The THS4509 device is a wideband, fully-differential op amp designed for 5-V data
acquisition systems. It has a low noise at 1.9 nV/√Hz, and low harmonic
distortion of –75 dBc HD2 and –80 dBc HD3 at 100 MHz
with 2 VPP, G = 10 dB, and 1-kΩ load. Slew rate is high at 6600 V/µs, and
with settling time of 2 ns to 1% (2-V step), it is ideal for pulsed applications. It is designed
for a minimum gain of 6 dB, but is optimized for gains of 10 dB.
To allow for DC coupling to analog-to-digital converters (ADCs), its unique output
common-mode control circuit maintains the output common-mode voltage within 3-mV offset (typical)
from the set voltage, when set within 0.5-V of midsupply, with less than 4-mV differential offset
voltage. The common-mode set point is set to midsupply by internal circuitry, which may be
overdriven from an external source.
The input and output are optimized for best performance with the common-mode voltages set
to midsupply. Along with high performance at low power-supply voltage, this design makes it ideal
for high-performance, single-supply 5-V data acquisition systems. The combined performance of the
THS4509 in a gain of 10 dB driving the ADS5500 ADC, sampling at 125 MSPS, is 81-dBc SFDR
and 69.1-dBc SNR with a –1 dBFS signal at 70 MHz.
The THS4509 is offered in a quad, leadless VQFN-16 package (RGT), and is characterized
for operation over the full industrial temperature range from –40°C to +85°C.