应用与设计

Electronic Scale

详情介绍

Electronic Scale

Overview

Electronic scales are widely used in kitchens and as bathrooms because they can quickly make accurate weight measurements.
A load sensor called a load cell is used for weight measurement. Because the output voltage of this sensor is very small, the signal is amplified by an op-amp, or operational amplifier (instrumentation amplifier), and input to an A/D converter. A microcontroller (MCU) converts the signal to weight based on the conversion results of the A/D converter and displays it on an LCD.
Renesas Smart Analog devices provide the instrumentation amplifier necessary for processing sensor signals, helping to reduce the time and effort required for circuit design and adjustment. The Smart Analog IC 101 has a built-in high-precision 16-bit delta-sigma A/D converter, which can be used in combination with a low cost microcontroller to realize a highly precise and low cost end product.
Renesas offers a rich lineup of microcontrollers that can be used for system control. The RL78/L1x and R8C/Lx Series have a built-in LCD controller/driver that enables the number of external components to be reduced. For highly precise measuring, we offer the RX21A Group with built-in high-precision delta-sigma A/D converter

System Block Diagram

Recommended Products

Block Semiconductor device Recommended products Features, etc.
Control MCU MCU RL78/L1C 12-bit A/D Converter, LCD driver,
USB Host / Function Module
RL78/L12 , RL78/L13 10-bit A/D converter, LCD driver
R8C/Lx Series
RX21A Group 24-bit ΔΣ A/D converter, E2 Data Flash
Analog front end Smart Analog IC Smart Analog IC101 16-bit delta-sigma A/D converter
Programmable gain instrumentation amplifier: 1 channels
Serial interface (SPI communications or UART communications selectable)
Operating voltage: 2.7 to 5.5 V
Smart Analog IC301 Programmable gain instrumentation amplifier: 1 channels
Serial interface (SPI communications)
Operating voltage: 2.2 to 3.6 V (low-voltage product)
Smart Analog IC501 Programmable gain instrumentation amplifier: 1 channels
Serial interface (SPI communications)
Operating voltage: 3.0 to 5.5 V
MCU peripheral Reset IC RNA519xx Series Variable detection voltage
EEPROM R1EX24xxx Series I 2 C(*1) bus interface for saving settings
R1EX25xxx Series SPI(*2) bus interface for saving settings

*1 I 2 C: Inter-Integrated Circuit
*2 SPI: Serial Peripheral Interface