1 Features
1• 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 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 commonmode
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.