Electrical Characteristics
Tables of Data
68HC(9)12DG128 Rev 1.0
MOTOROLA
Electrical Characteristics
363
9-elec
Use of an external circuit to condition V
FP
is recommended.
Figure 63
shows a simple circuit that maintains required voltages and filters
transients. V
FP
is pulled to V
DD
via Schottky diode D2. Application of
programming voltage via diode reverse-biases D2, protecting V
DD
from
excessive reverse current. D2 also protects the FLASH from damage
should programming voltage go to 0. Programming power supply
voltage must be adjusted to compensate for the forward-bias drop
across D1. The charge time constant of R1 and C1 filters transients,
while R2 provides a discharge bleed path to C1. Allow for RC charge and
discharge time constants when applying and removing power. When
using this circuit, keep leakage from external devices connected to the
V
FP
pin low, to minimize diode voltage drop.
Table 72 Flash EEPROM Characteristics (68HC912DG128 only)
V
DD
=
5.0 Vdc
±
10%, V
SS
=
0 Vdc, T
A
=
T
L
to T
H
, unless otherwise noted
Characteristic
Symbol
Min
Typical
Max
Units
Program/erase supply voltage:
Read only
Program / erase / verify
V
FP
V
DD
0.35
11.4
V
DD
12
V
DD
+
0.5
12.6
V
V
Program/erase supply current
Word program(V
FP
= 12V)
Erase(V
FP
= 12V)
I
FP
30
4
mA
mA
Number of programming pulses
n
PP
50
pulses
Programming pulse
t
PPULSE
20
25
μ
s
Program to verify time
t
VPROG
10
μ
s
Program margin
p
m
100
(1)
%
Number of erase pulses
n
EP
5
pulses
Erase pulse
t
EPULSE
5
—
10
ms
Erase to verify time
t
VERASE
1
ms
Erase margin
e
m
100
(1)
%
Program/erase endurance
100
cycles
Data retention
10
years
1. The number of margin pulses required is the same as the number of pulses used to program or erase.