cui.com

date

11/23/2011 │ page 5 of 6

CUI Inc

│ SERIES: V78-1000-SMT │ DESCRIPTION: NON-ISOLATED SWITCHING REGULATOR

EMC RECOMMENDED CIRCUIT

V7805-1000-SMT

1

7,9

5

+Vin

GN D

C1

6

10

ON /O FF

47 0p F

C2

TVS

L1

RL

+Vo

GND

1

7,9

5

+Vo

GND

C3

6

10

ON/O FF

470 pF

C4

RL

L2

GND

+Vin

V7805-1000-SMT

TVS: SMCJ18A, 1500W

L1: 68 μH

C1: 680 μF / 50 V electrolytic capacitors

L2: 516 μH

C3: 1 μF / 50 V ceramic capacitor

ADJUSTMENT RESISTOR VALUES

MODEL

V7802

V7803

V7805

Vo (nominal)

2.5 V

3.3 V

5.0 V

Vadj (V)

R1 (kΩ)

R2 (kΩ)

R1 (kΩ)

R2 (kΩ)

R1 (kΩ)

R2 (kΩ)

1.5

51.1

-

-

-

-

-

1.8

104.3

-

15.4

-

-

-

2.5

-

-

87

-

9.7

-

3.0

-

88.7

339

-

30.5

-

3.3

-

41.3

-

-

48.8

-

3.6

-

20.1

-

121

75

-

3.9

-

8.0

-

51.0

115

-

4.5

-

-

-

16.6

338

-

4.9

-

-

-

8.0

1,835

-

5.0

-

-

-

6.5

-

-

5.1

-

-

-

5.2

-

426

5.5

-

-

-

1.1

-

58.7

6.0

----

-

16.9

6.5

----

-

3.2

The R1, R2 in the above table are used to set the output voltage. If no need to adjust the output voltage, connect a ceramic capacitor to

GND with 470pF typical value for increase immunity. Insure the output voltage is in the adjust range or else may cause permanent

damage to the device. Fine-tune output voltage must appease Vin-Vo>2V.