THS4631 - High Speed FET-Input Operational Amplifier

The THS4631 is a high-speed, FET-input operational amplifier designed for applications requiring wideband operation, high-input impedance, and high-power supply voltages. By providing a 210-MHz gain bandwidth product, ±15-V supply operation, and 100-pA input bias current, the THS4631 is capable of simultaneous wideband transimpedance gain and large output signal swing. The fast 1000 V/µs slew rate allows for fast settling times and good harmonic distortion at high frequencies. Low current and voltage noise allow amplification of extremely low-level input signals while still maintaining a large signal-to-noise ratio.

The characteristics of the THS4631 make it ideally suited for use as a wideband photodiode amplifier. Photodiode output current is a prime candidate for transimpedance amplification as shown below. Other potential applications include test and measurement systems requiring high-input impedance, ADC and DAC buffering, high-speed integration, and active filtering.

The THS4631 is offered in an 8-pin SOIC (D), and the 8-pin SOIC (DDA) and MSOP (DGN) with PowerPAD™ package.

• High Bandwidth:
  • 325 MHz in Unity Gain
  • 210 MHz Gain Bandwidth Product
• High Slew Rate:
  • 900 V/µs (G = 2)
  • 1000 V/µs (G = 5)
• Low Distortion of –76 dB, SFDR at 5 MHz
• Maximum Input Bias Current: 100 pA
• Input Voltage Noise: 7 nV/√Hz
• Maximum Input Offset Voltage: 500 µV at 25°C
• Low Offset Drift: 2.5 µV/°C
• Input Impedance: 10⁹ || 3.9 pF
• Wide Supply Range: ± 5 V to ± 15 V
• High Output Current: 95 mA