1 Features

1• High-Drive Mode:

– GBW (G = 100): 120 MHz

– Slew Rate: 115 V/μs

– 16-Bit Settling at 4-V Step: 280 ns

– Low Voltage Noise: 2.5 nV/√Hz at 10 kHz

– Low Output Impedance: 1 Ω at 1 MHz gain–

Offset Voltage: ±100 μV (max)

– Offset Voltage Drift: ±3 μV/ºC (max)

– Low Quiescent Current: 2 mA (typ)

• Low-Power Mode:

– GBW: 1 MHz

– Low Quiescent Current: 270 μA (typ)

• Power-Scalable Features:

– Ultrafast Transition from Low-Power to High-

Drive Mode: 170 ns

• High AC and DC Precision:

– Low Distortion: –122 dBc for HD2 and –140

dBc for HD3 at 100 kHz

– Input Common-Mode Range Includes Negative

Rail

– Rail-to-Rail Output

– Wide Temperature Range: Fully Specified from

–40°C to +125°C

2 Applications

• Precision SAR ADC Drivers

• Precision Voltage Reference Buffers

• Programmable Logic Controllers

• Test and Measurement Equipment

• Power-Sensitive Data Acquisition Systems

3 Description

The OPAx625 family of operational amplifiers are

excellent 16-bit and 18-bit, high-precision, SAR ADC drivers with low THD and noise that allow for a

unique power-scalable solution. This family of devices

is fully characterized and specified with a 16-bit

settling time of 280 ns that enables a true 16-bit effective number of bits (ENOB). With a high dc

precision of only 100 μV offset voltage, a wide gain–

bandwidth product of 120 MHz, and a low wideband

noise of 2.5 nV/√Hz, this family is optimized for driving high-throughput, high-resolution SAR ADCs,

such as the ADS88xx family of SAR ADCs.

The OPAx625 features two operating modes: high-

drive and low-power. In the innovative low-power

mode, the OPAx625 tracks the input signal allowing

the device to transition from low-power mode to high- drive mode at 16-bit ENOB within 170 ns.

The OPAx625 family is available in 6-pin SOT and

10-pin VSSOP packages and is specified for operation from –40°C to +125°C.