MC908AB32CFUE Datasheet, PDF (383/392 Pages) Freescale Semiconductor, Inc – Microcontrollers

Electrical Specifications
23.12 Clock Generation Module Characteristics
23.12.1 CGM Operating Conditions
Characteristic
Operating Voltage
Crystal Reference Frequency
Module Crystal Reference
Frequency
Range Nominal Multiplier
VCO Center-of-Range Frequency
(MHz)
VCO Operating Frequency (MHz)
Symbol Min
Typ
V_DD
4.5 V
—
f_RCLK
1
—
f_XCLK
—
4.9152 MHz
f_NOM
—
4.9152 MHz
f_VRS
4.9152
—
f_VCLK
4.9152
—
Max
5.5 V
8.4
—
—
32.0
32.0
Comments
Same Frequency as
f_RCLK
4.5 to 5.5 V, V_DD only
4.5 to 5.5 V, V_DD only
23.12.2 CGM Component Information
Characteristic
Symbol Min
Typ
Max
Unit
Crystal load capacitance
C_L
—
—
—
Consult crystal
manufacturer’s data
Crystal fixed capacitance
C₁
—
2 × C_L
—
Consult crystal
manufacturer’s data
Crystal tuning capacitance
C₂
—
2 × C_L
—
Consult crystal
manufacturer’s data
Feedback bias resistor
R_B
—
22MΩ
—
Series resistor
R_S
—
330kΩ
1MΩ Not required
Filter capacitor multiply factor
C_Fact
—
0.0154
—
F/s V
Filter capacitor
See 9.5.3 External Filter
C_F
—
C_Fact × (V_DDA/f_XCLK)
—
Capacitor Pin
(CGMXFC).
Bypass capacitor
C_BYP
—
0.1 µF
C_BYP must provide low
AC impedance from f =
—
f_XCLK/100 to 100 ×
f_VCLK, so series
resistance must be
considered.
MC68HC908AB32 — Rev. 1.1
Freescale Semiconductor
Electrical Specifications
Technical Data
383