Datasheet

122
AT89C51AC3
4383D–8051–02/08
Notes: 1. Operating I
CC
is measured with all output pins disconnected; XTAL1 driven with T
CLCH
, T
CHCL
= 5 ns (see Figure 67.), V
IL
=
V
SS
+ 0.5V,
V
IH
= V
CC
- 0.5V; XTAL2 N.C.; EA = RST = Port 0 = V
CC
. I
CC
would be slightly higher if a crystal oscillator used (see Figure
64.).
2. Idle I
CC
is measured with all output pins disconnected; XTAL1 driven with T
CLCH
, T
CHCL
= 5 ns, V
IL
= V
SS
+ 0.5V, V
IH
= V
CC
-
0.5V; XTAL2 N.C; Port 0 = V
CC
; EA = RST = V
SS
(see Figure 65.).
3. Power-down I
CC
is measured with all output pins disconnected; EA = V
CC
, PORT 0 = V
CC
; XTAL2 NC.; RST = V
SS
(see Fig-
ure 66.). In addition, the WDT must be inactive and the POF flag must be set.
4. Capacitance loading on Ports 0 and 2 may cause spurious noise pulses to be superimposed on the V
OL
s of ALE and Ports 1
and 3. The noise is due to external bus capacitance discharging into the Port 0 and Port 2 pins when these pins make 1 to 0
transitions during bus operation. In the worst cases (capacitive loading 100pF), the noise pulse on the ALE line may exceed
0.45V with maxi V
OL
peak 0.6V. A Schmitt Trigger use is not necessary.
5. Typicals are based on a limited number of samples and are not guaranteed. The values listed are at room temperature.
6. Under steady state (non-transient) conditions, I
OL
must be externally limited as follows:
Maximum I
OL
per port pin: 10 mA
Maximum I
OL
per 8-bit port:
Port 0: 26 mA
Ports 1, 2, 3 and 4: 15 mA
Maximum total I
OL
for all output pins: 71 mA
If I
OL
exceeds the test condition, V
OL
may exceed the related specification. Pins are not guaranteed to sink current greater
than the listed test conditions.
Figure 64. I
CC
Test Condition, Active Mode
I
CC
Power Supply Current
I
CCOP
= 0.4 Frequency (MHz) + 8
I
CCIDLE
= 0.2 Frequency (MHz) + 8
mA Vcc = 5.5V
(1)(2)
Table 71. DC Parameters in Standard Voltage (Continued)
Symbol Parameter Min Typ
(5)
Max Unit Test Conditions
EA
V
CC
V
CC
I
CC
(NC)
CLOCK
SIGNAL
V
CC
All other pins are disconnected.
RST
XTAL2
XTAL1
V
SS
V
CC
P0