Page 1
3 1/2 AUTO DMM
ES51981
Features
• 2000 count display
• Full automatic measurement
*Voltage measurement
*Current measurement
*Resistor measurement
• Range change function
• Data hold function
• Diode measurement
• ADP mode with external reference
voltage
Description
ES51981 is an integrated analog-to-digital
Converter(ADC) with 2000 counts LCD
display ,automatic range selection, and 3V
DC power supply. Automatic range
selection is provided for voltage(AC/DC)
measurement, resistor measurement and
current measurement. Expensive and
bulky mechanical range switches are not
required. Other features include data
holding, diode measurement, temperature
measurement, continuity checking, low
battery detection, auto- power off, re-
power on, and RS232 data
output.
• Serial data output (RS232 format)
• Auto power off (10 mins) and re-power
on
• Low battery detect (3V and 9V)
• 3V DC power supply
• Back light function
Application
Digital Multimeter
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Page 2
NCNCN
N
Pin Assignment
AGND
AGND
DGND
V-
V-
LBAT9
SDO
NC
3 1/2 AUTO DMM
FC3
FC2
FC1
NC
C+
C-
90100
FC5
FC4
ES51981
SLACDC
RANGE
HOLD
KEY
1
80
+
+
+
-
10
20
70
60
30
VA +
ADP
VA -
SGND
03/01/06
NC
VR1
VBAR
NC
40
C
2
SLEEP
NC
C
RS232
BKLIT
SEG16
50
SEG13
SEG14
SEG15
Page 3
Pin Description
3 1/2 AUTO DMM
ES51981
Pin No Symbol Type
1
2 V+ P Positive supply voltage, output of on-chip DC-DC converter.
3 V+ P Positive supply voltage, output of on-chip DC-DC converter.
4NC
5 CL+ IO High resolution positive connection for reference capacitor.
6 CL- IO High resolution negative connection for reference capacitor.
7 CIL O High resolution integrator output. Connected to integral capacitor
8 CAZL O High resolution auto-zero capacitor connection.
9 BUFL O Integral resistor connection for high resolution buffer output
10 IVSH I High current measurement input.
11 IVSL I Low current measurement input
12 OVX I Input high voltage for resistance measurement
13 OVH I Output connection for resistance measurement
14 OVSG I Sense low voltage for resistance measurement
15 NC
16 OR1 O Reference resistor connection for 399.9Ω range
17 VR5 O Voltage measurement ÷10000 attenuator(2000V)
18 VR4 O Voltage measurement ÷1000 attenuator(200.0V)
19 VR3 O Voltage measurement ÷100 attenuator(20.00V)
20 VR2 O Voltage measurement ÷10 attenuator(2.000V)
21 TEST 5 I/O Test pin
22 ACVL O Negative output of AC to DC converter
23 ACVH O Positive output of AC to DC converter.
24 NC
25 ADI I Negative input of internal AC to DC Opamp.
26 NC
27 ADO O Output of internal AC to DC Opamp.
28 NC
29 VRH O Output of band-gap voltage reference .Typically –1.2V
30 VR I Reference input voltage connection. Typically –100mV
31 VA+ I For ADP. Deintegrating voltage positive input. The input should
32 VA- For ADP. Deintegrating voltage negative input. The input should
33 ADP I ADP input
34 SGND G Signal Ground
35 VR1 I Measurement input
36 NC
37 VBAR I Decimal point control for temperature measurement in ADP mode.
38 NC
39 NC
40 NC
41 NC
42 SLEEP O Asserts low in the sleep mode. See page 8, function description
43 NC
44 NC
45 RS232 I Pulse low to enable serial data output.
46 BKLIT I Back light function. Pulse low to set BKOUT pin output
47~50
Continued on next page…….
NC
SEG16~SEG13
be higher than VA-.
be lower than VA+.
O LCD segment line 16~13
Description
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.
ES51981
3 1/2 AUTO DMM
…continued from previous page
51
52
53~64
65 BP4 O LCD backplane 4
66 BP3 O LCD backplane 3
67 BP2 O LCD backplane 2
68 BP1 O LCD backplane 1
69 ANNUNC O Square wave output at the backplane frequency, synchronized to
70 NC
71 BUZIN I Enables the buzzer. Low active.
72 BUZOUT O Outputs an 2KHz audio frequency signal for driving piezoelectric
73 NC
74 OSC2 O Crystal oscillator output connection
75 OSC1 I Crystal oscillator input connection
76 NC
77 XTAL I The chip uses internal RC oscillator if pin is connected to V-, and
78 NC
79 BKOUT O If BKLIT function is enabled, this pin will change from –3V to +3V
80 NC
81 HOLD I Pulse low to enable HOLD mode.
82 RANGE I Pulse low to enable manual mode and manual range selection.
83 SLACDC I Select AC/DC initial state. This pin is pull low
84 KEY I Pulse low to change mode. In ADP mode, if this pin is connected to
85 FC5 I Switch 5 for function selection.
86 FC4 I Switch 4 for function selection.
87 FC3 I Switch 3 for function selection.
88 FC2 I Switch 2 for function selection.
89 FC1 I Switch 1 for function selection.
90 NC
91 C+ O Positive capacitor connection for on-chip DC-DC converter.
92 C- O Negative capacitor connection for on-chip DC-DC converter.
93 NC
94 SDO O RS232 compliant serial data output.
95 LBAT9 I Low battery configuration. If 3V battery is used, connect it to AGND
96 V- P Negative supply voltage. Connecting to battery negative terminal.
97 V- P Negative supply voltage. Connecting to battery negative terminal.
98 DGND G Digital ground, connected to battery positive terminal.
99 AGND G Analog ground.
100 AGND G Analog ground.
NC
NC
SEG12~SEG01
O LCD segment line 12~01
BP1. ANNUNC can be used to control display annunciator. Connect an LCD segment to ANNUNC to turn it on; connect an LCD
segment to its backplane to turn it off.
buzzer when BUZIN is low.
uses external crystal oscillator if this pin is floating or connected to
DGND
for 60 sec, once press BKLIT pin again within 60 sec, this pin will
change back to –3V.
V-, the buzzer output will be off when the ADP input overflows.
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)
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A
V
A
D
P
n
ES51981
3 1/2 AUTO DMM
Absolute Maximum Ratings
Characteristic Rating
Supply Voltage (V- to AGND) -4V
nalog Input Voltage V- -0.6 to V+ +0.6
+
GND/DGND
igital Input V- -0.6 to DGND +0.6
ower Dissipation. Flat Package 500mW
Operating Temperature
Storage Temperature
Electrical Characteristics
Parameter Symbol Test Condition Min. Typ. Max Units
Power supply V- -3.5 -3.0 -2.2 V
I
TC
I
DD
SS
REF
RF
In DCV mode
Voltage roll-over error REV
Voltage nonlinearity NLV
Input Leakage -10 1 10 PA
Low battery flag voltage V- to AGND -2.5 -2.3 -2.1 V
Zero input reading 10MΩ input resistor -000 000 +000 counts
Reference voltage and open circuit
Voltage for 200Ω measurement V
Peak to peak backplane
Drive voltage
Counter time base period f
Open circuit voltage for Ω
Measurement (except 200Ω)
Internal pull-high to 0V
Current
Internal pull-low to VCurrent
AC frequency response at
2.000V range
Reference voltage temperature
Coefficient
V+
≥ (AGND/DGND+0.5V)
AGND/DGND
0℃ to 70℃
-25℃ to 125℃
Normal operation
In sleep mode
resistor
Best case straight
line
100KΩ resistor
between VRH and
AGND
-3.5V
≤ V ≤-2.2V
= 4MHZ
OSC
Ω and Continuity
Mode
Between V- pin and
HOLD, RANGE,
KEY, FC1, FC2,
FC3, FC4, FC5,
XTAL, BKLIT
Between V- pin
and RS232
Between GND Pi
and SLACDC
±1%
±5%
100KΩ resister
Between VRH
0℃<TA<70℃
≥ (V- -0.5V)
TA=2 5℃, V- = -3V
—
—
——
——
-1.3 -1.2 -1.1 V
3.00 3.2 3.40 V
—
-0.54 -0.47 -0.4 V
—
—
—
—
—
0.9 1.1 mAOperating supply current
0.1 5 µA
±0.1 %F.S10MΩ input
±0.1 %F.S
1
1.2
11
1.5 µA
40-400
400-2000
50
—
—
—
—
—
— ppm/℃
sec
µA
HZ
Note
:
1. Full Scale
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ES51981
3 1/2 AUTO DMM
Function Description
1. Operating Modes
1.1 Voltage Measurement
A reconfigurable voltage divider automatically provides a suitable range in voltage
measurement mode. The following table summarizes the full scale ranges in each
configuration.
Configuration Full Scale Range Divider Ratio Resister Connection
VR1 200.0mV 1 VR2 2.000V 1/10 R2 / (R1+R2)
VR3 20.00V 1/100 R3 / (R1+R3)
VR3 200.0V 1/1000 R4 / (R1+R4)
VR5 2000V 1/10000 R5 / (R1+R5)
1. 200.0mV range only exists in manual mode.
2. In the 2000V range, if the digit numbers is larger than 1000V, LCD will display
“OL”.
The measurement of true RMS using ES636
If ES636 (or other true RMS-to-DC converter chip) is used for true RMS measurement,
the suggested application circuit is shown below. When ES636 is used for true RMS,
ADO and ADI pin short together, TEST5 pin keeps floating, and ACVL pin connects to
SGND.
OVSG
100
OR1
1K
VR5
10K
VR4
101K
1.11M
VR3
VR2
ACVL
ACVH
ADI
ADO
200
-Vs
6
7
1
2
3
4
5
Cav
ES636
14
13
12
11
10
9
+Vs
+Vs
150
8
470K
500K
-Vs
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ES51981
3 1/2 AUTO DMM
1.2 Resistance Measurement
A reconfigurable divider automatically provides a suitable full scale range in resistance
measurement mode. The following table summarizes the full scale ranges and the
reference resistors in each configuration.
Configuration Full Scale Range Divider Ratio Resister Connection
OR1 200.0Ω R6 100Ω
OR2 2.000KΩ R5 1KΩ
OR3 20.00KΩ R4 10KΩ
OR4 200.0KΩ
OR5 2.000MΩ
OR6 20.00MΩ R1 10MΩ
1.3 Current measurement
R1
R1
‖
‖
R3
R2
100KΩ
1MΩ
Current measurement has three modes. The following table summarizes the full scale
range of each mode.
Mode Range Selection Full Scale
Automatic Mode 1
Automatic Mode 2 mA 20.00mA / 200.0mA
Automatic Mode 3 A 20.00A/2.000A
Manual Mode A 20.00A
µA
200.0µA / 2000µA
1.4 Continuity Check
Continuity check shares the same configuration with 200.0Ω manual resistance
measurement mode, but with buzzer output to indicate continuity. The buzzer generates a
2KHz sound whenever the digit number less than 25Ω. Because the cycle time of
measurement is only 50ms, the least significant digit will not display.
1.5 Diode Measurement
Diode measurement mode shares the same configuration with 2.000V manual voltage
measurement mode. If the test circuit is open or the voltage drop between the two ports
of the device (diode) under test is larger than 2V, the LCD panel will show “OL”. The
buzzer generates a 2KHz sound whenever the digit number is less than 0.25V. Because
the cycle time of measurement is only 50ms, the least significant digit will not display.
1.6 Auto power off
ES51981 has a default auto power off function. If the meter idles for more than 10
minutes, the chip automatically turns the power off. When this happens, the state of the
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ES51981
3 1/2 AUTO DMM
meter is saved. In order to disable auto power off function, power on the meter when
any of the push function, except for HOLD, is pressed down. In addition, when RS232
output is active, the auto power-off function is also disabled. The APO sign on the LCD
panel indicates whether the auto power-off is enabled or not.
Note: Powering on the meter while pressing HOLD turns on all LCD segment until
HOLD is pressed again.
1.7 Sleep
The meter enters sleep mode after auto power off. The SLEEP pin asserts low (-3V) in
the sleep mode, and asserts high (+3V, not 0V) after re-power on.
1.8 Re-power on
After auto power-off, pushing any of the push function or changing the rotary mode can
turn on the meter again. If the meter is re-powered on by changing the rotary mode, the
saved state is cleared. If the meter is re-powered on by push functions, the chip restores
the saved state and enters HOLD mode. The LCD displays the saved value.
2. Measurement Mode Switching
Measurement mode depends on the logic level of FC1, FC2, FC3, FC4, FC5, and KEY.
When FC5 is HIGH, the measurement modes are listed in the following table.
SLACDC FC1 FC2 FC3 FC4 Mode Function of KEY
0 1011 Voltage Measurement
0 1101Current Measurement(µA)
0 1111Current Measurement(mA)
0 1001
0 0000Auto Current Measurement(A)DCA(initial)
1 1011 Voltage Measurement
1 1101Current Measurement(µA)
1 1111Current Measurement(mA)
1 1001
1 0000Auto Current Measurement(A)ACA (initial)
X 0011Resistance Measurement Ω ↔ Continuity
X 0101Resistance Measurement Ω ↔ Diode
X 0001 Continuity Check Continuity Diode
X 0111Resistance MeasurementΩ ↔ Continuity ↔Diode
X 0100
Manual Current Measurement(A)
Manual Current Measurement(A)
Temperature(℃)
DCV(initial)
DCA(initial)
DCA(initial)
DCA (initial) ↔ACA
ACV (initial)
ACA(initial)
ACA (initial)
ACA (initial) ↔DCA
↔ACV
↔ACA
↔ ACA
↔DCV
↔DCA
↔DCA
—
Ps. X means “don’t care”
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)
)
ES51981
3 1/2 AUTO DMM
When FC5 is LOW, KEY is disable. The corresponding measurement modes are list
below
SLACDC FC1 FC2 FC3 FC4 Mode
0 1011AC Voltage Measurement
0 1101AC Current Measurement(µA)
0 1111AC Current Measurement(mA
0 1001
0 0000
1 1011DC Voltage Measurement
1 1101DC Current Measurement(µA)
1 1111DC Current Measurement(mA
1 1001
1 0000
X 0011Resistance Measurement
X 0101Resistance Measurement
X 0001 Continuity Check
X 0111 diode Measurement
X 0100
Manual AC Current Measurement(A)
Auto AC Current Measurement(A)
Manual DC Current Measurement(A)
Auto DC Current Measurement(A)
Temperature(℉)
Ps. X means “don’t care”
The other combinations of FC1, FC2, FC3, and FC4 are for ADP modes. In ADP modes
, if FC5 is LOW, the minus sign on the LCD panel will not be displayed. And if KEY pin
is floating, the buzzer beeps when the input signal is overflow. The ADP mode function
is summarized below.
FC1 FC2 FC3 FC4 Mode
1110 ADP0
1100 ADP1
1000 ADP2
1010 ADP3
Note: Temperature measurement mode takes input signal from ADP pin. In temperature
measurement mode, VBAR pin is used to control the right most digit point on the
LCD panel. When VBAR is LOW, this digit point is displayed.
3. Push function
3.1 HOLD
HOLD mode makes the meter stop updating the LCD panel. This mode can be nested in
most of the special modes. Enabling HOLD function in automatic mode makes the
meter switch to manual mode, but the full scale range remains the same. HOLD function
can be cancelled by changing the measurement mode, pressing RANGE, or push HOLD
again.
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p
ES51981
3 1/2 AUTO DMM
3.2 Range
RANGE pin switches to and from automatic and manual mode, and while in manual
mode, changes the full scale range. The following figure shows the state transition.
1 push < 1 sec
Automatic
Mode
1 push > 1 sec
Measurement Mode Auto Manual Control Range Initial Range
V(DC/AC) VR2 – VR5
µA(DC/AC) R1 – R2
mA
(AC/DC)
Auto A(DC/AC) R1 – R2
A(DC/AC) fixed fixed 20.00A 20.00A
Ω OR1- OR6
Continuity fixed fixed 200.0Ω 200.0Ω
Diode Fixed fixed 2.000V 2.000V
R1－R2 R1 → R2
VRi →
VRi + 1,
VR5 → VR1
R1 → R2,
R2 → R1
R2 → R1
R1 → R2,
R2 → R1
ORi →
ORi + 1,
OR6 → OR1
Note: Pushing RANGE resets all existing special modes.
Manual
Mode
1
ush < 1 sec
200.0mV – 2000V 2.000V
200.0µA - 2000µA 200.0µA
20.00mA –
200.0mA
2.000A – 20.00A 2.000A
200.0Ω – 20.00MΩ 200.0Ω
Range up
20.00mA
3.3 KEY
See Section “Measurement Mode Switching” for the function of this pin.
4. Serial Data Output
The serial data sent to SDO pin twice every A/D conversion cycle. The data format
complies with JIS 7Bits transmission code with a baud rate of 19230. The host can use
RS232 interface to read the data. A single data packet includes a start bit (always 0), 7
data bits, an odd parity check bit, and a stop bit (always 1). The high and low voltage
levels correspond to DGND and V- respectively. SDO remains at 1 (high) when it is
inactive. Hence the start bit (0) could be used as the triggering signal to begin the
reading process. The following figure shows the data format of a single packet. The
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LSB is sent first and the MSB is sent last.
single package
ES51981
3 1/2 AUTO DMM
0V
-3V
0
D0 ~D6
p
1P
LSB MSB
One data block consists of 11 packets, or 110 bits. The following figure shows the
format of a data block. The range packet indicates the full scale range of the meter.
Digit 3 through digit 0 are just the digits on the LCD panel. The function packet
indicates the measurement mode of the meter. Status, option 1 and option 2 give the
status of the meter. CR and LF are delimiters used to separate the blocks.
All package
0
range
0
p
1
0
p
1 0
p
1 0
digit2digit3
p
1 0
p
1
p
1
digit0digit1
0
status
0
CR LF
The meter always outputs the current input value to the serial port in spite of HOLD
mode. Each block is repeated twice in one conversion cycle. The detailed data format of
each packet is listed below.
p
1 0
option1
p
1 0
p
1 0
p
1
function
option2
p
1
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ES51981
3 1/2 AUTO DMM
4.1 FUNCTUON
This packet indicates the measurement mode of the meter. The following table
summarizes the transmitted code for each mode. Note that the encoding of this packet is
different from the encoding of FC1-FC4 switch.
Code Measurement Mode
0111011 Voltage
0111101 µA Current
0111111 mA Current
0110000 Auto A current
0111001 Manual A Current
0110011
0110101 Continuity
0110001 Diode
0110100 1*Temperature
0111110 ADP0
0111100 ADP1
0111000 ADP2
0111010 ADP3
Note: 1*.The judge bit in the Status packet determines whether the unit is Celcius or
Ω
Fahrenheit.
4.2 RANGE
This packet indicates the full scale range of the meter. When the meter operates in
continuity mode, diode mode, or current (A) mode, this packet is always 0110000 since
the full scale range in these modes are fixed. The following table lists the code for each
range in each measurement mode.
Code V mA µA Auto A
0110000 2.000V 20.00mA 200.0µA 2.000 A 200.0Ω
0110001 20.00V 200.0mA 2000µA 20.00 A 2.000KΩ
0110010 200.0V 20.00KΩ
0110011 2000V 200.0KΩ
0110100 200.0mV 2.000MΩ
0110101 20.00MΩ
0110110
Ω
4.3 DIGIT 3 – DIGIT 0
Digit 3 is the most significant digit on the LCD panel, and digit 0 is the least significant
digit. When the LCD panel shows OL, the serial port outputs 2000.
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ES51981
3 1/2 AUTO DMM
Digit Code
0 0110000
1 0110001
2 0110010
3 0110011
4 0110100
5 0110101
6 0110110
7 0110111
8 0111000
9 0111001
Because the cycle time of measurement for continuity/diode mode is only 50ms, the
least significant digit may not be accurate.
4.4 STATUS
The format of this shown below. The Judge field is meaningful only when the Function
packet indicates Temperature mode. In Temperature mode, judge is 1 if the unit is ℃
and is 0 of the unit is ℉ . Sign field indicates whether the minus sign on the LCD
panel is on or off. BATT field is one of battery low condition is true. OL indicates input
overflow.
0 1 1 Judge Sign BATT OL
BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT1 BIT 0
4.5 OPTION 1
This packet is not used.
011HOLD000
BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT1 BIT 0
If Hold field is 1, Hold function is active. Hold function will not influence Digital 3~0
which is related to current measured value.
4.6 OPTION 2
This packet contains information on the operation mode of the meter. The format is
shown below. The DC field indicates that the meter operates in DC measurement mode,
either voltage or current. The AC field indicates that the meter operates in AC
measurement mode, either voltage or current. The AUTO field is set to one if the meter
operates in automatic mode, and is set to zero when the meter operates in manual mode.
011DCACAUTO0
BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT1 BIT 0
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ES51981
3 1/2 AUTO DMM
4.7 CR
Carrage return. The transmitted code is 0001101.
4.8 LF
Line feed. The transmitted code is 0001010.
5. Miscellaneous
The conditions which the meter turns on the buzzer include:
(1) Changing measurement mode generates one beep.
(2) Pressing any of the push junctions generates one beep, if the function is valid.
(3) Power on and re-power on generate one beep.
(4) Input overflow in voltage and current mode generates one beep every 0.3 seconds
(or 3.33 beeps per second.)
(5) Continuity(diode) check generates a continuous 2KHz beep whenever the
measurement is less then 25Ω(0.25V)
(6) Auto power off generates a 2KHz beep which lasts for 1.5 seconds.
The following figures shows the output waveform from the BUZOUT pin.
0.5 mS
(a) Continuous 2KHz beep
0.15 sec
0.3 sec
(b) 3.33 beep/sec
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5.1 LCD Panel
3 1/2 AUTO DMM
ES51981
AUTO
℃ ℉
n µ1 m1 F
µ2 m2 V A
APO
M KΩ HZ
SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08
BP1 BATT DC AUTO MANU A3 B3 HOLD A2
BP2ACF4A4B4F3G3F2B2
BP3 APO
BP4 RS232 E4 D4 P3 D3 P2 D2 C2
SEG09 SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16
F1 A1 B1 M × × u1
E1 G1 C1 HZ × × m1 ×
P1 D1 K Ω ××F×
—
G4 C4 E3 C3 E2 G2
V A m2 u2 n
℃
℉
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5.2 LCD Backplane Waveform
3 1/2 AUTO DMM
ES51981
V- +3.1
V-
V- +3.1
V-
V- +3.1
V-
V- +3.1
V-
5.3 LCD display on condition
LCD Annunciator Condition
V In voltage measurement mode, and diode measurement mode.
A In current measurement mode.
Ω In resistance measurement mode, and continuity mode.
F In capacitance measurement mode.
In continuity check mode.
In diode mode.
Hz In frequency mode.
DC In DC voltage or DC current mode.
AC In AC voltage or AC current mode.
AUTO When automatic full scale range selection is enabled.
MANU In manual mode.
HOLD When HOLD function is enabled.
m1 In capacitor measurement mode and the full scale range is in the order of mF.
u1 In capacitor measurement mode and the full scale range is in the order of uF.
n In capacitor measurement mode and the full scale range is in the order of nF.
m2 In voltage or current measurement mode and the full scale range is in the order of
u2 In current measurement mode and the full scale range id in the order of uA.
M In resistance measurement mode and the full scale range is in the order of MΩ
K In resistance measurement mode and the full scale range is in the order of KΩ
℃ In temperature measurement mode and when the unit is ℃
℉ In temperature measurement mode and when the unit is ℉
APO When auto power off function is enabled.
- In voltage or current measurement mode and when the input is negative.
10
-3
.
V- +3.1
V-
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ES51981
3 1/2 AUTO DMM
5.4 Operating Timing
ES51981 incorporates a dual slope ADC with four phases: ZI, AZ, INT and DINT.
The timing of each phase is listed below.
*Voltage /ohm/ADP measurement:
Phase Time
ZI 100ms
AZ 100ms
INT 100ms
DINT 200ms
Ps. In the voltage and ohm measurement with auto mode, if the range is changed,
the internal clock rate will increase ten times and the new measurement cycle
becomes 1/10 times of the original cycle until the range is stable.
*Current mode
Phase Time
ZI 100ms
AZ 100ms
INT 100ms
DINT 100ms
*Continuity/diode measurement
Phase Time
ZI 10ms
AZ 10ms
INT 10ms
DINT 20ms
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Page 18
Z
GND0V
00mV
5
mAu
OVSG
6.Test circuit
1. Voltage test
3 1/2 AUTO DMM
ES51981
10K
1.0u
5K
2.Resistor test
2
AGND
VR5
VR4
VR2
ADO
ACVH
TEST
Voltage input
100
V
R
-1
OVX
OVH
OVSG
OR1
VR5
VR4
VR3
VR2
SGND
AGND
4.Current
4.5
A
mA
uA
45
450
5.ADP test
ADPin+
ADPin-
test
-
AGND
SGND
100K
A
100K
IVSH
IVSL
VA +
VA -
ADP
SGND
AGND
3.Diode test
6. Low battery
AGND
100
03/01/06
OVH
VR1
VR2
18
BA
TT
A
-
Page 19
ADP
N
N
(
)
N
VA
N
NC
00
0
0
00100
00K0.47u
0.22u
0.1u
+
0.1u
+
+
0u
0.1u
0.1u4.7u
C
7.Application circuit
3 1/2 AUTO DMM
ES51981
mA
SGND
uA
R
A
450
uA
uA
45
4.5
0.45
0.045
0.005
K
1.5K
PTC
Zener 6V
mA
mA
6A
60A
110pF
7.5V
100K
1
1
1
1K
K
1
1K
1
5.6V ZI
-
3V
1
DGND
AGND
AGND
V-
V-
LBAT9
SDO
C-
C+
C
FC2
FC1
FC4
FC3
FC5
KEY
SLACDC
HOLD
RANGE
-3V
4MHz
-3V
LCD Display
(50)SEG14
40
SGND
VA -
+
100K
03/01/06
VR1
10M
VBAR
C
-3V
19
NC
C
NC+
NC-
SLEEP
NC
RS232
C
BKLIT
SEG17
SEG16
SEG15
-
Page 20
Package
1 100 Pin QFP Package
W
L
3 1/2 AUTO DMM
A
ES51981
BC
2 Dimension Paramenters
Symbol
W 19.90 20.00 20.10 783.5 787.4 791.3
L 13.90 14.00 14.10 547.2 551.2 551.2
A 0.425 16.7
B 0.20 0.30 0.40 7.9 11.8 11.8
C 0.65 25.6
d 1.05 1.20 1.35 41.3 47.2 47.2
a 2.57 2.72 2.87 101.2 107.1 107.1
D 2.50 98.4
θ
b
θ
D
d
Milimeter Mill
Min. Typ. Max. Min. Typ. Max.
o
0
10
o
a
03/01/06
20
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