Incorporating an adaptive algorithm which has the ability to ‘learn’ from a stable GPS signal over a period of 2 days, the algorithm can be adjusted to allow for errors. Frequency is accurate to within ±1E-12 when locked to a 1PPS GPS signal and can compete with the performance of many atomic clock references.
The module incorporates a low drop out voltage regulator coupled to a highly stable internal OCXO which is conditioned by a digital-to-analogue converter which in turn is fed from an ARM microcontroller. This controls an FPGA which provides the 1PPS output and is fed from the accurate GPS signal. The IQCM-100 operates over a temperature range from -10 to +60°C.
An interesting feature of this product is the availability to the user of some 21 internal algorithm parameters. Using a serial data word output, the user can access information including current status (warm up, holdover or lock); time since attaining lock status; current phase shift between signal input & output; average phase shift over the last hour.
Housed in a 65x65mm hermetically sealed thru-hole package, the IQCM-100 offers an HCMOS output, 5V supply voltage and a current input of 2mA during warm up.