Data Sheet

AD9912

1 GSPS Direct Digital Synthesizer with 14-Bit DAC

Rev. G

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FEATURES

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1 GSPS internal clock speed (up to 400 MHz output directly)

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Integrated 1 GSPS 14-bit DAC

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48-bit frequency tuning word with 4 µHz resolution

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Differential HSTL comparator

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Flexible system clock input accepts either crystal or external

reference clock

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On-chip low noise PLL REFCLK multiplier

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2 SpurKiller channels

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Low jitter clock doubler for frequencies up to 750 MHz

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Single-ended CMOS comparator; frequencies of <150 MHz

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Programmable output divider for CMOS output

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Serial I/O control

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Excellent dynamic performance

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Software controlled power-down

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Available in two 64-lead LFCSP packages

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Residual phase noise @ 250 MHz

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10 Hz offset: −113 dBc/Hz

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1 kHz offset: −133 dBc/Hz

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100 kHz offset: −153 dBc/Hz

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40 MHz offset: −161 dBc/Hz

APPLICATIONS

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Agile LO frequency synthesis

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Low jitter, fine tune clock generation

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Test and measurement equipment

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Wireless base stations and controllers

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Secure communications

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Fast frequency hopping

GENERAL DESCRIPTION

The AD9912 is a direct digital synthesizer (DDS) that features an

integrated 14-bit digital-to-analog converter (DAC). The AD9912

features a 48-bit frequency tuning word (FTW) that can synthesize

frequencies in step sizes no larger than 4 μHz. Absolute frequency

accuracy can be achieved by adjusting the DAC system clock.

The AD9912 also features an integrated system clock phase-locked

loop (PLL) that allows for system clock inputs as low as 25 MHz.

The AD9912 operates over an industrial temperature range, span-

ning −40°C to +85°C.

BASIC BLOCK DIAGRAM

Figure 1.