mfrc522 NXP Semiconductors, mfrc522 Datasheet - Page 69

• Manufacturer Part Number: mfrc522
• Description: Contactless Reader Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
15. Oscillator Circuitry
112132
Product data sheet
The clock applied to the MFRC522 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.
Fig 22. Ouartz Connection
Rev. 3.2 — 22 May 2007
OSC
OUT
RC522
27.12 MHz
OSCIN
Contactless Reader IC
MFRC522
© NXP B.V. 2007. All rights reserved.
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