Manufacturer Analog Devices
Manufacturer Part Number AD9548BCPZ
Stock Code W006838
Download Technical Datasheet

The AD9548 provides synchronization for many systems, including synchronous optical networks (SONET/SDH). The AD9548 generates an output clock synchronized to one of up to four differential or eight single-ended external input references. The digital PLL allows for reduction of input time jitter or phase noise associated with the external references. The AD9548 continuously generates a clean (low jitter), valid output clock even when all references have failed by means of a digitally controlled loop and holdover circuitry.

The AD9548 operates over an industrial temperature range of −40°C to +85°C.


  • Supports Stratum 2 stability in holdover mode
  • Supports reference switchover with phase build-out
  • Supports hitless reference switchover
  • Auto/manual holdover and reference switchover
  • 4 pairs of reference input pins with each pair configurable as a single differential input or as 2 independent singleended inputs
  • Input reference frequencies from 1 Hz to 750 MHz
  • Reference validation and frequency monitoring (1 ppm)
  • Programmable input reference switchover priority
  • 30-bit programmable input reference divider
  • 4 pairs of clock output pins with each pair configurable as a
  • single differential LVDS/LVPECL output or as 2 singleended CMOS outputs
  • Output frequencies up to 450 MHz
  • 30-bit integer and 10-bit fractional programmable feedback divider
  • Programmable digital loop filter covering loop bandwidths from 0.001 Hz to 100 kHz
  • Optional low noise LC-VCO system clock multiplier
  • Optional crystal resonator for system clock input
  • On-chip EEPROM to store multiple power-up profiles
  • Software controlled power-down
  • 88-lead LFCSP package

Number of Pins






Supply Current

190 mA

Supply Voltage (DC)

1.89 V (max), 3.46 V (max), 1.71 V (min)

Operating Temperature

-40.0 °C (min)

Mounting Style

Surface Mount


1.00 GHz

Input Current

24.0 mA

Lead-Free Status

Contains Lead

Lifecycle Status