ES237 6000 Counts DMM

ES237
6000 Counts DMM
Features
＊ Back Light function

6,000 counts LCD display with 31 analog bar-graph
＊ KEY function

LQFP 128L package
＊ Data Hold and delayed-hold function

3V DC power supply
＊ Range change function

Slow ADC Conversion rate : 3 times/s
＊ Semi-auto calibration operation

Bar-graph ADC conversion rate : 30 times/s

Full automatic measurement
(Taiwan patent no.: 367334)

(Taiwan patent no.: 362409)
＊ Voltage measurement : 600.0mV, 6.000V – 1000V
＊ Current measurement : μA/mA/A

Band-gap reference voltage output
＊ Frequency with Voltage or Current :

Voltage overflow selection ( DC / AC : 1010V, DC /
＊ Resistance measurement :
AC : 610V)
60.00Ω – 60.00MΩ

Serial data output ( RS232 format )

LCD segment check when power on
6.000nF – 60.00mF

Auto power off ( 30min / 15min )
( Taiwan patent no.: 323347, 453443 )

Sleep state indicative signal output

Re-power on

On-chip buzzer driver

Low battery detection
＊ Capacitance measurement :
＊ Capacitance measurement for Clampmeter mode :
6.000nF – 60.00mF
＊ Smart auto check for R / S / D / C mode
Resistance : 0.0Ω – 6.000MΩ

Capacitance : 0.500nF – 600.0uF
(Taiwan patent no.: 326361)
＊ Not contact AC electric field detection
＊ Frequency counter :
600.0Hz – 60.00MHz
＊ Duty cycle measurement :
5% – 95% (< 10kHz)

Diode measurement & continuity check

Hazardous AC/DC voltage (HV) indication

4 ADP modes with external reference voltage and
independent “ADP” user-defined segment on LCD
Temperature mode with internal scale translation
circuit from 0C to 0F

K-type thermocouple reference table compensation
(-200 ~ 1350oC range)

Description
ES237 is an integrated analog-to-digital converter
with 6,000-count LCD with bar-graph display,
automatic range selection, and 3V DC power
supply. Automatic range selection is provided for
ACV/DCV measurement, resistance measurement,
current measurement, capacitance measurement,
and frequency counter. Expensive and bulky
mechanical range switches are not required. Other
features include relative value display, offset
removing feature for DCA clamp mode, data
holding, maximum and minimum value holding,
duty cycle measurement, diode measurement,
temperature measurement, continuity checking,
low battery detection, auto power off, re-power on,
backlight driver, buzzer driver and RS232 data
output.
(Buz. On when R < 30Ω)

Low pass filter mode for ACA/ACV measurement
Push functions :
＊ VAHz function
＊ MAX/MIN function
＊ Relative function
＊ Zero function: DCA clampmeter only
V 2.1
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24
25
26
27
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31
32
33
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38
102
101
100
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69
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Digital multimeter

Clamp meter
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
V 2.1
NC
HZ
MMX
REL
BKLIT
KEY
HOLD
RANGE
FC5
FC4
FC3
FC2
FC1
SLACDC
CN
CP
LBAT9
VVV+
V+
DGND
AGND
AGND
NC
NC
RSOUT
OSC1
OSC2
RS232
VBAR
APOSEL
VST
TSEL
DIS
SEL1
SEL2
CESEL
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
SEG24
SEG25
SEG26

IVS
ADP
TEMPin
CLAMPin
CHP
CHN
CIH
BUFH
CAZH
CLN
CLP
CIL
CAZL
BUFL
RAZ
VRH
DACO
VR_CLAMP
VR_ADP
OHMC4
OHMC3
OHMC2
OHMC1
OVSG
OR1
VR5
VR4
VR3
VR2
ACVL
ACVH
ADI
ADO
TEST5
SGND
VR1
mVin
LPFout
ES237
6000 Counts DMM
Application
Pin Assignment
 128L LQFP package
Cyrustek.
com.tw
ES237
2
SEG27
SEG28
SEG29
BP1
BP2
BP3
BP4
ALARM
ALARM1
BKOUT
BZOUT
SCLP
SDAP
CALENP
FREQ
SLEEP
OVH1
OVH
OVX
R1K
R10K
CAP
CAN
LPC3
LPC2
LPC1
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
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ES237
6000 Counts DMM
Pin Description
Pin No
Symbol
Type
1
IVS
I
Measurement input in uA/mA current mode.
2
ADP
I
Measurement input in ADP mode.
3
TEMPin
I
Measurement input in Temperature mode.
4
CLAMPin
I
Current measurement input in CLAMP mode.
5
CHP
I/O
Positive connection for reference capacitor of high-speed A/D.
6
CHN
I/O
Negative connection for reference capacitor of high-speed A/D.
7
CIH
O
High-speed integrator output. Connect to integral capacitor.
8
BUFH
O
High-speed buffer output pin. Connect to integral resistor.
9
CAZH
O
High-speed auto-zero capacitor connection.
10
CLN
I/O
Negative connection for reference capacitor of high-resolution A/D.
11
CLP
I/O
Positive connection for reference capacitor of high- resolution A/D.
12
CIL
O
High-resolution integrator output. Connect to integral capacitor. (Metalized
Polypropylene Film Capacitor type is recommended)
13
CAZL
O
High-resolution auto-zero capacitor connection.
14
BUFL
O
High-resolution buffer output pin. Connect to integral resistor
15
RAZ
O
Buffer output pin in AZ and ZI phase.
16
VRH
O
Output of band-gap voltage reference. Typically –1.23V.
17
DACO
O
Output of band-gap voltage reference. Typically –400 m V.
18
VR_CLAMP
I
Reference input voltage connection. Typically –400 mV.
19
VR_ADP
I
Reference input voltage connection. Typically –400mV.
20
OHMC4
O
Filter capacitor connection for resistance mode.
21
OHMC3
O
Filter capacitor connection for resistance mode.
22
OHMC2
O
Filter capacitor connection for resistance mode.
23
OHMC1
O
Filter capacitor connection for resistance mode.
24
OVSG
O
Sense low voltage for resistance/voltage measurement
25
OR1
O
Reference resistor connection for 60.00/600.0Ω range
26
VR5
O
Voltage measurement ÷10000 attenuator(1000V)
27
VR4
O
Voltage measurement ÷1000 attenuator(600.0V)
28
VR3
O
Voltage measurement ÷100 attenuator(60.00V)
29
VR2
O
Voltage measurement ÷10 attenuator(6.000V)
30
ACVL
I
31
ACVH
I
32
ADI
I
Negative input of internal AC to DC OP Amp.
33
ADO
O
Output of internal AC to DC OP Amp.
34
TEST5
O
Buffer output of OVSG.
35
SGND
I
Signal Ground input.
36
VR1
I
Measurement Input. Connect to a precised 10MΩ resistor.
V 2.1
Description
Rectified signal low input in ACV/ACA mode. Connect to negative output of
external AC to DC converter.
Rectified signal high input in ACV/ACA mode. Connect to positive output of
external AC to DC converter.
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ES237
6000 Counts DMM
Pin Description ( Continued )
Pin No
Symbol
Type
37
mVin
I
Measurement input in 600.0mV mode.
38
LPFout
O
Capacitor C1 connection for internal low-pass filter.
39
LPC1
O
Capacitor C1 connection for internal low-pass filter.
40
LPC2
O
Capacitor C2 connection for internal low-pass filter.
41
LPC3
O
Capacitor C3 connection for internal low-pass filter.
42
CAN
I/O
Negative auto-zero capacitor connection for capacitor measurement.
43
CAP
I/O
Positive auto-zero capacitor connection for capacitor measurement.
44
R10K
O
Connect to a precised 10KΩ resister for capacitor measurement.
45
R1K
O
Connect to a precised 1KΩ resister for capacitor measurement.
46
OVX
I
Sense input for resistance / capacitance measurement.
47
OVH
O
Output connection for resistance measurement.
48
OVH1
O
Output connection for resistance measurement. (Optional)
49
SLEEP
O
Sleep mode indicator, asserts low in SLEEP mode.
50
FREQ
I
Frequency counter input, offset V-/2 internally by the chip.
51
CALENP
I
Pulled to V- to enable the calibration scheme.
52
SDAP
I/O
53
SCLP
O
Output to EEPROM 24LC02 clock.
54
BZOUT
O
Outputs a 2KHz audio frequency signal for driving piezoelectric buzzer
55
BKOUT
O
If BKLIT function is enabled, this pin will change from V- to V+. Once press
BKLIT pin again within 300 sec, this pin will change back to V-.
56
ALARM1
O
Short circuit indication output.
57
ALARM
O
HV signal detection in Voltage mode and EF mode indication output.
58
BP4
O
LCD backplane 4.
59
BP3
O
LCD backplane 3.
60
BP2
O
LCD backplane 2.
61
BP1
O
LCD backplane 1.
62 - 90
SEG29 - SEG01
O
LCD segment line 01 – 29.
91
CESEL*
I
Voltage OL selection feature control pin. (1010V/610V)
92
SEL2*
I
Diode OL level and HV indication selection pin.
93
SEL1*
I
Set current mode OL level selection pin. (DMM or Clamp mode)
94
DIS*
I
Control warning buzzer output at LPF and HV mode
95
TSEL*
I
96
VST*
I
97
APOSEL
I
98
VBAR
I
V 2.1
Description
Input / Output from to EEPROM 24LC02 data.
Temperature mode controls the automatic mode or manual mode and enable or
disable input terminal symbol displayed on the LCD panel selection pin.
Enable the auto range voltage mode to start from 600.0V or disable ADP input
terminal symbol displayed on the LCD panel selection pin.
Idle time selection for auto power off feature.
In µA or mA modes, it is used to control the ‘µ’ or ‘m’ sign.
Set to V- to enable clamp current mode.
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ES237
6000 Counts DMM
Pin Description ( Continued )
Pin No
Symbol
Type
Description
99
RS232
I
Assert low (V-) to make serial data output function not available.
100
OSC2
O
Crystal oscillator output connection.
101
OSC1
I
Crystal oscillator input connection.
102
RSOUT
O
Serial data output.
103
NC
-
Not connected
104
HZ
I
Pulse to V- to enable VAHZ mode or duty cycle measurement in Freq. mode.
105
MMX
I
Pulse to V- to enable MAX/MIN function.
Pulse to V- to enable/disable Relative function or Zero function. Pulse to V-
106
REL
I
larger than one second to enable RS232 output. When RS232 output is enabled,
the APO will be disabled automatically.
107
BKLIT
I
Back light function. Pulse low to set BKOUT pin output.
108
KEY
I
Pulse to V- to change mode.
109
HOLD
I
110
RANGE
I
Pulse to V- to enable manual mode and manual range selection.
111
FC5
I
Switch 5 for function selection.
112
FC4
I
Switch 4 for function selection.
113
FC3
I
Switch 3 for function selection.
114
FC2
I
Switch 2 for function selection.
115
FC1
I
Switch 1 for function selection.
116
SLACDC
I
Select initial DC/AC state.
117
CN
O
Negative capacitor connection for on-chip DC-DC converter.
118
CP
O
Positive capacitor connection for on-chip DC-DC converter.
119
LBAT9
I
Multi-level low battery configuration input. Simple external resistor divider is
required.
120
V-
P
Negative supply voltage.
121
V-
P
Negative supply voltage.
122
V+
O
Output of on-chip DC-DC converter.
123
V+
O
Output of on-chip DC-DC converter.
124
DGND
P/G
Digital ground.
125
AGND
P/G
Analog ground.
126
AGND
P/G
Analog ground.
127
NC
-
Not connected
128
NC
-
Not connected
Pulse to V- to enable HOLD function. Pulse to V- larger than one second to
enable Delayed Hold function.
Note: Pin91-Pin96 are 4-level logic definition: (V+/DGND/Floating/V-), see section Operation mode
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ES237
6000 Counts DMM
Absolute Maximum Ratings
Characteristic
Rating
Supply Voltage (V- to AGND)
-4V
Analog Input Voltage
V- -0.6 to V+ +0.6
V+
V+ ≥ (AGND/DGND+0.5V)
AGND/DGND
AGND/DGND ≥ (V- -0.5V)
Digital Input
V- -0.6 to DGND +0.6
Power Dissipation. Flat Package
500mW
Operating Temperature
-20℃ to 70℃
Storage Temperature
-45℃ to 125℃
Electrical Characteristics
Parameter
Power supply
Symbol
Voltage roll-over error
VIDD
ISS
REV
Voltage nonlinearity
NLV
Operating supply current In
DCV mode
Test Condition
Normal operation
In sleep mode
10MΩ input resistor
Best case straight line
CIL=MPR capacitor
Min.
Typ.
Max
Units
2.4
—
—
—
-3.0
1.8
—
—
3.3
2.5
10
±0.1
V
mA
µA
%F.S1
—
—
±0.1
%F.S1
Zero input reading
10MΩ input resistor
-000
000
+000
counts
Band-gap reference voltage
100KΩ resistor between
VRH and AGND
-1.30
-1.23
-1.16
V
—
-3.0
—
V
-1.19
-1.08
-0.97
V
-3.5V≤ V ≤-2.2V
3.0
3.1
3.2
V
Between V- pin and
HOLD, RANGE, KEY,
FC1-FC5, BKLIT,
—
1.2
—
µA
Between V- pin
and RS232
—
11
—
µA
±1%
±5% (No compensated)
—
—
40-400
400-2000
—
—
HZ
F3dB = 1kHz
—
1k
—
kHz
F3dB = Full
100k
—
—
kHz
—
2.15
—
—
1.82
—
—
100
—
ppm/℃
-2.52
-3
—
—
2.52
3
%
counts
VREF
Open circuit voltage for 600Ω
measurement
V-=3V
Open circuit voltage for other Ω
measurement
Peak to peak backplane voltage
Internal pull-high to 0V current
AC frequency response at
6.000V range
3dB frequency for LPF mode
Multi-level low battery detector
Reference voltage temperature
coefficient
Capacitance measurement
accuracy
Vt1
Vt2
TCRF
LBAT9 vs. V-20℃<T A<70℃
6.0nF – 60mF
V
Note:
1. Full Scale.
2. When capacitance measurement (Clamp mode) is selected, the additional error 1% should be increased.
V 2.1
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ES237
6000 Counts DMM
Function Description
1. Operating Modes
1.1.
Semi-auto calibration scheme
ES237 includes DMM & Clamp-on meter features in single chip. DMM manufacturers need the calibration
process in production. The traditional solution needs the variable resistors for calibration by manual adjustment.
ES237 provide another calibration scheme and the most variable resistors could be ignored. When ES237 is at
OFF-state, pull CALENP (pin 51) to V- to active the calibration scheme after re-power on. A digital controlled
voltage output will be active from DACO. When semi-auto calibration scheme is active, use HOLD (or
BKLIT) key to decrease voltage and use RANGE (or MMX) key to increase the voltage. Decrease the
reference voltage means the counts on display will be increased. Increase the reference voltage means the
counts on display will be decreased. The adjustment step is approximate one count. If coarse adjustment is
required, push HOLD (or BKLIT) and RANGE (or MMX) larger than one second to speed up to
approximate 10 counts per second. After calibration process is finished, push HOLD (or BKLIT) and
RANGE (or MMX) less than 1 sec. simultaneously to save the digital control code to external EEPROM
(24LC02).
The semi-auto calibration scheme supports the following nine measurement modes. When CALENP pin is
active, set the proper function switches or push KEY to choose the target measurement mode. When mode is
selected, the LCD segment of Unit at related measurement will be blinking.
Mode
Default Range For CAL
Remark
Voltage Measurement
6.000V (DC/AC separated)
mV Voltage Measurement
600.0mV (DC/AC separated)
Accuracy of other ranges is guaranteed
by external resistor.
DC Current Measurement For
Multimeter (uA/mA)
600.0μA or 6000μA
( 2 modes choose one for calibration )
600.0μA or 6000μA
(2 modes choose one for calibration )
AC Current Measurement For
Multimeter (uA/mA)
Auto 2 ranges choose one, proposed to
use a large range to calibration.
Auto 2 ranges separated for calibration
is necessary.
DC Current Measurement For
Multimeter (A)
6A or 20A
Auto 2 ranges choose one, proposed to
use a large range to calibration.
AC Current Measurement For
Multimeter (A)
6A or 20A
Auto 2 ranges individual
calibration is necessary.
DC Current Measurement For
Clampmeter
600.0A or 6000A
( 6 modes choose one for calibration )
Auto 2 ranges choose one, proposed to
use a large range to calibration.
AC Current Measurement For
Clampmeter
600.0A or 6000A
( 6 modes choose one for calibration )
Auto 2 ranges separated for calibration
is necessary.
Capacitor Measurement
60.00nF
Temperature Measurement
600.0℃
ADP Measurement
6000 / 600.0 / 60.00 / 6.000
for
Lower range in auto temperature
measurement.
4 ranges separated for calibration.
After calibration procedure is finished, set ES237 to OFF-state and set CALENP (pin51) to DGND or kept
floating to return to normal mode operation after re-power on.
V 2.1
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ES237
6000 Counts DMM
1.2. Voltage Measurement
A re-configurable voltage divider automatically provides a suitable range in voltage measurement
mode. 600.0mV range is independent and manual mode. It takes input signal from mVin pin. The
following table summarizes the Full-Scale ranges in each configuration.
Configuration
Full Scale Range
Divider Ratio
Resister Connection
Input Pin
VR1
600.0mV
1
-
mVin V.S. SGND
VR2
6.000V
1/10
VR2 (1.111MΩ)
VR1 V.S. SGND
VR3
60.00V
1/100
VR3 (101KΩ)
VR1 V.S. SGND
VR4
600.0V
1/1000
VR4 (10KΩ)
VR1 V.S. SGND
VR5
1000V
1/10000
VR5 (1KΩ)
VR1 V.S. SGND
The VST pin is used to control the voltage start range from 6.000V or 600.0V, refer to the table.
VST
Initial state
V+
DGND
Floating
V-
600.0V
6.000V
600.0V
6.000V
The ES237 provide two types of the hazardous live voltage warning by different condition.
SEL2
V+
DGND
Floating
DCV
35V
70V
ACV
16V
33V
V-
When the voltage measured exceeds the level defined, the buzzer generates 2KHz beep and
ALARM (pin 57) drive high output (V+ level) periodically. It can remind the user to notice the
hazardous voltage. The buzzer sound warning could be cancelled by DIS (pin94).
DIS
V+
Buzzer
V 2.1
DGND
Disable
Floating
V-
Enable
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ES237
6000 Counts DMM
1.2.1. OL Selection
ES237 has a voltage OL selection feature archived by configuring the pin CESEL. In automatic
voltage mode, ES237 will show OL when the voltage is exceed the overflow level. If CESEL is
connected to V+, ES237 will have a 1010V overflow level in voltage mode. If CESEL connected to
DGND, the overflow level will be set to 610V in DCV and ACV mode. The configuration of CESEL
is listed below.
For ACV/DCV voltage modes:
CESEL
OL level
V+
DGND
1010V
610V
Note: V-/Floating level is not available.
1.3. Low Pass Filter (LPF) Mode For ACA/ACV Mode
ES237 provides a 3rd order low-pass filter to reduce the influence of high frequency noise. This
LPF feature is available in ACV or ACA modes. Set FC5 to low in these modes, the KEY button is
used to activate the LPF feature. Press KEY button for less than 1 second to select the 3dB bandwidth
of LPF sequentially ( Full / 1kHz ) and the relative LCD symbol on LCD panel will be active also.
The DIS (pin94) could enable/disable the Low Pass Filter feature available.
DIS
LPF
V 2.1
V+
DGND
Floating
V-
Disable
Enable
Disable
Enable
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ES237
6000 Counts DMM
1.4. Current Measurement For Multi-meter
ES237 has 3 automatic current measurement modes for multimeter. The following table
summarizes the Full-Scale range of each mode. When ES237 operates in the current measurement
modes for multi-meter, it takes high input from pin IVS, low input from pin SGND and reference
voltage from calibration scheme.
1
VBAR
Full Scale
Input Terminal
1,1,0,1
1
600.0µA / 6000µA
IVS V.S. SGND
Automatic2
1,1,1,1
1
60.00mA / 600.0mA
IVS V.S. SGND
Automatic3
0,0,0,0
1
6.000A /10.00A2
IVS V.S. SGND
Mode
FC1~4
Automatic1
Note:
1. Connect VBAR to V- will disable the “µ2” / ”m2” symbol on LCD panel.
2. Connect SEL1 to V+(or Floated) or V- (or DGND) will set maximum readings of input for Automatic3 mode.
SEL1
OL level
V+
DGND
Floating
V-
10.00A
20.00A
10.00A
20.00A
1.5. Current Measurement For Clamp-meter
ES237 has 2 automatic and 4 manual current measurement modes for Clampmeter. The following
table summarizes the Full-Scale range of each mode. When ES237 operate in the automatic modes
and the manual mode1~4, it takes high input from CLAMPin pin, low input from SGND and
reference voltage from VR_CLAMP.
Mode
FC1~4
1
VBAR
Full Scale
Input Terminal
2
Automatic1
1,1,0,1
0
600.0A / 6000A
CLAMPin V.S. SGND
Automatic2
1,1,1,1
0
60.00A / 600.0A
CLAMPin V.S. SGND
Manual1
1,1,0,0
X
6.000A
CLAMPin V.S. SGND
Manual2
1,0,0,0
X
60.00A
CLAMPin V.S. SGND
Manual3
1,0,1,0
X
600.0A
Manual4
1,0,0,1
CLAMPin V.S. SGND
2
X
CLAMPin V.S. SGND
1000A or 2000A
Note:
1. Connect VBAR to V- will disable the “µ2” / ”m2” symbol on LCD panel.
2. Connect SEL1 to DGND or V- will set maximum of input for Automatic1 & Manual4 modes.
3. In DC current modes for clamp-meter, ES237 provides Zero Function for offset removing.
SEL1
V+
OL level
V 2.1
DGND
1000A
Floating
V-
2000A
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ES237
6000 Counts DMM
1.6. SCAN RSDC measurement
ES237 provide the smart auto check mode for the DUT type. It could scan the four types of device
Resistor / Shorted / Diode / Capacitor. Push KEY to change to individual function is available. It
could increase the measurement ranges.
The following table summarizes the detective range for the smart scan RSDC mode.
Mode
FC1~4
SLACDC
Available scanning range
R: ~ 6MΩ (Parasitic capacitance < 100pF)
Scan RSDC
1,1,1,0
0
S: < 30Ω buzzer ON
D: forward/reverse diode direction
C: ~ 600uF (Minimum 500pF)
1.7.
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.
V 2.1
Configuration
Full Scale Range
Relative Resistor
Equivalent value
OR0
60.00Ω
OR1
100Ω
OR1
600.0Ω
OR1
100Ω
OR2
6.000KΩ
VR5
1KΩ
OR3
60.00KΩ
VR4 || VR1
10KΩ
OR4
600.0KΩ
VR3 || VR1
100KΩ
OR5
6.000MΩ
VR2 || VR1
1MΩ
OR6
60.00MΩ
VR1
10MΩ
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6000 Counts DMM
1.8. Capacitance Measurement
The following table summarizes the eight ranges of capacitance measurement mode.
Configuration1
Full Scale Range
Relative Resistor
Measurement Period
C1
3
6.000nF
Ratio to C2
0.36 sec
C2
2
60.00nF
CAL
0.36 sec
C3
600.0nF
Ratio to C2
1.15 sec
C4
6.000uF
Ratio to C2
1.15 sec
C5
60.00uF
R10K
0.33 sec
C6
600.0uF
R10K
3.3 sec(max)
C7
6.000mF
R1K
1.32 sec(max)
C8
60.00mF
R1K
13.2 sec(max)
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 main-display shows
dIS.C. Discharging through the chip is quite slow. We recommend users to discharge the capacitor with some
other apparatus.
2. The C2 range is calibrated in calibration scheme.
3. The C1 range residual offset could be compensated by the small capacitors near to OVH pin.
1.9.
Continuity Check
Continuity check shares the same configuration with 600.0Ω manual resistance measurement
mode and has buzzer output to indicate continuity. The buzzer generates 2KHz beep and ALARM1
(pin 56) drive high output (V+ level) whenever the reading is less than 30Ω. The ES237 built in a
high speed short detection circuit and the detection could be less than 10ms.
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6000 Counts DMM
1.10. Diode Measurement
Diode measurement mode shares the same configuration with 6.000V manual voltage measurement
mode and has buzzer output to indicate continuity. The buzzer generates a 2KHz sound and ALARM1
(pin 56) drive high output (V+ level) whenever the reading is less than 30mV. If the test circuit is
open or the voltage drop between the two ports of the diode under test is larger than 2V or 2.5V
(depends on SEL2 pin level), the LCD panel will show “OL”.
SEL2
OL
V+
DGND
Floating
V-
2.500V
2.000V
2.500V
2.000V
The ES237 also support a LED forward voltage measurement mode. It is necessary to use external
source to achieve the measurement. The following table & diagram summarizes the diode & LED
measurement mode.
Mode
SLACDC
FC1~4
SEL2
Full Scale
Input Terminal
LED
1
0,0,1,0
V+ or FLOAT
3.500V
VR1 V.S. SGND
External Source
V
Internal Source
V+
OVH
ES235 / 236 / 238 / 239
PTC
PTC
LED Mode
Diode Mode
10M
LED
R
1.111M
OVSG
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6000 Counts DMM
1.11. Frequency Counter
The time base of the frequency counter is derived from an external crystal oscillator by
4,000,000
Tcounter =
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 600.0Hz to 60.00MHz. The following
table summarizes the Full-Scale range of the frequency counter.
Range
Full Scale
FR1
600.0Hz
FR2
6.000KHz
FR3
60.00KHz
FR4
600.0KHz
FR5
6.000MHz
FR6
60.00MHz
*If input frequency is less than 1.0Hz, ES237 will show 0.0Hz
1.12. Duty Cycle Measurement
When frequency mode is selected, push HZ key to enter duty cycle measurement. The duty cycle
mode range is within 5.0% to 95.0% (< 10kHz@3Vpp). The minimum resolution is 0.1%. If the
source frequency duty cycle is smaller than 5.0%, the UL will be shown on the LCD display. If the
duty cycle is larger than 95.0%, the OL will be shown on the LCD. When the frequency is zero, the
duty cycle display will be 0.0% or “UL” shown.
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6000 Counts DMM
1.13. Electrical field detection mode
ES237 supports a non-contact AC voltage measurement, which is called electric field measurement
also. The ADC input is configured from ADP pin vs. SGND. When no or less electric field is detected,
the LCD display shows “EF”. If the electric field is detected, the strength will be showed on the LCD
display by “-“ not digits type. Level 1(equivalent to 12.5% full scale of ADC) is “-“ and the level
4(equivalent to 100% full scale of ADC) is “----“. Additional beeper (BUZOUT pin) and LED alarm
(ALARM pin) will be output from ES237. The frequency of buzzer and LED alarm depends on the
strength of electric field also. The Faster beeper means the stronger electric field (AC voltage) is
sensed.
Mode
FC1~4
SLACDC
Full Scale
Input Terminal
EF
1,1,1,0
1
-
ADP V.S. SGND
EF test circuit
100k
EFin+
ADP
100M
EFin-
SGND
AGND
-400mV
VRADP
1.14. Temperature Measurement mode
Temperature measurement mode takes input signal from TEMPin pin. The ES237 has ºC to ºF scale
translation circuit and standard K-type thermocouple reference table is built-in. External
cold-junction compensation circuit is still necessary. In temperature measurement mode, there is
automatic mode and manual mode. The TSEL pin (pin95) is used to control the automatic mode
(0.1OC/1OC resolution) or manual mode (0.1OC resolution) selection. It also could enable or disable
display of input terminal symbol on the LCD panel (SEG28).
Manual range
Auto Range
ºC range
-200.0 ºC ~ 600.0 ºC
-200.0 ºC ~ 600.0 ºC
/ -200 ºC ~ 1350 ºC
ºF range
-328.0 ºF ~ 999.9 ºF
-328.0 ºF ~ 999.9 ºF /
-328 ºF ~ 2462 ºF
The following table summarizes the operation of TSEL pin:
TSEL
V 2.1
Range select
V+
Manual range
DGND
Auto range
Floating
Manual range
VAuto range
LCD SEG28
Display Symbol ON
Display Symbol ON
Display Symbol OFF
Display Symbol OFF
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6000 Counts DMM
Temperature mode circuit example:
1.15. ADP
ES237 provides 4 manual range ADP measurement modes for user define. The ADP pin is
auxiliary input terminal for ADC of ES237. The full scale for ADP mode is 600.0mV. If FC5=0, the
minus sign will not be shown on LCD segment.
Mode
FC1~4
SLACDC
Full Scale
Input Terminal
ADP0
0,0,1,1
1
6000
ADP V.S. SGND
ADP1
0,0,0,1
1
600.0
ADP V.S. SGND
ADP2
0,1,1,1
1
60.00
ADP V.S. SGND
ADP3
1
1
6.000
ADP V.S. SGND
0,0,1,0
Note:
1.
If SEL2 pin is set to V+ or kept floating, the ADP3 mode will be disabled and change to LED mode.
The VST pin (pin96) could be used to enable or disable input terminal symbol displayed on
LCD panel for ADP mode.
VST
V+
LCD SEG28
V 2.1
DGND
Display Symbol ON
16
Floating
V-
Display Symbol OFF
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ES237
6000 Counts DMM
1.16. Auto Power Off And Idle Time Selection
ES237 has a default auto power off function. If the meter is idle for more than the given idle time
duration, the chip automatically turns the power off. The idle time to trigger the auto power off
function is determined by APOSEL pin. If APOSEL is connected to V-, the idle time will be set to 30
minutes. If pin APOSEL is floating, the Idle Time will be set to 15 minutes. When APO is occurred,
the state of the meter is reserved. The APO symbol 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
automatically.
Note: Powering on the meter while pressing HOLD and lasts 2 seconds turns on all LCD segments until HOLD
is pressed again.
1.17. Sleep
The meter enters sleep mode after auto power off. The SLEEP pin asserts low (V-) in the sleep
mode, and asserts high (V+, not 0V) after re-power on.
1.18. 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.
1.19. Hazardous Voltage Indication
The
ES237
could
provide
the
AC/DC
hazardous
voltage
indication
for
voltage/resistor/capacitor/diode modes. Of course, the indication could support LCD symbol /LED
/Buzzer driving simultaneously. Especially ES237 could detect the AC voltage in DCV mode and
detects the DC voltage in ACV mode. It means if not proper AC or DC voltage signal exists on the
DUT when DCV or ACV measurement mode is set, the HV indication will be active.
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6000 Counts DMM
HV indication criterion
Function / Range
DC voltage (typ.)
AC voltage (typ.)
AC mV
> +3V
OL
AC 6V
> +20V
OL
AC 60V – 1000V
> +100V
Depends on SEL2
DC mV
OL
> 3Vrms (40-1kHz)
DC 6V
OL
> 20Vrms (40-1kHz)
DC 60V-1000V
Depends on SEL2
> 90Vrms (40-1kHz)
Res/Cap/Diode modes
> +10V
> 10Vrms (40-1kHz)
Note: If AC+DC signal is applied, the voltage criterion will be changed.
1.20. Multi-level Low Battery Voltage Detection
ES237 provides a voltage detection input (pin 121: LBAT9) for multi-level low battery application.
There are two internal voltage reference Vt1 & Vt2 for comparing with LBAT9. If LBAT9 is larger
than Vt1, the LCD segment of SLB1 – SLB3 will active always. This status implies Full battery.
When LBAT9 is less than Vt1 but larger than Vt2, the LCD segment of SLB1 will disappear and this
status implies Half battery. When LBAT9 is less than Vt2, the LCD segment of SLB2 will disappear
and this status implies Low battery. When the Low battery status lasts for 10 seconds, the LCD
segment of SLB3 will be blinking. When the SLB3 is blinking for 20 seconds, the operation of meter
will be inhibited and LCD panel will show “ Lo.bt”. In this case, it is suggested to replace a new
battery immediately. After “Lo.bt” appears and lasts for 60 seconds, ES237 will enter to auto power
off mode.
Full battery
Half battery
Low battery condition > 30s
Operation not allowed
Low battery
blinking
AUTO
AUTO
AUTO
AUTO
DC
DC
DC
DC
1.8 0 0
V
1.8 0 0
Low battery test circuit (a)
V
1.8 0 0
L o.b t
Low battery test circuit (b)
3V
9V
BA
120K
TTE
BA
LBAT9
0.1u
470K
910K
TTE
AGND
V-
LBAT9
0.1u
300K
0V
V 2.1
V
AGND
V-
0V
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6000 Counts DMM
2. Measurement Mode Switching
Measurement mode depends on the logic level of SLACDC, FC1, FC2, FC3, FC4, FC5 and KEY
selection. When FC5 is high, the measurement mode list is shown below:
SLACDC
FC1
FC2
FC3
FC4
0
1
0
1
1
0
0
1
1
1
1
0
1
1
23
1
23
0
0
0
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
Mode
KEY selection
DC Voltage Measurement
DCV ↔ ACV
Auto DC Current Measurement(µA)
DCA ↔ ACA
Auto DC Current Measurement(mA)
DCA ↔ ACA
23
Auto DC Current Measurement(A)
DCA ↔ ACA
Scan RSDC
Ω  Continuity  Diode  Cap  Scan
0
3
Manual DC 6.000A
DCA ↔ ACA
0
3
DCA ↔ ACA
DCA ↔ ACA
Manual DC 60.00A
0
1
0
1
0
3
0
1
0
0
1
3
0
0
0
1
0
0
0
0
0
0
Manual DC 600.0A
Manual DC 6000A
DCA ↔ ACA
1
Resistance Measurement
Ω ↔ Continuity
0
1
Continuity Check
Continuity ↔ Diode
1
1
1
Resistance Measurement
Ω Continuity  Diode
0
0
1
0
Frequency Measurement
----
0
0
1
1
0
Capacitance Measurement
----
0
0
1
0
0
Auto Temperature Measurement
℃↔ ℉
0
0
1
0
1
DCmV
DCmV ↔ ACmV
1
1
0
1
1
AC Voltage Measurement
ACV ↔ DCV
1
1
1
1
1
1
0
1
1
23
1
23
1
0
0
0
0
1
1
1
1
0
1
1
1
1
1
0
0
0
Auto AC Current Measurement(µA)
ACA ↔ DCA
Auto AC Current Measurement(mA)
ACA ↔ DCA
23
Auto AC Current Measurement(A)
EF mode
----
0
3
Manual AC 6.000A
ACA ↔ DCA
0
3
ACA ↔ DCA
ACA ↔ DCA
Manual AC 60.00A
1
1
0
1
0
3
1
1
0
0
1
3
1
1
1
0
0
0
0
0
1
1
0
1
ACA ↔ DCA
Manual AC 600.0A
Manual AC 6000A
ACA ↔ DCA
1
1
ADP0 ( 6000 )
----
1
1
ADP1 ( 600.0 )
----
1
1
ADP2 ( 60.00 )
----
1
ADP3 ( 6.000 )
Set to LED mode if SEL2 is kept float
1
0
0
1
0
1
0
1
1
0
Capacitance Measurement (Clamp)
----
1
0
1
0
0
Auto Temperature Measurement
℉↔℃
1
0
1
0
1
ACmV
ACmV ↔ DCmV
Note:
1. When FC5 is high, the ADP0, ADP1, ADP2 and ADP3 modes can display minus sign.
2. These modes could be designed for multimeter current modes, please refer to section 1.4.
3. These modes could be designed for clampmeter current modes, please refer to section 1.5.
.
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6000 Counts DMM
Measurement Mode Switching (Continued)
Measurement mode depends on the logic level of SLACDC, FC1, FC2, FC3, FC4, FC5 and KEY
selection. When FC5 is low, the KEY function is disabled in most modes. The measurement mode list
is shown below:
SLACDC
FC1
FC2
FC3
FC4
0
1
0
1
1
0
0
1
1
1
1
0
1
1
23
1
23
0
0
0
0
0
0
1
1
1
0
Mode
KEY selection & Remaks
DC Voltage Measurement
----
Auto DC Current Measurement(µA)
----
Auto DC Current Measurement(mA)
----
23
Auto DC Current Measurement(A)
----
Scan RSDC
Ω  Continuity  Diode  Cap  Scan
Manual DC 6.000A
----
0
1
1
0
0
3
0
1
0
0
0
3
----
0
3
----
3
0
1
0
1
Manual DC 60.00A
Manual DC 600.0A
Manual DC 6000A
----
1
Resistance Measurement
----
0
1
Continuity Check
----
1
1
1
Diode Measurement
----
0
0
1
0
Frequency Measurement
----
0
0
1
1
0
Capacitance Measurement
----
0
0
1
0
0
Auto Temperature Measurement
℃
0
0
1
0
1
DCmV
----
1
1
0
1
1
AC Voltage Measurement
LPF Full1K
0
1
0
0
1
0
0
0
1
0
0
0
0
0
0
1
1
1
1
1
1
0
1
1
23
1
23
1
0
0
0
0
1
1
1
1
0
Auto AC Current Measurement(µA)
LPF Full1K
Auto AC Current Measurement(mA)
LPF Full1K
23
Auto AC Current Measurement(A)
LPF Full1K
EF mode
----
Manual AC 6.000A
LPF Full1K
1
1
1
0
0
3
1
1
0
0
0
3
LPF Full1K
0
3
LPF Full1K
1
3
1
1
1
1
1
1
1
0
0
0
0
0
0
0
1
1
0
1
0
1
Manual AC 60.00A
Manual AC 600.0A
Manual AC 6000A
LPF Full1K
1
1
ADP0 ( 6000 )
----
1
1
ADP1 ( 600.0 )
----
1
1
ADP2 ( 60.00 )
----
1
ADP3 ( 6.000 )
Set to LED mode if SEL2 is kept float
1
0
0
1
0
1
0
1
1
0
Capacitance Measurement (Clamp)
----
1
0
1
0
0
Auto Temperature Measurement
℉
1
0
1
0
1
ACmV
LPF Full1K
Note:
1. When FC5 is low, the ADP0, ADP1, ADP2 and ADP3 modes can’t display minus sign.
2. These modes could be designed for multi-meter current modes, please refer to section 1.4.
3. These modes could be designed for clamp-meter current modes, please refer to section 1.5.
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6000 Counts DMM
3. Push Function
All the enabled push functions will be reset when the measurement mode is changed when
FC1-FC5 modes are changed. The following table lists the available function versus every
measurement mode.
HZ
MMX
REL/RS2325
BKLIT
KEY
HOLD
RANGE
Voltage mode
AC
O
O
O
O
O
O
mV mode
AC
O
O
O
O
O
X
Current Mode
for Multimeter
AC
O
O
O
O
O
O
Current Mode
for Clampmeter
AC
O
O3
O
O
O
X
Resistance
X
O
O
O
O
O
O
Continuity
X
O
O
O
O
O
X
Diode mode
X
O
O
O
O
O
X
Frequency
O
X
O
O
X
O
O
Capacitance
X
O
O
O
X
O
O
Temperature
X
O
O
O
O
O
O4
Scan RSDC
X
X
O
O
O
O
X
EF Mode
X
X
O
O
X
X
X
ADP mode
X
O
O
O
X
O
X
1
2
Note:
1
Include automatic μA, automatic mA and manual A modes, please refer to section 1.4.
2
Include 2 automatic modes and 4 manual modes, please refer to section 1.5.
3
When clamp-meter DCA mode is selected, the REL function will be changed to ZERO function operation automatically.
4
Only auto range temperature mode is available.
5
When RS232 (pin99) is pulled to V-, push REL key and lasts for 2 seconds will active the UART output.
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6000 Counts DMM
3.1. Range
Push RANGE1 key to switch from automatic to manual mode, and while in manual mode, changes
the full-scale range. The following figure shows the state transition.
Automatic
Mode
1 push < 1 sec
Manual
Mode
1 push > 1 sec
Range up
1 push < 1 sec
Measurement Mode
Auto
Manual
Control Range
Initial Range
V
VR2 – VR5
VRi → VRi + 1,
VR5 → VR2
6.000V – 1000V
6.000V2
Auto µA
R1 – R2
R1 → R2,
R2 → R1
600.0µA – 6000µA
600.0µA
Auto mA
R1－R2
R1 → R2
R2 → R1
60.00mA – 600.0mA
60.00mA
Auto A
R1－R2
R1 → R2
R2 → R1
6.000A – 10.00A
6.000A
Auto 60A/600A
(clamp)
R1－R2
R1 → R2
R2 → R1
60.00A – 600.0A
60.00A
Auto 600A/6000A
(clamp)
R1－R2
R1 → R2
R2 → R1
600.0A – 6000A
600.0A
Capacitance
C1 – C8
Ci → Ci + 1,
C8 → C1
6.000nF– 60.00mF
6.000nF
Capacitance (Clamp)
C1 – C8
Ci → Ci + 1,
C8 → C1
6.000nF– 60.00mF
6.000nF
Ω
OR0 – OR6
ORi → ORi + 1,
OR6 → OR0
60.00Ω – 60.00MΩ
60.00Ω
Temp
T1-T2
T1T2
T2T1
600.0oC~1350oC
600.0oC
Frequency
FR1 – FR7
FRi → FRi + 1
FR7 → FR1
600.0Hz – 60.00MHz
600.0Hz
Note:
1. Pushing RANGE resets all existing special modes except for VAHZ mode.
2. Initial range of voltage mode depends on VST pin configuration
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6000 Counts DMM
3.2. HOLD and Delayed Hold Feature
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. ES237 provides a Delay HOLD feature. To activate
Delay HOLD feature, press down the HOLD bottom and last for 2 seconds. The meter will delay for
6 seconds, than enters HOLD mode. In the 6-secnod delayed time, the HOLD symbol on LCD panel
will blink. HOLD function and the delayed state can be cancelled by changing the measurement
mode, pressing RANGE, or push HOLD again.
Push > 2s
6sec past
Normal mode Push < 2s HOLD mode
(Auto/Manual) Push < 2s
(Manual)
Delay State
(Auto/Manual)
Push > 2s
Push < 2s
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 N = 1, 2, 3, … , DN is the last value before
REL key is pushed, and DN+K is the current value. The meter returns to normal operation if REL is
pressed again. Pressing HOLD in REL mode makes the meter stop updating the LCD panel.
push REL
Original State
(Auto/Manual)
push REL
push HOLD
〝REL〞active.
〝REL〞and〝H〞active.
The relative value
Hold the relative value
push HOLD
Note:
1. It’s possible that relative value (DN+K - DN) exceeds 6,000 or -6,000 counts. The LCD shows OL in REL mode only
if DN or DN+K is more than 6,000 counts.
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6000 Counts DMM
3.5. Max/Min + HOLD
The meter displays the maximum or minimum value of the input in Max/Min mode. When MMX
key is pressed for the first time, the meter displays the maximum value. The meter displays the
minimum value, when it is pressed again. When MMX key is pressed for the third time, the meter
displays current value. The meter returns to normal operation if MMX 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
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 MMX is pressed in REL mode. Pressing HOLD under REL +
Max/Min makes the meter stop updating the LCD panel.
Original State
(Auto/Manual)
Push REL
Push REL
〝REL〞active.
The relative value
Push MMX > 1s
Push MMX
〝REL〞and〝Max〞active.
〝REL〞and〝Min〞active.
〝REL〞
〝Max〞
〝Min〞blink.
Maximum rel. value
Minimum rel. value
Current rel. value
Push MMX
Push MMX
Push HOLD
〝REL〞,〝Max〞,
〝H〞active. Hold
max. rel. value
Push HOLD
〝REL〞,
Push MMX
〝Min〞,
〝H〞active. Hold
min. rel. value
Push MMX
Push HOLD
〝REL〞
〝Max〞
,
〝Min〞
,
,
〝H〞blink. Hold the
current rel. value
Push MMX
V 2.1
24
2015/03/05
ES237
6000 Counts DMM
3.7. ZERO Function
In manual DC 6.000A, 60.00A, 600.0A and 6000A, auto DC 60.00A/600.0A, and auto DC
600.0A/6000A (please refer to section 1.5) mesurement modes, ES237 provides ZERO function to
remove the residual current value. Push REL key less than one second to enter ZERO mode. In
ZERO mode, the LCD panel displays DN+K - DN, where N = 1, 2, 3, … , DN is the last conversion
value before REL key is pushed, and DN+K is the current conversion value. If REL key 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 REL key is pressed and held for longer than one second.
Pressing HOLD in ZERO mode makes the meter stop updating the LCD panel. In 2-range auto DCA
modes for clampmeter (600.0A/6000A or 60.00A/600.0A), the system will stay in automatic mode,
even if the ZERO function is activated. In other words, It could achieve real automatic operation. In
automatic mode, ZERO function could not be entered from higher range, but it could be still activated
if current range is lower one. This is because most residual current value is so small that the range
could not be higher one in automatic mode. When enter ZERO mode from lower range, the system
will store the nonzero counts (residual current value). If the range goes up to higher one automatically,
the nonzero counts will be divided by ten. So this function will still work well in automatic modes.

State diagram for ZEROmode :
Original State
Press Zero
Press Zero > 1s
‘Zero’ Active
Show DN+K - DN

Press Zero < 1s
State diagram for ZERO + HOLD mode :
Original State
Press Zero
Press Zero > 1s
‘Zero’ Active
Show DN+K - DN
Press Zero < 1s
Press Hold
‘Zero’ ‘Hold’ Active
Stop LCD upgrading
V 2.1
25
2015/03/05
ES237
6000 Counts DMM

State diagram for ZERO + Max/Min + HOLD mode :
Original State
(Auto/Manual)
Push REL
Push REL > 1s
‘Zero’ Active
Push REL < 1s
Show DN+K - DN
Push MMX > 1s
Push MMX
‘Zero’ ‘Max’ Active
‘Zero’ ‘Min’ Active
〝Zero〞
〝Max〞
〝Min〞blink.
Show Max. DN+K - DN
Show Min. DN+K - DN
Current DN+K - DN
Push MMX
Push MMX
Push HOLD
Push HOLD
Push HOLD
〝Zero〞
〝Max〞
,
〝Min〞
,
,
‘Zero’ ‘Max’ ‘Hold’
‘Zero’ ‘Min’ ‘Hold’
〝H〞blink. Hold the
active Hold Max.
active Hold Min.
Push MMX
Push MMX
DN+K - DN Value
DN+K - DN Value
current DN+K - DN
Push MMX
3.8. VAHZ Function
When voltage or current measurement mode is selected, the VAHz funtion is available. Push HZ
key to select this frequency measurement mode. The frequency is measured by auto ranging. The
maximum frequency range is 60KHz. The sensitivity of signal input is 5% full scale of signal in
voltage or current mode typically.
V 2.1
Configuration
RANGE
FR1
600.0Hz
FR2
6.000KHz
FR3
60.00KHz
26
2015/03/05
ES237
6000 Counts DMM
4. Serial Data Output
The RS232 function will be activated if press down the REL key and last for 2 seconds, RS232
symbol will be shown on the LCD display. The serial data sent to SDO pin periodically at every A/D
conversion cycle by 15 times per second. The data format complies with 8Bits transmission code with
a baud rate of 9600. The host can use RS232 interface to read the data. A single data packet includes a
start bit (always 0), 8 data bits with no 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.
Single packet
0V
-3V
0 D7 D6
MSB
D4 D3 D2 D1 D0
D5
LSB
1
One data block consists of 17 packets. The following figure shows the format of a data block. The
Header and Device code leads the whole packets. The range packet indicates the decimal point
position on LCD panel of meter. Main_Digit1-3 consists of the readings on the LCD panel. The
function packet indicates the measurement mode of the meter. Status1-4, Unit and Bargraph give the
other status of the meter. CR and LF are delimiters used to separate the blocks.
V 2.1
27
2015/03/05
ES237
6000 Counts DMM
All packets
D7
0
D0
Header
1 0
1 0
Device
Range
1 0
1
Main_Digit1
0
1 0
1 0
1 0
1
Main_Digit2 Main_Digit3
Function1
Function2
0
0
0
Function3
Status4
1 0
1 0
Status1
1 0
1 0
Unit
Status2
Bargraph
1 0
1 0
Status3
1
1
CR
1
LF
The meter always outputs the current value shown on LCD screen to the serial port. The detailed data
format of each packet is listed below.
D0
D1
D2
D3
D4
D5
D6
D7
a01
0
0
0
0
1
1
1
1
Header
a02
1
0
0
0
0
0
0
1
Device
a03
X
X
X
X
M_DP1
M_DP2
M_DP3
X
Range
a04
M_SIGN
X
X
X
X
X
X
X
Main_Digit1
a05
M16
M15
M14
M13
M12
M11
M10
M09
Main_Digit2
a06
M08
M07
M06
M05
M04
M03
M02
M01
Main_Digit3
a07
V
A
Ohm
Continuity
Diode
Capacitance
Hz
Duty
Function1
a08
VAHZ
℃
℉
X
EFmode
SCAN
Clamp
LED
Function2
a09
ADP0
ADP1
ADP2
ADP3
X
X
X
X
Function3
a10
AUTO
MANU
AC
DC
OL
UL
X
X
Status1
a11
SLB3
SLB2
SLB1
LBAT30s
BW_full
X
BW1K
HOLD
Status2
a12
REL
ZERO
MAX
MIN
CURRENT
X
X
X
Status3
a13
Danger
OPEN
SHORT
DISCH
X
X
X
X
Status4
a14
Mega
Kilo
X
Mili
X
Micro
X
Nano
Unit
a15
B_SIGN
X
B<06>
B<05>
B<04>
B<03>
B<02>
B<01>
Bargraph
a16
0
0
0
0
1
1
0
1
CR
a17
0
0
0
0
1
0
1
0
LF
Note：
1. X  undefind.
2. Whole packet is shown by LSB first.
V 2.1
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2015/03/05
ES237
6000 Counts DMM
4.1. RANGE
This packet indicates range state of the meter. The M_DP1 – M_DP3 corresponding DP1 – DP3 of
LCD segment (see section 5). In DCV 6.000V range, this a03 packet will set xxxx001x. If change to
60.00V the packet will be xxxx010x.
a03
D0
D1
D2
D3
D4
D5
D6
D7
X
X
X
X
M_DP1
M_DP2
M_DP3
X
4.2. Main_Digit1 –Main_Digit3
Main_Digit1 – Main_Digit3 is the readings of measurement result shown on LCD panel. M16 –
M01 consist of 16-bit unsigned binary code. The M_SIGN is the sign bit of readings.
D0
D1
D2
D3
D4
D5
D6
D7
a04
M_SIGN
X
X
X
X
X
X
X
a05
M16
M15
M14
M13
M12
M11
M10
M09
a06
M08
M07
M06
M05
M04
M03
M02
M01
4.3. FUNCTION
The packets of a07-a09 indicate the measurement mode of the meter. The following table
summarizes the transmitted bit for each mode. Note that the encoding of this packet is different from
the encoding of FC1-FC5 switch.
For example, if the meter operates in Voltage mode, this a07 packet is 10000000. If VAHZ key is
pushed to VAHZ mode, the a08 will be 10000000 also.
D0
D1
D2
D3
D4
D5
D6
D7
a07
V
A
Ohm
Continuity
Diode
Capacitance
Hz
Duty
a08
VAHZ
℃
℉
X
EFmode
SCAN
Clamp
LED
a09
ADP0
ADP1
ADP2
ADP3
X
X
X
X
4.4. STATUS
The a10-a13 packets indicate the whole status when ES237 is in normal operation. For example, if
meter is operated at ACV / MANU range, then a10 packet will set 011000xx.
The format of the four packets are shown below.
V 2.1
D0
D1
D2
D3
D4
D5
D6
D7
a10
AUTO
MANU
AC
DC
OL
UL
X
X
a11
SLB3
SLB2
SLB1
LBAT30s
BW_full
X
BW1K
HOLD
a12
REL
ZERO
MAX
MIN
CURRENT
X
X
X
a13
Danger
OPEN
SHORT
DISCH
X
X
X
X
29
2015/03/05
ES237
6000 Counts DMM
AUTO: When auto range is selected.
MANU: When manual mode is selected.
AC: When AC mode is selected.
DC: When DC mode is selected.
OL: When ‘OL’ is displayed on LCD.
UL: When’UL’ is displayed on LCD.
SLB3/SLB2/SLB1: When low battery segment is shown on LCD.
LBAT30s: When ‘Lobt’ is shown on LCD.
BW1k/full: Indication of low-pass-filter 3dB bandwidth.
HOLD: When Data HOLD mode is active.
REL: When Relative mode is active.
ZERO: When Zero mode is active.
MAX/MIN/CURRENT: When MAX/MIN mode is active. If CURRENT=1 means MAX/MIN symbol is blinking on
LCD.
Clamp: When clamp current mode is selected.
Danger: Hazard voltage warning symbol is active on LCD.
OPEN: Open state is detected on Scan mode.
SHORT: Short circuit is detected on Continuity or diode mode.
DISC: The ‘DisC’ is shown on LCD. It means the DUT is necessary to be discharged on Cap mode.
4.5. Unit
This packet indicates the measurement unit of the LCD display.
a14
D0
D1
D2
D3
D4
D5
D6
D7
Mega
Kilo
X
Mili
X
Micro
X
Nano
4.6. Bargraph
The a15 packet is the readings of bar-graph shown on LCD panel. B06 – B01 consist of 6-bit
unsigned binary code. The B_SIGN is the sign bit of bar-graph. The result is necessary to be divided
by 2 to match the bar-graph of LCD panel.
The format of this packet is shown below.
a15
D0
D1
D2
D3
D4
D5
D6
D7
B_SIGN
X
B06
B05
B04
B03
B02
B01
4.7. CR
Carriage return: The transmitted code is 00001101.
4.8. LF
Line feed: The transmitted code is 00001010.
V 2.1
30
2015/03/05
ES237
6000 Counts DMM
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 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
0.15 sec
0.3 sec
(b) 3.33 beep/sec
V 2.1
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2015/03/05
ES237
6000 Counts DMM
5.1.
LCD Panel
S01
BP1 SLB1
S02
APO
S03
S04
S05
SCAN AUTO
S06
S07
S08
S09
S10
S11
S12
S13
S14
S15
4F
4A
4B
HOLD
3F
3A
3B
Buz
2F
2A
BP2 SLB2 RS232 MAN
AC
Minus
4E
4G
4C
DP3
3E
3G
3C
DP2
2E
2G
BP3 SLB3 Danger bar0
DC
bar3
bar5
4D
bar8
bar10
bar12
3D
bar15
bar17
bar19
2D
BP4
bar21
bar-
bar1
bar2
bar4
bar6
bar7
bar9
bar11
bar13
bar14
bar16
bar18
bar20
S16
S17
S18
S19
S20
S21
S22
S23
S24
S25
S26
S27
S28
S29
BP1
2B
Diode
1F
1A
1B
REL
LED
μ2
M
n
Vin
ADP0
BP2
2C
DP1
1E
1G
1C
MAX
℃
m2
K
μ1
COM ADP1
BP3 bar22
bar24
bar26
1D
bar29
MIN
℉
V
Ω
m1
mAin ADP2
BP4 bar23
bar25
bar27
bar28
bar30
A
Hz
F
%
Full
1K
Ain
ADP3
LCD Backplane Waveform
V- +3.1
BP1
VV- +3.1
BP2
VV- +3.1
BP3
VV- +3.1
BP4
V-
V 2.1
32
2015/03/05
ES237
6000 Counts DMM
5.2.
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.
%
In duty cycle measurement.
Hz
In frequency mode.
ADP1
When ADP1 mode is active.
ADP2
When ADP2 mode is active.
ADP3
When ADP3 mode is active.
ADP4
When ADP4 mode is active.
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.
When Relative function is enabled.
MAX
When MAX function is enabled.
MIN
When MIN function is enabled.
SCAN
When smart (resistance, continuity, diode, capacitance auto check mode) is active.
m1
In capacitor measurement mode and the full scale range is in the order of mF.
µ1
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 10-3.
µ2
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 ℉ .
When the reading is exceeding default hazardous live voltage or OL in DCV or ACV,
the HV warning symbol will be display.
APO
When auto power off function is enabled.
SLB1
When voltage (ref. to V-) of LBAT9 pin is less than Vt1, SLB1 will disappear.
SLB2
When voltage (ref. to V-) of LBAT9 pin is less than Vt2, SLB2 will disappear.
SLB3
When SLB2 disappears for 8 seconds, SLB3 will be blinking.
RS232
When RS232 output is enabled.
TEST
V 2.1
When LED measurement function is enabled.
33
2015/03/05
ES237
6000 Counts DMM
5.3
Operating Timing
ES237 incorporates a dual slope ADC with four phases: ZI, AZ, INT and DINT. The timing of each
phase are listed below.
(1) Voltage / Diode /ADP / Manual Current (for clampmeter) measurement:
Phase
High resolution
High speed
ZI
50ms
5ms
AZ
25ms
2.5ms
INT
100ms
10ms
DINT
155ms
15.5ms
(2) Current mode for multimeter/Auto Current mode for clampmeter/2-range auto voltage mode:
Phase
DC / AC
DC Lower Range
ZI
50ms
50ms
AZ
25ms
25ms
INT
100ms
1000ms
DINT
155ms
175ms
(3) Continuity / Ohm measurement:
Phase
Time
ZI
50ms
AZ
100ms
INT
25ms*
DINT
155ms
Note: INT time = 250ms for 60.00Ω range
(4) Capacitance measurement:
Range
Total Measurement Time
6.000nF
0.36sec
60.00nF
0.36sec
600.0nF
1.15sec
6.000μF
1.15sec
60.00μF
0.33sec
600.0μF
3.3sec (max)
6.000mF
1.32sec(max)
60.00mF
13.2sec(max)
(5) Frequency / Duty cycle / VAHz measurement: Every conversion takes 1.05 second.
(6) Temperature measurement: Every conversion takes 1.25 second.
Note:
1. 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.
V 2.1
34
2015/03/05
Application Circuit
D
1
C3
C2
10uF
C6
C7
ZR1
Bat+ DC3.0V Bat-
HZ
MMX
SW1
MMX
HZ
7.5V
0.1uF
V + ZR2
10uF
Power Switch
5.6V
SW8
0.1uF
SW9
SW10
V-
V-
U1
2
Y1
4MHz
3
ES237
4
Q4 2N3904 Q6 2N3904
R15 2.2K PTC
Q5 2N3904 Q7 2N3904
C10 2.2uF
5
Fin
C12
5
Q10
Q9
C11
REL
1
R25
SW12
Fixed 10K
REL
R14
2.2K PTC
C8
200
R18
BKLIT
R24
C22 Close toIC
2.2K PTC
BKLIT
SEG27
SEG28
SEG29
BP1
BP2
BP3
BP4
ALARM
ALARM1
BKOUT
BZOUT
SCLP
SDAP
CALENP
200
SLEEP
R22
900
VR2
200
180K
R17
VV+
R21
9K
VR1
2K
R23
SW16
RC_SW
2.2K PTC
SW13
HOLD
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
1
1
200
R16
KEY
SEG27
SEG28
SEG29
BP1
BP2
BP3
BP4
ALARM
ALARM1
BKOUT
BZOUT
SCLP
SDAP
CALENP
FREQ
SLEEP
OVH1
OVH
OVX
R1K
R10K
CAP
CAN
LPC3
LPC2
LPC1
4
220pF
C29
SW14
3
Fixed 1K
KEY
NC
HZ
MMX
REL
BKLIT
KEY
HOLD
RANGE
FC5
FC4
FC3
FC2
FC1
SLACDC
CN
CP
LBAT9
VVV+
V+
DGND
AGND
AGND
NC
NC
R37
10M VR1
Bottompolygon plane
Vin
Gnd
470nF
HOLD
SW15
103
HZ
104
105
MMX
106
REL
BKLIT 107
108
KEY
109
HOLD
RANGE 110
111
FC5
112
FC4
FC3
113
114
FC2
FC1
115
SLACDC 116
470nF 117
118
LBAT9 119
120
121
122
123
124
125
126
127
128
10K CLAMPin
1nF
Metallized Polypropylene Film Capacitor : C19
Metallized Polyester Capacitor : C9, C14 , C18, C20
SW17
ACV_SW
300pF
C9
0-100pF
Q11
Q12
Size
B
Date:
File:
Title
2N3904 2N3904
RANGE
R7
C27
220pF
2.2nF
C26
0-100pF
2N3904 2N3904
RANGE
V-
SLACDC
D6
SW11
uA/mA/A
D4
100K
mVin R8
SW2
R38
99
R39
0.99
D7
ACVL
ACVH
ADI
ADO
TEST5
SLACDC
uA
mA
FC5
uA
mA
D5
VRH
DACO
VR_CLAMP
VR_ADP
22nF
47nF
220nF
1uF
OVSG
C16
C22
C21
C23
Precision Resistors
R32
100
R33
1K
R34
10.01K
R35
101K
R36
1.111M
SW4
SW18
SW19
FC4
FC3
FC2
FC1
F?
F?
220nF
100nF
SW3
SW5
SW6
SW7
1
1
R40
0.01
C19
C20
470K
FC5
FC4
FC3
FC2
FC1
J4
uA/mA
A
J5
1
2
22nF
R30
C
B
A
J6
COM
1
22nF
100nF
C14
470K
C15
C18
R29
2N3904 2N3904
Q13
Q14
R41
R27
15K
3.9K
BZOUT
BKOUT
D1
ALARM
D2
R26
1
2
3
4
D3
ALARM1
V-
+ C5
1uF
ADO
D8 1N4148 D9 1N4148
R9
R1
R2
R3
100
8
7
6
5
6
R10
V-
Revision
10K
JackChang
V-
V1
R20
47K
BZ1
Buzzer
Q2
2N3904
VQ3
2N3904
VQ8
2N3904
CALENP
SCLP
SDAP
R19
47K
C4
0.1uF
ACVH
ADI
TEST5
100
100K
100
100K
100K
Q1
2N3906
10K
R11
BKOUT
R12
HV
R13
Short
4.7uF
U2
VCC
A0
A1
WP
A2
SCL
GND SDA
R28
15K
C30
24A02
10K
C13
1uF
R42 56K
R43 56K
6
ACVL
AVG Demo Board Circuit
Number
ES237
30-Oct-2014
Sheet of
D:\Protel 99\Protelfile\KA035\KA035_SPEC.ddbDrawn By:
D
C
B
A
2015/03/05
35
V 2.1
IVS
ADP
TEMPin
CLAMPin
CHP
CHN
CIH
BUFH
CAZH
CLN
CLP
CIL
CAZL
BUFL
RAZ
VRH
DACO
VR_CLAMP
VR_ADP
OHMC4
OHMC3
OHMC2
OHMC1
OVSG
OR1
VR5
VR4
VR3
VR2
ACVL
ACVH
ADI
ADO
TEST5
SGND
VR1
mVin
LPFout
10nF
C25
RS232
VBAR
APOSEL
VST
TSEL
DIS
SEL1
SEL2
CESEL
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
SEG24
SEG25
SEG26
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
C17
C24
RSOUT
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
RSOUT
OSC1
OSC2
RS232
VBAR
APOSEL
VST
TSEL
DIS
SEL1
SEL2
CESEL
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
SEG24
SEG25
SEG26
100K
100K
100K
IVS R4
ADP R5
TEMPin
R6
+
+

+
ES237
6000 Counts DMM
1. AVG Circuit
+
SW1
Power Switch
5.6V
10uF
+
MMX
HZ
7.5V
0.1uF
V + ZR2
0.1uF
SW8
SW9
REL
V-
V-
U1
2
Y1
4MHz
3
ES237
4
SEG27
SEG28
SEG29
BP1
BP2
BP3
BP4
ALARM
ALARM1
BKOUT
BZOUT
SCLP
SDAP
CALENP
200
SLEEP
R14
Q4 2N3904 Q6 2N3904
C22 Close toIC
R15 2.2K PTC
VR2
200
R22
900
C10 2.2uF
Q5 2N3904 Q7 2N3904
R21
9K
VR1
2K
1
SW16
RC_SW
VS-
VR3
500K
VS+
5
Fin
Q9
Q10
R26
R27
5
Q11
Q12
Title
Size
B
Date:
File:
100K
4.7K
2N3904 2N3904
Q13
Q14
1
2
3
4
5
6
7
BZOUT
D1
BKOUT
D2
ALARM
D3
ALARM1
V-
1
2
3
4
R9
R1
R2
R3
100
6
R10
V-
10K
BZ1
Buzzer
Q2
2N3904
V-
Q3
2N3904
V-
Q8
2N3904
R20
47K
V-
C4
10uF
C5
+
VS+
10uF
VS-
R19
47K
CALENP
SCLP
SDAP
VS+
VS-
22uF
8
7
6
5
100
100K
100
100K
100K
Q1
2N3906
10K
R11
BKOUT
R12
HV
R13
Short
C31
4.7uF
14
13
12
11
10
9
8
C30
U2
A0
VCC
A1
WP
A2
SCL
GND SDA
24A02
ADI
U3
Buff In
Buff Out
NC
Vin
Common
NC
Output Offset
+ VS
CS
- VS
DEN Input RMS OUT
NC
Cav
ES5
6-Mar-2015
Sheet of
D:\Protel 99\Protelfile\KA035\KA035_SPEC.ddbDrawn By:
6
JackChang
TRMS ( ES5 ) Demo Board Circuit
Number
Revision
ES237
V1
ACVH
+
1
C3
C2
10uF
C6
C7
ZR1
Bat+ DC3.0V Bat-
HZ
MMX
SW10
C8
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
1
1
Fixed 10K
REL
BKLIT
SEG27
SEG28
SEG29
BP1
BP2
BP3
BP4
ALARM
ALARM1
BKOUT
BZOUT
SCLP
SDAP
CALENP
FREQ
SLEEP
OVH1
OVH
OVX
R1K
R10K
CAP
CAN
LPC3
LPC2
LPC1
Gnd
Vin
R37
10M VR1
Bottompolygon plane
C12
SW12
10K CLAMPin
200
200
BKLIT
NC
HZ
MMX
REL
BKLIT
KEY
HOLD
RANGE
FC5
FC4
FC3
FC2
FC1
SLACDC
CN
CP
LBAT9
VVV+
V+
DGND
AGND
AGND
NC
NC
R7
C13
220pF
SW17
ACV_SW
Metallized Polypropylene Film Capacitor : C19
Metallized Polyester Capacitor : C9, C14 , C18, C20
R24
R25
V-
103
HZ
104
MMX
105
REL
106
BKLIT 107
KEY
108
HOLD
109
RANGE 110
FC5
111
FC4
112
FC3
113
FC2
114
FC1
115
SLACDC 116
470nF 117
118
LBAT9 119
120
121
122
123
124
125
126
127
128
D6
SW11
uA/mA/A
D4
2.2K PTC
2.2K PTC
SW13
V+
uA
R38
99
R39
0.99
D7
R17
R18
KEY
HOLD
uA
mA
mA
D5
Fixed 1K
KEY
SW14
V-
SW18
SW19
R40
0.01
4
220pF
C29
HOLD
RANGE
SLACDC
FC5
FC4
FC3
FC1
FC2
F?
F?
3
C11
0-100pF
2N3904 2N3904
SW15
SW2
SW4
SW3
SW5
SW6
SW7
1
1
1
1nF
470nF
0-100pF
2N3904 2N3904
RANGE
SLACDC
FC5
FC4
FC3
FC2
FC1
J4
uA/mA
A
J5
2
C26
C9
D
C
B
A
J6
COM
1
2.2nF
300pF
180K
R23
2.2K PTC
R16
C24
C25
RS232
VBAR
APOSEL
VST
TSEL
DIS
SEL1
SEL2
CESEL
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
SEG24
SEG25
SEG26
1
2
3
4
C17
10nF
5
6
C14
22nF
7
R29
470K
8
C15
22nF
9
C18
100nF
10
11
C19
220nF
12
C20
100nF
13
R30
470K
14
15
VRH
16
DACO
17
VR_CLAMP 18
VR_ADP
19
C16
22nF
20
C22
47nF
21
C21
220nF
22
C23
1uF
23
Precision Resistors
OVSG 24
R32
100
25
R33
1K
26
R34
10.01K
27
R35
101K
28
R36
1.111M
29
30
31
ACVH
32
33
ADI
34
35
36
mVin R8
100K 37
38
+
RSOUT
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
RSOUT
OSC1
OSC2
RS232
VBAR
APOSEL
VST
TSEL
DIS
SEL1
SEL2
CESEL
SEG01
SEG02
SEG03
SEG04
SEG05
SEG06
SEG07
SEG08
SEG09
SEG10
SEG11
SEG12
SEG13
SEG14
SEG15
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
SEG24
SEG25
SEG26
IVS
ADP
TEMPin
CLAMPin
CHP
CHN
CIH
BUFH
CAZH
CLN
CLP
CIL
CAZL
BUFL
RAZ
VRH
DACO
VR_CLAMP
VR_ADP
OHMC4
OHMC3
OHMC2
OHMC1
OVSG
OR1
VR5
VR4
VR3
VR2
ACVL
ACVH
ADI
ADO
TEST5
SGND
VR1
mVin
LPFout
100K
100K
100K
IVS R4
ADP R5
TEMPin
R6
D
C
B
A
2015/03/05
36
V 2.1
+
ES237
6000 Counts DMM
2. Ture RMS Circuit
+
ES237
6000 Counts DMM

Package Information
1. 128L LQFP Outline drawing
2. Dimension parameters
V 2.1
37
2015/03/05