
Electrical Characteristics
MPC5510 Microcontroller Family Data Sheet, Rev. 3
Freescale Semiconductor
31
2.8
Oscillators Electrical Characteristics
Table 10. 3.3V High Frequency External Oscillator
Num
Characteristic
Symbol
Min.
Value
Max.
Value
Unit
1
Frequency Range1
1 Since this is an amplitude controlled oscillator the use of overtone oscillators is not recommended. Only use fundamental
frequency oscillators.
fref
42
2 When PLL frequency modulation is active, reference frequencies less than 8MHz will distort the modulated waveform and the
effects of this on emissions is not characterized.
40
MHz
2
Duty Cycle of reference
tdc
40
60
%
3
EXTAL Input High Voltage
External crystal mode 3
External clock mode
3 This parameter is meant for those who do not use quartz crystals or resonators, but CAN osc, in crystal mode. In that case,
Vextal – Vxtal ≥ 400mV criteria has to be met for oscillator’s comparator to produce output clock.
VIHEXT
VXTAL + 0.4
0.65 x VDDSYN
VDDSYN + 0.3
V
4
EXTAL Input Low Voltage
External clock mode
VILEXT
VDDSYN – 0.3
VXTAL – 0.4
0.35 x VDDSYN
V
5
XTAL Current 4
4 I
xtal is the oscillator bias current out of the XTAL pin with both EXTAL and XTAL pins grounded.
IXTAL
26
mA
6
Total On-chip stray capacitance on XTAL
CS_XTAL
—3
pF
7
Total On-chip stray capacitance on EXTAL
CS_EXTAL
—3
pF
8
Crystal manufacturer’s recommended
capacitive load
CL
See crystal
specification
See crystal
specification
pF
9
Discrete load capacitance to be connected
to EXTAL
CL_EXTAL
—2
×C
L – CS_EXTAL –
CPCB_EXTAL
5
5 C
PCB_EXTAL and CPCB_XTAL are the measured PCB stray capacitances on EXTAL and XTAL, respectively
pF
10
Discrete load capacitance to be connected
to XTAL
CL_XTAL
—2
×C
L – CS_XTAL –
CPCB_XTAL
5
pF
11
Startup Time
tstartup
—10
ms
Table 11. 5V Low Frequency (32 kHz) External Oscillator
Num
Characteristic
Symbol
Min.
Value
Max.
Value
Unit
1
Frequency Range
fref32
32
38
kHz
2
Duty Cycle of reference
tdc32
40
60
%
3
XTAL32 Current 1
1 I
xtal32 is the oscillator bias current out of the XTAL32 pin with both EXTAL32 and XTAL32 pins grounded.
IXTAL32
0.5
3
μA
4
Crystal manufacturer’s recommended
capacitive load
CL32
See crystal
specification
See crystal
specification
pF
5
Startup Time
tstartup
—2
s