Analog Devices

The AD9847 is a highly integrated CCD signal processor for digital still camera applications. The AD9847 includes a complete analog front end with A/D conversion, combined with a programmable timing driver. The Precision Timing core allows adjustment of high speed clocks with approximately 500 ps resolution at clock speeds of 40 MHz.The AD9847 is specified at pixel rates of 40 MHz. The analog front end includes black level clamping, CDS,PxGA, VGA, and a 10-bit A/D converter. The timing driver provides the high speed CCD clock drivers for RG and H1–H4. Operation is programmed using a 3-wire serial interface.Packaged in a space-saving 48-lead LQFP, the AD9847 is specified over an operating temperature range of –20°C to +85°C.APPLICATIONSDigital Still Cameras

The AD9850 is a highly integrated device that uses advanced DDS technology coupled with an internal high speed, high performance, D/A converter and comparator, to form a complete digitally programmable frequency synthesizer and clock generator function. When referenced to an accurate clock source, the AD9850 generates a spectrally pure, frequency/ phase-programmable, analog output sine wave. This sine wave can be used directly as a frequency source or converted to a square wave for agile-clock generator applications. The AD9850’s innovative high speed DDS core provides a 32-bit frequency tuning word, which results in an output tuning resolution of 0.0291 Hz, for a 125 MHz reference clock input. The AD9850’s circuit architecture allows the generation of output frequencies of up to one-half the reference clock frequency (or 62.5 MHz), and the output frequency can be digitally changed (asynchronously) at a rate of up to 23 million new frequencies per second. The device also provides five bits of digitally controlled phase modulation, which enables phase shifting of its output in increments of 180°, 90°, 45°, 22.5°, 11.25° and any combination thereof. The AD9850 also contains a high speed comparator that can be configured to accept the (externally) filtered output of the DAC to generate a low jitter square wave output. This facilitates the device’s use as an agile clock generator function.The frequency tuning, control, and phase modulation words are loaded into the AD9850 via a parallel byte or serial loading format. The parallel load format consists of five iterative loads of an 8-bit control word (byte). The first byte controls phase modulation, power-down enable, and loading format; bytes 2–5 comprise the 32-bit frequency tuning word. Serial loading is accomplished via a 40-bit serial data stream on a single pin. The AD9850 Complete-DDS uses advanced CMOS technology to provide this breakthrough level of functionality and performance on just 155 mW of power dissipation (+3.3 V supply).The AD9850 is available in a space saving 28-lead SSOP, surface mount package. It is specified to operate over the extended industrial temperature range of –40°C to +85°C

The AD9851 is a highly integrated device that uses advanced DDS technology, coupled with an internal high-speed, high performance D/A converter, and comparator, to form a digitally-programmable frequency synthesizer and clock generator function. When referenced to an accurate clock source, the AD9851 generates a stable frequency and phase-programmable digitized analog output sinewave. This sinewave can be used directly as a frequency source, or internally converted to a square wave for agile-clock generator applications.The AD9851's innovative high-speed DDS core provides a 32-bit frequency tuning word, which results in an output tuning resolution of 40 milli-Hertz, for a 180 MHz reference clock. The AD9851 contains a unique X6 reference clock multiplier circuit that obviates the need for a high-speed reference oscillator. The 6X PLL multiplier has minimal impact on SFDR and phase noise characteristics. The device provides 5-bits of digitally-controlled phase modulation which enables phase shifting of its output in increments of 180°, 90°, 45°, 22.5°, 11.25°, and any combination thereof.

The AD9852 digital synthesizer is a highly integrated device that uses advanced DDS technology, coupled with an internal high speed, high performance D/A converter to form a digitally programmable, agile synthesizer function. When referenced to an accurate clock source, the AD9852 generates a highly stable frequency-, phase-, and amplitude-programmable cosine output that can be used as an agile LO in communications, radar, and many other applications. The innovative high speed DDS core of the AD9852 provides 48-bit frequency resolution (1 μHz tuning resolution with 300 MHz SYSCLK). Retaining 16 bits for phase-to-amplitude conversion ensures excellent spurious-free dynamic range (SFDR).The circuit architecture of the AD9852 allows the generation of output signals at frequencies up to 150 MHz, which can be digitally tuned at a rate of up to 100 million new frequencies per second. The (externally filtered) cosine wave output can be converted to a square wave by the internal comparator for agile clock generator applications. The device provides two 14-bit phase registers and a single pin for BPSK operation.For higher-order PSK operation, the I/O interface can be used for phase changes. The 12-bit cosine DAC, coupled with the innovative DDS architecture, provides excellent wideband and narrow-band output SFDR. When configured with the comparator, the 12-bit control DAC facilitates static duty cycle control in the high speed clock generator applications.The 12-bit digital multiplier permits programmable amplitude modulation, on/off output shaped keying, and precise amplitude control of the cosine DAC output. Chirp functionality is also included for wide bandwidth frequency sweeping applications. The AD9852 programmable 4× to 20× REFCLK multiplier circuit internally generates the 300 MHz system clock from a lower frequency external reference clock. This saves the user the expense and difficulty of implementing a 300 MHz system clock source.Direct 300 MHz clocking is also accommodated with either single-ended or differential inputs. Single-pin, conventional FSK and the enhanced spectral qualities of ramped FSK are supported. The AD9852 uses advanced 0.35 μ CMOS technology to provide this high level of functionality on a single 3.3 V supply.The AD9852 is pin-for-pin compatible with the AD9854 single-tone synthesizer. The AD9852 is specified to operate over the extended industrial temperature range of −40°C to +85°C.ApplicationsAgile LO frequency synthesisProgrammable clock generatorFM chirp source for radar and scanning systemsTest and measurement equipmentCommercial and amateur RF exciter