Varistor Products

©2009 Littelfuse, Inc.

Revision: October 29, 2009

DA/DB Varistor Series

Industrial High Energy Terminal Varistors > DA/DB Series

Specifications are subject to change without notice.

Please refer to www.littelfuse.com/series/da or /db.html for current information.

Note : Average power dissipation of transients not to exceed 2.0W.

DA/DB Series Ratings & Specifications

Part Number

Device Branding

Maximum Rating (85ºC)

Specifications (25ºC)

Continuous

Transient

Varistor Voltage at 1mA

DCTest Current

Maximum

Clamping

Volt V

200A Current

(8/20μs)

Typical

Capaci-

tance f =

1MHz

V

RMS

V

DC

Energy

(2ms)

Peak

Current

8 x 20μs

V

M(AC)

V

M(DC)

W

TM

I

TM

Min

V

NOM

Max

V

C

C

DA

DB

(V)

(V)

(J)

(A)

(V)

(V)

(V)

(A)

(pF)

V131DA40

V131DB40

130

175

270

184

200

228

345

10000

V151DA40

V151DB40

150

200

300

212

240

268

405

8000

V251DA40

V251DB40

250

330

370

40000

354

390

429

650

5000

V271DA40

V271DB40

275

369

400

40000

389

430

473

730

4500

V321DA40

V321DB40

320

420

460

40000

462

510

561

830

3800

V421DA40

V421DB40

420

560

600

40000

610

680

748

1130

3000

V481DA40

V481DB40

480

640

650

40000

670

750

825

1240

2700

V511DA40

V511DB40

510

675

700

40000

735

820

910

1350

2500

V571DA40

V571DB40

575

730

770

40000

805

910

1000

1480

2200

V661DA40

V661DB40

660

850

900

40000

940

1050

1160

1720

2000

V751DA40

V751DB40

750

970

1050

40000

1080

1200

1320

2000

1800

Should transients occur in rapid succession, the

average power dissipation required is simply the energy

(watt- seconds) per pulse times the number of pulses

per second. The power so developed must be within

the specifications shown on the Device Ratings and

Specifications table for the specific device. Furthermore,

the operating values need to be derated at high

temperatures as shown above. Because varistors can only

dissipate a relatively small amount of average power they

are, therefore, not suitable for repetitive applications that

involve substantial amounts of average power dissipation.

Power Dissipation Ratings

100

90

80

70

60

50

40

30

20

10

0

-55

50

60

70

80

90

100 110 120 130 140 15

100

90

50

10

T

TIME

Peak Pulse Current Test Waveform

0

T = Time from 10% to 90% of Peak

T

T

Example - For an 8/20 μs Current Waveform:

8μs = T

20μs = T

NOTES:

1. Peak current Applies to applications rated up to 115VRMS. Peak

current is 30kA for applications greater than 115V.

2. Peak current applies to applications rated up to 132VRMS. Peak

Current is 30kA for applications greater than 132V.

Figure 1

Figure 2