ia3513 integration, ia3513 Datasheet - Page 17

• Manufacturer Part Number: ia3513
• Description: Headset Voice And Power Solution
• Manufacturer: integration

Crystal Oscillator frequency trimming
The 26 MHz crystal oscillator frequency can be trimmed using a 6bit word in register 23.
The frequency adjustment is done by changing the IA3513 internal load capacitance array connected to pin MXclkin.
The total trim capacitance is 3.465pF, and the LSB capacitance value is 55fF. For the midrange code the total capacitance is
9pF (Cl + Clt), in order to be compatible with the specification for the crystal typically used on the application.
For the typical crystal, the tuning range is 53.7 ppm. This will guarantee the +/- 10ppm post trimming accuracy needed in the
application.
The Clk26Out clock output will settle to the final frequency value 2ms after the occurrence of a write to the 6 bit trim word.
Crystal Oscillator Startup
The crystal oscillator is enabled by input pin CLK26Rqst. The clock CLK26out becomes active after converging to its final
precision 8.65ms after the CLK26Rqst transition.
Parameter
Nominal Frequency
Tolerance
Load Capacitance
Pulling sensitivity
Typical crystal specification
1V/div
1ms/div
Min
26Mhz
+/-10ppm
9pF
15.5ppm/pF+/-10%
IA3513
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