SUPERTEX SR036

SR036/SR037
SR036
SR037
Demo Kit
Available
Inductorless, Dual Output Off-Line Regulators
Features
General Description
❑ Accepts peak input voltages up to 700V
The Supertex SR036 and SR037 are inductorless, dual output
off-line controllers. They do not require any transformers,
inductors, or high voltage input capacitors. The input voltage,
HVIN, is designed to operate from an unfiltered full wave
rectified 120V or 240V AC line. It is designed to control an
external N-channel MOSFET. When HVIN is between VGS(th) to
40V, where VGS(th) is the threshold voltage of the external
MOSFET, the external N-channel MOSFET is turned on allowing
it to charge an external capacitor connected to VSOURCE. An
unregulated DC voltage will develop on VSOURCE. Once HVIN is
above 45V, the N-channel MOSFET is turned off. The maximum
gate voltage for the external MOSFET is 24V. The unregulated
voltage is approximately 18V. The SR036 also provides a
regulated 3.3V whereas the SR037 provides a regulated 5.0V.
❑ Operates directly off of rectified 120V AC or 240V AC
❑ Integrated linear regulator
❑ Minimal power dissipation
❑ No high voltage capacitors required
❑ No transformers or inductors required
Applications
❑ 3.3V or 5.0V power supplies
❑ SMPS house keeping power supplies
WARNING!!! Galvanic isolation is not provided. Dangerous
voltages are present when connected to the AC line. It is
the responsibility of the designer to assure adequate
safeguards are in place to protect the end user from
electrical shock.
❑ White goods
❑ Appliances
❑ Small off-line low voltage power supplies
❑ Lighting controls
SR03x Typical Application Circuit
~18V Unregulated
Surge
Protection
120VAC
or
240VAC
Gate
100µF
SR036
or SR037
VSOURCE
SR036: VOUT=3.3V Regulated
SR037: VOUT=5.0V Regulated
VOUT
1.0µF
06/13/02
Supertex Inc. does not recommend the use of its products in life support applications and will not knowingly sell its products for use in such applications unless it receives an adequate "products liability
indemnification insurance agreement." Supertex does not assume responsibility for use of devices described and limits its liability to the replacement of devices determined to be defective due to
workmanship. No responsibility is assumed for possible omissions or inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications, refer to the
Supertex website: http://www.supertex.com. For complete liability information on all Supertex products, refer to the most current databook or to the Legal/Disclaimer page on the Supertex website.
1
SR036/SR037
Ordering Information
HVIN Maximum
Voltage
Gate Voltage
(max)
700V
Package Options
VOUT
24V
MSOP-8
SO-8 w/ Heat Slug
3.3V
SR036MG*
SR036SG
5.0V
SR037MG*
SR037SG
* Product supplied on 2500 piece carrier tape reel.
Pin Configuration
Absolute Maximum Ratings*
VIN, High Voltage Input
+700V
VOUT, Low Voltage Output
+6.0V
Storage Temperature
HVIN
1
8
Gate
N/C
2
7
Source
N/C
3
6
VOUT
GND
4
5
N/C
-65°C to +150°C
Soldering Temperature
+300°C
Power Dissipation, MSOP-8
300mW
Power Dissipation, SO-8 slug
MSOP-8
(top view)
1.50W
* All voltages are referenced to GND.
HVIN
1
8
Gate
N/C
2
7
Source
N/C
3
6
VOUT
GND
4
5
N/C
SO-8 Slug
Backside: GND
(top view)
Electrical Characteristics
(Over operating supply voltages unless otherwise specified, TA=0°C to +125°C)
Symbol
Parameter
Min
Typ
Max
700
Units
HVIN
Input voltage
VTH
HVIN voltage when Gate is pulled to ground
40
45
50
V
VGS
Gate to source clamp voltage
±10
±15
±20
V
VGATE
Gate to ground clamp voltage
18
20
24
V
VOUT
Regulated output voltage for the
MSOP-8
SR036
2.97
3.30
3.63
SR037
4.50
5.00
5.50
VOUT
Regulated output voltage for the SO-8
with heat slug
SR036
2.97
3.30
3.63
SR037
4.5
5.00
5.50
Freq
Input AC frequency
407
40
2
100
V
V
V
Hz
Conditions
Peak transient voltage
Peak rectified AC voltage
IGS = ±100µA
VSOURCE = 10V, IOUT = 15mA
VSOURCE = 10V, IOUT = 15mA
VSOURCE = 10V, IOUT = 30mA
VSOURCE = 10V, IOUT = 30mA
SR036/SR037
Typical Performance Curves
Gate Clamp
HVIN (off)
60
25
50
20
HVIN (V)
Vgate (V)
40
15
10
30
20
5
10
0
0
-40
-10
20
50
80
110
140
-40
-10
20
Temperature (°C)
50
80
110
140
Temperature (°C)
Gate Voltage
Regulator Output (SR037)
20
6
18
5
16
14
VGate (V)
VOUT (V)
4
3
12
10
8
2
6
4
1
2
0
0
0
5
10
15
20
25
0
10
20
Source Voltage (V)
30
40
50
60
70
80
HVIN (V)
Load Regulation (SR037)
HV Input Current
5.05
2100
125°C
5.00
1800
25°C
4.95
-40°C
VOUT (V)
1500
IIN (µA)
1200
900
4.90
Source=15V
25°C
4.85
4.80
600
Source=8V
25°C
4.75
300
4.70
4.65
0
0
50
100
150
200
250
300
350
0
400
HVIN (V)
5
10
15
20
IOUT (mA)
3
25
30
35
SR036/SR037
Applications Information
Functional Block Diagram
Operating Principle
HVIN
The SR03x operates by controlling the conduction angle of the
external MOSFET as shown in Figure 1. When the rectified AC
voltage is below the VTH threshold, the pass transistor is turned
on. The pass transistor is turned off when the rectified AC is
above HVIN(off). Output voltage (Vunreg) decays during the periods
when the switch is off and when the rectified AC is below the
output voltage. The amount of decay is determined by the load
and the value of C1. Since the switch only conducts with low
voltages across it, power dissipation is minimized.
VREF
Gate
Source
CM
Reg
VOUT
GND
Switch ON
HVIN
V TH
VUNREG
VREG
not to scale
Figure 1: Typical Waveforms
4
SR036/SR037
Applications Information, continued
VN2460N8
Fuse
VUNREG
220µF
Surge
Protection
120VAC
or
240VAC
1KΩ
IOUT typical 40mA
(IUNREG + IREG)
Gate
HVIN
ON/OFF
Source
SR036
or SR037
TN2106K1
VOUT
VREG
1µF
GND
Figure 2: Example Circuit with Enable Control
Figure 2 is an example circuit using the SR036 or SR037 along
with a Supertex VN2460N8 MOSFET to generate an unregulated voltage of approximately 18V and a regulated voltage of
3.3V for the SR036 or 5.0V for the SR037. The combined total
120VAC
or
240VAC
VN2460N8
2N3904
Vout1=5.0V
220µF
Surge
Protection
Fuse
output current is typically 40mA. The TN2106K1 in series with a
1KΩ resistor can be added for applications requiring an enable
control.
Gate
HVIN
1MΩ
1µF
Vz
5.6V
Source
VOUT
SR036
10KΩ
Vout2=3.3V
1µF
GND
Figure 3: Generating Two Regulated Voltages
For applications requiring two regulated voltages, an inexpensive discrete linear regulator can be added to regulate the
unregulated output as show in Figure 3. The discrete linear
regulator consists of a Zener diode, a resistor and a bipolar
transistor. The regulated voltage, Vout1, is determined by the
Zener diode voltage minus the base-to-emitter voltage drop of
0.6V. Figure 3 uses a 5.6V Zener diode to obtain a 5.0V output.
Different Zener diode voltages can be used to obtain different
regulated output voltages.
5
SR036/SR037
Applications Information, continued
VN2460N8
120VAC
or
240VAC
Surge
Protection
Fuse
Unregulated Voltage
1N4001
220µF
Gate
HVIN
12V Coil
Relay
Source
3.3V
SR036
VOUT
1µF
GND
Logic
Control
Circuit
VN2110K1
Figure 4: Driving 12V Relay Coils
The circuit shown in Figure 4 uses the SR036 to supply a
regulated 3.3V for the logic control circuitry while the unregulated voltage is used to drive a 12V relay coil. The operating
voltage for a 12V relay coil is typically very wide and can
therefore operate directly from the unregulated line.
VN2460N8
120VAC
or
240VAC
Surge
Protection
Fuse
Unregulated Voltage
1N4001
220µF
Gate
HVIN
Source
SR037
GND
VOUT
5.0V
Logic
Control
Circuit
5V Coil
Relay
1KΩ
1µF
2N3904
100Ω
Figure 5: Driving 5V Relay Coils
The circuit shown in Figure 5 uses the SR037 to supply a
regulated 5.0V for the logic control circuitry while the unregulated voltage is used to drive a 5.0V coil relay. To overcome the
voltage variation of the unregulated line, a bipolar transistor is
5.0V R =
used to drive the coil with a constant current. The resistor value
from the emitter to ground sets the desired coil current. For an
arbitrary coil current of 40mA, the resistor value can be calculated as:
40mA
1KΩ - Vbe
β
, where Vbe = 0.6V and β = 100
40mA
= 100Ω
6
SR036/SR037
Applications Information, continued
Surge
Protection
120VAC
or
240VAC
Unregulated Voltage
VN2460N8
Fuse
Vz
5.1V
220µF
Gate
HVIN
5V Coil
Relay
Source
SR037
VOUT
Logic
Control
Circuit
5.0V
1µF
GND
Figure 6: Driving 5V Relay Coils with Zener Diode Clamp
The circuit shown in Figure 6 uses the SR037 to supply a
regulated 5.0V for the logic control circuitry. A 5.1V Zener diode
is used in parallel with the 5.0V relay coil to ensure that the relay
coil’s maximum operating voltage is not exceeded. The Zener
120VAC
Unregulated Voltage
TN2425N8
Surge
Protection
Fuse
diode also acts as the catch diode when the coil is switched to the
off state. An external series resistor is used to limit the amount
of Zener current.
220µF
Gate
HVIN
Source
SR036 or
SR037
GND
VOUT
VREG
1µF
330Ω
330Ω
Figure 7: Driving LEDs from 120VAC
The circuit shown in Figure 7 uses the SR036 or SR037 to drive
12 high efficient red LEDs from a 120V AC line. The average LED
current is approximately 20mA.
06/13/02rev.12
©2002 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited.
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www.supertex.com