Ultra-low-power CMOS quad op-amp for sensor conditioning
The STMicroelectronics TS27L4AIDT is a quad CMOS operational amplifier designed for applications where supply current is the primary constraint. Each of the four channels draws 10 µA, making the total quiescent current 40 µA for the entire package. The gain bandwidth product is 100 kHz with a slew rate of 0.04 V/µs, which places this part firmly in the domain of DC and low-frequency signal conditioning — think thermocouple amplifiers, strain-gauge bridges, battery-voltage monitoring, and photodiode front ends where the signal changes slowly. Input bias current is 1 pA, so it does not load high-impedance sources.
The 14-SOIC (3.90 mm width) package is a standard JEDEC outline, so PCB layout is straightforward and second-source footprints are widely available. The ROHS3 compliance covers the current EU directive without exemptions.
What the 0.04 V/µs slew rate means for the BOM
A slew rate of 0.04 V/µs limits the large-signal bandwidth to roughly 6.4 kHz at 1 V peak output. This is not a part for audio line drivers, switching power-supply error amplifiers, or any loop that must settle quickly. It is, however, perfectly adequate for filtering and amplifying DC-coupled sensor outputs where the signal of interest changes at a few hertz to a few hundred hertz. The 100 kHz gain bandwidth supports closed-loop gains up to about 100 before the -3 dB point drops below 1 kHz. If your design needs to pass a 10 kHz square wave cleanly, look at a faster CMOS op-amp like the TS274 (3.5 MHz GBW, 5.5 V/µs slew rate) — but that part draws 1 mA per channel, 100× the supply current.
Output drive and input offset
Each channel can source or sink 45 mA, which is generous for a micropower op-amp and enough to drive a 2 kΩ load to within a volt of the rails. Input offset voltage is specified at 900 µV maximum — not precision territory, but acceptable for general-purpose sensor interfaces where the signal is several millivolts or more. The CMOS input stage gives the 1 pA bias current, so source impedance up to 1 MΩ does not create a significant voltage error.