OPA323

ACTIVE

Single, 5.5V, 20MHz, zero-cross low-noise (6nV/√Hz) RRIO operational amplifier

Product details

Number of channels 1 Total supply voltage (+5 V = 5, ±5 V = 10) (max) (V) 5.5 Total supply voltage (+5 V = 5, ±5 V = 10) (min) (V) 1.7 Rail-to-rail In, Out GBW (typ) (MHz) 20 Slew rate (typ) (V/µs) 30 Vos (offset voltage at 25°C) (max) (mV) 1.25 Iq per channel (typ) (mA) 1.6 Vn at 1 kHz (typ) (nV√Hz) 8 Rating Catalog Operating temperature range (°C) -40 to 125 Offset drift (typ) (µV/°C) 0.4 Features Zero Crossover Input bias current (max) (pA) 5 CMRR (typ) (dB) 110 Iout (typ) (A) 0.04 Architecture CMOS Input common mode headroom (to negative supply) (typ) (V) -0.1 Input common mode headroom (to positive supply) (typ) (V) 0.1 Output swing headroom (to negative supply) (typ) (V) 0.01 Output swing headroom (to positive supply) (typ) (V) -0.01
Number of channels 1 Total supply voltage (+5 V = 5, ±5 V = 10) (max) (V) 5.5 Total supply voltage (+5 V = 5, ±5 V = 10) (min) (V) 1.7 Rail-to-rail In, Out GBW (typ) (MHz) 20 Slew rate (typ) (V/µs) 30 Vos (offset voltage at 25°C) (max) (mV) 1.25 Iq per channel (typ) (mA) 1.6 Vn at 1 kHz (typ) (nV√Hz) 8 Rating Catalog Operating temperature range (°C) -40 to 125 Offset drift (typ) (µV/°C) 0.4 Features Zero Crossover Input bias current (max) (pA) 5 CMRR (typ) (dB) 110 Iout (typ) (A) 0.04 Architecture CMOS Input common mode headroom (to negative supply) (typ) (V) -0.1 Input common mode headroom (to positive supply) (typ) (V) 0.1 Output swing headroom (to negative supply) (typ) (V) 0.01 Output swing headroom (to positive supply) (typ) (V) -0.01
SOT-SC70 (DCK) 5 4.2 mm² 2 x 2.1
  • Zero cross amplifier for 1.7V to 5.5V applications
  • High rail-to-rail CMRR: 114dB typical
  • High gain-bandwidth product: 20MHz
  • Fast slew-rate: 33V/µs typical
  • Fast 0.01% settling: 200ns typical for 2V step
  • Low input offset voltage: ±150µV typical
  • Low noise floor: 5.5nV/√Hz typical at 10kHz
  • High output current: ±110mA typical ISC at 5.5V
  • Quiescent current: 1.6mA/ch typical
  • Rail-to-rail input and output
  • Unity-gain stable
  • Drives up to 150pF without sustained oscillations
  • Internal RFI and EMI filtered input pins
  • Operating temperature range: –40°C to 125°C
  • Zero cross amplifier for 1.7V to 5.5V applications
  • High rail-to-rail CMRR: 114dB typical
  • High gain-bandwidth product: 20MHz
  • Fast slew-rate: 33V/µs typical
  • Fast 0.01% settling: 200ns typical for 2V step
  • Low input offset voltage: ±150µV typical
  • Low noise floor: 5.5nV/√Hz typical at 10kHz
  • High output current: ±110mA typical ISC at 5.5V
  • Quiescent current: 1.6mA/ch typical
  • Rail-to-rail input and output
  • Unity-gain stable
  • Drives up to 150pF without sustained oscillations
  • Internal RFI and EMI filtered input pins
  • Operating temperature range: –40°C to 125°C

The OPAx323 family of op amps includes single (OPA323), dual (OPA2323), and quad-channel (OPA4323), low-voltage (1.7V to 5.5V), high-bandwidth (20MHz) amplifiers (op amps) with a zero-crossover input stage and a rail-to-rail output stage. The zero-crossover input stage enables OPAx323 to achieve high linearity and low distortion for input signals with rail-to-rail swing that are typical in ADC driver applications. Gain-bandwidth of 20MHz provides a fast settling response for ADC sampling speeds between 0.5MSPS to 5MSPS depending on the settling performance required. The OPAx323 is well-optimized for power savings as the device consumes just 1.6mA typical quiescent current.

The OPAx323 easily supports precision performance in high gain voltage sensing applications such as the wheatstone bridge, because of a maximum offset drift of 2µV/°C and thermal noise floor of 5.5nV/rt-Hz with a minimum of 100dB CMRR. This unique combination of higher precision (low offset, drift, noise, distortion, and CMRR) and higher gain-bandwidth (fast settling and slewing) enables use in multiple applications such as the motor rotary encoders, microphone audio pre-amplifiers and ultrasonic transducers.

The OPAx323 achieves a high slew-rate of 33V/µs allowing for fast detection of faults in motor current sensing applications. Unlike traditional amplifiers, the zero-cross over input stage allows for identical precision performance for both low and high-side sensing applications, thus making OPAx323 the best choice for current sensing in a variety of end equipments such as the solar string inverters, power delivery, grid and EV infrastructure. OPAx323S devices provide shutdown functionality for additional power savings and help disable the amplifier when idle. The family features standard and small size as well as leaded and QFN packages across all the channel variants.

The OPAx323 family of op amps includes single (OPA323), dual (OPA2323), and quad-channel (OPA4323), low-voltage (1.7V to 5.5V), high-bandwidth (20MHz) amplifiers (op amps) with a zero-crossover input stage and a rail-to-rail output stage. The zero-crossover input stage enables OPAx323 to achieve high linearity and low distortion for input signals with rail-to-rail swing that are typical in ADC driver applications. Gain-bandwidth of 20MHz provides a fast settling response for ADC sampling speeds between 0.5MSPS to 5MSPS depending on the settling performance required. The OPAx323 is well-optimized for power savings as the device consumes just 1.6mA typical quiescent current.

The OPAx323 easily supports precision performance in high gain voltage sensing applications such as the wheatstone bridge, because of a maximum offset drift of 2µV/°C and thermal noise floor of 5.5nV/rt-Hz with a minimum of 100dB CMRR. This unique combination of higher precision (low offset, drift, noise, distortion, and CMRR) and higher gain-bandwidth (fast settling and slewing) enables use in multiple applications such as the motor rotary encoders, microphone audio pre-amplifiers and ultrasonic transducers.

The OPAx323 achieves a high slew-rate of 33V/µs allowing for fast detection of faults in motor current sensing applications. Unlike traditional amplifiers, the zero-cross over input stage allows for identical precision performance for both low and high-side sensing applications, thus making OPAx323 the best choice for current sensing in a variety of end equipments such as the solar string inverters, power delivery, grid and EV infrastructure. OPAx323S devices provide shutdown functionality for additional power savings and help disable the amplifier when idle. The family features standard and small size as well as leaded and QFN packages across all the channel variants.

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* Data sheet OPAx323 20MHz High Bandwidth, 114dB CMRR, Low Voltage (1.7V to 5.5V), RRIO Zero-Cross Operational Amplifier datasheet (Rev. C) PDF | HTML 10 Apr 2025
Application note Create Automated SPICE Designs Using PSpice-for-TI PDF | HTML 27 Oct 2025
Circuit design Half-Wave Rectifier Circuit (Rev. B) PDF | HTML 17 May 2024
Circuit design Photodiode Amplifier Circuit (Rev. B) PDF | HTML 02 May 2024
Application brief Zero-crossover Amplifiers: Features and Benefits (Rev. B) PDF | HTML 08 Nov 2023

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