mc68hc908kx8 Freescale Semiconductor, Inc, mc68hc908kx8 Datasheet - Page 188

• Manufacturer Part Number: mc68hc908kx8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Electrical Specifications
17.9 Trimmed Accuracy of the Internal Clock Generator
The unadjusted frequency of the low-frequency base clock (IBASE), when the comparators in the
frequency comparator indicate zero error, can vary as much as ±25% due to process, temperature, and
voltage. The trimming capability exists to compensate for process affects. The remaining variation in
frequency is due to temperature, voltage, and change in target frequency (multiply register setting). These
affects are designed to be minimal, however variation does occur. Better performance is seen at 3 V and
lower settings of N.
17.9.1 2.7-Volt to 3.3-Volt Trimmed Internal Clock Generator Characteristics
17.9.2 4.5-Volt to 5.5-Volt Trimmed Internal Clock Generator Characteristics
188
Absolute trimmed internal oscillator tolerance
Variation over temperature
Variation over voltage
Absolute trimmed internal oscillator tolerance
Variation over temperature
Variation over voltage
1. These specifications concern long-term frequency variation. Each measurement is taken over a 1-ms period.
2. Absolute value of variation in ICG output frequency, trimmed at nominal V
3. Specification is characterized but not tested.
4. Variation in ICG output frequency for a fixed N and voltage
5. Variation in ICG output frequency for a fixed N
1. These specifications concern long-term frequency variation. Each measurement is taken over a 1-ms period.
2. Absolute value of variation in ICG output frequency, trimmed at nominal V
3. Specification is characterized but not tested.
4. Variation in ICG output frequency for a fixed N and voltage
5. Variation in ICG output frequency for a fixed N
–40°C to 85°C
–40°C to 125°C
25°C
–40°C to 85°C
–40°C to 125°C
–40°C to 85°C
–40°C to 125°C
25°C
–40°C to 85°C
–40°C to 125°C
are allowed to vary for a single given setting of N.
are allowed to vary for a single given setting of N.
Characteristic
Characteristic
(3), (5)
(3), (5)
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
(3), (4)
(3), (4)
(1)
(1)
(2), (3)
(2), (3)
Symbol
Symbol
V
V
F
F
V
V
ar_temp
ar_temp
abs_tol
abs_tol
ar_volt
ar_volt
DD
DD
Min
Min
—
—
—
—
—
—
—
—
—
—
—
—
and temperature, as temperature and V
and temperature, as temperature and V
0.03
0.05
Typ
Typ
2.5
4.0
0.5
0.7
0.7
4.0
5.0
1.0
1.0
1.0
Freescale Semiconductor
Max
Max
0.05
10.0
0.08
5.0
5.7
2.0
2.0
2.0
7.0
2.0
2.0
2.0
Unit
%/C
Unit
%/C
%/V
%/V
%
%
DD
DD