INSTRUMENTATION AMPLIFIER INA 122
LOW OFFSET VOLTAGE: 250µV max
SUPPLY RANGE –Single Supply: 2.2V to 36V, Dual Supply: –0.9/+1.3V to ±18V
FIGURE 1- PINOUT
FIGURE 2- GAIN EQUATION & GAIN TABLE
FIGURE 3- BASIC CIRCUIT
SAMPLE APPLICATION -INA122 AS LOAD CELL CZL601
AMPLIFIER
FIGURE 5 – LOAD CELL AMPLIFIER USING SINGLE SUPPLY
GAIN RESISTOR DESIGN
Since input signal is in the range of uV range we need maximum gain.there is problem of non linearity at higher gain . I recommends two amplifiers for this purpose .The gain is selected above 40000. ie i have set the pot nearer to minimum position .ie near to 5 ohms.
LOAD CELL CZL601
EQUIVALENT CIRCUIT OF LOAD CELL