V

BATT

GND

MCLK_IN

LDO

Switch/

Decoder

EN

V

CC

V

LDO

CLK_OUT1

CLK_REQ1

CLK_OUT2

CLK_REQ2

EN

V

CC

CDC3RL02

www.ti.com

SCHS371C – NOVEMBER 2009 – REVISED JANUARY 2016

8 Detailed Description

8.1 Overview

The CDC3RL02 is a two-channel clock fan-out buffer and is ideal for use in portable end-equipment, such as

mobile phones, that require clock buffering with minimal additive phase noise and fan-out capabilities. It buffers a

single master clock, such as a temperature compensated crystal oscillator (TCXO) to multiple peripherals. The

device has two clock request inputs (CLK_REQ1 and CLK_REQ2), each of which enable a single clock output.

The CDC3RL02 accepts square or sine waves at the master clock input (MCLK_IN), eliminating the need for an

AC coupling capacitor. The smallest acceptable sine wave is a 0.3-V signal (peak-to-peak). CDC3RL02 has been

designed to offer minimal channel-to-channel skew, additive output jitter, and additive phase noise. The adaptive

clock output buffers offer controlled slew-rate over a wide capacitive loading range which minimizes EMI

emissions, maintains signal integrity, and minimizes ringing caused by signal reflections on the clock distribution

lines.

The CDC3RL02 has an integrated Low-Drop-Out (LDO) voltage regulator which accepts input voltages from 2.3

V to 5.5 V and outputs 1.8 V, 50 mA. This 1.8-V supply is externally available to provide regulated power to

peripheral devices such as a TCXO.

8.2 Functional Block Diagram

8.3 Feature Description

8.3.1 Low Additive Noise

The CDC3RL02 features –149 dBc/Hz at 10 kHz offset phase noise and 0.37 ps (RMS) of output jitter, to make

sure that the buffered signals are clean.

8.3.2 Regulated 1.8-V Externally Available I/O Supply

The CDC3RL02 allows users to connect to the output of the internal LDO, for providing power to other ICs. For

more information, refer to LDO.

8.3.3 Ultra-Small 8-bump YFP 0.4-mm Pitch WCSP Package

Using the ultra-small YFP package, the CDC3RL02 is very small and allows it to be placed on a board with

minimum work.

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