XE1203F データシートの表示（PDF） - Semtech Corporation

部品番号

コンポーネント説明

メーカー

XE1203F

433 MHz / 868 MHz / 915 MHz Low-Power, Integrated UHF Transceiver

Semtech Corporation 

XE1203F

4.3 THE FREQUENCY SYNTHESIZER

The Frequency Synthesizer generates the local oscillator (LO) signal for the receiver section as well as the

continuous phase FSK (CPFSK) modulated signal for the transmitter section. The core of the synthesizer is

implemented with a Sigma-Delta PLL architecture. The frequency is programmable with a minimum step-size of 500

Hz in the 433, 868 and 915 MHz frequency bands. This block includes a crystal oscillator which provides the

frequency reference for the PLL. This reference frequency can also be used as a reference clock for the external

microcontroller on the CLKOUT pin.

4.3.1 Clock Output for external processor

A reference clock can be generated by XE1203F for use by an external microcontroller. The RTParam_Clkout

configuration bit determines the status of the CLKOUT pin. When set high CLKOUT is enabled, otherwise it’s

disabled. The output frequency at CLKOUT is defined by the value of the ADParam_Clkfreq parameter. The output

frequency at CLKOUT is the reference oscillator frequency divided by 4, 8, 16 or 32. With the reference oscillator

frequency at 39 MHz this provides a reference clock at 9.75 MHz, 4.87 MHz, 2.44 MHz or 1.22 MHz, respectively.

This clock signal is disabled in Sleep Mode.

© Semtech 2007

www.semtech.com

17

Share Link: