1 Features

• Fully-Differential Architecture
• Centered Input Common-Mode Range
• Output Common-Mode Control
• Minimum Gain of 2 V/V (6 dB)
• Bandwidth: 1900 MHz
• Slew Rate: 6600 V/μs
• 1% Settling Time: 2 ns
• HD₂: –75 dBc at 100 MHz
• HD₃: –80 dBc at 100 MHz
• OIP₃: 37 dBm at 70 MHz
• Input Voltage Noise: 1.9 nV/√Hz (f > 10 MHz)
• Power-Supply Voltage: 3 V to 5 V
• Power-Supply Current: 37.7 mA
• Power-Down Current: 0.65 mA

2 Applications

• 5-V Data Acquisition Systems High
  Linearity ADC Amplifiers
• Wireless Communication
• Medical Imaging
• Test and Measurement

3 Description

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 V_PP, 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.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Test Configuration

Measured 3rd Order Intermodulation Spurious Signal Level