MPC555
/
MPC556
CDR MoneT FLASH EEPROM
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
19-38
Figure 19-9 VPP and VDDL
Power Switching
Use of an external circuit to condition VPP is recommended.
shows a
simple circuit that maintains required voltages and filters transients. VPP is pulled up
to VDDL via Schottky diode D2, protecting VDDL from excessive reverse current. D2
also protects the FLASH from damage should the programming voltage go to zero.
Programming power supply voltage must be adjusted to compensate for the forward-
100 ns
Maximum
6.0 V
5.25 V
4.75 V
3.6 V
3.0 V
2.65 V
0.0 V
-0.35 V
Power On
Normal
Program/Erase
Power Down
Maximum Overshoot
5.5 V
VPP Envelope
VDDL* Envelope
Suggested VPP
Suggested VDDL
Normal
Combined VPP and
VDDL
*This assumes that VDDL = VDDI = VDDF = VDDSYN.
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..