, VCC pin is
connected to a 20Ω resistor
40
–
100
mA
1
V
Synchronous Voltage Detect
VTHON
Gate Turn On Threshold
–
0
–
VTHOFF
Gate Turn Off Threshold
–
-20
-12.5
-5
mV
tDON
Turn On Delay Time
From VTHON to VDRISR=1V
–
70
130
ns
tDOFF
Turn Off Propagation Delay Time
From VTHOFF to VDRISR=3V
–
100
150
ns
tRG
Gate Turn On Rising Time
From 1V to 3V, CL=4.7nF
–
50
100
ns
tFG
Gate Turn Off Falling Time
From 3V to 1V, CL=4.7nF
ns
tLEB_S
Minimum On Time
tLEB_L
VDRISR_HIGH
VS_MIN
tOVP_LAST
Kqs
Notes:
–
50
100
–
0.9
1.8
2.7
–
–
–
6.5
3.7
–
–
V
μs
Drive Output Voltage
VCC=5V
SR Minimum Operating Voltage
(Note 6)
–
–
–
4.5
V
Added OVP Discharge Time
–
–
1.0
–
ms
(Note 7)
(VDET-VCC)*tONP = 25Vµs
0.325
–
0.515
mA*μs
6. This item specifies the minimum SR operating voltage of VIN_DC, VIN_DC≥NPS*VS_MIN.
7. This item is used to specify the value of RAREF.
APR34150
Document number: DS37985 Rev. 2 - 2
4 of 10
www.diodes.com
October 2015
© Diodes Incorporated
APR34150
Electrical Characteristics
(@TA =+25°C, unless otherwise specified. Cont.)
MOSFET Static Characteristics
Parameters
Drain to Source Breakdown
Voltage
NEW PRODUCT
Gate Threshold Voltage
Zero Gate Voltage Drain
Current
Gate to Source Leakage
Current
Drain to Source On-state
Resistance
Symbol
Conditions
Min
Typ
Max
Unit
VDSS(BR)
VGS=0V, ID=0.25mA
50
–
–
V
VGS(TH)
VDS=VGS, ID=0.25mA
0.5
0.9
2
V
IDSS
VDS=50V, VGS=0V
–
–
1
μA
IGSS
VGS=10V, VDS=0V
–
–
±10
μA
RDS(ON)
VGS=4.5V, ID=15A
12
17
30
mΩ
Min
Typ
Max
Unit
–
1316
–
–
97
–
–
85
–
–
3.2
–
–
5.7
–
–
15.2
–
–
0.85
–
MOSFET Dynamic Characteristics
Parameters
Symbol
Input Capacitance
Ciss
Output Capacitance
Coss
Reverse Transfer Capacitance
Crss
Gate to Source Charge
Qgs
Gate to Drain Charge (Miller
Charger)
Qgd
Total Gate Charge
Qg
Gate Resistance
Rg
Conditions
VGS=0V, VDS=25V, f=1MHz
VGS=0V to 10V, VDD=25V,
ID=15A
–
pF
nC
Ω
Operation Description
MOSFET Driver
The operation of the SR is described with timing diagram shown in Figure 1. APR34150 monitors the MOSFET drain-source voltage. When the
drain voltage is lower than the turn-on threshold voltage VTHON, the IC outputs a positive drive voltage after a turn-on delay time (tDON). The
MOSFET will turn on and the current will transfer from the body diode into the MOSFET’s channel.
In the process of drain current decreasing linearly toward zero, the drain-source voltage rises synchronically. When it rises over the turn off
threshold voltage VTHOFF, APR34150 pulls the drive signal down after a turn off delay (tDOFF).
I,V
VDET
IS
VTHON
0
t
VTHOFF
VDRISR
0.9VDRISR
0.9VDRISR
0.1VDRISR
0
tDON
tRG
tDOFF
0.1VDRISR
t
tFG
Figure 1. Typical Waveforms of APR34150
APR34150
Document number: DS37985 Rev. 2 - 2
5 of 10
www.diodes.com
October 2015
© Diodes Incorporated
APR34150
Operation Description (Cont.)
Minimum On Time
When the controlled MOSFET gate is turned on, some ringing noise is generated. The minimum on-time timer blanks the VTHOFF comparator,
keeping the controlled MOSFET on for at least the minimum on time. If VTHOFF falls below the threshold before minimum on time expires, the
MOSFET will keep on until the end of the minimum on time.
The minimum on time is in direct proportion to the (VDET-VCC)*tONP. When (VDET-VCC)*tONP=5V*5μs, the minimum on time is about 1.8μs.
NEW PRODUCT
The Value and Meaning of AREF Resistor
As to DCM operation Flyback converter, after secondary rectifier stop conduction the primary MOSFET Drain-to-source ringing waveform is
resulted from the resonant of primary inductance and equivalent switch device output capacitance. This ringing waveform probably leads to
Synchronous Rectifier error conduction. To avoid this fault happening, APR34150 has a special function design by means of volt-second product
detecting. From the sensed voltage of VDET pin to see, the volt-second product of voltage above VCC at primary switch on time is much higher
than the volt-second product of each cycle ringing voltage above VCC. Therefore, before every time Synchronous Rectifier turning on, APR34150
judges if the detected volt-second product of VDET voltage above VCC is higher than a threshold and then turn on synchronous Rectifier. The
purpose of AREF resistor is to determine the volt-second product threshold. APR34150 has a parameter, Kqs, which converts RAREF value to voltsecond product,
Area2  R AREF * Kqs
In general, Area1 and Area3, the value of which should be test on system, depend on system design and are always fixed after system design
frozen. As to BCD PSR design, the Area1 value changes with primary peak current value and Area3 value generally keeps constant at all
conditions. So the AREF resistor design should consider the worst case, the minimum primary peak current condition. Since of system design
parameter distribution, Areas1 and Area3 have moderate tolerance. So Aarea2 should be designed between the middle of Area1 and Area3 to
keep enough design margin.
Area3  R AREF * Kqs  Area1
Area1=(VDET-VCC)*tONP
Area3
VDET
VCC
Area2=Kqs*RAREF
Figure 2. AREF Function
SR Minimum Operating Voltage
APR34150 sets a minimum SR operating voltage by comparing the difference between V DET and output voltage (VCC). The value of VDET–VCC must
be higher than its internal reference, then APR34150 will begin to integrate the area of (VDET–VCC)*tONP. If not, the area integrating will not begin
and the SR driver will be disabled.
SR Turning off Timing Impact on PSR CV Sampling
As to synchronous rectification on Flyback power system, SR MOSFET need to turn off in advance of secondary side current decreasing to zero to
avoid current flowing reversely. When SR turns off in advance, the secondary current will flow through the body diode. The SR turning off time is
determined by the VTHOFF at a fixed system. When VTHOFF is more close to zero, the SR turning on time gets longer and body diode conduction time
gets shorter. Since of the different voltage drop between SR MOSFET and body diode, the PSR feedback signal VFB appears a voltage jump at the
time of SR MOSFET turning off. If the PSR CV sampling time tSAMPLE is close to even behind this voltage jump time, there will be system unstable
operation issue or the lower output voltage issue.
APR34150
Document number: DS37985 Rev. 2 - 2
6 of 10
www.diodes.com
October 2015
© Diodes Incorporated
APR34150
Operation Description (Cont.)
To ensure stable operating of system, it must be met:
tBODYDIODE<tONS*(1- tSAMPLE)
tSAMPLE
SR Turnoff,
Bodydiode operating
SR Operating
NEW PRODUCT
tBODYDIODE
VFB
tONS
Figure 3. SR Turning off Timing Impact on PSR CV Sampling
Recommended Application Circuit Parameters
The two resistors R23 and R24 are used to pass ESD test. The value of R23 and R24 should be over 20Ω and below 47Ω respectively because of
the undershoot performance. The package of R23 and R24 should be at least 0805 and there isn’t any trace under these two resistors.
CAREF is suggested to parallel with AREF resistor to keep the volt-second product threshold stable. And the recommended value of CAREF is 100nF.
The recommended value of C24 is 100nF.
Ordering Information
APR34150 X XX - XX
Product Name
Package
Temperature Range
SO-8
-40 to +85C
Package
Packing
RoHS/Green
M : SO-8
TR : Tape & Reel
G1 : Green
Part Number
APR34150MTR-G1
Marking ID
34150M-G1
Packing
4000/Tape & Reel
Marking Information
(Top View)
34150
M-G1
YWWAXX
-
APR34150
Document number: DS37985 Rev. 2 - 2
First and Second Lines: Logo and Marking ID
Third Line: Date Code
Y: Year
WW: Work Week of Molding
A: Assembly House Code
th
th
XX: 7 and 8 Digits of Batch No.
7 of 10
www.diodes.com
October 2015
© Diodes Incorporated
APR34150
Package Outline Dimensions (All dimensions in mm(inch).)
(1)
Package Type: SO-8
4.700(0.185)
5.100(0. 201)
7°
~ 9°
0.320(0. 013)
TYP
1.350(0. 053)
1.750(0. 069)
NEW PRODUCT
8°
8°
~ 9°
7°
0.600(0. 024)
0.725(0. 029)
D
5.800(0. 228)
6.200(0. 244)
1.270(0. 050)
TYP
D
20:1
0.300(0. 012)
R0.150(0.006)
0.100(0. 004)
1.000(0. 039)
TYP
3.800(0. 150)
Option 1
4.000(0. 157)
0.300(0. 012)
0.150(0. 006)
0.250(0. 010)
Option 1
0°
8°
1°
7°
0.510(0. 020)
R0.150(0.006)
0.450(0. 017)
0.820(0. 032)
Option 2
0.350(0. 014)
TYP
Note: Eject hole , oriented hole and mold mark is optional .
APR34150
Document number: DS37985 Rev. 2 - 2
8 of 10
www.diodes.com
October 2015
© Diodes Incorporated
APR34150
Suggested Pad Layout
(1)
Package Type: SO-8
NEW PRODUCT
Grid
placement
courtyard
G
Z
Y
E
Dimensions
Value
Z
(mm)/(inch)
6.900/0.272
APR34150
Document number: DS37985 Rev. 2 - 2
G
(mm)/(inch)
3.900/0.154
X
X
(mm)/(inch)
0.650/0.026
9 of 10
www.diodes.com
Y
(mm)/(inch)
1.500/0.059
E
(mm)/(inch)
1.270/0.050
October 2015
© Diodes Incorporated
APR34150
IMPORTANT NOTICE
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
NEW PRODUCT
Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes
without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or
trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume
all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated
website, harmless against all damages.
Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel.
Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and
hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or
indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.
Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings
noted herein may also be covered by one or more United States, international or foreign trademarks.
This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the
final and determinative format released by Diodes Incorporated.
LIFE SUPPORT
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express
written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the
labeling can be reasonably expected to result in significant injury to the user.
B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and
acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any
use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related
information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its
representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2015, Diodes Incorporated
www.diodes.com
APR34150
Document number: DS37985 Rev. 2 - 2
10 of 10
www.diodes.com
October 2015
© Diodes Incorporated
Similar pages