TC826

TC826 Analog-to-Digital Converter with Bar Graph Display Output Features Bipolar A/D Conversion 2.5% Resolution Direct LCD Display Drive ‘Thermometer’ BAR or DOT Display 40 Data Segments Plus Zero Over Range Plus Polarity Indication Precision On-Chip Reference: 35ppm/°C Differential Analog Input Low Input Leakage: 10pA Display Flashes on Over Range Display HOLD Mode Auto-Zero Cycle Eliminates Zero Adjust Potentiometer 9V Battery Operation Low Power Consumption: 1.1mW 20mV to 2.0V Full Scale Operation Non-Multiplexed LCD Drive for Maximum Viewing Angle General Description In many applications, a graphical display is preferred over a digital display. Knowing a process or system operates, for example, within design limits is more valuable than a direct system variable read out. A bar or moving dot display supplies information precisely without requiring further interpretation by the viewer. The TC826 is a complete analog-to-digital converter with direct liquid crystal (LCD) display drive. The 40 LCD data segments plus zero driver give a 2.5% resolution bar display. Full scale differential input voltage range extends from 20mV to 2V. The TC826 sensitivity is 500µV. A low drift 35ppm/°C internal reference, LCD backplane oscillator and driver, input polarity LCD driver, and over range LCD driver make designs simple and low cost. The CMOS design required only 125µA from a 9V battery. In +5V systems, a TC7660 DC to DC converter can supply the -5V supp...