Preliminary

PLL103-53

DDR SDRAM Buffer with 5 DDR or 3 SDR/3 DDR DIMMS

47745 Fremont Blvd., Fremont, California 94538 TEL (510) 492-0990 FAX (510) 492-0991

Rev 12/01/00 Page 1

FEATURES

• Generates 30-output buffers from one input.

• Supports up to 4 DDR DIMMS or 3 SDR DIMMS

and 2 DDR DIMMS.

• Supports 266MHz DDR SDRAM.

• One additional output for feedback.

• Less than 5ns delay.

• Skew between any outputs is less than 100 ps.

• 2.5V or 3.3V Supply range.

• Enhanced DDR and SDRAM Output Drive

selected by I2C.

• Available in 56 pin SSOP.

BLOCK DIAGRAM

PIN CONFIGURATION

Note: #: Active Low

DESCRIPTIONS

The PLL103-53 is designed as a 3.3V/2.5V buffer to

distribute high-speed clocks in PC applications. The

device has 30 outputs. These outputs can be

configured to support 4 unbuffered DDR (Double

Data Rate) DIMMS or to support 3 unbuffered

standard SDR (Single Data Rate) DIMMS and 2 DDR

DIMMS. The PLL103-53 can be used in conjunction

with the PLL202-14/-54 or similar clock synthesizer

for the VIA Pro 266 chipset.

The PLL103-53 also has an I2C interface, which can

enable or disable each output clock. When power up,

all output clocks are enabled (has internal pull up).

DDR4C_SDRAM7

DDR4T_SDRAM6

GND

VDD3.3_2.5

DDR3C_SDRAM5

DDR3T_SDRAM4

GND

VDD3.3_2.5

DDR2C_SDRAM3

GND

VDD3.3_2.5

DDR1C_SDRAM1

DDR0C_SDRAM11

DDR0T_SDRAM10

GND

VDD3.3_2.5

FBOUT

DDR2T_SDRAM2

DDR10C

VDD2.5

GND

DDR9T

DDR9C

VDD2.5

PD#

GND

DDR8T

DDR8C

VDD2.5

SEL_DDR

VDD2.5

GND

DDR11T

DDR11C

DDR10T

GND

DDR7T

DDR7C

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

48

47

46

45

44

43

42

41

40

39

38

37

49

50

52

51

53

54

55

56

BUF_IN

DDR1T_SDRAM0

DDR5C_SDRAM9

SDATA

VDD3.3_2.5

DDR5T_SDRAM8

DDR6T

GND

SCLK

21

22

23

24

36

35

34

33

DDR6C

VDD2.5

DDR12C

DDR12T

GND

VDD2.5

DDR13C

DDR13T

25

26

27

28

32

31

30

29

GND

BUF_IN

SDATA

SCLK

I2C

Control

PD#

DDR0T_SDRAM10

DDR0C_SDRAM11

DDR1T_SDRAM0

DDR1C_SDRAM1

DDR2T_SDRAM2

DDR2C_SDRAM3

DDR3T_SDRAM4

DDR3C_SDRAM5

DDR4T_SDRAM6

DDR4C_SDRAM7

DDR5T_SDRAM8

DDR5C_SDRAM9

DDR(6:13)T

DDR(6:13)C

FBOUT