TC815

DS21474B-page 6

© 2002 Microchip Technology Inc.

35

ΩR1

Standard resistor connection for 200

Ω full scale.

36

ΩR2

Standard resistor connection for 2000

Ω full scale.

37

ΩR3

Standard resistor connection for 20k

Ω full scale range.

38

ΩR4

Standard resistor connection for 200k

Ω full scale range.

39

ΩR5

Standard resistor connection for 2000k

Ω full scale range.

40

VR3

Voltage measurement ÷ 100 attenuator.

41

VR2

Voltage measurement ÷ 10 attenuator.

42

VR5

Voltage measurement ÷ 10,000 attenuator.

43

VR4

Voltage measurement ÷ 1000 attenuator.

44

Unknown voltage input ÷ 1 attenuator.

45

Unknown current input.

46

ACVL

Low output of AC to DC converter.

47

Integrator capacitor connection. Nominally 0.1µf. (Low dielectric absorption. Polypropylene

dielectrics suggested.)

48

NC

No connection.

49

Auto-zero capacitor connection; nominally 0.1µf.

50

Unknown resistance input.

51

CFI

Input filter connection.

52

AD1

Negative input of internal AC to DC operational amplifier.

53

AD0

Output of internal AC to DC operational amplifier.

54

R

ΩBUF

Active buffer output for resistance measurement. Integration resistor connection. Integrator

resistor nominally 220k

Ω.

55

RVIBUF

Active buffer output for voltage and current measurement. Integration resistor connection.

Integration resistor nominally 150k

Ω.

56

ACVH

Positive output of AC to DC converter.

57

Negative supply connection for analog circuits. Connect to negative terminal of 9V battery.

58

DGND

59

RANGE

Input to set manual operation and change ranges.

60

HOLD

Input to hold display. Connect to DIG GND.

61

-MEM

Input to enter Memory Measurement mode for relative measurements. The two LSD’s are

stored and subtracted from future measurements.

62

DS/AC

Ω/LOWΩ

Input that selects AC or DC option during voltage/current measurements. For resistance

measurements,

63

I

Input to select current measurement. Set to logic “0” (Digital ground) for

current measurement

64

NC

No connection.

TABLE 2-1:

PIN FUNCTION TABLE (CONTINUED)

Pin Number

(64-Pin Plastic)

Quad Flat Package

Symbol

Description