1 Features
• Gain bandwidth product: 900 MHz
• Internal switches for programmable gain
• High impedance FET inputs
• Input voltage noise: 2.2 nV/√Hz
• Slew rate: 350 V/μs
• Supply voltage range: 3.3 V to 5.25 V
• Quiescent current: 22 mA/channel
• Power down mode IQ: 75 μA
• Temperature range: -40 °C to 125 °C

2 Applications
• Switchable transimpedance amplifier
• Smart munitions
• Laser distance measurement
• Optical time domain reflectometry (OTDR)
• Silicon photomultiplier (SiPM) buffer
• Photomultiplier tube post amplifier
• High speed programmable gain amplifier

3 Description
The OPA3S2859 is a wideband, low-noise
programmable gain amplifier with CMOS inputs
for wideband transimpedance and voltage amplifier
applications. When the device is configured as a
transimpedance amplifier (TIA), the 0.9-GHz gain
bandwidth product (GBWP) enables high closedloop
bandwidths in low-capacitance photodiode (PD)
applications.
The three internal switched feedback paths along
with an optional parallel non-switched feedback path
allows for up to four selectable gain configurations.
The internal switches minimize parasitic contributions
to increase performance compared to systems that
use discrete external switches. Each switch is
optimized for feedback resistor values ranging from
< 1 kΩ to > 100 kΩ for wide dynamic range
applications. The selected switch path is controlled for
both channels using a 2-wire parallel interface. For
each channel selected, the gain path can also be held
constant by exerting the latch pin, which subsequently
disables switch control for the selected channel and
prevents the channel from changing gain.