ES51981
3 1/2 AUTO DMM
…continued from previous page
49~50 SEG14~SEG1
O
3
51~52
NC
53~64 SEG12~SEG0
O
1
65
BP4
O
66
BP3
O
67
BP2
O
68
BP1
O
69
ANNUNC
O
LCD segment line 14~13
LCD segment line 12~01
LCD backplane 4
LCD backplane 3
LCD backplane 2
LCD backplane 1
Square wave output at the backplane frequency, synchronized to
BP1. ANNUNC can be used to control display annunciator. Con-
nect an LCD segment to ANNUNC to turn it on; connect an LCD
segment to its backplane to turn it off.
Enables the buzzer. Low active.
Outputs an 2KHz audio frequency signal for driving piezoelectric
buzzer when BUZIN is low.
Crystal oscillator output connection
Crystal oscillator input connection
The chip uses internal RC oscillator if pin is connected to V-, and
uses external crystal oscillator if this pin is floating or connected to
DGND
If BKLIT function is enabled, this pin will change from –3V to +3V
for 60 sec, once press BKLIT pin again within 60 sec, this pin will
change back to –3V.
Pulse low to enable HOLD mode.
Pulse low to enable manual mode and manual range selection.
Select AC/DC initial state. This pin is pull low
Pulse low to change mode. In ADP mode, if this pin is connected to
V-, the buzzer output will be off when the ADP input overflows.
Switch 5 for function selection.
Switch 4 for function selection.
Switch 3 for function selection.
Switch 2 for function selection.
Switch 1 for function selection.
Positive capacitor connection for on-chip DC-DC converter.
Negative capacitor connection for on-chip DC-DC converter.
RS232 compliant serial data output.
Low battery configuration. If 3V battery is used, connect it to AGND.
The default low-battery threshold voltage is –2.3V. If 9V battery is
used, the low battery annunciator is displayed when the voltage of
this pin is less than VRH (-1.2V)
Negative supply voltage. Connecting to battery negative terminal.
Negative supply voltage. Connecting to battery negative terminal.
Digital ground, connected to battery positive terminal.
Analog ground.
Analog ground.
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
NC
BUZIN
BUZOUT
NC
OSC2
OSC1
NC
XTAL
NC
BKOUT
NC
HOLD
RANGE
SLACDC
KEY
FC5
FC4
FC3
FC2
FC1
NC
C+
C-
NC
SDO
LBAT9
I
O
O
I
I
O
I
I
I
I
I
I
I
I
I
O
O
O
I
96
97
98
99
100
V-
V-
DGND
AGND
AGND
P
P
G
G
G
4
08/09/09
CYRUSTEK [ Cyrustek corporation ]
