CDC3RL02_16 Datasheet, PDF (9/20 Pages) Texas Instruments – Low Phase-Noise Two-Channel Clock Fan-Out Buffer

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8 Detailed Description
CDC3RL02
SCHS371C – NOVEMBER 2009 – REVISED JANUARY 2016
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
V_BATT
GND
LDO
V_CC
EN
V_LDO
CLK_OUT1
CLK_REQ1
MCLK_IN
V_CC
EN
CLK_OUT2
CLK_REQ2
Switch/
Decoder
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.
Copyright © 2009–2016, Texas Instruments Incorporated
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