Date: 18/08/2009

ADI's new clock ICs replaces VCOs and any such costly oscillators

Analog Devices has launched jitter performance improving clock ICs; new AD9552 oscillator frequency upconverter and the AD9547 clock synchronizer.

The AD9552 replaces comparatively costly and space consuming high-frequency VCOs (voltage-controlled oscillators), including OCXO (oven-controlled crystal oscillator), VCXO (voltage-controlled crystal oscillator) and TCXO (temperature-compensated crystal oscillator) components.

The key features and specs of AD9552 are,


1. Converts a low frequency input reference signal to a high frequency output signal
2. Input frequencies from 6.6 MHz to 125 MHz
3. Output frequencies up to 900 MHz
4. Preset pin-programmable frequency translation ratios
5. Arbitrary frequency translation ratios via SPI port
6. On-chip VCO
7. Accepts a crystal resonator and/or an external oscillator as a reference frequency source
8. Secondary output (either integer-related to the primary output or a copy of the reference input)
9. RMS jitter: <0.5 ps (50 kHz to 80 MHz)
10. SPI-compatible, 3-wire programming interface
11. Single supply (3.3 V)
12. Very low power: <400 mW (under most conditions)

The url to download datasheet is
http://www.analog.com/static/imported-files/data_sheets/AD9552.pdf

Price (AD9552): Each $7.65 for 1K pieces
Package (AD9552): 5mmx5mm 32 lead LFCSP

The AD9547 is more advanced versions of ADI's popular AD9549. AD9547 offers 66 percent better jitter, 100 times narrower loop-filter bandwidths (as narrow as 1 milliHertz) with twice as many inputs and outputs, and it supports Stratum-2 level holdover in comparison to AD9549. The AD9547 saves external clock distribution ICs by generating an output clock that synchronizes to one of the two differential or four single-ended external input references.


The key features and specs of AD9547 are,

1. Supports Stratum 2 stability in holdover mode
2. Supports reference switchover with phase build-out
3. Supports hitless reference switchover
4. Automatic/manual holdover and reference switchover
5. 2 pairs of reference input pins, with each pair configurable as a single differential input or as 2 independent single-ended inputs
6. Input reference frequencies from 1 kHz to 750 MHz
7. Reference validation and frequency monitoring (1 ppm)
8. Programmable input reference switchover priority
9. 30-bit programmable input reference divider
10. 2 pairs of clock output pins, with each pair configurable as a single differential LVDS/LVPECL output or as 2 single-ended CMOS outputs
11. Output frequencies up to 450 MHz
12. 20-bit integer and 10-bit fractional programmable feedback divider
13. Programmable digital loop filter covering loop bandwidths from 0.001 Hz to 100 kHz
14. Optional low noise LC-VCO system clock multiplier
15. Optional crystal resonator for system clock input
16. On-chip EEPROM to store multiple power-up profiles
17. Software controlled power-down

The url to download datasheet is
http://www.analog.com/static/imported-files/data_sheets/AD9547.pdf

Price (AD9547): Each $13.97 for 1K pieces
Package (AD9547): 9mmx9mm 64 lead LFCSP

The applications suggested for these clock ICs are high definition TVs, DAQ, wireless/cellular base-stations, test-and-measurement, communication and networking equipments.


Operating Temp Range of both the above devices: -40°C to +85°C