Smallest CMOS op-amp optimised for smartphones and compact IoT devices

ROHM has developed an ultra-compact 1.8V-5V, rail-to-rail CMOS op–amp, the TLR377GYZ. It is optimised for amplifying signals from sensors such as temperature, pressure, and flow rate, which are used in smartphones, small IoT devices, and similar applications.

Smartphones and IoT devices continue to shrink in size, requiring smaller components. Op-amps must improve low input offset voltage and noise performance while continuing to shrink the form factor to amplify small signals as required in high-precision sensing accurately.

The device successfully balances miniaturisation with high accuracy (which has been difficult to attain with conventional op-amps) by further evolving proprietary circuit design, process, and packaging technologies cultivated over many years.

Op-amps' input offset voltage and noise generation degrade amplification accuracy and can be suppressed by growing the size of the built-in transistors but at the expense of miniaturisation. In response, the company developed proprietary circuits which attain a maximum offset voltage as low as 1mV without increasing the size of the transistors. Also, proprietary process technology greatly reduces flicker noise, while ultra-low noise is achieved with an input equivalent noise voltage density of 12nV/√Hz by optimising the resistive components at the element level. Also, the new product adopts a WLCSP with a ball pitch of only 0.3mm, using original packaging technology. This decreases size by approximately 69% compared to conventional products and 46% over existing compact products.

The IC-mounted conversion board that can replace SSOP6 packages is also offered to support replacement considerations and initial evaluation.