Atmel AT89C51ED2 - Page 17

Appendix C: Board Schematics
AT89STK-11 Hardware User Guide 4-16
7676B–8051–08/07
Figure 4-2. AT89STK-11 Schematics (1 of 4)
P3.3/INT1P3.2/INT0
Vcc
Vcc
Vcc
Vcc
Vcc
/EA
P3_2/INT0
/ALE
P3_3/INT1
Default State : Closed
R2 1K R2 1K
CD5
100n
CD5
100n
R3 820 R3 820
R8 10K R8 10K
Vin Vout
ADJ
U2 LM317EMP/SOT223 SOT223 U2 LM317EMP/SOT223 SOT223
R4 10K R4 10K
1
TP1 Vcc TPTP1 Vcc TP
D2 ALE D2 ALE
1
TP3TP3
1 2
J1 SIP2 SOCKET Alternate Power Supply J1 SIP2 SOCKET Alternate Power Supply
1
3
2
4
- +
U1 DF005S
- +
U1 DF005S
1
TP2
GND TP
TP2
GND TP
SW3 INT1 SW3 INT1
SW2 INT0 SW2 INT0
CD3 100n CD3 100n
SP1SP1
R9 10K R9 10K
D1 Power D1 Power
R1 270 R1 270
R5 1K R5 1K
CD1
100n
CD1
100n
3 2 1
J2 CONNECTOR JACK PWR Power Supply J2 CONNECTOR JACK PWR Power Supply
C1 1µF C1 1µF