87C51 Intel Corporation, 87C51 Datasheet - Page 10

• Manufacturer Part Number: 87C51
• Description: CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER
• Manufacturer: Intel Corporation

87C51 80C51BH 80C31BH
NOTES
1 ‘‘Typicals’’ are based on a limited number of samples taken from early manufacturing lots and are not guaranteed The
values listed are at room temp 5V
2 Capacitive loading on Ports 0 and 2 may cause noise pulses above 0 4V to be superimposed on the V
Ports 1 2 and 3 The noise is due to external bus capacitance discharging into the Port 0 and Port 2 pins when these pins
change from 1 to 0 In applications where capacitive loading exceeds 100 pF the noise pulses on these signals may exceed
0 8V It may be desirable to qualify ALE or other signals with a Schmitt Trigger or CMOS-level input logic
3 Capacitive loading on Ports 0 and 2 may cause the V
cation when the address bits are stabilizing
4 See Figures 6 through 8 for I
5 Under steady state (non-transient) conditions I
10
If I
Pins are not guaranteed to sink greater than the listed test conditions
OL
exceeds the test condition V
CC
test conditions Minimum V
OL
Maximum I
Maximum I
Maximum total I
Figure 5 87C51 BH I
may exceed the related specification
OL
OL
OL
must be externally limited as follows
per port pin
per 8-bit port
OL
OH
for all output pins
Ports 1 2 and 3
on ALE and PSEN to momentarily fall below the 0 9V
CC
for Power Down is 2V
CC
Port 0
vs Frequency
10 mA
26 mA
15 mA
71 mA
OL
s of ALE and
272335 –26
CC
specifi-