The IIS Chip Gallery
Chopper_Amplifier (1995)
by
| Application | Amplifier |
| Technology | 1000 |
| Manufacturer | ES2 |
| Type | Research Project |
| Package | DIP24 |
| Dimensions | 1260μm x 1100μm |
| Voltage | 5 V |
| Power | 3.5 mW |
A notable trend in microsystem research are intelligent sensors integrated on the same silicon die and fabricated in the same technology as the electronic circuits. Given the strict cost limitations imposed by the sensor market, a combination of micro sensor and circuit fabricated in a standard CMOS technology makes the resulting micro-system competitive in price by reducing the cost and complexity of packaging and by tapping the strong manufacturing base of these IC technologies.
Sensors implemented in a standard (CMOS) technology, however, tend to lower sensitivity compared to those in specialized technologies. This loss in performance must be compensated by the integrated interface electronics, which makes the design of the latter a challenging task.
In this project a highly sensitive chopper instrumentation amplifier system for CMOS compatible thermo electric infrared sensors has been developed. The system consists of a three-stage amplifier chain and an on-chip oscillator for clock generation. The amplifier features a digitally programmable gain of up to 800 with a 500Hz bandwidth and a CMRR of more than 70dB. The equivalent input low-frequency noise is 15nV/sqrt(Hz) and the typical residual input offset is as low as 1.5uV. The total power spe consumption of the system is 3.5mW.