Datasheet SR036MG, SR036SG, SR037MG, SR037SG Datasheet (Supertex)

Demo Kit

Available

SR036/SR037

SR036
SR037

Inductorless, Dual Output Off-Line Regulators

Features

❑ Accepts peak input voltages up to 700V

❑ 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

❑ White goods

❑ Appliances

❑ Small off-line low voltage power supplies

❑ Lighting controls

General Description

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,

, is designed to operate from an unfiltered full wave

HV

IN

rectified 120V or 240V AC line. It is designed to control an
external N-channel MOSFET. When HVIN is between V
40V, where V

is the threshold voltage of the external

GS(th)

MOSFET, the external N-channel MOSFET is turned on allowing
it to charge an external capacitor connected to V
unregulated DC voltage will develop on V

. Once HVIN is

SOURCE

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.

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.

GS(th)

SOURCE

to

. An

SR03x Typical Application Circuit

~

18V Unregulated

100µF

Gate

120VAC

or

240VAC

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.

Surge

Protection

SR036

or SR037

1

V

SOURCE

V

OUT

SR036: V
SR037: V

1.0µF

=3.3V Regulated

OUT

=5.0V Regulated

OUT

Ordering Information

SR036/SR037

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NI

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V

TUO

V3.3*GM630RSGS630RS

V007V42

V0.5*GM730RSGS730RS

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Absolute Maximum Ratings*

VIN, High Voltage Input +700V

V

, Low Voltage Output +6.0V

OUT

Storage Temperature -65°C to +150°C

Soldering Temperature +300°C

Power Dissipation, MSOP-8 300mW

Power Dissipation, SO-8 slug 1.50W

* All voltages are referenced to GND.

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8-POSMgulStaeH/w8-OS

Pin Configuration

1

HVIN Gate

2

N/C Source

3

N/C V

4

GND N/C

MSOP-8

(top view)

1

HVIN Gate

2

N/C Source

3

N/C V

GND N/C

4

SO-8 Slug

Backside: GND

(top view)

8

7

6

OUT

5

8

7

6

OUT

5

Electrical Characteristics

(Over operating supply voltages unless otherwise specified, TA=0°C to +125°C)

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VH

NI

V

HT

V

SG

V

ETAG

V

TUO

V

TUO

VH

NI

egatlovtupnI

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egatlovpmalcecruosotetaG01±51±02±VISGAµ001±=

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8-POSM

8-OSehtrofegatlovtuptuodetalugeR

gulstaehhtiw

630RS79.203.336.3

730RS05.400.505.5V

630RS79.203.336.3

730RS5.400.505.5V

qerFycneuqerfCAtupnI04001zH

007

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V

V

V

V

V

ECRUOS

ECRUOS

ECRUOS

ECRUOS

egatlovtneisnartkaeP

I,V01=

TUO

I,V01=

TUO

I,V01=

TUO

I,V01=

TUO

Am51=

Am51=

Am03=

Am03=

2

Typical Performance Curves

SR036/SR037

Gate Clamp

25

20

15

10

Vgate (V)

5

0

-40 -10 20 50 80 110 140

Temperature (°C)

Regulator Output (SR037)

6

5

4

(V)

3

OUT

V

2

1

0

051015 20

Source Voltage (V)

HVIN (off)

60

50

40

(V)

30

IN

HV

20

10

0

-40 -10 20 50 80 110

140

Temperature (°C)

Gate Voltage

20

18

16

14

12

(V)

10

Gate

V

8

6

4

2

0

25

010203040506070

80

HVIN (V)

HV Input Current

2100

1800

1500

1200

900

(µA)

IN

I

600

300

0

050100 150 200 250 300 350

HV

IN

(V)

125°C

25°C

-40°C

400

Load Regulation (SR037)

5.05

5.00

4.95

4.90

(V)

4.85

OUT

V

4.80

4.75

4.70

4.65

051015 20 25 30

I

(mA)

OUT

Source=15V
25°C

Source=8V
25°C

35

3

Applications Information Functional Block Diagram

SR036/SR037

Operating Principle

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 HV
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.

. Output voltage (Vunreg) decays during the periods

IN(off)

HV

IN

Switch ON

V

HV

REF

Gate Source

IN

CM

Reg

GND

V

OUT

V

V

TH

REG

V

UNREG

Figure 1: Typical Waveforms

not to scale

4

Applications Information, continued

SR036/SR037

Fuse

120VAC

or

240VA

C

Surge

Protection

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

VN2460N

8

V

UNREG

220µF

TN2106K1ON/OFF

1KΩ

Gate Source

HV

IN

SR036

or SR037

GND

V

OUT

1µF

I

typical 40mA

OUT

(

I

UNREG

V

REG

+

I

REG)

output current is typically 40mA. The TN2106K1 in series with a
1KΩ resistor can be added for applications requiring an enable
control.

Fuse

VN2460N

8

120VAC

or

240VAC

Surge

Protection

Gate Source

HV

IN

SR036

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

2N3904

V

=5.0V

out1

220µF

10K

Ω

1µF1MΩ

Vz

5.6V

V

OUT

V

out2

=3.3V

1µF

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

Applications Information, continued

SR036/SR037

Fuse

VN2460N

120VAC

or

240VAC

Surge

Protection

HV

IN

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.

8

Gate Source

SR036

GND

Unregulated Voltage

220µF

1N4001

12V Coil

3.3V

V

OUT

1µF

Logic

Control

Circuit

Relay

VN2110K1

Fuse

VN2460N8

120VAC

or

240VAC

Surge

Protection

HV

IN

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 =

= 100

40mA

1K - V

β

Ω

40mA

Ω

Unregulated Voltage

220µF

Gate Source

5.0V

V

GND

OUT

1µF

SR037

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:

be

where V = 0.6V and =100

,

be

Logic

Control

Circuit

1N4001

5V Coil

1KΩ

Relay

2N3904

100Ω

β

6

Applications Information, continued

SR036/SR037

Unregulated Voltage

220µF

120VAC

Fuse

VN2460N8

or

240VAC

Surge

Protection

HV

IN

Gate Source

SR037

GND

5.0V

V

OUT

1µF

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

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.

Logic

Control

Circuit

Vz

5.1V

5V Coil

Relay

Fuse

TN2425N8

120VAC

Surge

Protection

HV

IN

SR036 or

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.

Gate Source

SR037

GND

Unregulated Voltage

220µF

V

OUT

V

1µF

REG

330Ω330Ω

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06/13/02rev.12

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TEL: [phone] • FAX: [phone]

7

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