Motorola ColdFire MCF5281 - Manual (Page 692)

Electrical Characteristics
33-8 Freescale Semiconductor
33.6 QADC Electrical Characteristics
6
Load Capacitance determined from crystal manufacturer specifications and will include circuit board parasitics.
7 This specification applies to the period required for the PLL to relock after changing the MFD frequency control bits in the
synthesizer control register (SYNCR).
8
Assuming a reference is available at power up, lock time is measured from the time V
DD
and V
DDPLL
are valid to
RSTO negating. If the crystal oscillator is being used as the reference for the PLL, then the crystal start up time
must be added to the PLL lock time to determine the total start-up time.
9 PLL is operating in 1:1 PLL mode.
10 Jitter is the average deviation from the programmed frequency measured over the specified interval at maximum f
sys
.
Measurements are made with the device powered by filtered supplies and clocked by a stable external clock signal.
Noise injected into the PLL circuitry via V
DDPLL
and V
SSPLL
and variation in crystal oscillator frequency increase the
Cjitter percentage for a given interval
11
Based on slow system clock of 40 MHz measured at f
sys
max.
Table 33-9. QADC Absolute Maximum Ratings
Parameter Symbol Min Max Unit
Analog Supply, with reference to V
SSA
V
DDA
–0.3 6.0 V
Internal Digital Supply
1
, with reference to V
SS
1
For internal digital supply of V
DD
= 3.3V typical.
V
DD
–0.3 4.0 V
Reference Supply, with reference to V
RL
V
RH
–0.3 6.0 V
V
SS
Differential Voltage V
SS
– V
SSA
–0.1 0.1 V
V
DD
Differential Voltage
2
2
Refers to allowed random sequencing of power supplies.
V
DD
– V
DDA
–6.0 4.0 V
V
REF
Differential Voltage V
RH
– V
RL
–0.3 6.0 V
V
RH
to V
DDA
Differential Voltage
3
3
Refers to allowed random sequencing of power supplies.
V
RH
– V
DDA
–6.0 6.0 V
V
RL
to V
SSA
Differential Voltage V
RL
– V
SSA
–0.3 0.3 V
V
DDH
to V
DDA
Differential Voltage V
DDH
– V
DDA
–1.0 1.0 V
Maximum Input Current
4, 5, 6
4 Transitions within the limit do not affect device reliability or cause permanent damage. Exceeding limit may cause
permanent conversion error on stressed channels and on unstressed channels.
5 Input must be current limited to the value specified. To determine the value of the required current-limiting resistor,
calculate resistance values using V
POSCLAMP
= V
DDA
+ 0.3V and V
NEGCLAMP
= –0.3 V, then use the larger of the
calculated values.
6
Condition applies to one pin at a time.
I
MA
–25 25 mA
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3