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CDCE937-Q1, CDCEL937-Q1

SCAS892C – FEBRUARY 2010 – REVISED DECEMBER 2016

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Product Folder Links: CDCE937-Q1 CDCEL937-Q1

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Copyright © 2010–2016, Texas Instruments Incorporated

Typical Application (continued)

11.2.3 Application Curves

Figure 19, Figure 20, Figure 21, and Figure 22 show CDCE937-Q1 measurements with the SSC feature enabled.

Device configuration: 27-MHz input, 27-MHz output.

Figure 19. fOUT = 27 MHz,

VCO frequency < 125 MHz, SSC (2% Center)

Figure 20. fOUT = 27 MHz,

VCO frequency > 175 MHz, SSC (1%, Center)

Figure 21. Output Spectrum With SSC Off

Figure 22. Output Spectrum With SSC On,

2% Center

12 Power Supply Recommendations

There is no restriction on the power-up sequence. In case VDDOUT is applied first, TI recommends grounding VDD.

In case VDDOUT is powered while VDD is floating, there is a risk of high current flowing on the VDDOUT pins.

The device has a power-up control that is connected to the 1.8-V supply. This keeps the whole device disabled

until the 1.8-V supply reaches a sufficient voltage level. Then the device switches on all internal components,

including the outputs. If a 3.3-V VDDOUT is available before the 1.8-V, the outputs stay disabled until the 1.8-V

supply has reached a certain level.