ON Semiconductor – Current-sense amplifiers achieve high accuracy and high stability over temperature


ON Semiconductor’s NCS199x and NCS21x are current-shunt amplifiers which measure the voltage across a shunt resistor at common-mode voltages between -0.3V and 26V, independent of the supply voltage. The two series of parts offer the designer a wide choice of fixed gain values.

The low input offset of their zero-drift architecture enables these devices to perform current sensing at a maximum voltage drop across the shunt as low as 10mV full-scale. This helps system designers to achieve high energy efficiency and to minimise power losses.

The NCS199x and NCS21x devices can operate from a single 2.7V to 26V power supply, drawing a maximum 100μA quiescent current. All versions are specified over the extended operating temperature range of -40°C to 125°C. Drain current is typically 0.065mA.


  • 7ppm/°C gain error over temperature
  • ±0.01% non-linearity error
  • ±0.1μV/V power-supply rejection ratio
  • 100dB minimum common-mode rejection ratio for NCS199A2 and NCS199A3
  • 97dB minimum common-mode rejection ratio for NCS199A1


  • Power monitors
  • Power adapters
  • Feedback control loops
  • Current sensors
  • E-cigarettes
  • Mobile-device fast chargers
  • Telecoms DC-DC power modules
Part NumberGain (V/V)Maximum Gain Error (%)Gain Bandwidth (MHz)Maximum Input Offset Voltage (mV)Maximum Input Offset Voltage Drift (μV/°C)