Használati útmutató Microchip SR087

Microchip nincs kategorizálva SR087

Olvassa el alább 📖 a magyar nyelvű használati útmutatót Microchip SR087 (16 oldal) a nincs kategorizálva kategóriában. Ezt az útmutatót 4 ember találta hasznosnak és 2 felhasználó értékelte átlagosan 4.5 csillagra

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 2017 Microchip Technology Inc. DS20005544A-page 1

SR086/SR087

Features

• Efficient Operation without Magnetics

• No High-voltage Capacitors

• Adjustable Main Output Voltage (9V to 50V)

• Additional Internal Linear Regulator:

- 3.3V for SR086

- 5V for SR087

• Up to 100 mA Combined Output Current

• Single BOM for 120 VAC/230 VAC

• Built-in Soft Start

• Less than 200 mW Standby Power

Applications

• White Goods

• Household Appliances

• Lighting Controls

• Circuit Breakers

• Keep-alive Supplies

General Description

The SR086/SR087 are inductorless switching

regulators designed to operate directly from a rectified

AC line. The operating principle is to turn on a pass

transistor when the rectified AC is below the output

voltage and to turn it off when the output voltage

reaches a specific level. The ICs feature an adjustable

main output voltage of 9V to 50V and an additional

fixed output of 3.3V for SR086 and 5V for SR087.

Efficiencies of around 55% may be realized for loads

up to 1W in 120 VAC applications and about 50%

efficiencies for loads up to 800 mW in 230 VAC

applications.

A logic-level enable input allows the SR086/SR087 to

be disabled—useful when they are employed as

keep-alive power supplies.

Package Type

Backside on the SOIC package is at ground potential and may be connected to

ground or left unconnected. See Table 2-1 for pin information.

8-lead SOIC

(with Heat Slug)

(Top view)

VIN

GND

VREG

GATE

VGD

VOUT

VFB

Heat Slug

WARNING

Galvanic isolation is not provided. Dangerous voltages are present when connected to the AC line. It is

the responsibility of the designer using the SR086/SR087 to ensure that adequate security measures are

in place to protect the end user from electrical shock.

The circuits shown in this data sheet are not guaranteed to meet surge and conducted EMI

requirements. The effectiveness of these circuits may vary with a particular application. The designer

must conduct tests to ascertain compliance with applicable standards and regulations.

Adjustable Offline Inductorless Switching Regulators

SR086/SR087

DS20005544A-page 2  2017 Microchip Technology Inc.

Functional Block Diagram

1.0kV

1.0A

275V

50A

90 to

270VAC

50/60Hz

RGD

1.1MΩ

STGD5NB120SZ

VOUT - 1

1.25V

RFB(HI) = RFB(LO)

3.3V

CREG

100nF

GND

VREG

VOUTVGDGATEVIN

1.25A

9.0 - 50VDC

SR086

FB(LO)

12.4kΩ

100nF

COUT

470μF

RPD

390kΩ COUT1

1.0μF

Upper circuitry

Lower circuitry

Level

Translator

1.25V

REG

13V

s





1.0kV

1.0A

275V

50A

90 to

270VAC

50/60Hz

RGD

1.1MΩ

STGD5NB120SZ

VOUT - 1

1.25V

RFB(HI) = RFB(LO)

5.0V

CREG

100nF

GND

VREG

VOUTVGDGATEVIN

1.25A

9.0 - 50VDC

SR087 RFB(LO)

12.4kΩ

CGD

100nF

COUT

470μF

RPD

390kΩ COUT 1

1.0μF

Upper circuitry

Lower circuitry

Level

Translator

1.25V

REG

13V

 2017 Microchip Technology Inc. DS20005544A-page 3

SR086/SR087

Typical Application

1.0kV

1.0A

275V

50A

90 to

270VAC

50/60Hz

390kΩ 1.1MΩ

STGD5NB120SZ

VOUT - 1

1.25V

R1 = R2

3.3V

@60mA

100nF

GND

VREG

VOUTVGDGATE

VIN

Enable

1.25A

VOUT

9.0 - 50VDC

@100mA - IREG

SR086 R2

12.4k

1.0μF

100nF

470μF

Circuits

1.0kV

1.0A

275V

50A

90 -

270VAC

50/60Hz

390kΩ 1.1MΩ

STGD5NB120SZ

VOUT - 1

1.25V

R1 = R2

5.0V

@60mA

100nF

GND

VREG

VOUTVGDGATE

VIN

Enable

1.25A

VOUT

9.0 - 50VDC

@ 100mA - IREG

SR087

12.4k

1.0μF

100nF 470μF

SR086/SR087

DS20005544A-page 4  2017 Microchip Technology Inc.

1.0 ELECTRICAL CHARACTERISTICS

Absolute Maximum Ratings †

Output Voltage, VOUT ..................................................................................................................................–0.3V to 56V

Feedback Voltage, VFB ..............................................................................................................................–0.3V to 6.5V

Enable Voltage, VEN ...................................................................................................................................–0.3V to 6.5V

Operating Junction Temperature, TJ.................................................................................................... –40°C to +125°C

† Notice: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the

device. This is a stress rating only, and functional operation of the device at those or any other conditions above those

indicated in the operational sections of this specification is not intended. Exposure to maximum rating conditions for

extended periods may affect device reliability.

RECOMMENDED OPERATING CONDITIONS

Parameter Sym. Min. Typ. Max. Unit Conditions

Output Voltage V

OUT 9 — V50

Load on V

OUT

, including Feedback Divider and Load on V

REG IOUT 100 — — µA

Headroom for Internal Linear Regulation (V

OUT–VREG) VHR 4 — — V

ELECTRICAL CHARACTERISTICS

Electrical Specifications: Unless otherwise noted, T

A = –40°C to +85°C. Voltages referenced to GND pin.

Parameter Sym. Min. Typ. Max. Unit Conditions

Current Consumption at V

GD IGD — — 60 µA

Current Consumption of the Lower Circuitry I

OUT(INT) — — V400 µA OUT = 9V–50V

Gate Drive Supply Voltage V

GD 11 13 15 V Note 1

Gate Output High Voltage V

GATE(HI) 11 — V15 Note 1

Gate Output Low Voltage V

GATE(LO) — — V0.5 Note 1

Feedback Voltage (Gate Off) V

FB(OFF) 1.18 1.25 1.31 V

Feedback Voltage (Hysteresis) V

FB(HYST) — —50 mV

Feedback Input Current I

FB — — 500 nA

VIN Trip Voltage (Gate On) VTRIP(ON) 0 — 3 V Note 1

VIN Trip Voltage (Gate Off) VTRIP(OFF) 9 — V15 Note 1

Enable Voltage, On V

EN(ON) 0.2 — — V

Enable Voltage, Off V

EN(OFF) — — V0.75 REG

VIN Gate Turn-on Delay tDIG(ON) 0 — 1 Cµs GATE = 1 nF

VIN Gate Turn-off Delay tDIG(OFF) — — C600 ns GATE = 1 nF

Feedback Gate Turn-off Delay t

DFG(OFF) — — C450 ns GATE = 1 nF, VFB = 1.5V

Regulated Output Voltage SR086 VREG 3.125 V3.3 3.465 ILOAD = 1 mA, VOUT = 9V

SR087 4.750 5 V5.250

VREG Load Regulation Δ

I VREG –50 — +50 mV 0 mA < ILOAD < 60 mA,

VOUT = 9V, TAMB = 25°C

Gate VGD Diode Drop VD— — 1 V I = 20 mA

Note 1: Referenced to VOUT

TEMPERATURE CHARACTERISTICS

Electrical Characteristics: Unless otherwise noted, for all specifications T

A =TJ = +25°C.

Parameter Sym. Max.Min. Typ. Unit Conditions

TEMPERATURE RANGE

Operating Junction Temperature TJ —–40 +125 °C

PACKAGE THERMAL RESITANCE

8-lead SOIC (with Heat Slug) θJA — —84 °C/W

 2017 Microchip Technology Inc. DS20005544A-page 5

SR086/SR087

DS20005544A-page 6  2017 Microchip Technology Inc.

SRO86 and SR087 Timing Diagram

Pass Transistor on

VIN

VOUT

not to scale

VFB(OFF) 1+

RFB(HI)

RFB(LO)

Pass Transistor is turned

on when VIN falls below:

VOUT + VTRIP(ON)

Pass Transistor is on but

not conducting since the

input voltage is lower

than the output voltage

Pass Transistor is on

and conducting

Pass Transistor is

turned off once VOUT

reaches the trip point

 2017 Microchip Technology Inc. DS20005544A-page 7

SR086/SR087

2.0 PIN DESCRIPTION

The descriptions of the SR086/SR087 pins are listed

on Table 2-1. Refer to Package Type for the location of

pins.

TABLE 2-1: PIN FUNCTION TABLE

Pin Number SR086

Pin Name

SR087

Pin Name Description

1 VIN VIN Rectified AC input voltage

2 EN EN Active low enable input

3 GND GND ( )Circuit ground Note 1

4 )VREG VREG Regulated output voltage (Note 2

5 FB FB Feedback input

6 VOUT VOUT Output voltage (9V–50V adj.)

7 VGD VGD Gate drive supply (referenced to VOUT)

8 GATE GATE Drives external IGBT pass transistor

Note 1: Circuit ground will be at the AC line potential.

2: Fixed 3.3V for SR086 and fixed 5V for SR087

SR086/SR087

DS20005544A-page 8  2017 Microchip Technology Inc.

3.0 APPLICATION INFORMATION

1.0kV

1.0A

275V

50A

90 to 270VAC

50/60Hz

1.0A

12.4kΩ

113kΩ

VOUT

12.6VDC

510kΩ

*R3

510kΩ

*R1

200kΩ

*R2

200kΩ

* Two resistors used in

series for reasons of

high voltage creepage

and resistor voltage rating.

Enable

100kΩ

1.0μF

470μF

100nF

VREG

3.3VDC

STGD5NB120SZ

VIN GATE VGD VOUT

VREG

GND

6781

SR086

FIGURE 3-1: SR086 Typical Application Circuit.

1.0kV

1.0A

275V

50A

VIN

90 to 270VAC

50/60Hz

1.0A

12.4kΩ

113kΩ

VOUT

12.6VDC

*R4

510kΩ

*R3

510kΩ

*R1

200kΩ

*R2

200kΩ

* Two resistors used in

series for reasons of

high voltage creepage

and resistor voltage rating.

Enable

100kΩ

1.0μF

470μF

100nF

VREG

5.0VDC

STGD5NB120SZ

VIN GATE VGD VOUT

VREG

GND

SR087

FIGURE 3-2: SR087 Typical Application Circuit.

3.1 Output Voltage

VOUT may be adjusted in the range of 9V to 50V by

changing feedback resistor R5 based on Equation 3-1.

EQUATION 3-1:

R5R6VOUT 1.25V 1– =

Leave R6 at 12.4 kΩ or less as it assures a minimum

100 µA load required for the proper operation of

SR086/SR087. Change R3 and R4 according to

Equation 3-4. Select C2 and C3 with appropriate

voltage ratings. For C3

, use a low-ESR capacitor with

an adequate ripple current rating (800 mARMS). Use

ceramic for C2.

Since VREG is a linear regulator supplied from VOUT,

the maximum current available from VREG is reduced

as V

OUT is increased due to power considerations.

Refer to Equation 3-2 for SR086 and Equation 3-3 for

SR087.

EQUATION 3-2:

IREG M A X 

1.5W

VOUT 3.3V– 

------------------------------------

=or 60 mA, whichever is

less

EQUATION 3-3:

IRE G MA X 

1.5W

VOUT 5V– 

-------------------------------

=or 60 mA, whichever is

less

3.2 Input Voltage

To reduce standby power for 230 VAC-only

applications or for supply voltages less than 90 Vrms,

R3 and R4 should be changed according to

Equation 3-4. R1+R2 should remain at 400 kΩ or less.

Two resistors in series are used to ensure adequate

creepage distances for 230 VAC operation. For 120

VAC-only applications, single resistors may be used.

 2017 Microchip Technology Inc. DS20005544A-page 9

SR086/SR087

EQUATION 3-4: R3 + R4 EQUATION

R3R4

+ 

2VIN2VIN2

–Vx1Vx

2VIN



----------------------

 

 

 

cos–

 25 A

--------------------------------------------------------------------------------------



Where: Vx = VOUT + 15V

Use the minimum anticipated RMS value for

VIN. Take resistor tolerance into account,

selecting the next lower standard value.

Choosing a lower value has no effect other

than higher standby power.

3.3 Output Ripple

Storage capacitor C3 was sized to provide about 2VP-P

ripple at 100 mA load (IOUT + IREG). For lighter loads,

C3 may be reduced. Conversely, C3 may be increased

for lower ripple. Use a low-ESR capacitor with an

adequate ripple current rating (e.g. 800 mARMS for

100 mA loads). Efficiency and output current capability

may drop with increased capacitance because of a

smaller conduction angle associated with lower ripple.

Due to feedback hysteresis, ripple cannot be reduced

below 4%. See Equation 3-5.

EQUATION 3-5:

VRIPPLE P P–  IOUT IREG

+  2fIN

 C3

Note: VREG requires at least 4V of headroom.

Therefore, VOUT

, including ripple, must not fall

below 7.3V for SR086 and 9V for SR087.

3.4 Line Transformer

During initial testing, it is tempting to use an isolation

transformer or a variable transformer on the AC line.

However, the high inductance of the transformer

(frequently in mH range) should not be used because it

interferes with the normal operation of the

SR086/SR087. This is not a concern with the normal

inductance of the AC line or for AC line filters.

AC Line SR086

Circuitry

FIGURE 3-3: Line Transformer.

As shown in Figure 3-3, the SR086/SR087 draw

current from the AC line (in short, high current pulses).

The transformer’s high inductance tends to limit the

current pulse. Furthermore, inductive kickback on the

falling edge of the current pulse can create high voltage

spikes which must be absorbed by the transient

protector.

3.5 Electromagnetic Interference

(EMI) Capacitor

Small-value capacitors from circuit common to earth

ground should not be used as they prevent the

SR086/SR087 from operating. See Figure 3-4.

AC Line SR086 &

Circuitry

earth

ground

circuit

common

FIGURE 3-4: EMI Capacitor.

3.6 EMI

The SR086/SR087 circuits, as shown in the

Functional Block Diagrams, meet FCC Class B and

CISPR 14-1 (household appliances) requirements for

conducted emissions for combined loads of less than

20 mA (IOUT + IREG).

3.7 Fuse

Although the average current drawn from the AC line is

low, the RMS current is fairly high due to the current

being drawn in short high-current pulses. Since a fuse

is basically a resistor with a power dissipation given by

IRMS2 R, the fuse must be sized for the RMS current

and not the average current. For a 1W load at 120 VAC,

the RMS current is 700 mARMS, while the RMS current

for a 0.5W load at 230 VAC is 360 mARMS.

3.8 Load

Total load on the SR086/SR087 is the total load current

drawn from VOUT (IOUT

), and since the linear regulator

is supplied from VOUT

, it also includes the current

drawn from VREG (IREG). Total load is calculated in

Equation 3-6 Equation and 3-7.

SR086/SR087

DS20005544A-page 10  2017 Microchip Technology Inc.

EQUATION 3-6:

ILOAD IOUT IREG

EQUATION 3-7:

PLOAD VOUT IOUT IREG +=

3.9 Uninterruptible Power Supply

(UPS)

The SR086/SR087 will not operate from a UPS with a

square wave output. This type of output is usually

referred to as “modified sine wave.”

3.10 Transient Protection

The transient protector must be located before the

bridge rectifier. The reason for this is to minimize

capacitance to allow the rectified AC to fall below V

OUT.

Since there is no capacitor to absorb AC line transients,

complete transient protection must be provided by the

TVS or MOV device. Since the recommended IGBT is

rated at 1.2 kV and the SR086/SR087 never see the full

input voltage, the bridge rectifier becomes the limiting

element when selecting an MOV. When using a 1 kV

bridge, an MOV having a clamping voltage of greater

than 1 kV is recommended.

An RC network on the AC line, as shown in Figure 3-5

and Figure 3-6, affords additional protection from line

transients as well as reducing conducted EMI. It does,

however, reduce power supply efficiency.

10.0kΩ

1.0μF

240VAC

1.0kV

1.0A

275V

50A

90 to

270VAC

50/60Hz

200kΩ

STGD5NB120SZ

VOUT - 1

1.25V

R1 = R2

3.3V

@60mA

100nF

GND VREG

VOUT

VGD

GATE

VIN

Enable

1.0A

VOUT

9.0 - 50VDC

@ 100mA - IREG

SR086

100nF

10Ω, 3.0W

Wire Wound

470μF

200kΩ 510kΩ

510kΩ

FIGURE 3-5: SR086 Additional Transient Protection.

10.0kΩ

1.0μF

240VAC

1.0kV

1.0A

275V

50A

90 to

270VAC

50/60Hz

200kΩ

STGD5NB120SZ

VOUT - 1

1.25V

R1 = R2

5.0V

@60mA

100nF

GND VREG

VOUTVGD

GATE

VIN

Enable

1.0A

VOUT

9.0 - 50VDC

@ 100mA - IREG

SR087

100nF

10Ω, 3.0W

Wire Wound

470μF

200kΩ 510kΩ

510kΩ

FIGURE 3-6: SR087 Additional Transient Protection.

 2017 Microchip Technology Inc. DS20005544A-page 11

SR086/SR087

4.0 PACKAGING INFORMATION

4.1 Package Marking Information

Legend: XX...X Product Code or Customer-specific information

Y Year code (last digit of calendar year)

YY Year code (last 2 digits of calendar year)

WW Week code (week of January 1 is week ‘01’)

NNN Alphanumeric traceability code

Pb-free JEDEC® designator for Matte Tin (Sn)

*This package is Pb-free. The Pb-free JEDEC designator ( )

can be found on the outer packaging for this package.

Note: In the event the full Microchip part number cannot be marked on one line, it will

be carried over to the next line, thus limiting the number of available

characters for product code or customer-specific information. Package may or

not include the corporate logo.

8-lead SOIC Example

NNN

XXXXXXX

YYWW

e3e3

615

SR086SG

1725

e3e3

8-lead SOIC Example

NNN

XXXXXXX

YYWW

e3e3

612

SR087SG

1735

e3e3

8-Lead SOIC (Narrow Body w/Heat Slug) Package Outline (SG)

4.90x3.90mm body, 1.70mm height (max), 1.27mm pitch

Symbol A A1 A2 b D D1 E E1 E2 e h L L1 L2 ș ș

Dimension

(mm)

MIN 1.25* 0.00 1.25 0.31 4.80* 3.30†5.80* 3.80* 2.29†

1.27

BSC

0.25 0.40

1.04

REF

0.25

BSC

0O5O

NOM - - - - 4.90 - 6.00 3.90 - - - - -

MAX 1.70 0.15 1.55* 0.51 5.00* 3.81†6.20* 4.00* 2.79†0.50 1.27 8O15O

JEDEC Registration MS-012, Variation BA, Issue E, Sept. 2005.

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Drawings not to scale.

Seating

Plane

Gauge

Plane

Top View

Side View View A - A View B

View B

θ1

E1 E

A A2

Seating

Plane

Bottom View

Exposed

Thermal

Pad Zone

Note 1

(Index Area

D/2 x E1/2)

Note:

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Note: For the most current package drawings, see the Microchip Packaging Specification at www.microchip.com/packaging.Note: For the most current package drawings, see the Microchip Packaging Specification at www.microchip.com/packaging.

SR086/SR087

DS20005544A-page 12  2017 Microchip Technology Inc.