New Trend of Digital Multimeters chip
© 2016 HYCON Technology Corp. www.hycontek.com
New Trend of Digital Multimeters chip
Table of Contents
1. Foreward ........................................................................................................................... 錯誤! 尚未定義書籤。
2. Technological progress of protable electrical measurement meter .................. 錯誤! 尚未定義書籤。
3. Function introduction of new chip trend .................................................................. 錯誤! 尚未定義書籤。
3.1. Programmable switch network .............................................................................. 錯誤! 尚未定義書籤。
3.2. High-resolution Σ-Δ ADC ....................................................................................... 錯誤! 尚未定義書籤。
3.3. Digital RMS circuit ................................................................................................... 錯誤! 尚未定義書籤。
3.4. Operational amplifier ................................................................................................ 錯誤! 尚未定義書籤。
3.5. Low-pass filter ............................................................................................................ 錯誤! 尚未定義書籤。
3.6. Peak hold measurement circuit .............................................................................. 錯誤! 尚未定義書籤。
3.7. Inrush current measurement....................................................................................................................... 10
3.8. Temperature sensor ....................................................................................................................................... 10
3.9. Standard serial interface ........................................................................................... 錯誤! 尚未定義書籤。
3.10. MCU .............................................................................................................................. 錯誤! 尚未定義書籤。
3.11. Wider temperature usage range.............................................................................. 錯誤! 尚未定義書籤。
4. References ......................................................................................................................... 錯誤! 尚未定義書籤。
5. Modificaiton record ....................................................................................................... 錯誤! 尚未定義書籤。
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
1. Foreword
When repairing machine or conducting experiments, electrical/electronic technicians often use analogue
multimeters or digital multimeters (DMM). Previously, the portable digital meter industry usually adopts the analog to
digital converter (ADC), provided by large international companies, designed for digital multimeters to convert the
inputted analog signals to digital signals and then further process the signals. However, the product has long life cycle,
the product also has low demand and various different types; therefore, these large international companies have no
longer designed new ADC for digital multimeters, or even leaved the market of the ADCs designed for digital
multimeters. A digital multimeter only needs a chip and resistors, capacitors and protection components to finish a
product, so the threshold is low and the market of the industry is also limited; therefore, price war must finally take
place; further, the profit of the product is also lower than consumable products. For digital multimeters, the core is the
analog to digital converter; the large international companies, such as American Fluke, can design the dedicated DCC
chips by themselves; on the contrary, as the domestic portable meter industry is smaller the other countries, the
domestic companies cannot design the dedicated DCC chips by themselves.
The document will introduce the DMM dedicated chips, including the HYCON HY12P-series
Mixed-Signal Microcontroller, and HYCON HY313x-series Analog Front End.。
2. Technological progress of portable electrical measurement meter The first kind of portable electrical measurement meter is the analogue multimeters; this electrical
measurement meter is of low price, but has low accuracy, low resolution, no input protection and is poor in
function.
After the development of IC started, chip providers designed the analog to digital converter, the
handheld manual range digital multimeter was developed, which not only had the voltage, resistance and
current measurement functions, but also provided the capacitance, frequency and temperature measurement
functions; further, DMM manufacturers further added the input protection circuit to this meter; however,
almost all functions should be switched by an additional circuit, so users should manually select the range,
which is inconvenient in use.
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
In order to simplify the operation, chip provides designed the analog to digital converter dedicated for
the DMM; for the reason, the handheld auto range digital multimeter was developed, which usually designed
all functions into the chip, so it only needed to add the resistors and capacitors; further, users did not need to
manually select the range.
However, users had new requirements, which were high accuracy, high resolution and special functions,
such as computer connection function; thus, chip providers designed a component for the analog front end
dedicated for the DMM, or combined the analog front end with the MCU; the chip integrated with the MCU
satisfied the new requirements. However, previously, the chip of this kind of product could only provide the
voltage, resistance and current measurement functions, but needed additional circuits to realize other
functions; thus, the product was not an ideal product.
For the purpose of satisfying the above new requirements, HYCON provides new-generation DMM
dedicated chips, such as HY12P-series and HY313x-series chips to solve the problems.
3. Function introduction of new chip trend
The new trend of the portable digital meter industry should have unique product function planning in
order to prevent from price war, such as intelligent electrical meter; moreover, more flexible DMM
dedicated chip is necessary; the functions of the new chip trend can be classified into the following items:
3.1. Programmable switch network
Previously, the DMM dedicated chips had constant function and range switch networks; the advantages
of which were easy to design; however, unique product function planning cannot be realized by flexibly
switching multi-function network. All of the DMM dedicated chips introduced by the document have a
programmable switch network, such that the portable digital meter can have more space for development.
Please refer to HY313x configuration settings and HY12P65 configuration settings for more information
about detail function network settings.
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
RLU
capacitor array
RLD
RLU
RLD
FBSENSE
PA<0>
PA<1>
PA<2>
PA<3>
PA<4>
PA<5>
PA<6>
PA<7>
VREF
AGND
10M
1M
100k
10k
1k
PTC + 100
VOLT/OHM/CAP/DT
OH
M/C
AP
/DT/
mV
PS7
DS7
FS7
SS7
PS6
DS6
FS6
SS6
PS5
DS5
FS5
SS5
PS4
DS4
FS4
SS4
PS3
DS3
FS3
SS3
PS2
DS2
FS2
SS2
PS1
DS1
FS1
SS1
PS0
DS0
FS0
SS0
ACC<6:0>
SMODE<5>
SM
OD
E<4
>
SVSO1
SV
SO
2
SV
SO
2
SV
SO
2
SCP
SCN
PA<8>PS8
DS8
FS8
SS8
PA<9>PS9
DS9
FS9
SS9
AGND VSS VDD
SV
DD
SV
SS
SA
GN
D
MUX
VREF VDS<17>VDS<16>VDS<15>
VDS<1>VDS<2>VDS<3>
AGNDN<9>AGNDN<8>AGNDN<7>AGNDN<6>
PB<7>
AGNDP<9>AGNDP<8>AGNDP<7>AGNDP<6>AGNDP<0>
FUVR<3:0>SMODE<3>
CPO
VREF
PB<0>PB<0>900K
PB<8>PB<8>100KSDIO
AGND
30
7.5p
1 0 0 0 0 0 0
SA
GN
DS
VD
DS
VS
SS
VS
O1
SV
SO
2S
CP
SC
NSMODE<3:0> C
PO
0 1 0 0 0 0 0
0 0 0 0 X0 0 0 1 X
0 0 1 0 0 0 00 0 1 0 X0 0 1 1 X0 1 0 0 X0 1 0 1 X0 1 1 0 X0 1 1 1 X
0 0 0 0 0 0 0
0 0 0 1 0 0 01 0 0 1 0 0 00 1 0 0 1 1 00 0 1 0 1 0 1
1 0 0 0 0 0 00 1 0 0 0 0 0
1 0 0 X 01 0 0 X 1
0 0 1 0 0 0 01 0 1 X 01 0 1 X 11 1 0 X 01 1 0 X 11 1 1 X 01 1 1 X 1
0 0 0 0 0 0 0
0 0 0 1 0 0 01 0 0 1 0 0 00 1 0 0 1 1 00 0 1 0 1 0 1
▲HY3131 Analog Switch Network
3.2. High-resolution Σ-Δ ADC
Previously, the ADCs of the DMM dedicated chips manufactured by large international companies
adopted the double slope integrating structure. however, the conversion speed of the analog to digital
converter of the structure was slow, and the quality of the integrating capacitor could influence the overall
stability and error of the converter. In general, the integrating capacitor needed to use high-cost materials,
such as MPE or MPP, and was hard to achieve high resolution.
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
In recent years, the Σ-ΔADC is gradually used for industrial controls and high-class meters; the most
important advantage of the ADC is that the ADC has less peripheral circuits and high conversion speed, high
resolution and high accuracy; besides, the ADC is not easily influenced by the 50/60 HZ frequency of the
power system; moreover, the peripheral cost of the ADC is lower than that of the double slope integrating
ADC. 。
3.3. Digital RMS circuit
The AC signal measurement is necessary for either voltage or current. However, , the AC signal
measurement circuit could be divided into the average response circuit measurement circuit and the true
RMS conversion dedicated component measurement circuit previously; both of which needed additional
components. All of the DMM dedicated chips introduced by the document have a high-precision Σ-ΔADC,
and the conversion result will be processed by the high-speed calculation of the inner hardware to realize the
digital RMS and inrush current measurement functions; besides, which can be integrated with the peak hold
measurement to realize higher peak factor signal measurement.
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
SADFRN<1:0>
OP1OOP2O
PB<4>PB<7>
MUX
SADFIP<1:0>
ADFIP
RLUAGNDPB<3>PB<5>
MUX
SADFIN<1:0>
ADFIN
AD2IN
FBREFOVREF
PB<6>
MUX
SADFRP<1:0>
ADFRP
ADFVR+
RLUAGNDPB<3>PB<5>
MUX
ADFRN
ADFVR-
AD2IP
ADFIG[1:0]ADFRG
ΣΔAD
VR+ VR-
ADF_CLKENAD2
+ VR:x1,x1/3 -
1bit
Comb Filter
3
ADFOSR[2:0]
19bit
ADCIFInterrupt
AD2
INX
ADFCHP
OP1OOP2O
PB<4>PB<7>
MUX
SADPIP<1:0>
ADPIP
RLUAGNDPB<3>PB<5>
MUX
SADPIN<1:0>
ADPIN
ADPIN
ADPIP
ADPIG[1:0]ADPRG
ΣΔAD
VR+ VR-
ADF_CLKENAD3
SI:x1/2,x1,x3/2,x2
+ VR:x1,x1/3 -
1bit
Comb Filter
3
ADFOSR[2:0]
19bit
ADCIFInterrupt
AD3
INX
ADPCHP
MUX
FAST ADC MUL
LPF/n _
X
LPFBW<2:0>
19
FAST ADC
LPF/n
_Y
LPFBW<2:0>
19
38MUX
SD
O23
SI:x1/2,x1,x3/2,x2
HPF/n
HPF/n
Y
MUXAD3DATA<18:0>AD2DATA<18:0>
SD
O23
AD2<18:0> Peak Hold
EN
PK
H
PKHMAX<18:0>
LPFDATA<18:0>AD2<18:0> PKHMIN<18:0>
AD1<23:5>
PK
HS
EL<
1:0>
MUXAD3_LPF<18:0>AD2_LPF<18:0>
SD
O23
LPFDATA <18:0>
RMSDATA [37:0]
AD2DATA<18:0>
AD3DATA<18:0>
AD3_LPF<18:0>
AD2_LPF<18:0>
SV
XI
Square
LPF/n
LPF/n
RMS_V
RMS_I
38
38
X
▲ RMS measurement structure block diagram of HY3131
3.4. Operational amplifier
In general, under the lower voltage range, current range and temperature measurement function, small
signals are amplified to the allowable range of the converter and then the signal quantization conversion is
executed. The DMM dedicated chips introduced by the document can be integrated with the
programmable switch network to form a signal buffer or non-inverting amplifying circuit.。
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
OP1 OP1O
SENSEFB
RLUAGND
PB<1>PB<2>PB<3>
PB<0>MUX
IN_OP2
OP2
SENSEFB
RLUAGND
PB<1>PB<2>PB<8>
PB<0>MUX
IN_OP1
OPS<2>
OPS<2>
OPS<1>
OPS<1>
OP2O
OPCHP<1:0>
OP
1N
OP
1O
OP
2N
OP
2O
◄ HY3131 OPAMP Switch Network
3.5. Low-pass filter
。In some electromechanical measurement applications, the signals to be measured may include surges
or other high-frequency signals. The low pass filter can be used to filter out the high-frequency signals, and HY313x can use the OP inside the chip to realize the function of the third-order LPF.
▲According to the above figure, the original waveform is 1V/60Hz plus 0.1V/4KHz; after
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
the waveform passes through the low pass filter, the waveform is filtered to be 1V/60Hz.
VSENSEFB
RLUAGND
PB<1>PB<2>PB<3>
PB<0>MUX
SOP2P<2:0>
IN_OP2
OP2
OPS<2>
OPS<2>
OP2O
OP
2O
OP
2N
1.21k 470nF
OP1 OP1O
VSENSEFB
RLUAGND
PB<1>PB<2>PB<8>
PB<0>MUX
IN_OP1
SOP1P<2:0>
90kAGND
10k
OPS<1>
OPS<1>
OPCHP<1:0>
OP
1O
OP
1N
4.02k 2.47k
100nF100nF
AGND AGND
PB
<2>
▲The function of the third-order LPF is realized by HY3131.
3.6. Peak hold measurement circuit
Some electromechanical measurement applications need to measure the peak value; then, it is necessary
to use the peak hold circuit to lock the voltage, and the use the analog to digital converter to convert the
voltage. However, the capacitor used by this kind of circuit to lock the voltage tends to be influenced by the
external environment. All of the DMM dedicated chips introduced by the document have the digital peak
hold function to compare the analog-to-digital conversion results so as to achieve higher accuracy.
Peak Hold
ENPK
H
PKHMAX<18:0>
LPFDATA<18:0>AD2<18:0> PKHMIN<18:0>
AD1<23:5>
PKH
SEL<
1:0>
◄ HY3131 Peak Hold Block Diagram
INPUT3
26
+
-
OUTPUT
3
26
+
-
▲ Low Drift Peak Detector
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
3.7. Inrush current measurement
In recent years, some tong-test ammeter providers proposed the in-rush current measurement, which
means “in a three-phase motor, the in-rush current usually lasts 75~150mS and has a current peak between
500%~1200%, which is short but the instantaneous increase will result in some problem”. All of the DMM
dedicated chips introduced by the document have the swift AC signal conversion function, which can
capture the in-rush current.
Cur
rent
In-Rush Current100 ms
Time
Running Current
▲ In-Rush Current
3.8. Temperature sensor
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
Some portable electrical measurement devices have the temperature measurement function in addition
to the electricity measurement and component measurement functions. The most frequently-used
temperature detectors are the following 4 types: the thermocouple detector, the resistance temperature
detector (RTD), the thermistor detector and IC detector. In general, the portable electrical measurement
devices adopt the thermocouple measurement structure; its principle is that the contact of two metals will
result in the voltage caused by Seebeck effect. However, as the voltage is 0 when the temperature to be
measured is equal to the environmental temperature, it is necessary to perform “Cold-Junction
Compensation”. All of the DMM dedicated chips introduced by the document have a temperature sensor.
▲ Temperature Measurement Circuit. (data resource: Texas Instruments OPAx235
Datasheet)
3.9. Standard serial interface
HY12P-sereis chips have the UART (Universal Asynchronous Receiver/Transmitter) interface. The
new-generation portable digital meters usually have the UART interface and the computer communication
function, which can achieve the automatic test and the automatic calibration functions to reduce to cost of
the manpower. The UART interface can completely change the usage habit of users; for example, the
product can be integrated with the wireless communication module, such as Bluetooth or WiFi module to
communicate with a smart phone or tablet computer to separately perform measurement, displaying and data
statistics analysis.
© 2016 HYCON Technology Corp www.hycontek.com
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New Trend of Digital Multimeters chip
HY313x-sereis chips have the SPI interface; the component is a DMM analog front end dedicated chip,
which can be integrated with the MCU control chip to realize the products with special displaying screens, such as the following products. The SPI is the standard serial transmission interface most frequently used in microcomputer systems, and can provide higher transmission speed. 3.10. MCU
HY12P-series chips not only have the DMM dedicated analog front end circuit, but also is integrated with the MCU having the 80bit RISC, which is suitable for middle-class or low-class meters, and can save the circuit layout space for the products in order to reduce the size of the products. 3.11. Wider temperature usage range
Previously, the operation temperature of the DMM dedicated chips manufactured by the large international companies is about 0 ℃~50℃; however, some users need wider usage range; thus, the operation temperature of all products of HYCON is -40 ℃~85℃. 4. References
HY3131 (50,000 counts DMM Analog Front End) Datasheet HY12P65 (DMM Specialized IC Embedded Digital T-RMS) Datasheet HY12P (Digital Multimeter) Family User’s Guide HY313x configuration settings HY12P65 configuration settings
5. Modification record
The following content describes the major differences from the document, and the changes of punctuation
marks and character forms are not described in the following content. 。
Date Document
version Page Remark
2016/08*20 V01 ALL New release
© 2016 HYCON Technology Corp www.hycontek.com
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