1

2

3

4

A

B

C

D

4

3

2

1

D

C

B

A

Title

Number

Revision

Size

Orcad A

Date:

27-Sep-2001

Sheet of

File:

C:\ISP\isp_cable\rev5\isp_r5.ddb

Drawn By:

R16 100

1

2

3

4

5

6

7

8

9

10

JP1

HEADER 5X2

R22

4.7k

R21

4.7k

R26

4.7k

1A1

2

1Y1

18

1A2

4

1Y2

16

1A3

6

1Y3

14

1A4

8

1Y4

12

2A1

11

2Y1

9

2A2

13

2Y2

7

2A3

15

2Y3

5

2A4

17

2Y4

3

1G

1

VCC

20

2G

19

GND

10

U1

74VHC244

R17 100

R1
330ohm

R18 100

R19 100

R23

4.7k

R20 100

D1

1N4148

R24

4.7k

C1

0.1uF

L1

LED

R25

4.7k

INI

TCK

AF

TMS

TDI

INIT

SEL_IN

AUTO

STROBE

nACK

BUSY

TDO

TDO

INI
AF

TCK

TMS

TDI

D7

D0

GND

GND

GND

VCC

VCC

GND

VCC

20-SOIC

Buffer/Line Driver

10 Pin Header to ISP Board

1

2

3

4

A

B

C

D

4

3

2

1

D

C

B

A

Title

Number

Revision

Size

Orcad A

Date:

10-Jun-2002

Sheet of

File:

C:\ISP\isp_cable\rev5\isp_r5.ddb

Drawn By:

R15

30K

R11

4.7K

R3

100

R13

4.7K

R14

3.3K

R10

4.7K

D4

1N4148

R4

100

D3

1N4148

D2

1N4148

R2

100

R7

100

R6

100

13

25

12

24

11

23

10

22

9

21

8

20

7

19

6

18

5

17

4

16

3

15

2

14

1

P1

DB25

-

+

5

6

7

8

4

U2B

LM393

R8

100

R5

100

R9

100

-

+

3

2

1

8

4

U2A

LM393

R12

10K

STROBE

AUTO

INIT

SEL_IN

ERROR

D0

ERROR

D7

BUSY

nACK

GND

VCC

GND

VCC

GND

VCC

VCC

Parallel Port Section

Vref

1.5V - 1.6V

Voltage Detection

8-SOP

8-SOP

3V = 0
5V = 1

1.36V at VCC = 3.3

2.06V at VCC = 5.0