CLRC632 Datasheet, PDF (97/163 Pages) NXP Semiconductors – Multiple Protocol Contactless Reader IC

Philips Semiconductors
Multiple Protocol Contactless Reader IC
12 OSCILLATOR CIRCUITRY
Product Specification Rev. 3.0; May 2003
CL RC632
MF RC531
OSCOUT
OSCIN
13.56 MHz
15 pF
15 pF
Figure 12-1: Quartz Connection
The clock applied to the CL RC632 acts as time basis for the coder and decoder of the synchronous system.
Therefore stability of the clock frequency is an important factor for proper performance. To obtain highest
performance, clock jitter has to be as small as possible. This is best achieved by using the internal oscillator
buffer with the recommended circuitry. If an external clock source is used, the clock signal has to be applied
to pin OSCIN. In this case special care for clock duty cycle and clock jitter is needed and the clock quality
has to be verified. It needs to be in accordance with the specifications in chapter 22.5.3.
Remark: We do not recommend to use an external clock source.
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