no way to compare when less than two revisions

Differences

This shows you the differences between two versions of the page.

@@ Line 1: / Line 1: @@
+====== Precise frequency and clock signal generator GPSDO01A ======
+This design is focused to generating precise frequency signal with good long term stability for laboratory use. (As frequency and time normal GPS satellite clocks are used)
+This design is bypass product of developing [[en:rmds]] and [[cs:acounter|Atomic counter]].
+{{ :cs:designs:tools:gpsdo_prototype.jpg?400 |GPSDO01A prototype}}
+The output frequency can be stabilized anywhere in 10-810 MHz range.
+===== Device construction =====
+{{ :cs:designs:tools:gpsdo_system.png?500 |GPSDO01A block schematics}}
+Device consist following modules:
+  * [[en:clkgen]]
+  * [[en:clkhub]]
+  * [[en:clkdiv]]
+  * [[cs:ttlpecl]]
+  * [[cs:gps]]
+  * [[cs:pic16f87xtq44]]
+  * [[cs:usbi2c]]
+===== Function principle =====
+Source of high frequency signal is free-running oscillator Si570 in module [[en:clkgen|CLKGEN01B]]. This module is connected to divider [[en:clkdiv|CLKDIV01A]] and  PIC16F887 MCU, which measures frequency of this oscillator.
+Interval of measurement is variable. Basic measurement calculates with  one second τ interval. (period of [[cs:gps|GPS01A]] PPS signal can be adjusted. Thus frequency measurement can be averaged over period in fraction of seconds or tens of seconds for long term stability measurement.)
+Measured data are stored in MCU memory and can be read by I²C interface. This is usually operated by host computer which computes frequency correction and apply a new frequency to si570 chip oscillator.
+Frequency correction method is in principle software defined and AVAR characteristics of this frequency generator system can be adjusted to meet application requirements.
+===== Related pages =====
+  * [[cs:time_sync]]
+  * [[cs:time_interval_counter]]
+===== References =====
+  * [[http://en.wikipedia.org/wiki/GPS_disciplined_oscillator|GPS disciplined oscillator]]
+  * [[http://www.febo.com/pages/stability/|Oscillator stability]]