ETC ES51918

ES51918
11,000 Counts Auto DMM
Features
• High Crest Factor signal detection
• 11,000 counts LCD display
(R.O.C patent No. I 234661)
• Conversion rate : 4 times/s
• Band-gap reference voltage output
• Full automatic measurement
• CE selection
*Voltage measurement:
110.00mV – 1000.0V
• On-chip independent OPAMP
• Serial data output (RS232 format)
*Current measurement: µA/mA/A
• LCD segment check when power on
*Resistance measurement:
• Auto power off with idle time selection
110.00Ω – 110.00MΩ
• Sleep output
*Capacitance measurement:
• Re-power on
11.000nF – 110.00mF(12.5sec)
*Frequency counter:
1.1000KHz – 110.00MHz
• On-chip buzzer driver
• 3V DC power supply
• Low battery detection for 3V or 9V battery
• Current modes for clamp meter
• Back light function
• Diode measurement
Description
• Continuity check
• ADP mode with independent reference
voltage
• Temperature mode with internal scale
conversion circuit from 0C to 0F
• Range change function
• VAHZ function
• Peak Hold with automatic calibration
• Relative function
• Zero function in manual DCA mode
• Data hold function
• MAX/MIN function
• SHIFT function
v1.02
ES51918 is an integrated analog-to-digital
converter (ADC) with 11,000 counts LCD
display, automatic range selection, and 3V DC
power supply. Automatic range selection is
provided for voltage (AC/DC) measurement,
resistance measurement, current measurement,
capacitance measurement, and frequency
counter. Expensive and bulky mechanical
range switches are not required. Other features
include peak detection with calibration mode,
relative value display, zero-offset removing
feature in manual DCA mode for clampmeter,
data holding, maximum and minimum holding,
diode measurement, temperature measurement,
continuity checking, low battery detection,
auto power off, re-power on, and RS232 data
output.
1
05/06/30
ES51918
11,000 Counts Auto DMM
Application
Digital multimeter
Clamp meter
Thermometer
Cyrustek.
com.tw
90
25
20
15
5
100
10
ES51918
95
45
40
35
30
55
60
65
70
75
85
50
SEG17
SEG18
BKLIT
SHIFT
RS232
FREQ
SLEEP
OHMC
CA+
CAR1K
R9K
PMAX
PMIN
VBAR
VR1
SGND
ADP
VAVA+
V+
V+
CREF+
CREFCINT
CAZ
BUFF
RAZ
IVSH
IVSL
OVX
OVH
OVSG
OR1
VR5
VR4
VR3
VR2
TEST5
ACVL
ACVH
ADI
ADO
ADOHZ
OPO
OPIN+
OPINPWD
VRH
VR
OSC1
OSC2
APOSEL
CESEL
NC
KEY
SLACDC
FC5
FC4
FC3
FC2
FC1
LBAT9
SDO
C+
CVDGND
AGND
AGND
80
RANGE
HOLD
REL_ZERO
PEAK
VAHZ
MAX/MIN
BKOUT
BUZOUT
BUZIN
ANNUNC
BP1
BP2
BP3
BP4
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
Pin Assignment
v1.02
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05/06/30
ES51918
11,000 Counts Auto DMM
Pin Description
Pin No
Symbol
Type
1
2
3
4
5
6
7
8
V+
V+
CREF+
CREFCINT
CAZ
BUFF
RAZ
O
O
I/O
I/O
O
I
O
O
9
10
11
12
13
14
15
16
17
18
19
20
IVSH
IVSL
OVX
OVH
OVSG
OR1
VR5
VR4
VR3
VR2
TEST 5
ACVL
I
I
I
I
I
O
O
O
O
O
I/O
O
21
ACVH
O
22
23
24
25
26
27
28
29
30
31
ADI
ADO
ADOHZ
OPO
OPIN+
OPINPWD
VRH
VR
VA+
I
O
I
O
I
I
I
O
I
I
32
VA-
I
33
34
35
36
ADP
SGND
VR1
VBAR
I
G
I
I
37
38
39
40
41
42
43
PMIN
PMAX
R9K
R1K
CACA+
OHMC
O
O
O
O
I/O
I/O
O
v1.02
Description
Output of on-chip DC-DC converter.
Output of on-chip DC-DC converter.
Positive connection for reference capacitor.
Negative connection for reference capacitor.
Integrator output. Connect to integral capacitor
Auto-zero capacitor connection.
Buffer output pin. Connect to integral resistor
Buffer output pin in high-speed mode. Connect to high-speed integral
resistor.
Current measurement input for 1100µA, 110mA and 11A modes.
Current measurement input for 110µA, 11mA.
Input high voltage for resistance measurement
Output connection for resistance measurement
Sense low voltage for resistance measurement
Reference resistor connection for 110.00Ω range
Voltage measurement ÷10000 attenuator(1000.0V)
Voltage measurement ÷1000 attenuator(110.00V)
Voltage measurement ÷100 attenuator(11.000V)
Voltage measurement ÷10 attenuator(1.1000V)
Test pin
DC signal low input in ACV/ACA mode. Connect to negative output
of external AC to DC converter.
DC signal high input in ACV/ACA mode. Connect to positive output
of external AC to DC converter.
Negative input of internal AC to DC OP Amp.
Output of internal AC to DC OP Amp.
Frequency input under voltage/current mode, offset to AGND.
Output of internal independent OP Amp.
Positive input terminal of on-chip independent OP Amp.
Negative input terminal of on-chip independent OP Amp.
Power-down enable for on-chip independent OP Amp.
Output of band-gap voltage reference. Typically –1.23V
Reference input voltage connection. Typically –100mV
For ADP mode. De-integrating voltage positive input. The input
should be higher than VA-.
For ADP mode. De-integrating voltage negative input. The input
should be lower than VA+.
Measurement input in ADP mode.
Signal Ground.
Measurement input.
In capacitance mode, a compensation capacitor is connected.
In temperature mode, it is used to control decimal point.
In µA or mA modes, it is used to control the ‘µ’ or ‘m’ sign.
Minimum peak hold output
Maximum peak hold output.
Connect to a precise 9KΩ resister for capacitor measurement.
Connect to a precise 1KΩ resister for capacitor measurement.
Negative auto-zero capacitor connection for capacitor measurement
Positive auto-zero capacitor connection for capacitor measurement
Filter capacitor connection for resistance mode.
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05/06/30
ES51918
11,000 Counts Auto DMM
44
45
46
47
SLEEP
FREQ
RS232
SHIFT
48
BKLIT
49 - 66 SEG18 – SEG01
67
BP4
68
BP3
69
BP2
70
BP1
71
ANNUNC
O
I
I
I
I
O
O
O
O
O
O
72
73
BUZIN
BUZOUT
I
O
74
BKOUT
O
75
76
77
78
79
80
81
82
83
84
85
86
MAXMIN
VAHZ
PEAK
REL_ZERO
HOLD
RANGE
OSC1
OSC2
APOSEL
CESEL
NC
KEY
I
I
I
I
I
I
I
O
I
I
87
88
89
90
91
92
93
SLACDC
FC5
FC4
FC3
FC2
FC1
LBAT9
94
95
96
97
98
99
100
SDO
C+
CVDGND
AGND
AGND
v1.02
Sleep mode indicator, asserts low in SLEEP mode.
Frequency counter input, offset V-/2 internally by the chip.
Assert low to enable serial data output.
Assert low to enable LCD SHIFT future, only works in 110MΩ,
continuity and diode measurement modes.
Back light function. Pulse low to set BKOUT pin output.
LCD segment line 01 – 18
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. Connect a
LCD segment to ANNUNC to turn it on; connect an LCD segment to
its backplane to turn it off.
Pull to V- to enable the BUZOUT.
Outputs a 2KHz audio frequency signal for driving piezoelectric buzze
when BUZIN is low.
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 to V- to enable MAX/MIN function.
Pulse to V- to enable VAHZ mode.
Pulse to V- to enable Peak Hold mode.
Pulse to V- to enable Relative function or Zero function.
Pulse to V- to enable HOLD function.
Pulse to V- to enable manual mode and manual range selection.
Crystal oscillator input connection
Crystal oscillator output connection
Idle time selection for auto power off feature.
CE selection feature control pin.
I
Pulse to V- to change mode. In ADP mode, if this pin is connected to
V-, the buzzer output will be off when the ADP input overflows.
I
Select initial state. Please refer to page 15
I
Switch 5 for function selection.
I
Switch 4 for function selection.
I
Switch 3 for function selection.
I
Switch 2 for function selection.
I
Switch 1 for function selection.
I
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)
O RS232 compliant serial data output.
O Positive capacitor connection for on-chip DC-DC converter.
O Negative capacitor connection for on-chip DC-DC converter.
P Negative supply voltage. Connecting to 3V battery negative terminal.
P/G Digital ground. Connecting to 3V battery positive terminal.
P/G Analog ground.
P/G Analog ground.
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ES51918
11,000 Counts Auto DMM
Absolute Maximum Ratings
Characteristic
Supply Voltage (V- to AGND)
Analog Input Voltage
V+
AGND/DGND
Digital Input
Power Dissipation. Flat Package
Operating Temperature
Storage Temperature
Rating
-4V
V- -0.6 to V+ +0.6
V+ ≥ (AGND/DGND+0.5V)
AGND/DGND ≥ (V- -0.5V)
V- -0.6 to DGND +0.6
500mW
0℃ to 70℃
-25℃ to 125℃
Electrical Characteristics
TA=25℃, V- = -3V
Parameter
Power supply
Operating supply current
In DCV mode
Voltage roll-over error
Voltage nonlinearity
Input Leakage
Low battery flag voltage
Zero input reading
Reference voltage and open circuit
voltage for 110Ω measurement
Peak to peak backplane
drive voltage
Counter time base period
Open circuit voltage for Ω
measurement (except 110Ω)
Internal pull-high to 0V
current
Internal pull-low to Vcurrent
AC frequency response at 1.1000V
range
Sensitivity in VAHZ mode
Sensitivity in Frequency mode
v1.02
Symbol
Test Condition
VIDD
Normal operation
ISS
In sleep mode
REV 10MΩ input resistor
NLV
VREF
Best case straight
line
V- to AGND
10MΩ input resistor
100KΩ resistor
between VRH and
AGND
-3.5V≤ V ≤-2.2V
fOSC = 4MHZ
Ω and Continuity
Mode
Between V- pin and
HOLD, RANGE,
KEY, FC1~FC5,
BKLIT,MAXMIN
Between V- pin
and RS232
Between GND Pin
and PWN
±1%
±5%
Input from ADOHZ
Duty Cycle=50%
Input from FREQ
Duty Cycle=50%
5
Min.
-3.5
—
—
—
Typ.
-3.0
1.8
2.5
—
Max
-2.2
2.0
5
±0.05
Units
V
mA
µA
%F.S1
—
—
±0.05
%F.S
-10
-2.4
-000
1
-2.3
000
10
-2.2
+000
pA
V
counts
-1.33
-1.23
-1.13
V
3.1
3.2
3.3
V
—
1
—
sec
-0.21
-0.19
-0.17
V
—
1.2
—
µA
—
11
—
1.5
—
—
40-400
400-2000
µA
—
—
HZ
600
mV(Vpp)
600
mV(Vpp)
05/06/30
ES51918
11,000 Counts Auto DMM
Reference voltage temperature
coefficient
TCRF
Minimum pulse width for Peak
Hold feature
TPW
100KΩ resister
Between VRH
0℃<TA<70℃
4MHz
crystal
oscillator
11nF
110nF/1.1µF
Capacitance measurement accuracy2
11µF/110µF/1.1mF
11mF/110mF
—
50
—
100
ppm/℃
µs
1.5
15
1.0
10
1.0
5
1.5
5
%
Digits
%
Digits
%
Digits
%
Digits
Note:
1.Full Scale
2.Above specification from 11nF to 1.1uF ranges are specified under REL mode.
Function Description
1. Operating Modes
1.1 Voltage Measurement
A re-configurable voltage divider automatically provides a suitable range in voltage
measurement mode. The following table summarizes the full-scale ranges in each
configuration.
Configuration
VR1
VR2
VR3
VR4
VR5
Full Scale Range
110.00mV
1.1000V
11.000V
110.00V
1100.0V
Divider Ratio
1
1/10
1/100
1/1000
1/10000
Resister Connection
R1
R2 / (R1+R2)
R3 / (R1+R3)
R4 / (R1+R4)
R5 / (R1+R5)
Note: 110.00mV range only exists in manual mode.
1.1.2 CE selection
ES51918 has a CE selection feature archived by configuring an CESEL pin. If pin
CESEL is connected to DGND or floating, ES51918 will have a 610.0V overflow level
in DC and AC 1100.0V ranges. If pin CESEL is connected to V-, ES51918 will have a
1010.0V overflow level in DC and AC 1100.0V ranges. The meter will Show OL when
the measuring signal reaches the overflow level. The configuration of CESEL is listed
below.
CESEL
DCV
ACV
V1010.0V
1010.0V
DGND or floating
610.0V
610.0V
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05/06/30
ES51918
11,000 Counts Auto DMM
1.1.3 HCF signal detection
ES51918 provides detection of high-crest-factor (HCF) signal in ACV mode. When this
function is enabled, ES51918 senses the signal and determines it as HCF if the Vpp is
large enough. Once the signal is determined as HCF, ES51918 will jump up one
measuring range regardless of current measurement value. It takes 60ms to jump one
range up. The jumping up process will continue until the maximum range is reached.
With HCF detection, a more accurate result could be obtained. For example, when a
input signal with Vpp=500V, Vrms=100V(CF=5) was applied, traditional 4000 counts
DMMs might stay at 400V range but shows counts with the amount of error up to 10%
or even bigger. The error rises from limited input/output swing at internal ADC. With
HCF detection, DMM will stay at 4000V and exhibits more accurate results.
In addition to accuracy improvement, HCF will speed up the measuring process for
high voltage signals. For example, a 1000Vrms is applied, ES51918 will take about
180ms (3 HCF jumps) to enter 1100.0 V range. And it takes 1 or 2 measuring processes
to obtain the stable result. Thus a stable LCD reading could be obtained within 1 sec.
In determining whether the input signal is HCF, ES51918 senses the signal at VR1 for
fast response. However if a signal consists of a small ac part and a large enough dc part,
ES51918 might incorrectly treat it as HCF. This could incur range looping phenomenon,
i.e., the measurement could not settle to a specific range.
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ES51918
11,000 Counts Auto DMM
1.1.4 The true RMS-to-DC conversion with ES636
If ES636 is used for true RMS-to-DC measurement, the test circuit is shown in Figure 1.
Make ADO and ADI pin short, and TEST5 pin keeps float. Connect OVSG pin to
AGND through a switch in ACV measurement mode. If the DCV and ACV
measurement modes are in the same rotary switch, please also add this switch in the
rotary switch. The configuration of this switch will not influence the precision of DCV
measurement.
AGND
+Vs -Vs
7
2.2u
+
4.7u
ES636
200
-Vs
1
2
3
4
5
6
7
2
14
13
12
11
10 100
9
8
4
TL061
3
+Vs
1 100K
6
5
N1
AGND
AGND
+
ACVH
10K
OP+
1.5K
-Vs
1K +Vs
AGND
+Vs
500K
1u
AGND
30K
N2
PWD
OP-
0.1u
ADI
+Vs
-Vs
OVSG
OR1
VR5
VR4
VR3
VR2
TEST5
ACVL
ES51918
99.5
1K
10K
101K
1.111M
ACV
ADO
-Vs
30K
100K
1M
Note: The filter capacitors for +Vs and -Vs
are recommended to near to the power
terminals of ES636 and external OPAMP.
OPO
ADOHZ
AGND
10K
AGND
Figure 1. The true RMS-to-DC conversion with ES636
v1.02
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ES51918
11,000 Counts Auto DMM
1.1.5
The true RMS-to-DC conversion with ES7
If ES7 is used for true RMS-to-DC measurement, the test circuit is shown in Figure 2.
Make ADO and ADI pin short, and TEST5 pin keeps float. Connect OVSG pin to
AGND through a switch in ACV measurement mode. If the DCV and ACV
measurement modes are in the same rotary switch, please also add this switch in the
rotary switch. The configuration of this switch will not influence the precision of DCV
measurement.
AGND
AGND
1
2
3
4
ES7
4.7u
TEST5
ACVL
7
47K
-Vs
+Vs -Vs
AGND
+
2.2u
8
7
6
5
4
+Vs
2
3
+
1u
6
TL061
5
1 100K
N2
N1
AGND
30K
10K
-Vs
AGND
ACVH
OP+
1.5K
AGND
OVSG
OR1
VR5
VR4
VR3
VR2
ES51918
99.5
1K
10K
101K
1.111M
ACV
+Vs
PWD
OP-
0.1u
ADI
+Vs
ADO
30K
100K
-Vs
1M
Note: The filter capacitors for +Vs
and -Vs are recommended to near to
the power terminals of ES7 and
external OPAMP.
10K
OPO
ADOHZ
AGND
AGND
Figure 3. True RMS-to-DC conversion with ES7
v1.02
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ES51918
11,000 Counts Auto DMM
1.1.6
The true RMS-to-DC conversion with ES7R
If ES7R is used for true RMS-to-DC measurement, the test circuit is shown in Figure 3.
Make ADO and ADI pin short, and TEST5 pin keeps float. Connect OVSG pin to
AGND through a switch in ACV measurement mode. If the DCV and ACV
measurement modes are in the same rotary switch, please also add this switch in the
rotary switch. The configuration of this switch will not influence the precision of DCV
measurement. The 500kΩ VR, 1kΩ resistor and 10Ω resistor are used for external
offset trim. If users don’t want to use external offset trim, please remove these 3
resistors and connect pin1 of ES7R to pin8 of ES7R.
-Vs
500K
AGND
1K
+Vs -Vs
100
1
2
3
4
ES7R
4.7u
+Vs
AGND
TEST5
ACVL
7
47K
-Vs
AGND
+
2.2u
8
7
6
5
4
+Vs
+
1u
2
TL061
3
1 100K
6
5
N2
N1
AGND
OVSG
OR1
VR5
VR4
VR3
VR2
AGND
30K
10K
OP+
1.5K
-Vs
AGND
ACVH
ES51918
99.5
1K
10K
101K
1.111M
ACV
+Vs
PWD
OP-
0.1u
ADI
+Vs
ADO
30K
100K
-Vs
1M
Note: The filter capacitors for +Vs
and -Vs are recommended to near to
the power terminals of ES7R and
external OPAMP.
10K
OPO
ADOHZ
AGND
AGND
Figure 3. The true RMS-to-DC conversion with ES7R
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ES51918
11,000 Counts Auto DMM
1.2 Resistance Measurement
A re-configurable 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. In 110.00MΩ, if SHIFT pin connects
to V-, the least digit will not be displayed and the other digits and decimal point will
shift right away. So the full scale becomes 110.0MΩ instead of 110.00MΩ.
Configuration
OR1
OR2
OR3
OR4
OR5
OR6
OR7
Full Scale Range
110.00Ω
1.1000KΩ
11.000KΩ
110.00KΩ
1.1000MΩ
11.000MΩ
110.00MΩ
Divider Ratio
R6
R5
R4
R1‖ R3
R1‖ R2
R1
R1
Resister Connection
100Ω
1KΩ
10KΩ
100KΩ
1MΩ
10MΩ
10MΩ
1.3 Current measurement
ES51918 has 2 automatic and 1 manual current measurement modes for multimeter and
5 manual current measurement modes for clampmeter. The following table summarizes
the full-scale range of each mode. When ES51918 operate in the current measurement
modes for multimeter, It takes high input from pin IVSH or IVSL, low input from pin
SGND and reference voltage from pin VR. When ES51918 operate in the current
measurement modes for Clampmeter, It takes high input from pin ADP, low input from
pin SGND and reference voltage from pins VA+ and VA-. The test circuits are shown in
page 31.
Mode
Automatic Mode 1
Automatic Mode 2
Manual Mode 1
Range Selection
µA
mA
A
Full Scale
110.00µA / 1100.0µA
11.000mA / 110.00mA
11.000A
Designed for
Multimeter
Multimeter
Multimeter
Manual Mode 2
Manual Mode 3
Manual Mode 4
Manual Mode 5
Manual Mode 6
A
A
A
A
A
1.1000A
11.000A
110.00A
1100.0A
11000A
Clampmeter
Clampmeter
Clampmeter
Clampmeter
Clampmeter
Note:
1. In Manual DC current measurement modes for clampmeter, ES51918 provides Zero function for offset
removing.
2. In Automatic mode1 and Automatic mode2, the pin VBAR is used to control the display of “µ” and
“m” sign on the LCD panel. If pin VBAR is floating or connected to DGND, the “µ” and “m” sign will
be displayed. If pin VBAR is connected to V-, the “µ” and “m” sign will not be displayed.
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ES51918
11,000 Counts Auto DMM
1.4 Capacitance Measurement
The following table summarizes the eight ranges of capacitance measurement mode.
Configuration
C1
C2
C3
C4
C5
C6
C7
C8
Full Scale Range
11.000nF
110.00nF
1.1000uF
11.000uF
110.00uF
1.1000mF
11.000mF
110.00mF
Resistance Ratio
R1‖ R2
R1‖ R3
R4
-
Note:
1. In order to obtain an accurate reading, a capacitor must be discharged before
measurement begins. The chip has a built-in discharge mode to automatically
discharge the capacitor. In discharge mode, the LCD displays dS.C
2. Discharging through the chip is quite slow. We recommend the user to discharge the
capacitor with some other apparatus.
1.5 Continuity Check
Continuity check shares the same configuration with 110.00Ω manual resistance
measurement mode, but with buzzer output to indicate continuity. The buzzer generates a
2KHz sound whenever the digit number is less than 30Ω. In this mode, if SHIFT pin
connect to V-, the least digit will not be displayed and the other digits and decimal point
will shift rightward. So the full scale becomes 110.0Ω instead of 110.00Ω.
1.6 Diode Measurement
Diode measurement mode shares the same configuration with 1.1000V manual voltage
measurement mode.. The buzzer generates a 2KHz sound whenever the digit number is
less than 30mV. In this mode, if SHIFT pin connect to V-, the least digit will not be
displayed and the other digits and decimal point will shift rightward. So the full scale
becomes 1.100V instead of 1.1000V.
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ES51918
11,000 Counts Auto DMM
1.7 Frequency counter
The time base of the frequency counter is derived from an external crystal oscillator by
Tcounter =
4,000,000
Fosc
where Fosc is the frequency of the crystal oscillator. Thus, the counter has a 1-second
time base when a 4MHz oscillator is used. The frequency counter can select the proper
range automatically or manually. Auto-range operation extends over six decades, from
1111.1Hz to 110.00MHz. The following table summarizes the full-scale range of the
frequency counter.
Range
FR11
FR2
FR3
FR4
FR5
FR6
Full Scale
1111.1Hz
11.000KHz
110.00KHz
1.1000MHz
11.000MHz
110.00MHz
NOTE:
1
In the range FR1, if input frequency is less than 11.1Hz, ES51918 will show 0.0Hz.
1.8 Temperature measurement mode
Temperature measurement mode takes input signal from ADP pin and reference voltage
from (VA+ - VA-). ES51918 has a built-in ℃-to-℉ scale translation circuit, and only
needs an external ℃ scale application circuit. The application circuit for ℉ scale is
not required. In temperature measurement mode, the default range is 1100.0 ℃ or ℉.
VBAR pin is used to control the second decimal point (DP2) on the LCD panel. When
VBAR is LOW, DP2 is turned on and the first decimal point (DP1) is turned off.
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1.9 Auto power off and Idle Time selection
ES51918 has a default auto power off function. If the meter is idle for more than the
given Idle Time, the chip automatically turns the power off. The Idle Time to trigger the
auto power off function is determined by pin ‘APOSEL’. If pin APOSEL is connected
to V-, the Idle Time will be set to 30 minutes. If pin APOSEL is connected to DGND or
floating, the Idle Time will be set to 15 minutes. When APO happens, the state of the
meter is saved. The APO sign on the LCD panel indicates whether the auto power off is
enabled or not. In some cases, user might want to disable Auto power off. There are
two ways to disable this feature as following:
1. Power on the meter when any of the push functions, except for HOLD, is pressed
down.
2. In addition, when RS232 output is active, the auto power off function is also
disabled.
Note: Powering on the meter while pressing HOLD and lasts 2 seconds turns on all
LCD segments until HOLD is pressed again.
1.10 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.
1.11 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.
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11,000 Counts Auto DMM
2
Measurement Mode Switching
Measurement mode depends on the logic level of SLACDC, FC1, FC2, FC3, FC4, FC5,
and KEY. When FC5 is high, the measurement mode list is below
SLACDC
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
X
FC1
1
1
1
0
1
1
1
1
1
0
0
0
0
0
0
1
1
1
0
1
1
1
1
1
0
0
0
0
0
0
0
FC2
0
1
1
0
1
1
0
0
0
0
0
1
0
1
1
0
1
1
0
1
1
0
0
0
0
0
1
0
1
1
1
FC3
1
0
1
0
1
0
0
1
0
1
0
1
1
1
0
1
0
1
0
1
0
0
1
0
1
0
1
1
1
0
0
FC4
1
1
1
0
0
0
0
0
1
1
1
1
0
0
0
1
1
1
0
0
0
0
0
1
1
1
1
0
0
0
1
Mode
Voltage Measurement
Auto DC Current Measurement(µA)
Auto DC Current Measurement(mA)
11A DC Current Measurement(A)
Manual DC 1.1000A
Manual DC 11.000A
Manual DC 110.00A
Manual DC 1100.0A
Manual DC 11000A
Resistance Measurement
Continuity Check
Resistance Measurement
Frequency Measurement
Capacitance Measurement
Temperature Measurement
Voltage Measurement
Auto AC Current Measurement(µA)
Auto AC Current Measurement(mA)
11A AC Current Measurement(A)
Manual AC 1.1000A
Manual AC 11.000A
Manual AC 110.00A
Manual AC 1100.0A
Manual AC 11000A
*ADP0
*ADP1
*ADP2
*ADP3
*ADP4
Temperature Measurement
Resistance Measurement
Function of KEY
DCV ↔ ACV
DCA ↔ ACA
DCA ↔ ACA
DCA ↔ ACA
DCA ↔ ACA
DCA ↔ ACA
DCA ↔ ACA
DCA ↔ ACA
DCA ↔ ACA
Ω ↔ Continuity
Continuity ↔ Diode
Ω ↔ Continuity ↔ Diode
—
—
℃ ↔ ℉
ACV ↔ DCV
ACµA ↔ DCµA
ACmA ↔ DCmA
ACA ↔ DCA
ACA ↔ DCA
ACA ↔ DCA
ACA ↔ DCA
ACA ↔ DCA
ACA ↔ DCA
—
—
—
—
—
℉ ↔ ℃
Ω ↔ Diode
X means “don’t care”.
*When FC5 is high, the ADP0, ADP1, ADP2, ADP3 and ADP4 modes can display minus sign.
Note1: The Manual DC/AC 1.1A, 11A, 110A, 1100A and 11000A modes are designed for clampmeter.
Note2: The 11A DC And 11A AC Current Measurement modes, (FC1~4) = (0, 0, 0, 0), are designed for
multimeter.
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11,000 Counts Auto DMM
When FC5=low, KEY is disabled and the measurement mode list is below.
SLACDC
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
X
FC1
1
1
1
0
1
1
1
1
1
0
0
0
0
0
0
1
1
1
0
1
1
1
1
1
0
0
0
0
0
0
0
FC2
0
1
1
0
1
1
0
0
0
0
0
1
0
1
1
0
1
1
0
1
1
0
0
0
0
0
1
0
1
1
1
FC3
1
0
1
0
1
0
0
1
0
1
0
1
1
1
0
1
0
1
0
1
0
0
1
0
1
0
1
1
1
0
0
FC4
1
1
1
0
0
0
0
0
1
1
1
1
0
0
0
1
1
1
0
0
0
0
0
1
1
1
1
0
0
0
1
Mode
DC Voltage Measurement
Auto DC Current Measurement(µA)
Auto DC Current Measurement(mA)
11A DC Current Measurement(A)
Manual DC 1.1000A
Manual DC 11.000A
Manual DC 110.00A
Manual DC 1100.0A
Manual DC 11000A
Resistance Measurement
Continuity Check
Diode Measurement
Frequency Measurement
Capacitance Measurement
Temperature Measurement (℉)
AC Voltage Measurement
Auto AC Current Measurement(µA)
Auto AC Current Measurement(mA)
11A AC Current Measurement(A)
Manual AC 1.1000A
Manual AC 11.000A
Manual AC 110.00A
Manual AC 1100.0A
Manual AC 11000A
*ADP0
*ADP1
*ADP2
*ADP3
*ADP4
Temperature Measurement (℃)
Resistance Measurement
X means “don’t care”.
*When FC5 is low, the ADP0, ADP1, ADP2, ADP3 and ADP4 modes can not display minus sign.
Note1: The Manual DC1.1A/11A/110A/1100A/11000A modes are designed for clampmeter.
Note2: The 11A DC Current Measurement mode, (FC1~4) = (0, 0, 0, 0), is designed for multimeter.
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3
Push function
All the enabled push functions will be reset when the measurement mode is changed by
rotary switch. Change measurement mode by KEY function will reset enabled Range,
Hold, Max/Min, REL, Zero and Peak functions. The following table lists the available
function versus measurement mode.
Function
Mode
Range
Hold
Max/Min
REL
Zero
Peak
VAHz
Voltage
O
O
O
O
X
O
O
Current1
O
O
O
O
X
O
O
Current2
X
O
O
AC
DC
O
O
Resistance
O
O
O
O
X
X
X
Capacitance
O
O
O
O
X
X
X
Frequency
O
O
O
O
X
X
X
Continuity
X
O
O
O
X
X
X
Diode
X
O
O
O
X
X
X
Temperature
X
O
O
O
X
X
X
ADP
X
O
O
O
X
O
X
Note:
Current1 includes Auto µA, Auto mA and 11A modes.
Current2 includes Manual 1.1A, 11A, 110A, 1100A and 11000A modes.
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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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
Manual
Mode
1 push > 1 sec
Range up
1 push < 1 sec
Measurement Mode
Auto
V(DC/AC)
VR2 – VR5
Auto µA(DC/AC)
R1 – R2
Auto mA(AC/DC)
R1－R2
11 A(DC/AC)
fixed
Ω
OR1 - OR7
Capacitance
C1 – C8
Continuity
Diode
fixed
fixed
Frequency
FR1 – FR6
Manual
Control Range
Initial Range
VRi → VRi + 1,
110.00mV – 1100.0V
1.1000V
VR5 → VR1
R1 → R2,
110.00µA – 1100.0µA 110.00µA
R2 → R1
R1 → R2
11.000mA – 110.00mA 11.000mA
R2 → R1
fixed
11.000A
11.000A
ORi → ORi + 1,
110.00Ω – 110.00MΩ
110.00Ω
OR7 → OR1
Ci → Ci + 1,
11.000nF – 110.00mF
11.000nF
C8 → C1
fixed
110.00Ω
110.00Ω
fixed
1.1000V
1.1000V
FRi → FRi + 1
1111.1Hz – 110.00MHz 1111.1Hz
FR6 → FR1
Note: Pushing RANGE resets all existing special modes.
3.3 KEY
See Section “Measurement Mode Switching” for the function of this pin.
3.4 REL + HOLD
In REL mode, the LCD panel displays DN+K - DN, where DN = 1, 2, 3, … , DN is the last
value before REL is pushed, and DN+K is the current value. If REL is pushed again in
REL mode, the meter displays the reference value. The meter returns to normal
operation if REL is pressed and held for longer than one second. Pressing HOLD in
REL mode makes the meter stop updating the LCD panel.
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11,000 Counts Auto DMM
1 push < 1s
Original State
(Auto/Manual)
1 push > 1s
1 push < 1s
〝REL〞active.
The relative value
1 push > 1s
〝REL〞blink.
The DN value
push HOLD
push HOLD
〝REL〞and〝H〞active.
Hold the relative value
〝REL〞and〝H〞blink.
1 push < 1s
The DN value
Note: It’s possible that the relative value exceeds 11,000 or –11,000 counts, but never
exceeds 19,999 or –19,999 counts. Such relative values are displayed. The LCD shows
OL in REL mode only if DN or DN+K is more than 10,999 counts or the relative value is
more than 19,999.
3.5 Max/Min + HOLD
The meter displays the maximum or minimum value of the input in Max/Min mode.
When Max/Min is pressed for the first time, the meter displays the maximum value.
When Max/Min is pressed again, the meter displays the minimum value. When
Max/Min is pressed for the third time, the meter displays current value. The meter
returns to normal operation if Max/Min is pressed and held for longer than one second.
Pressing HOLD in Max/Min mode makes the meter stop updating the maximum or the
minimum value.
1 push<1s
Original state
(Automatic/manual)
1 push>1s
1 push>1 sec
1 push>1 sec
“MAX” active 1push<1s “MIN” active 1push<1s “Max” “MIN” blink
min value
current value
max value
Push HOLD
1push<1s
Push HOLD
Push HOLD
“MAX”“MIN” “H” blink
“MIN” “H” active
“MAX” “H” active
hold max value. 1push<1s hold min value. 1push<1s hold current value.
1push<1s
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11,000 Counts Auto DMM
3.6 Relative + Max/Min + HOLD
Max/Min mode can be nested in REL mode. The meter displays the maximum or
minimum value relative to the reference when Max/Min is pressed in REL mode.
Pressing HOLD under REL + Max/Min makes the meter stop updating the LCD panel.
Original State
(Auto/Manual)
1 push < 1s
1 push >1s
〝REL〞active.
〝REL〞blink.
The relative value
The DN value
1 push < 1s
push Max/Min
push Max/Min > 1s
〝REL〞and〝Max〞active.
〝REL〞and〝Min〞active.
〝REL〞〝Max〞〝Min〞
Maximum relative value
Minimum relative value
blink. The DN value
1 push < 1s
1 push < 1s
push HOLD
push HOLD
〝REL〞,〝Max〞,
〝H〞active.
Hold max. rel. value
〝REL〞,〝Min〞,
1 push < 1s
〝REL〞,〝Max〞,
〝H〞active.
Hold min. rel. value
push HOLD
〝Min〞,〝H〞blink.
1 push < 1s
The DN value
1 push < 1s
3.7 Zero : In manual DC 1.1000A, 11.000A, 110.00A, 1100.0A and 11000A
measurement modes, the REL_ZERO pin changes to control Zero function instead of
relative function. In Zero mode, the LCD panel displays DN+K - DN, where DN = 1, 2,
3, … , DN is the last conversion value before Zero is pushed, and DN+K is the current
conversion value. If Zero is pushed again in Zero mode, the meter will refresh the DN
value and displays the DN+K - DN again. The meter returns to normal operation if Zero is
pressed and held for longer than one second. Pressing HOLD in Zero mode makes the
meter stop updating the LCD panel. In Zero mode, LCD will not show any symbol to
remind users of Zero mode is active.
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11,000 Counts Auto DMM
State diagram for Zero mode:
Original State
Press Zero
Press Zero > 1s
‘Zero’ Active
Press Zero < 1s
Show DN+K - DN
State diagram for Zero + HOLD mode:
Original State
Press Zero
Press Zero > 1s
‘Zero’ Active
Press Zero < 1s
Show DN+K - DN
Press Hold
‘Zero’ ‘Hold’ Active
Stop LCD upgrading
State diagram for Zero + Max/Min + HOLD mode:
Original State
Press Zero
Press Zero > 1s
‘Zero’ Active
Press Zero < 1s
Show DN+K - DN
Press Max/Min
Press Max/Min > 1s
‘Zero’ ‘Max’ Active
‘Zero’ ‘Min’ Active
Show Max. DN+K - DN Value
Show Min. DN+K - DN Value
Press HOLD
Press Max/Min < 1s
‘Zero’ ‘Max’ ‘Hold’ Active
Hold Max. DN+K - DN Value
Press HOLD
‘Zero’ ‘Min’ ‘Hold’ Active
Hold Min. DN+K - DN Value
Press Max/Min < 1s
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3.8 Peak + HOLD
Peak mode takes input from Pmax or Pmin pin. The peak values are stored in external
capacitors. Polyster mylar capacitors are recommended. The precision of Peak mode
measurement can be enhanced by calibration. Calibration for Peak mode is invoked by
pressing Peak bottom for more than 2 seconds. Entering Peak mode will automatically
execute peak calibration, if peak calibration was never done before. The Calibration
process measures and stores the offset voltage of internal operation amplifiers. High
precision is achieved by substracting this offset from reading. When power off the
ES51918 or switch the measurement mode to temperature mode, the calibrated offset
value will be cleared. ES51918 will automatically execute peak calibration, if peak
mode was activated again after the calibrated offset value was cleared.
CALIBRATION
Done
No
CALIBRATION
1 push > 2 s
1 push > 2 s
End
Original State
(Auto/Manual)
1 push > 1 s
1 push < 1 s
Already calibrated
Yes
〝Pmax〞active.
Max. Peak Value
1 push < 1 s
〝Pmin〞active.
Min. Peak Value
push HOLD
push HOLD
〝Pmax〞
〝HOLD〞
,
active.
〝Pmin〞
〝HOLD〞
,
active.
push
<
1
s
1
Max. Peak Value
Min. Peak Value
4
Serial Data Output
The RS232 function will be activated if the RS232 pin is pulled to and asserts at V-.
The serial data sent to SDO pin once 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
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11,000 Counts Auto DMM
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
LSB is sent first and the MSB is sent last.
single package
0V
-3V
D0 ~D6
0
LSB
p
P 1
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
p 1 0
0
range
p 1 0
digit3
p 1 0
0
digit1
p 1 0
option1
p 1 0
CR
p 1
function
digit0
status
0
digit2
p 1 0
p 1 0
0
p 1
p 1
option2
p 1
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.
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11,000 Counts 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-FC5 switch.
Code
0111011
0111101
0111111
0110000
0111001
0110011
0110101
0110001
0110010
0110110
0110100
0111110
Measurement Mode
Voltage
Auto µA Current
Auto mA Current
11 A current
Manual A Current
Ω
Continuity
Diode
Frequency
Capacitance
*Temperature
ADP
*The judge bit in the Status packet determines whether the unit is Celsius or Fahrenheit.
4.2 RANGE
This packet indicates the full-scale range of the meter. When the meter operates in
continuity mode or diode mode, this packet is always 0110000 since the full-scale
ranges in these modes are fixed. The following table lists the code for each range in
each measurement mode.
Code
0110000
0110001
0110010
0110011
0110100
0110101
0110110
0110111
v1.02
V
Auto mA Auto µA 11 A
1.1000V 11.000mA 110.00µA
11.000V 110.00mA 1100.0µA 11.000 A
110.00V
1100.0V
110.00mV
Manual A
1.1000A
11.000A
110.00A
1100.0A
11000A
24
ADP
ADP4
ADP3
ADP2
ADP1
ADP0
Ω
Frequency
110.00Ω 1111.1Hz
1.1000KΩ
11.000KΩ 11.000KHz
110.00KΩ 110.00KHz
1.1000MΩ 1.1000MHz
11.000MΩ 11.000MHz
110.00MΩ 110.00MHz
Capacitor
11.000nF
110.00nF
1.1000µF
11.000µF
110.00µF
1.1000mF
11.000mF
110.00mF
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11,000 Counts Auto DMM
4.3 DIGIT 3 – DIGIT 0
Digit 3 is the second significant digit on the LCD panel, and digit 0 is the least
significant digit.
Digit
0
1
2
3
4
5
6
7
8
9
Code
0110000
0110001
0110010
0110011
0110100
0110101
0110110
0110111
0111000
0111001
Note:
1. The RS232 code of digit4 is in the packet OPTION1
2. 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 package 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 °F and is 0 of the unit is °C. Sign field indicates whether the minus sign on the
LCD panel is on or off. BATT field is one when battery low condition is true. OL
indicates input overflow.
0
BIT6
1
BIT 5
1
BIT 4
Judge
BIT 3
Sign
BIT 2
BATT
BIT1
OL
BIT 0
1
BIT 5
1
BIT 4
UL
BIT 3
PMAX
BIT 2
PMIN
BIT1
Digit4
BIT 0
4.5 OPTION 1
0
BIT 6
UL field will be 1, only when input frequency is less than 11.1Hz in FR1 range of
frequency mode.
If PMAX field is 1, PMAX is active and LCD panel display maximum peak value.
If PMIN field is 1, PMIN is active and LCD panel display minimum peak value.
The digit4 field will be 1, when the MSD on the LCD is one.
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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.
0
BIT 6
1
BIT 5
1
BIT 4
DC
BIT 3
AC
BIT 2
AUTO
BIT 1
VAHZ
BIT 0
4.7 CR
Carriage returns. The transmitted code is 0001101.
4.8 LF
Line feed. The transmitted code is 0001010.
5
Miscellaneous
The conditions on which the meter turns on the buzzer include:
(1) Changing measurement mode generates one beep.
(2) Pressing any of the push functions 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 30Ω(30mV)
(6) Auto power off generates a 2KHz beep which lasts for 1.5 seconds.
The following figures show the output waveform from the BUZOUT pin.
0.5 mS
(a) Continuous 2KHz beep
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0.15 sec
0.3 sec
(b) 3.33 beep/sec
5.1 LCD Panel
S1 S2
S3
S4 S5
S6S7
S12 S17
S8 S9S10 S11 S15
BATT AUTO MANU HOLD
BP1
S18 S13
S16 S14
REL MAX MIN
PMAX PMIN
APO
DC
℉
n µ1
µ2 m2
M K
BP2
AC
BP3
BP4 RS232
℃
m1 F
V A
Ω Hz
SEG01 SEG02 SEG03 SEG04 SEG05 SEG06 SEG07 SEG08 SEG09
BP1
APO
BATT AUTO
BP2
-
DC
F4
BP3
AC
BC5
BP4 RS232
MANU
A3
B3
HOLD
A2
A4
B4
F3
G3
F2
B2
E4
G4
C4
E3
C3
E2
G2
DP4
D4
DP3
D3
DP2
D2
C2
SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18
BP1
µ2
BP2
F1
A1
B1
m2
V
BP3
E1
G1
C1
K
A
BP4
DP1
D1
M
Ω
Hz
℉
REL
PMAX
n
℃
MAX
PMIN
µ1
MIN
m1
F
Note: The MSD on LCD panel will not shows Zero
v1.02
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ES51918
11,000 Counts Auto DMM
LCD Backplane Waveform
V- +3.2
V- +3.1
VV-
V- +3.2
V- +3.1
VV-
V- +3.2
V- +3.1
VV-
V- +3.2
V- +3.1
VV-
V- +3.2
V- +3.1
V-
5.2 LCD display on condition
LCD Annunciator
V
A
Ω
F
Hz
DC
AC
AUTO
MANU
HOLD
REL
MAX / MIN
PMAX / PMIN
m1
µ1
n
m2
µ2
M
K
℃
℉
APO
RS232
v1.02
Condition
In voltage measurement mode, and diode measurement mode.
In current measurement mode.
In resistance measurement mode, and continuity mode.
In capacitance measurement mode.
In continuity check mode.
In diode mode.
In frequency mode.
In DC voltage or DC current mode.
In AC voltage or AC current mode.
When automatic full scale range selection is enabled.
In manual mode.
When HOLD function is enabled.
When Relative function is enabled.
When Maximum or Minimum function is enabled.
When PMAX or PMIN function is enabled.
In capacitor measurement mode and the full scale range is in the order of mF.
In capacitor measurement mode and the full scale range is in the order of µF.
In capacitor measurement mode and the full scale range is in the order of nF.
In voltage or current measurement mode and the full scale range is in the order of 10-3.
In current measurement mode and the full scale range id in the order of µA.
In resistance measurement mode and the full scale range is in the order of MΩ
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 ℉
When auto power off function is enabled.
When RS232 output is enabled.
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11,000 Counts Auto DMM
5.3 Operating Timing
ES51918 incorporates a dual slope ADC with four phases: ZI, AZ, INT and DINT.
The timing of each phase are listed below.
*Voltage /Current /ohm /ADP measurement:
Phase
ZI
AZ
INT
DINT
Time
20ms
20ms
100ms
110ms
P.S. In the DC voltage and ohm measurement with auto mode, if the range is
changed, the internal clock rate will increase five times and the new measurement
cycle becomes 1/5 times of the original cycle until the range is stable.
*Continuity/diode measurement
Phase
ZI
AZ
INT
DINT
Time
4ms
4ms
20ms
22ms
*Capacitance measurement:
Range
11.000nF
110.00nF
1.1000uF
11.000uF
110.00uF
1.1000mF
11.000mF
110.00mF
Total Measurement Time
0.25sec
0.25sec
0.25sec
0.25sec
0.5sec
1.0sec
2.5sec
12.5sec
*Frequency measurement
In range FR1, the measurement cycle = 0.5 sec
In range FR2~FR6, the measurement cycle = 1.05 sec
P.S. In the frequency 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.
v1.02
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ES51918
11,000 Counts Auto DMM
6
Test Circuit
1. Voltage test
4. Current test
AGND
OVSG
99.5
1K
10K
101K
1.111M
D2
D1 1.0u
4.7u
1.0u
OR1
VR5
VR4
VR3
VR2
ADO
88M
6.2K
7.5K
mA
9
2K
V
R
100K
uA
uA
mA
uA
V
R
1
mA
90
A
AGND
SGND
10A
0.99
ADI
ACVL
ACVH
TEST5
0.1u
7.5K
0.01
IVSH
100K
IVSL
900
5. Diode test
10M
AGND
-100mV
Voltage input
OVH
100
Z1
6V
Z2
PTC
1.5K
2. Resistor test
VR1
10M
OVX
PTC
1.5K
VR2
1.111M
OHMC
47n
OVSG
6. Low battery
OVH
OVSG
100
Z1
6V
Z2
99.5
1K
10K
101K
1.111M
OR1
VR5
VR4
VR3
VR2
9V
BA
680K
LBAT9
TT
SGND
AGND
270K
0.1u AGND
V-
0V
3. Current test for clamp meter
8. Frequency test
7. ADP test
F
R
E
Q
VA+
-100mV
RL
VR
100K
R
+
Vref
-
v1.02
ADP
SGND
AGND
VA-
ADPin+
ADPin-
ADP
100K
2.2u
SGND
AGND
VA+
200
PTC
1.5K
Fin
VA-
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ES51918
11,000 Counts Auto DMM
7. Application Circuit
5.6V ZI
7.5V ZI
+
V-
3V
+
10µ
0.1µ
10µ
0.1µ
0.47µ
4M
µA/mA
µA
900
mA
mA 90
0.1µ
V+
V+
CREF+
D2 4.7µ
+
VR (30)
100K
10M
ADP
10n
PMAX
10n
PMIN
100K
10K
VBAR
(35) VR1
SGND
ADP
VAVA+
1µ
Cp
C
1µ
+
V-
(50) SEG17
SEG18
BKLIT
SHIFT
RS232
200 2.2µ
(45) FREQ
SLEEP
47n
OHMC
CA+
CA- 470n
(40) R1K
R9K
91K
ADOHZ
OPO (25)
OPIN+
OPINPWD
VRH
5.6V ZI
LCD display
ES51918
D1
(80) RANGE
HOLD
REL_ZERO
PEAK
VAHZ
(75) MAX/MIN
BKOUT
BUZOUT
BUZIN
ANNUNC
(70) BP1
BP2
BP3
BP4
SEG01
(65) SEG02
SEG03
SEG04
SEG05
SEG06
(60) SEG07
SEG08
SEG09
SEG10
SEG11
(55) SEG12
SEG13
SEG14
SEG15
SEG16
...
CREFCINT (5)
mA
CAZ
9
BUFF
RAZ
10A 0.99
10A
IVSH
IVSL (10)
0.01
SGND
OVX
100 OVH
220p
OVSG
Ω
1.5K
OR1
PTC
99.5
VR5 (15)
1K
10K VR4
V/Ω/
VR3
101K
VR2
1.111M
6K
TEST5
ACVL (20)
2K
ACVH
0.1µ
ADI
7.5K 1µ
1µ +
ADO
7.5K
+ 88M
100n
470n
90k
30k
100K
100K
100K
OSC1
OSC2
APOSEL
OLSEL
NC (85)
KEY
SLACDC
FC5
FC4
FC3 (90)
FC2
FC1
LBAT9
SDO
C+ (95)
µA
CV-
DGND
AGND
AGND (100)
µA
9K
1K
V-
1.5K
PTC
Hz
Notes:
1. Most of pins are protected by the ESD protection circuits. However pins, V+, V-, AGND, DGND and
VR1 are not protected enough because the parasitic effect must be decrease. Therefore enough external
protection is needed for assembling, carrying and keeping. In addition, components connecting to these
unprotected pins have to be soldered on board before the IC is soldered.
2. Cp is the compensation capacitor for measuring capacitance. Its value depends on the parasitic
capacitor on the PCB board.
3. Light shielding for the diodes and Zeners.
v1.02
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ES51918
11,000 Counts Auto DMM
8. Package
1
100 Pin QFP Package
W
A
L
b
a
θ
B
2
D
C
d
Dimension Parameters
Symbol
W
L
A
B
C
d
a
D
θ
v1.02
Min.
Milimeter
Typ. Max.
Min.
19.90 20.00 20.10 783.5
13.90 14.00 14.10 547.2
0.425
0.20 0.30 0.40
7.9
0.65
1.05 1.20 1.35 41.3
2.57 2.72 2.87 101.2
2.50
o
0
10o
32
Mill
Typ.
787.4
551.2
16.7
11.8
25.6
47.2
107.1
98.4
Max.
791.3
551.2
11.8
47.2
107.1
05/06/30