US3034

4-4

Rev. 1.8

1/13/99

TYPICAL APPLICATION

TYPICAL APPLICATION

Pentium Core Supply Application (US3034 and US3033 Dual Layout)

Low Cost 4 Bit VID

**

3034app2-1.0

5V

12V

C3

R3

C5

C8

R9

L1

Q2

C1

L2

R4

C7

1

D1

R2

C4

R5A

R5B

R5C

R5D

R5E

2

3

4

5

6

7

8

JP1

R1

Vout

C2

R8

R6

C6

R7

1

2

3

4

5

6

7

8

Drv V12

Vfb Vhyst

Gnd

CS-/

Vfb2

CS+/

Drv2

SS/

V12

U1

Figure2- Typical application of US3034 in a flexible motherboard with the 4 bit VID output voltage selection. This circuit is done

using a dual layout with the US3033 part . The advantage of this circuit is that it uses a single jumper that programs the output voltage

in 16 steps with 0.1V steps from 2V to 3.5V, designed for Intel P55,P54 AMD K5 & K6 as well as Cyrix M1 and M2 applications.

JP1

JP1

JP1

JP1

Output

1-2

3-4

5-6

7-8

Voltage

0

0

0

0

3.5

0

0

0

1

3.4

0

0

1

0

3.3

0

0

1

1

3.2

0

1

0

0

3.1

0

1

0

1

3.0

0

1

1

0

2.9

0

1

1

1

2.8

1

0

0

0

2.7

1

0

0

1

2.6

1

0

1

0

2.5

1

0

1

1

2.4

1

1

0

0

2.3

1

1

0

1

2.2

1

1

1

0

2.1

1

1

1

1

2.0

0 = Jumper block is installed.

1 = Jumper block is not installed.

** R9 can be elimi-

nated if dual layout

with US3033 is not

desired.