4GHz Op Amps Achieve Less Than 1pA Input Bias Current

Linear Technology has introduced the LTC6268-10 single and dual LTC6269-10 4GHz FET-input op amps for high dynamic range and high-speed transimpedance amplifier (TIA) applications. These decompensated amplifiers extend the speed and dynamic range capabilities of this ultralow bias current op amp family for applications with a gain of 10 or higher. Input bias current is 0.9pA max over the -40°C to 85°C temperature range and just 4pA max over the entire -40°C to 125°C temperature range. Wideband voltage and current noise is 4nV/vHz and 7fA/vHz, respectively. With 0.45pF input capacitance and 1000V/µs slew rate, the LTC6268-10 and LTC6269-10 are well suited for photodiode and photomultiplier (PMT) circuits, high impedance sensor applications and for driving analog-to-digital converters (ADCs).

The LTC6268-10 data sheet features circuit and layout techniques to maximize TIA performance, with example circuits ranging from 20kO transimpedance gain at 210MHz bandwidth, to 402kO transimpedance gain at 34MHz bandwidth. The LTC6268-10 is available in a 6-lead SOT-23 package, as well as an 8-lead SOIC with guard pins to protect against board leakage currents. The LTC6269-10 is available in an MSOP-8 with exposed pad and in 3mm x 3mm DFN-10 packages. The LTC6268-10 and LTC6269-10 are fully specified over the industrial -40°C to 85°C and -40°C to 125°C temperature ranges. Prices start at $2.90 each for the LTC6268-10 and $4.90 each for the LTC6269-10 each in 1000-piece quantities.