Applicaitons | Home > Applicaitons |
| Applicaitons | Overview |
|---|---|
| HART Communication | The two-wire analog 4/20mA current loop became a standard for industrial control instrumentation in the mid-1970s. In the next decade, microcontrollers (MCU) started to be used by many intelligent control instruments. More and more information are transmitted between the instruments. There was an urgent need of a simple digital two-way communication standard. |
| Body Scale | Electronic body scale has become increasingly popular as people are paying more and more attention to their own health. Compare to the previous mechanical version, electronic body scale has the advantage of higher portability, digital display, and measuring accuracy. SD8000S is designed specifically to reduce the production cost of such application. |
| Pricing Scale | Nowadays there are two major kinds of electronic pricing scale circuits: one built with discrete components, the other with single ADC IC. The first type is more complex and expensive. The second type has the advantage of simple circuitry, high precision, and good stability. SD8102, with its built-in MCU and high precision ADC, is an excellent single chip solution for such application. It can ensure the scale’s accuracy and stability while reducing the circuit complexity and manufacturing cost. |
| Kitchen Scale | Electronic kitchen scale is becoming more popular in the kitchen. Unlike previous spring scale, the resolution and accuracy of electronic kitchen scale have been greatly improved with the coordination from pressure sensor and peripheral control circuit. SD8006 can be used in the design resulting in lower manufacturing cost. |
| DC Energy Meter | DC electric energy measurement is needed in solar battery, electric vehicle, storage battery, DC power supply, and other equipment that deals with DC signals. It is also used in mining and industrial enterprises, civil construction, building automation, and other area where DC power network exists. The DC electric energy metering solution using SD8103 has the advantage of high precision and simple periphery. |
| Digital Temperature Measure | Traditional temperature measurement requires several stand alone components. The signal has to be amplified, linearized, and frequently digitized before being used. All these functions are combined in SD5003, SD5020, or SD5075. |
| Digital DC/AC Voltage/Current Meter | Digital voltmeter/ammeter can be built with SD8110, SD8111, SD8103, and a small amount of peripheral devices. AC signal at 45-65Hz can be measured directly without converting to DC. |
| Single Phase Energy Meter | A single-phase energy meter can be built using SD3001 and a small amount of peripheral devices. Power source is the classical RC step down network. Voltage signal comes from resistor divider. Current is sampled through manganin resistor. High frequency CF output is provided for meter calibration. |
The two-wire analog 4/20mA current loop became a standard for industrial control instrumentation in the mid-1970s. In the next decade, microcontrollers (MCU) started to be used by many intelligent control instruments. More and more information are transmitted between the equipments. Highway Addressable Remote Transducer (HARTTM) fieldbus standard is compatible with the 4/20mA analog system. It is used in a wide range of applications, and has become the de facto international standard in the field of intelligent industrial control.
HART works in half-duplex communication mode. Digital signal communication is realized on top of the existing analog signal transmission line. Products with such capability have strong competitive advantage over the pure analog system.
SD2015 HART modem IC from Hangzhou SDIC Microelectronics is used in the HART communication module of intelligent field instruments. It offers simple peripheral circuitry and high operational reliability.
Electronic body scale has become increasingly popular as people are paying more and more attention to their own health. Compare to the previous mechanical version, electronic body scale has the advantage of higher portability, digital display, and measuring accuracy. SD8000S is designed specifically to reduce the production cost of such application. Two body scale designs are described here using SD8000S: one for LCD display, and the other for LED display.
Capacity of both designs can be either 150kg or 180kg at 0.1kg increment. They use 3V button or regular battery as power source. The periphery circuit comprises only seven capacitors (three 1uF and four 0.1uF). Calibration data is stored in the built-in OTP, thus there is no need for the external EEPROM. OTP programming voltage is 2.4V-3.6V. All I/O ports have 10mA source/sink capability. They can direct drive the LED display without using additional drive IC.
Typical body scale with SD8000S and LCD application diagram
Typical body scale with SD8000S and LED display application diagram
Nowadays there are two major kinds of electronic pricing scale circuits: one built with discrete components, the other with single ADC IC. The first type is more complex and expensive. The second type has the advantage of simple circuitry, high precision, and good stability. SD8102, with its built-in MCU and high precision ADC, is an excellent single chip solution for such application. It can ensure the scale’s accuracy and stability while reducing the circuit complexity and manufacturing cost.
Typical pricing scale with SD8102 application diagram
Electronic kitchen scale is becoming more popular in the kitchen. Unlike previous spring scale, the graduation and accuracy of electronic kitchen scale have been greatly improved with the coordination from pressure sensor and peripheral control circuit. Performance of the peripheral control circuit has to be enhanced too because of these improvements. One also has to consider the cost factor.
SD8000S can be used in 20,000:1 maximum dynamic range scales. SD8006 can be used in 30,000:1 maximum dynamic range scales. They both have timing and temperature measurement functions. SD8000S has 4X14 LCD drivers. SD8006 LCD drivers can be 4X28 or 8X24. The kitchen scale designs using SD8000S or SD8006 do not need any external EEPROM. They use 3V button or regular battery as power source. Periphery circuit of the LCD display solution comprises only six or seven capacitors and one backlight current-limiting resistor. Capacity and increment are chosen during calibration. Capacity options are 7kg, 5kg, 3kg, 2kg, and 1kg. Increment options are 1g, 0.5g, 0.2g, and 0.1g.
Typical kitchen scale with SD8006 and LCD application diagram
Digital multimeter is a multifunction, multi-range measuring instrument. It is used more and more often in daily life.
Previous multimeter design using 7106 type IC requires many peripheral components. The operator has to manually adjust a variable resistor in order to calibrate the meter. The production process is slow and inconvenient.
Digital multimeter design using SD8160 has the advantage of multiple functions, simple periphery, and software calibration. It is the optimal choice for multimeter design.
This multimeter design solution has 1999 or 3999 display options. Display symbols include Ω, kΩ, uV, mV, V, uA, mA, A, uF, nF, Hz, kHz, ℃,℉, and hFE. The design measures multiple parameters including AC / DC voltage, AC / DC current, resistance, capacitance, open/short circuit, diode, transistor beta, frequency, and temperature. Backlight and HOLD function are provided.
Typical multimeter with SD8160 application diagram
DC electric energy measurement is needed in solar battery, electric vehicle, storage battery, DC power supply, and other equipment that deals with DC signals. It is also used in mining and industrial enterprises, civil construction, building automation, and other area where DC power network exists.
The DC electric energy metering solution using SD8103 has the advantage of high precision and simple periphery. This solution performs the following functions:
Typical DC energy meter with SD8103 application diagram
Traditional temperature measurement requires several stand alone components. The signal has to be amplified, linearized, and frequently digitized before being used. All these functions are combined in SD5003, SD5020, or SD5075.
Digital temperature sensor IC combined the temperature sensor, amplifier, ADC, linearization functions all in one IC. Every part is calibrated in factory before shipment. The temperature data in digital format is sent out serially.
The following design uses SD5020 as temperature sensor. SD8103 reads the data from SD5020, and disply them in LED. The part works at -55 to +125C, display resolution is 0.1C. Error is ±0.5C at -10 to +85C, and ±1C at -55 to +125C range.
Typical temperature measurement with SD8001 application diagram
Digital voltmeter/ammeter can be built with SD8110, 8111, or 8103, and a small amount of peripheral devices. AC signals at 45 to 65 Hz can be measured directly without conversion. Calibration is done by software.
SD8110 supports 4 X 8 LCD or LED drives. Decimal point can be selected through jumper. Alarm output is optional.
SD8111 supports 4 X 14 LCD or LED drives. Decimal point, full scale range, pass code, signal ratio, and alarm output can be selected and set through switches.
SD8103 supports 4 X 20 LCD or LED drives. It can be used to build three phase voltmeter or ammeter. AC or DC measurement, decimal point, full scale range, pass code, signal ratio, alarm output , 485 communication, and current loop output can be selected and set through switches.
LCD DC/AC voltage meter with SD8110 typical application diagram
LED DC/AC current meter with SD8110 typical application diagram
LCD DC/AC voltage meter with SD8111 typical application diagram
LED DC/AC current meter with SD8111 typical application diagram
LCD DC/AC voltage meter with SD8103 typical application diagram
LED DC/AC current meter with SD8103 typical application diagram
A single-phase energy meter can be built using SD3001 and a small amount of peripheral devices. Power source is the classical RC step down network. Voltage signal comes from resistor divider. Current is sampled through manganin resistor. High frequency CF output is provided for meter calibration.
SD3001 single phase energy meter typical application diagram