ES51983
3 3/4 AUTO DMM
…continued from previous page
SEG14~13
49~50
51~52
53~64
65
66
67
O
LCD segment line 14~13
NC
SEG12~SEG01
BP4
O
O
O
O
O
O
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.
BP3
BP2
BP1
68
69
ANNUNC
70
71
72
NC
BUZIN
BUZOUT
I
O
Enables the buzzer. Low active.
Outputs an 2KHz audio frequency signal for driving piezoelectric
buzzer when BUZIN is low.
73
74
75
76
77
NC
OSC2
OSC1
NC
O
I
Crystal oscillator output connection
Crystal oscillator input connection
XTAL
I
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
78
79
NC
BKOUT
O
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.
80
81
82
83
84
NC
HOLD
RANGE
SLACDC
KEY
I
I
I
I
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.
85
86
87
88
89
90
91
92
93
94
95
FC5
FC4
FC3
FC2
FC1
NC
C+
C-
NC
SDO
LBAT9
I
I
I
I
I
O
O
Positive capacitor connection for on-chip DC-DC converter.
Negative capacitor connection for on-chip DC-DC converter.
O
I
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)
96
97
98
99
100
V-
V-
DGND
AGND
AGND
P
P
G
G
G
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.
4
11/01/05
CYRUSTEK [ Cyrustek corporation ]
