MC9S08QB8 Datasheet, PDF (17/36 Pages) Freescale Semiconductor, Inc – 8-Bit HCS08 Central Processor Unit

Electrical Characteristics
Table 11. ICS Frequency Specifications (Temperature Range = –40 to 85°C Ambient) (continued)
Num C
Characteristic
Symbol Min. Typical¹ Max. Unit
7
C
Resolution of trimmed DCO output frequency at fixed voltage
and temperature (not using FTRIM)
Δf_{dco_res_t}
—
± 0.2
± 0.4 %f_dco
Total deviation of DCO output from trimmed frequency³
8 C _{Over full voltage and temperature range}
Over fixed voltage and temperature range of 0 to 70 °C
Δf_{dco_t}
— –1.0 to 0.5 ± 2 %f_dco
±0.5
±1
10 C _{FLL acquisition time}⁴
t_Acquire
—
—
1
ms
Long term jitter of DCO output clock (averaged over 2-ms
11 C _interval)5
C_Jitter
—
0.02
0.2 %f_dco
1 _{Data in Typical column was characterized at 3.0 V, 25 °C or is typical recommended value.}
2 _{The resulting bus clock frequency should not exceed the maximum specified bus clock frequency of the device.}
3 _{This parameter is characterized and not tested on each device.}
4 _{This specification applies to any time the FLL reference source or reference divider is changed, trim value changed or changing}
from FLL disabled (FBELP, FBILP) to FLL enabled (FEI, FEE, FBE, FBI). If a crystal/resonator is being used as the reference,
this specification assumes it is already running.
5 _{Jitter is the average deviation from the programmed frequency measured over the specified interval at maximum fBus.}
Measurements are made with the device powered by filtered supplies and clocked by a stable external clock signal. Noise
injected into the FLL circuitry via V_DD and V_SS and variation in crystal oscillator frequency increase the C_Jitter percentage for
a given interval.
1.00%
0.50%
0.00%
-60
-40
-20
0
-0.50%
-1.00%
20
40
60
TBD
80
100
120
-1.50%
-2.00%
Temperature
Figure 12. Deviation of DCO Output from Trimmed Frequency (20 MHz, 3.0 V)
MC9S08QB8 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
17