167
7663E–8051–10/08
AT89C51RE2
Notes:
1. Operating I
CC is measured with all output pins disconnected; XTAL1 driven with TCLCH, TCHCL = 5 ns (see Figure 74), VIL = V
SS + 0.5V, VIH = VCC - 0.5V; XTAL2 N.C.; EA = RST = Port 0 = VCC. ICC would be slightly higher if a crystal oscillator used
2. Idle I
CC is measured with all output pins disconnected; XTAL1 driven with TCLCH, TCHCL = 5 ns, VIL = VSS + 0.5V, VIH = VCC -
0.5V; XTAL2 N.C; Port 0 = V
3. Power-down ICC is measured with all output pins disconnected; EA = VCC, PORT 0 = VCC; XTAL2 NC.; RST = VSS (see Fig- 4. Capacitance loading on Ports 0 and 2 may cause spurious noise pulses to be superimposed on the V
OLS 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 100 pF), 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. Typical values are based on a limited number of samples and are not guaranteed. The values listed are at room temperature
and 5V.
6. Under steady state (non-transient) conditions, I
OL must be externally limited as follows:
Maximum IOL per port pin: 10 mA
Maximum I
OL per 8-bit port:
Port 0: 26 mA
Ports 1, 2 and 3: 15 mA
Maximum total I
OL for all output pins: 71 mA
If I
OL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater
than the listed test conditions.
Figure 71. I
CC Test Condition, Active Mode
R
RST
RST Pull-down Resistor
50
200(5)
250
k
Ω
I
IL
Logical 0 Input Current ports 1, 2, 3, 4 and 5
-50
μAV
IN = 0.45V
I
LI
Input Leakage Current
±10
μA
0.45V < V
IN < VCC
I
TL
Logical 1 to 0 Transition Current, ports 1, 2, 3, 4
-650
μAV
IN = 2.0V
C
IO
Capacitance of I/O Buffer
10
pF
F
C = 3 MHz
TA = 25°C
IPD
Power-down Current
75
150
μA2.7 < V
CC < 5.5V
(3)
ICCOP
Power Supply Current on normal mode
0.4 x Frequency (MHz) + 5
mA
VCC = 5.5V
(1)
ICCIDLE
Power Supply Current on idle mode
0.3 x Frequency (MHz) + 5
mA
VCC = 5.5V
(2)
ICCWRITE
Power Supply Current on flash write
0.8 x Frequency (MHz) + 15
mA
VCC = 5.5V
tWRITE
Flash programming time
7
10
ms
2.7 < VCC < 5.5V
T
A = -40°C to +85°C; VSS = 0V; VCC =2.7V to 5.5V; F = 0 to 40 MHz (Continued)
Symbol
Parameter
Min
Typ
Max
Unit
Test Conditions
EA
V
CC
VCC
I
CC
(NC)
CLOCK
SIGNAL
V
CC
All other pins are disconnected.
RST
XTAL2
XTAL1
VSS
VCC
P0