High Bandwidth, High Precision, Low Noise & Distortion Amplifier SAR ADC Driver with Power Scaling

High Bandwidth, High Precision, Low Noise & Distortion Amplifier SAR ADC Driver with Power Scaling - OPA625


The OPAx625 family of operational amplifiers are excellent 16-bit and 18-bit, SAR ADC drivers that are high precision with low THD and noise 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). Along with a high dc precision of only 100 µV offset voltage, a wide gain-bandwidth product of 120 MHz, 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 OPAx625 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.


  • 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
    • Offset Voltage: ±100 µV (max)
    • Offset Voltage Drift: ±3 µV/ºC (max)
    • LowQuiescent 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

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Parametrics Compare all products in High-Speed Op Amps (GBW>=50MHz)

Number of Channels (#)
Total Supply Voltage (Min) (+5V=5, +/-5V=10)
Total Supply Voltage (Max) (+5V=5, +/-5V=10)
BW @ Acl (MHz)
Acl, min spec gain (V/V)
Slew Rate (Typ) (V/us)
Vn at Flatband (Typ) (nV/rtHz)
Vn at 1kHz (Typ) (nV/rtHz)
Iq per channel (Typ) (mA)
Vos (Offset Voltage @ 25C) (Max) (mV)
Operating Temperature Range (C)
Package Group
Package Size: mm2:W x L (PKG)
CMRR (Typ) (dB)
Input Bias Current (Max) (pA)
Offset Drift (Typ) (uV/C)
GBW (Typ) (MHz)
Output Current (Typ) (mA)
2nd Harmonic (dBc)
3rd Harmonic (dBc)
@ MHz
OPA625 OPA2625 OPA2626
Bipolar    Bipolar    Bipolar   
1    2    2   
2.7    2.7    2.7   
5.5    5.5    5.5   
115    115    115   
3.2    3.2    3.2   
2    2    2   
0.1    0.1    0.1   
In to V-
In to V-
In to V-
Shutdown    Shutdown    N/A   
Catalog    Catalog    Catalog   
-40 to 125    -40 to 125    -40 to 125   
SOT-23    VSSOP    VSSOP   
6SOT-23: 8 mm2: 2.8 x 2.9(SOT-23)    10VSSOP: 15 mm2: 4.9 x 3(VSSOP)    8VSSOP: 15 mm2: 4.9 x 3(VSSOP)   
115    117    117   
4000000    4000000    4000000   
0.5    0.5    0.5   
120    80    120   
100    100    100