CY2305C

CY2309C

3.3 V Zero Delay Clock Buffer

Cypress Semiconductor Corporation

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198 Champion Court

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San Jose

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408-943-2600

Document Number: 38-07672 Rev. *K

Revised February 3, 2011

Features

see Select Input Decoding for CY2309C on page 5

integrated circuit (SOIC) or 4.4 mm thin shrunk small outline

package (TSSOP) packages (CY2309C), and 8-pin, 150 Mil

SOIC package (CY2305C)

Functional Description

The CY2305C and CY2309C are die replacement parts for

CY2305 and CY2309.

The CY2309C is a low-cost 3.3 V zero delay buffer designed to

distribute high speed clocks and is available in a 16-pin SOIC or

TSSOP package. The CY2305C is an 8-pin version of the

CY2309C. It accepts one reference input and drives out five low

skew clocks. The -1H versions of each device operate up to

100–133 MHz frequencies and have higher drive than the -1

devices. All parts have on-chip phase locked loops (PLLs) which

lock to an input clock on the REF pin. The PLL feedback is

on-chip and is obtained from the CLKOUT pad.

The CY2309C has two banks of four outputs each that are

controlled by the select inputs as shown in the Select Input

Decoding for CY2309C on page 5. If all output clocks are not

required, Bank B is three-stated. The input clock is directly

applied to the outputs by the select inputs for chip and system

testing purposes.

The CY2305C and CY2309C PLLs enter a power down mode

when there are no rising edges on the REF input. In this state,

the outputs are three-stated and the PLL is turned off. This

results in less than 12.0

A of current draw for commercial

temperature devices and 25.0

A for industrial and automotive-A

temperature parts. The CY2309C PLL shuts down in one

additional case as shown in the Select Input Decoding for

CY2309C on page 5.

In the special case when S2:S1 is 1:0, the PLL is bypassed and

REF is output from DC to the maximum allowable frequency. The

part behaves as a non-zero delay buffer in this mode and the

outputs are not three-stated.

The CY2305C or CY2309C is available in two or three different

configurations as shown in the Ordering Information on page 11.

The CY2305C-1 or CY2309C-1 is the base part. The CY2305-1H

or CY2309-1H is the high drive version of the -1. Its rise and fall

times are much faster than the -1.

Logic Block Diagram for CY2305C

CLKOUT

REF

CLK4

PLL

CLK1

CLK2

CLK3

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