®

PWS750

9

V ±10V

IN

15

1

2

16

Power for

input signal

conditioning

circuitry

0.3µF

0.3µF

4

1

6

8

10

9

V

±10V

OUT

0.3µF

Power for

output

circuitry

0.3µF

1

4

ISO122P

7

D

PWS750-3U

S

5

6

7

4

D

S

3

2

TNO604

10µH

PWS750-1U

V

D

7

3

11

Input

Gnd

14

16

T

0.3µF

0.3µF

D

PWS750-3U

S

5

6

7

4

D

S

3

2

PWS750-4U

3

6

3

5V

TNO604

TN0604

TN0604

PWS750-4U

1

T

180mA

3 Turns

PWS750-1U

7

3

11

14

1

TNO604

D

S

G

47pF

Gnd

0.3µF

+5V

1µF

16

19

15

14

PWS726

41

30

32

–V

O

+V

O

V

D

TTL In

–

T

H7F

TO7-14-3.5

The minimum AC barrier voltage that initiates partial dis-

charge above 5pC is defined as the “inception voltage.”

Decreasing the barrier voltage to a lower level is required

before partial discharge ceases; this is known as “extinction

voltage.” We have developed a package insulation system to

yield an inception voltage greater than 1200Vrms so that

transient voltages below this level will not damage the

isolation barrier. The extinction voltage is above 750Vrms

so that even overvoltage-induced partial discharge will cease

once the barrier voltage is reduced to the rated value.

Previous high voltage test methods relied on applying a

large enough overvoltage (above rating) to break down

marginal units, but not so high as to permanently damage

good ones. Our partial discharge testing gives us more

confidence in barrier reliability than breakdown/no break-

down criteria.

FIGURE 5. A PWS750 Driver Can Be Used to Boost the Input Voltage to 15V to Power a PWS726 From a 5V Supply.

FIGURE 4. A Complete

±10V Signal Acquisition System Operating From a Single 5V Supply.