The ultra-wide, 900-MHz gain bandwidth product (GBWP) of the OPA859-Q1, combined with the broadband voltage noise of 3.3 nV/√Hz, produces a viable amplifier for wideband transimpedance applications, high-speed data acquisition systems, and applications with weak signal inputs that require low-noise and high-gain front ends. The OPA859-Q1 combines multiple features to optimize dynamic performance. In addition to the wide small-signal bandwidth, the OPA859-Q1 has 400 MHz of large-signal bandwidth (V_OUT = 2 V_PP), and a slew rate of 1150 V/µs.

The OPA859-Q1 is offered in a 2-mm × 2-mm, 8-pin WSON package that features a feedback (FB) pin for a simple feedback network connection between the amplifiers output and inverting input. Excess capacitance on an amplifiers input pin can reduce phase margin causing instability. This problem is exacerbated in the case of very wideband amplifiers like the OPA859-Q1. To reduce the effects of stray capacitance on the input node, the OPA859-Q1 pinout features an isolation pin (NC) between the feedback and inverting input pins that increases the physical spacing between them thereby reducing parasitic coupling at high frequencies. The OPA859-Q1 also features a very low capacitance input stage with only 0.8-pF of total input capacitance.