High-Speed, Low-Skew 1-to-10 Clock Buffer

for SDRAM (Synchronous DRAM) Clock

Buffering Applications

Output Skew, tsk(o), Less Than 250 ps

Pulse Skew, tsk(p), Less Than 500 ps

Supports up to Two Unbuffered SDRAM

DIMMs (Dual Inline Memory Modules)

I2C Serial Interface Provides Individual

Enable Control for Each Output

Operates at 3.3 V

Distributed VCC and Ground Pins Reduce

Switching Noise

ESD Protection Exceeds 2000 V Per

MIL-STD-883, Method 3015

Packaged in 28-Pin Shrink Small Outline

(DB) Package

description

The CDC319 is a high-performance clock buffer that distributes one input (A) to 10 outputs (Y) with minimum

skew for clock distribution. The CDC319 operates from a 3.3-V power supply, and is characterized for operation

from 0°C to 70°C.

The device provides a standard mode (100K-bits/s) I2C serial interface for device control. The implementation

is as a slave/receiver. The device address is specified in the I2C device address table. Both of the I2C inputs

(SDATA and SCLOCK) provide integrated pullup resistors (typically 140 kΩ) and are 5-V tolerant.

Three 8-bit I2C registers provide individual enable control for each of the outputs. All outputs default to enabled

at powerup. Each output can be placed in a disabled mode with a low-level output when a low-level control bit

is written to the control register. The registers are write only and must be accessed in sequential order (i.e.,

random access of the registers is not supported).

The CDC319 provides 3-state outputs for testing and debugging purposes. The outputs can be placed in a

high-impedance state via the output-enable (OE) input. When OE is high, all outputs are in the operational state.

When OE is low, the outputs are placed in a high-impedance state. OE provides an integrated pullup resistor.