The TSU111 and TSU112 from STMicroelectronics are operational amplifiers which may be used in circuits supplied by a lithium-ion coin cell battery, or by a regulated voltage in low-power applications.
The op amps draw just 900nA when operating from a supply voltage of 3.3V at 25°C. They work with any supply voltage in the range from 1.5V to 5.5V, fitting the output-voltage profile of standard lithium coin cells.
The TSU11x op amps provide accurate amplification of low-voltage sensor signals: the input-offset voltage is a maximum 150μV at an ambient temperature of 25°C. They also offer 11.5kHz of gain bandwidth.
The performance of two TSU111 op amps is demonstrated in ST’s P-NUCLEO-IKA02A1, a gas-sensing expansion board for STM32 Nucleo microcontroller development boards.
The TSU111 op amps perform signal conditioning for a choice of electrochemical gas sensors that may be mounted in standard sockets on the expansion board. The expansion board includes a low-current precision analogue temperature sensor, the STLM20, for compensation of gas readings.
- 3.6μVpp noise over 0.1Hz to 10Hz bandwidth
- Rail-to-rail input and output
- 10pA input bias current at 25°C
- 4kV ESD rating on the human body model
- Sensor signal conditioning
- Battery-powered and portable devices