ST VIPER12A-E User Manual

VIPER12A-E

Low power offline switched-mode power supply primary switcher

Features

■ Fixed 60 kHz switching frequency

■ 9 V to 38 V wide range V

■ Current mode control

■ Auxiliary undervoltage lockout with hysteresis

■ High voltage start-up current source

■ Overtemperature, overcurrent and overvoltage

protection with auto-restart

■ Typical power capability

– European (195 - 265 Vac) 8 W for SO-8,

13 W for DIP-8

– European (85 - 265 Vac) 5 W for SO-8,

8 W for DIP-8

Description

The VIPER12A combines a dedicated current mode PWM controller with a high voltage power MOSFET on the same silicon chip.

voltage

DD

DIP-8SO-8

Typical applications cover off line power supplies for battery charger adapters, standby power supplies for TV or monitors, auxiliary supplies for motor control, etc.

The internal control circuit offers the following benefits: Large input voltage range on the V accommodates changes in auxiliary supply voltage (This feature is well adapted to battery charger adapter configurations), automatic burst mode in low load condition and overvoltage protection in HICCUP mode.

DD

Figure 1. Block diagram

DRAIN

ON/OFF

REGULATOR

INTERNAL

VDD

FB

8/14.5V

42V

SUPPLY

_

+

_

OVERTEMP.

DETECTOR

R

FF

S

OVERVOLTAGE

Q

December 2010 Doc ID 11977 Rev 2 1/21

LATCH

60kHz

OSCILLATOR

S

FF

R1

R2

R4QR3

PWM

LATCH

BLANKING

+

_

0.23 V

230 Ω

1 kΩ

SOURCE

www.st.com

21

Contents VIPER12A-E

Contents

1 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.1 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Pin connections and function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 Rectangular U-I output characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5 Wide range of VDD voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

6 Feedback pin principle of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

7 Startup sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

8 Overvoltage threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

9 Operation pictures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

10 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

11 Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

12 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2/21 Doc ID 11977 Rev 2

VIPER12A-E Electrical data

1 Electrical data

1.1 Maximum rating

Stressing the device above the rating listed in the “absolute maximum ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Table 1. Absolute maximum rating

Symbol Parameter Value Unit

(2)

(1)

-0.3 ... 730 V

-0.3 ... 400 V

200

1.5

V

kV

V

Switching drain source voltage (TJ = 25 ... 125 °C)

DS(sw)

Start-up drain source voltage (TJ = 25 ... 125 °C)

V

DS(st)

I

Continuous drain current Internally limited A

D

Supply voltage 0 ... 50 V

V

DD

I

Feedback current 3 mA

FB

Electrostatic discharge:

V

Machine model (R = 0 Ω; C = 200 pF)

ESD

Charged device model

Junction operating temperature Internally limited °C

T

J

Case operating temperature -40 to 150 °C

T

C

T

1. This parameter applies when the start-up current source is OFF. This is the case when the VDD voltage has reached V

2. This parameter applies when the start up current source is ON. This is the case when the VDD voltage has not yet reached V

Storage temperature -55 to 150 °C

stg

and remains above V

DDon

or has fallen below V

DDon

DDoff

.

DDoff

1.2 Thermal data

Table 2. Thermal data

Symbol Parameter SO-8 DIP-8 Unit

R

thJC

R

thJA

1. When mounted on a standard single-sided FR4 board with 200 mm2 of Cu (at least 35 µm thick) connected to all DRAIN pins.

Thermal resistance junction-case Max 25 15 °C/W

Thermal resistance ambient-case

(1)

Max 55 45 °C/W

Doc ID 11977 Rev 2 3/21

Electrical characteristics VIPER12A-E

2 Electrical characteristics

TJ = 25 °C, V

= 18 V, unless otherwise specified

DD

Table 3. Power section

Symbol Parameter Test conditions Min Typ Max Unit

BV

Drain-source voltage ID = 1 mA; V

DSS

I

DSS

r

DS(on)

OFF State drain current

Static drain-source ON state resistance

tf Fall time

Rise time

t

r

Drain capacitance V

C

OSS

1. On clamped inductive load

= 500 V; V

V

DS

TJ = 125 °C

ID = 0.2 A ID = 0.2 A; 27 30

= 0.2 A ID = 0.2 A; TJ = 100 °C 54

I

D

= 0.1 A; V

I

D

(See Figure 9 on page 13)

I

= 0.2 A; V

D

(See Figure 9 on page 13)

= 25 V 40 pF

DS

= 2 V 730 V

FB

= 2 V;

FB

= 300 V

IN

= 300 V

IN

(1)

100 ns

50 ns

0.1 mA

Ω

Table 4. Supply section

Symbol Parameter Test conditions Min Typ Max Unit

≤ 400 V;

DS

DDon

HYST

(1)

-1 mA

0 mA

4.5 mA

I

DDch

I

DDoff

I

DD0

I

DD1

Start-up charging current

Start-up charging current in thermal shutdown

Operating supply current not switching

Operating supply current switching

100 V ≤ V

= 0 V ...V

V

DD

(See Figure 10 on page 13)

= 5 V; VDS = 100 V

V

DD

TJ > TSD - T

= 2 mA 3 5 mA

I

FB

I

= 0.5 mA; ID = 50 mA

FB

D

Restart duty-cycle (See Figure 11 on page 13) 16 %

RST

undervoltage

V

DDoff

V

DDon

V

DDhyst

V

DDovp

1. These test conditions obtained with a resistive load are leading to the maximum conduction time of the device.

DD

shutdown threshold

start-up

V

DD

threshold

V

threshold

DD

hysteresis

overvoltage

V

DD

threshold

(See Figure 10,

Figure 11 on page 13)

(See Figure 10,

Figure 11 on page 13))

(See Figure 10 on page 13) 5.8 6.5 7.2 V

4/21 Doc ID 11977 Rev 2

7 8 9 V

13 14.5 16 V

38 42 46 V

VIPER12A-E Electrical characteristics

Table 5. Oscillation section

Symbol Parameter Test conditions Min Typ Max Unit

F

Oscillator frequency

OSC

total variation

= V

V

DD

TJ = 0 ... 100 °C

DDoff

... 35 V;

54 60 66 kHz

Table 6. PWM comparator section

Symbol Parameter Test conditions Min Typ Max Unit

G

I

Dlim

I

FBsd

RFB

t

ID

d

I

to ID current gain (See Figure 12 on page 14) 320

FB

Peak current limitation

I

shutdown current (See Figure 12 on page 14) 0.9 mA

FB

FB pin input impedance

Current sense delay to turn-OFF

= 0 V

V

FB

(See Figure 12 on page 14)

= 0 mA

I

D

(See Figure 12 on page 14)

I

= 0.2 A 200 ns

D

0.32 0.4 0.48 A

1.2 kΩ

tb Blanking time 500 ns

t

ONmin

Minimum Turn-ON time

700 ns

Table 7. Overtemperature section

Symbol Parameter Test conditions Min Typ Max Unit

TSD

T

HYST

Thermal shutdown temperature

Thermal shutdown hysteresis

(See Figure 13 on page 14) 140 170 °C

(See Figure 13 on page 14) 40 °C

Table 8. Typical power capability

Mains type SO-8 DIP-8

European (195 - 265 Vac) 8W 13W

US / Wide range (85 - 265 Vac) 5W 8W

Doc ID 11977 Rev 2 5/21

Pin connections and function VIPER12A-E

3 Pin connections and function

Figure 2. Pin connection

SOURCE

FB

VDD

1

2

3

4

8

7

6

5

DRAIN

SO-8 DIP-8

Figure 3. Current and voltage conventions

I

DD

I

FB

V

DD

V

FB

VDD DRAIN

FB

VIPer12A

CONTROL

SOURCE

FB

VDD

1

2

3

4

I

D

V

D

8

DRAIN

7

DRAIN

6

DRAIN

5

DRAIN

Table 9. Pin function

Pin Name Pin Function

Power supply of the control circuits. Also provides a charging current during start up thanks to a high voltage current source connected to the drain. For this purpose, an hysteresis comparator monitors the V

V

DD

SOURCE Power MOSFET source and circuit ground reference.

DRAIN

FB

6/21 Doc ID 11977 Rev 2

: Voltage value (typically 14.5 V) at which the device starts switching and turns

- V

DDon

off the start up current source.

: Voltage value (typically 8 V) at which the device stops switching and turns on

- V

DDoff

the start up current source.

Power MOSFET drain. Also used by the internal high voltage current source during start up phase for charging the external VDD capacitor.

Feedback input. The useful voltage range extends from 0 V to 1 V, and defines the peak drain MOSFET current. The current limitation, which corresponds to the maximum drain current, is obtained for a FB pin shorted to the SOURCE pin.

voltage and provides two thresholds:

DD

VIPER12A-E Rectangular U-I output characteristics

4 Rectangular U-I output characteristics

Figure 4. Rectangular U-I output characteristics for battery charger

A complete regulation scheme can achieve combined and accurate output characteristics.

Figure 4. presents a secondary feedback through an optocoupler driven by a TSM101. This

device offers two operational amplifiers and a voltage reference, thus allowing the regulation of both output voltage and current. An integrated OR function performs the combination of the two resulting error signals, leading to a dual voltage and current limitation, known as a rectangular output characteristic. This type of power supply is especially useful for battery chargers where the output is mainly used in current mode, in order to deliver a defined charging rate. The accurate voltage regulation is also convenient for Li-ion batteries which require both modes of operation.

Doc ID 11977 Rev 2 7/21