pca2125 NXP Semiconductors, pca2125 Datasheet - Page 33

• Manufacturer Part Number: pca2125
• Description: Spi Real Time Clock / Calendar Semiconductors
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA2125_00
Preliminary data sheet
10.1.1 Method 1: fixed OSCI capacitor
10.1.2 Method 2: OSCI trimmer
10.1.3 Method 3: OSCO output
10.1 Quartz frequency adjustment
By evaluating the average capacitance necessary for the application layout, a fixed
capacitor can be used (see
32.768 kHz signal available after power-on at pin CLKOUT. The frequency tolerance
depends on the quartz crystal tolerance, the capacitor tolerance and the device-to-device
tolerance (on average ±5 × 10
easily achieved.
Using the 32.768 kHz signal available after power-on at pin CLKOUT, fast setting of a
trimmer is possible.
Direct measurement of OSCO out (accounting for test probe capacitance).
Rev. 00.11 — 30 January 2007
Figure
−6
). Average deviations of ±5 minutes per year can be
22). The frequency is best measured via the
SPI Real time clock / calendar
PCA2125
© NXP B.V. 2007. All rights reserved.
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