MC68HC908AS32A Datasheet, PDF (266/280 Pages) Freescale Semiconductor, Inc – Microcontrollers

Electrical Specifications
19.9 Clock Generator Module (CGM) Characteristics
19.9.1 CGM Operating Conditions
Characteristic
Symbol
Min
Typ
Max
Unit
Operating voltage
Crystal reference frequency
Module crystal reference frequency⁽¹⁾
Range nominal multiplier
VCO center-of-range frequency
V_DDA
V_SSA
f_CGMRCLK
f_CGMXCLK
f_NOM
f_CGMVRS
V_DD –0.3
V_SS –0.3
1
—
—
4.9152
—
—
4.9152
4.9152
4.9152
—
V_DD +0.3
V_SS +0.3
16
—
—
Note⁽²⁾
V
V
MHz
MHz
MHz
MHz
VCO operating frequency
f_CGMVCLK
4.9152
—
32.0
1. Same frequency as f_CGMRCLK.
2. f_CGMVRS is a nominal value described and calculated as an example in Chapter 5 Clock Generator Module (CGM) for the
desired VCO operating frequency, f_CGMVCLK.
19.9.2 CGM Component Information
Description
Symbol
Min
Typ
Max
Unit
Crystal load capacitance⁽¹⁾
Crystal fixed capacitance⁽¹⁾
Crystal tuning capacitance⁽¹⁾
Filter capacitor multiply factor
Filter capacitor⁽²⁾
Bypass capacitor⁽³⁾
C_L
C1
C2
C_FACT
C_F
C_BYP
—
—
—
—
2 x C_L
—
—
2 x C_L
—
—
0.0154
—
—
C_FACT x
(V_DDA/f_XCLK)
—
—
0.1
—
—
—
—
F/s V
—
µF
1. Consult crystal manufacturer’s data.
2. See 5.4.3 External Filter Capacitor Pin (CGMXFC).
3. C_BYP must provide low AC impedance from f = f_CGMXCLK/100 to 100 x f_CGMVCLK, so series resistance must be considered.
MC68HC908AS32A Data Sheet, Rev. 2.0
266
Freescale Semiconductor