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MC9S12C128V1 Datasheet, PDF (343/690 Pages) Freescale Semiconductor, Inc – MC9S12C Family MC9S12GC Family Reference Manual | |||
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Chapter 11
Oscillator (OSCV2) Block Description
11.1 Introduction
The OSCV2 module provides two alternative oscillator concepts:
⢠A low noise and low power Colpitts oscillator with amplitude limitation control (ALC)
⢠A robust full swing Pierce oscillator with the possibility to feed in an external square wave
11.1.1 Features
The Colpitts OSCV2 option provides the following features:
⢠Amplitude limitation control (ALC) loop:
â Low power consumption and low current induced RF emission
â Sinusoidal waveform with low RF emission
â Low crystal stress (an external damping resistor is not required)
â Normal and low amplitude mode for further reduction of power and emission
⢠An external biasing resistor is not required
The Pierce OSC option provides the following features:
⢠Wider high frequency operation range
⢠No DC voltage applied across the crystal
⢠Full rail-to-rail (2.5 V nominal) swing oscillation with low EM susceptibility
⢠Fast start up
Common features:
⢠Clock monitor (CM)
⢠Operation from the VDDPLL 2.5 V (nominal) supply rail
11.1.2 Modes of Operation
Two modes of operation exist:
⢠Amplitude limitation controlled Colpitts oscillator mode suitable for power and emission critical
applications
⢠Full swing Pierce oscillator mode that can also be used to feed in an externally generated square
wave suitable for high frequency operation and harsh environments
Freescale Semiconductor
MC9S12C-Family / MC9S12GC-Family
343
Rev 01.24
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