ZXGD3109N8
Document Number DS37178 Rev. 2 - 4
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SYNCHRONOUS MOSFET CONTROLLER IN SO-8
Description
The ZXGD3109N8 is intended to drive a MOSFET configured as an
ideal diode replacement. The device is comprised of a high-voltage
detector stage and gate driver. The detector monitors the voltage
between the drain and the source of the MOSFET, and if this voltage
is less than the turn-on threshold voltage of the controller, a positive
voltage is applied to the MOSFET’s Gate Pin. As the load current
decays to zero, and the voltage between the drain and source of the
MOSFET increases beyond the turn-off threshold value, the MOSFET
is rapidly turned off.
Intelligent features of this IC are the Minimum Off-Time (TOFF) and
Minimum On-Time (TON). These features blanket the noise generated
during the turn-on and turn-off instances of the power FET. Also Light
Load Detection (LLD) for improved efficiency at light and no load,
where synchronous rectification is no more beneficial. Other features
include, Undervoltage Lockout (UVLO) and low turn-off threshold
voltage for improved efficiency.
Applications
Flyback Converters in:
Power Adaptors
Auxiliary Power Supplies
PoE Power Devices
Resonant Converters in:
High Power Adaptors
85+/90+ Compliant ATX and Server Power Supplies
Features
Frequency of Operation Up to 500kHz
Suitable for Discontinuous Conduction Mode (DCM) and Critical
Conduction Mode (CrCM)
Minimum On-Time and Off-Time to Reduce Turn-On/Off
Oscillations
Intelligent Light Load Detection and Sleep Mode
Turn-Off Propagation Delay Time of 30ns Typically
Drain Voltage Rating of 200V
Recommended Operating Voltage from 4.5V up to 12V
Source and Sink Current of 2A and 4A Respectively
Low Component Count
Totally Lead-Free & Fully RoHS compliant (Notes 1 & 2)
Halogen and Antimony free. “Green” Device (Note 3)
For automotive applications requiring specific change
control (i.e. parts qualified to AEC-Q100/101/200, PPAP
capable, and manufactured in IATF 16949 certified
facilities), please contact us or your local Diodes
representative.
https://www.diodes.com/quality/product-definitions/
Mechanical Data
Case: SO-8
Case Material: Molded Plastic. “Green” Molding Compound.
UL Flammability Classification Rating 94V-0
Moisture Sensitivity: Level 1 per J-STD-020
Terminals: Finish – Matte Tin Plated Leads, Solderable per
MIL-STD-202, Method 208
Weight: 0.074 grams (Approximate)
Ordering Information (Note 4)
Product
Marking
Reel Size (inches)
Tape Width (mm)
Quantity per Reel
ZXGD3109N8TC
ZXGD3109
13
12
2,500
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.
4. For packaging details, go to our website at http://www.diodes.com/products/packages.html.
Top View
Pin-Out
SO-8
Top view
VCC
GND
TON
VS
VD
PGATE
TOFF/EN
GATE
PART OBSOLETE
NO ALTERNATE PART
ZXGD3109N8
Document Number DS37178 Rev. 2 - 4
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Marking Information
Functional Block Diagram
ZXGD = Product Type Marking Code, Line 1
3109 = Product Type Marking Code, Line 2
YY = Year (ex: 15 = 2015)
WW = Week (01 - 53)
ZXGD
3109
YY WW
ZXGD3109N8
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Pin Descriptions
Pin Number
Pin Name
Function
1
TON
Minimum On-Time
Minimum on-time setting pin. Connect this pin to Ground via RTON resistor.
2
TOFF/EN
Minimum Off-Time/Enable Pin
This pin combines the functions of setting the programmable minimum off-time as well as acting as the
Enable Pin. The device enters Undervoltage Lockout (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 resistor
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.
3
VS
Source Voltage
Connect this pin to the source of the synchronous MOSFET
4
VD
Drain Voltage
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 TOFF timer has expired before the MOSFET is able to be activated.
Once these conditions are met, and the voltage sensed on the VD Pin is 150mV lower than the VS Pin, the
Gate output to the synchronous MOSFET will go high and the TON (minimum on-time) period is started. The
MOSFET will remain on for at least the length of the minimum on-time. After the TON period, the MOSFET
will remain on until the VD to VS voltage has reached the VTHOFF threshold, at which point the Gate output will
go low. If the VTHOFF 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. The device will
come out of light load once the on-time of the synchronous MOSFET exceeds the set minimum on-time.
5
PGATE
Protection MOSFET Gate
A 100nF capacitor should be connected between this pin and GND.
6
GATE
Gate
Connect GATE to the gate of the synchronous MOSFET through a small-series resistor using short PC
board tracks to achieve optimal switching performance. The Gate output can source >2A peak source
current while turning on the sync MOSFET, and can sink >4A peak current while turning on the sync
MOSFET.
7
GND
Ground
This is the reference potential for all internal comparators and thresholds. A 10µF decoupling capacitor is
required to be placed as close as possible between VCC and GND Pins.
8
VCC
Power Supply Pin
VCC supplies all the internal circuitry of the device. A DC supply is required to be connected to this pin. A
10µF or larger capacitor must be connected between this pin and GND Pin as close as possible. The device
will not function until the VCC has risen above the UVLO threshold. The device can safely be turned off by
bringing VCC below the UVLO threshold (minus the UVLO threshold hysteresis). If VCC drops below the
UVLO threshold (minus UVLO threshold hysteresis), the MOSFET is turned off and the TOFF/EN Pin is
internally connected to GND.
ZXGD3109N8
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Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.)
Characteristic
Symbol
Value
Unit
Supply Voltage, Relative to GND
VCC
-0.3 to 15
V
Drain Pin Voltage
VD
-1 to +200
V
Gate Output Voltage
VG
12
V
Minimum On-Time (TOFF) Pin Voltage
VTOFF
-0.3 to 6
V
Minimum Off-Time (TON) Pin Voltage
VTON
-0.3 to 6
V
Gate Driver Peak Source Current
ISOURCE
5
A
Gate Driver Peak Sink Current
ISINK
5
A
Input Voltage Range VS
VS
-1 to 1
V
Thermal Characteristics
Characteristic
Symbol
Value
Unit
Power Dissipation
Linear Derating Factor
(Note 5)
PD
490
3.92
mW
mW/°C
(Note 6)
655
5.24
(Note 7)
720
5.76
(Note 8)
785
6.28
Thermal Resistance, Junction to Ambient
(Note 5)
RθJA
255
°C/W
(Note 6)
191
(Note 7)
173
(Note 8)
159
Thermal Resistance, Junction to Lead
(Note 9)
RθJL
55
°C/W
Thermal Resistance, Junction to Case
(Note 10)
RθJC
45
°C/W
Maximum Jundtion Temperature
TJ
+150
°C
Storage Temperature Range
TSTG
-65 to +150
ESD Ratings (Note 11)
Characteristic
Symbol
Value
Unit
JEDEC Class
Electrostatic Discharge - Human Body Model
ESD HBM
2,000
V
1C
Electrostatic Discharge - Machine Model
ESD MM
500
V
C
Notes: 5. For a device surface mounted on minimum recommended pad layout FR4 PCB with high coverage of single sided 1oz copper, in still air conditions; the
device is measured when operating in a steady-state condition.
6. Same as Note (5), except Pin 8 (VCC) and Pin 7 (GND) are both connected to separate 5mm x 5mm 1oz copper heatsinks.
7. Same as Note (6), except both heatsinks are 10mm x 10mm.
8. Same as Note (6), except both heatsinks are 15mm x 15mm.
9. Thermal resistance from junction to solder-point at the end of each lead on Pin 8 (VCC) and Pin 7 (GND).
10. Thermal resistance from junction to top of the case.
11. Refer to JEDEC specification JESD22-A114 and JESD22-A115.
ZXGD3109N8
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Recommended Operating Conditions
Symbol
Parameter
Min
Max
Unit
VCC
Supply Voltage Range
4.5
12
V
VDS
Voltage Cross Drain and Source
-1
200
FSW
Switching Frequency
20
600
kHz
TJ
Operating Junction Temperature Range
-40
+125
°C
RTOFF
TOFF Resistor Value
85
200
kΩ
RTON
TON Resistor Value
8.25
100
kΩ
CVCC
VCC Bypass Capacitor
10
—
μF
Thermal Derating Curve
020 40 60 80 100 120 140 160
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8 15mm x 15mm
5mm x 5mm
Minimum
Layout
Derating Curve
Junction Temperature (°C)
Max Power Dissipation (W)
10mm x 10mm
(°C)
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Electrical Characteristics (@TA = +25°C, unless otherwise specified.)
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
ICCSTART
Supply Current (Undervoltage)
VCC = 2.6V
—
160
220
µA
ICCSTANDBY
Supply Current (Disabled)
VCC = 5.5V, REN/OFF = 0Ω
—
380
500
VCC = 12V, REN/OFF = 0Ω
—
450
600
ICCON
Supply Current (Enabled)
VCC = 5.5V, FSW = 100KHz
CGATE = 0pF
—
1.5
1.8
mA
VCC = 12V, FSW = 100KHz
CGATE = 0pF
—
1.8
2.3
VCC = 5.5V, FSW = 100KHz
CGATE = 3,300pF
—
3.2
4
VCC = 12V, FSW = 100KHz
CGATE = 3,300pF
—
5
7
VEN-ON
TOFF/EN Turn-on Threshold, Rising
TOFF/EN Driven, VTON > 0.6V
1.31
1.4
1.49
V
VEN-OFF
TOFF/EN Turn-off Threshold, Falling
TOFF/EN Driven,
VTON > 0.2V
0.55
0.6
0.65
IEN-START
TOFF/EN Input Current (Disabled)
RTOFF = 50kΩ
-23
-20
-17
µA
IEN-ON
TOFF/EN Input Current (Enabled)
RTOFF = 100kΩ
-11.5
-10
-8.5
Undervoltage Lockout (UVLO)
UVLOTH
VCC Undervoltage Lockout Threshold Rising
—
2.8
3.0
3.20
V
UVLOHYS
VCC Undervoltage Lockout Threshold
Hysteresis
—
—
200
—
mV
MOSFET Voltage Sensing
VTHARM
Gate Re-Arming Threshold
VD to GND, Rising
-1.3
1.5
-1.7
V
VTHON
Gate Turn-On Threshold
(VD-VS) Falling, VS = 0V
-220
-150
-80
mV
VTHOFFLV
Gate Turn-Off Threshold
(VD-VS) Rising, VS = 0V,
VCC < 4.3V
-30
-20
-10
mV
VTHOFFHV
Gate Turn-Off Threshold
(VD-VS) Rising, VS = 0V,
VCC > 4.3V
-10
-4
-1
mV
TD(ON)
Gate Turn-On Propagation Delay
From VTHON to Gate > 1V
—
30
52
ns
TD(OFF)
Gate Turn-Off Propagation Delay
From VTHOFF to Gate < 4V
—
30
62
ns
Minimum On-Time
TON-LR
Minimum On-Time Low Resistance
RTON = 8.25kΩ
0.26
0.34
0.42
µs
TON-HR
Minimum On-Time High Resistance
RTON = 100kΩ
2.2
3
3.8
µs
ZXGD3109N8
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Electrical Characteristics (Continued) (@TA = +25°C, unless otherwise specified.)
Minimum Off-Time
TOFF-LR
Minimum Off-Time Low Resistance
RTOFF = 100kΩ
1.2
3
5
µs
TOFF-HR
Minimum Off-Time High Resistance
RTOFF = 200kΩ
15
21
25
µs
TOFF-LV
Minimum Off-Time Low Voltage
VEN/TOFF = 1V
—
3
—
µs
TOFF-HV
Minimum Off-Time High Voltage
VEN/TOFF = 2V
—
21
—
µs
TOFF-OV
Minimum Off-Time Over Voltage
2V < VEN/TOFF < VAVDD
—
21
—
µs
Gate Driver
RGUP
Gate Pull-Up Resistance Enabled
IGATE = -100mA
—
2.3
—
Ω
RGDN
Gate Pull-Down Resistance Enabled
IGATE = 100mA
—
1.1
—
ISOURCE
Peak Gate Source Current
CGATE = 22nF
—
3
—
A
ISINK
Peak Gate Sink Current
CGATE = 22nF
—
4
—
VOHG
Gate Output High Voltage
VCC = 5V
4.7
—
—
V
VCC = 12V
9
—
—
VOLG
Gate Output Low Voltage
VCC = 5V
—
—
0.3
TFGATE
Gate Fall Time
4V to 1V, CGATE = 3,300pF,
VCC = 5V
—
14
42
ns
9V to 1V, CGATE = 3,300pF,
VCC = 12V
—
20
42
TRGATE
Gate Rise Time
1V to 4V, CGATE = 3,300pF,
VCC = 5V
—
16
42
1V to 10V, CGATE = 3,300pF,
VCC = 12V
—
20
42
TDIS
Disable Delay (Note 8)
EN Falling to Gate Falling
—
160
—
Exception Handling
TOVER
Overtemperature
—
—
+150
—
°C
TRECOVER
Temperature to Recover from
Overtemperature Exception
—
—
+125
—
°C
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Typical Application Circuit
+Vout
PWM controller
CrCM/DCM
- Vout
ZXGD3109
Drain Gate Source RTON RTOFF/EN
PGATE
Vcc
RTON RTOFF
G
DS
C1 C2
Snubber
Transformer
Synchronous MOSFET
CPGATE
GND
CPGATE of 0.1µF must be connected
C1 of >10µF must be connected as close as possible to Vcc and ground with minimum
track length
ZXTR2012
IN
GND OUT
C3
C3 of 1µF must be connected
Less than 12V rails can be directly connected to the Vcc. For more than
12V operation, a regulator arrangement is suggested in the figure.
ZXGD3109N8
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Package Outline Dimensions
Please see http://www.diodes.com/package-outlines.html for the latest version.
SO-8
SO-8
Dim
Min
Max
Typ
A
1.40
1.50
1.45
A1
0.10
0.20
0.15
b
0.30
0.50
0.40
c
0.15
0.25
0.20
D
4.85
4.95
4.90
E
5.90
6.10
6.00
E1
3.80
3.90
3.85
E0
3.85
3.95
3.90
e
--
--
1.27
h
-
--
0.35
L
0.62
0.82
0.72
Q
0.60
0.70
0.65
All Dimensions in mm
Suggested Pad Layout
Please see http://www.diodes.com/package-outlines.html for the latest version.
SO-8
Dimensions
Value (in mm)
C
1.27
X
0.802
X1
4.612
Y
1.505
Y1
6.50
1
b
e
E
A
A1
9° (All sides)
4°± 3°
c
Q
h
45°
R 0.1
7°
D
E0
E1
L
Seating Plane
Gauge Plane
CX
Y
Y1
X1
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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).
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.
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