
Electrical Specifications
MC68HC908QC16 MC68HC908QC8 MC68HC908QC4 Data Sheet, Rev. 2
238
Freescale Semiconductor
DC injection current
(3)
(4)
(5)
(6)
Single pin limit
V
in
> V
DD
V
in
< V
SS
Total MCU limit, includes sum of all stressed pins
V
in
> V
DD
V
in
< V
SS
I
IC
0
0
0
0
—
—
—
—
2
–0.2
25
–5
mA
Ports Hi-Z leakage current
I
IL
0
—
±
1
μ
A
Capacitance
Ports (as input)
(3)
C
IN
—
—
8
pF
POR rearm voltage
V
POR
750
—
—
mV
POR rise time ramp rate
(3)(7)
R
POR
0.035
—
—
V/ms
Monitor mode entry voltage
(3)
V
TST
V
DD
+ 2.5
—
9.1
V
Pullup resistors
(8)
PTA0–PTA5, PTB0–PTB7, PTC3–PTC0, PTD7–PTD0
R
PU
16
26
36
k
Ω
Pulldown resistors
(6)
PTA0–PTA5
R
PD
16
26
36
k
Ω
Low-voltage inhibit reset, trip falling voltage
(9)
V
TRIPF
3.90
4.20
4.50
V
Low-voltage inhibit reset, trip rising voltage
V
TRIPR
4.00
4.30
4.60
V
Low-voltage inhibit reset/recover hysteresis
V
HYS
—
100
—
mV
1. V
DD
= 4.5 to 5.5 Vdc, V
SS
= 0 Vdc, T
A
= T
L
to T
H
, unless otherwise noted.
2. Typical values reflect average measurements at midpoint of voltage range, 25°C only. Typical values are for reference only
and are not tested in production.
3. Values are based on characterization results, not tested in production.
4. All functional non-supply pins are internally clamped to V
SS
and V
DD
.
5. Input must be current limited to the value specified. To determine the value of the required current-limiting resistor, calculate
resistance values for positive and negative clamp voltages, then use the larger of the two values.
6. Power supply must maintain regulation within operating V
DD
range during instantaneous and operating maximum current
conditions. If positive injection current (V
in
> V
DD
) is greater than I
DD
, the injection current may flow out of V
DD
and could
result in external power supply going out of regulation. Ensure external V
DD
load will shunt current greater than maximum
injection current. This will be the greatest risk when the MCU is not consuming power. Examples are: if no system clock is
present, or if clock rate is very low (which would reduce overall power consumption).
7. If minimum V
DD
is not reached before the internal POR reset is released, the LVI will hold the part in reset until minimum
V
DD
is reached.
8. R
PU
and R
PD,
is measured at
V
DD
= 5.0 V. Pulldown resistors only available when KBIx is enabled with KBIxPOL =1.
9. Functionality of MCU guaranteed by production test down to minimum LVI trip point. The electrical parameters are only
guaranteed within the specified operating voltage range.
Characteristic
(1)
Symbol
Min
Typ
(2)
Max
Unit