V 1.5

4

2015/12/11

ES278

4000 Counts Manual DMM

Pin Description ( Continued )

Pin No

Symbol

Type

Description

39

BKOUT

O

Push Hold key lager than 2 sec. to enable the back light function. This pin will

change from V- to V+ and lasts for 5 minutes.. Once press Hold key lager than 1

sec. again , this pin will change level back to V-.

40

CESEL

I

Voltage OL selection feature control pin. (1010V/610V)

41

DISDGBP

I

Control warning buzzer output at HV mode. Pulled to low and buzzer is disabled.

42

VST

I

In µA or mA modes, it is used to control the ‘µ’ or ‘m’ sign. Set to V- to enable

clamp current mode.

43

SLEEP

O

Sleep mode indicator, asserts low in SLEEP mode.

44

ASEL

I

Current mode OL indication for 2000A (VST = V-) or 20A (VST = Floating)

ranges

45

DIOV

I

Pulled to V- to set the 2.8V OL level in diode mode measurement

46

BUZIN

I

Pulled to V- to enable the buzzer output (BUZOUT) always.

47-50

BP4-1

O

LCD backplane 4 - LCD backplane1

51

NC

-

Not connected

52

ANNUNC

O

Square wave output at the backplane frequency, synchronized to BP1. ANNUNC

can be used to control display annunciator. Connect a LCD segment to ANNUNC

to turn it on; connect an LCD segment to its backplane to turn it off.

53-67

SEG15 - SEG01

O

LCD segment line 01 – 14.

68

MMX

I

Pulse to V- to enable MAX/MIN function.

69

KEY

I

Pulse to V- to change mode.

70

HOLD

I

Pulse to V- less than 1 second. to enable HOLD function.

71

S40uA

I

Pulled to V- to change 400.0uA to 40.00uA display.

72

OSC1

O

Connect to 4MHz crystal oscillator

73-77

NC

-

Not connected

78

OSC2

I

Connect to 4MHz crystal oscillator

79

BUZOUT

O

Outputs a 2KHz audio frequency signal for driving piezoelectric buzzer

80

FC6

I

Switch 6 for function selection.

81

FC5

I

Switch 5 for function selection.

82

FC4

I

Switch 4 for function selection.

83

FC3

I

Switch 3 for function selection.

84

FC2

I

Switch 2 for function selection.

85

FC1

I

Switch 1 for function selection.

86

SLACDC

I

Select initial DC/AC state.

87

CP

O

Positive capacitor connection for on-chip DC-DC converter.

88

CN

O

Negative capacitor connection for on-chip DC-DC converter.