14

83C51KB HIGH PERFORMANCE KEYBOARD MICROCONTROLLER

Output High Voltage (P3.0,

P3.2, P3.3 without 1.8K Ohm

pullup)

Output High Voltage (P3.0,

P3.2, P3.3 with 1.8K Ohm pul-

lup)

Reset Pulldown Resistor

40

225

K Ohm

Pull Up Resistance (P3.0,

P3.2, P3.3 with 1.8K Ohm pul-

lup)

1.2

1.8

2.9

K Ohm

Pin Capacitance

10

pF

@1MHz, 25°C

Logical 0 Input Current (Port

0, 1, 2, 3, except P3.0, P3.2,

P3.3)

-50

µA

Logical 0 Input Current (P3.0,

P3.2, P3.3 without 1.8K Ohm

pullup)

-250

µA

Logical 0 Input Current (P3.0,

P3.2, P3.2 with 1.8K Ohm pul-

lup)

-1.5

-4.5

mA

Logical 1-to-0 Transiton Cur-

rent (Port 0, 1, 2, 3)

-650

µA

Logical 1-to-0 Transition Cur-

rent (P3.0, P3.2 or P3.3 with

1.8K Ohm pullups)

-4.5

mA

Table 7. D.C. Characteristics (Continued)

Symbol

Parameter

Min

Typical

(note 1)

Max

Unit

Test

Condition

NOTE:

1.

2.

10mA

22mA

15mA

Ports 3:

95mA

110mA

to sink current greater than the listed test conditions.

3.

Capacitive loading on Ports 0 and 2 may cause spurious noise pulses above 0.4V to be superimposed

on the low level outputs of ALE and Ports 1, 2 and 3. The noise is due to external bus capacitance dis-

charging into the Port 0 and Port 2 pins when these pins change from 1 to 0. In applications where

capacitive loading exceeds 100pF, the noise pulses on these signals may exceed 0.8V. It may be

desirable to qualify signals with a Schmitt Trigger, or CMOS-level input logic.

4.

specification when the address lines are stabilizing.