Electrical Specifications
Clock Generation Module Characteristics
MC68HC908AB32 — Rev. 1.0 Technical Data
MOTOROLA Electrical Specifications 383
23.12 Clock Generation Module Characteristics
23.12.1 CGM Operating Conditions
23.12.2 CGM Component Information
Characteristic Symbol Min Typ Max Comments
Operating Voltage
V
DD
4.5 V — 5.5 V
Crystal Reference Frequency
f
RCLK
1 — 8.4
Module Crystal Reference
Frequency
f
XCLK
— 4.9152 MHz —
Same Frequency as
f
RCLK
Range Nominal Multiplier
f
NOM
— 4.9152 MHz — 4.5 to 5.5 V, V
DD
only
VCO Center-of-Range Frequency
(MHz)
f
VRS
4.9152 — 32.0 4.5 to 5.5 V, V
DD
only
VCO Operating Frequency (MHz)
f
VCLK
4.9152 — 32.0
Characteristic Symbol Min Typ Max Unit
Crystal load capacitance
C
L
———
Consult crystal
manufacturer’s data
Crystal fixed capacitance
C
1
—
2 × C
L
—
Consult crystal
manufacturer’s data
Crystal tuning capacitance
C
2
—
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
C
F
—
C
Fact
× (V
DDA
/f
XCLK)
—
See 9.5.3 External Filter
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.