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Affordable Precision Current Sensing


onsemi brings affordability to precision current sensing with the addition of the NCS199 & NCS21x family of devices. NCS199 & NCS21x are resistor shunt based devices, providing cost savings and PCB size reductions over hall sensor based solutions.
High Side vs. Low Side Sensing
High Side Sensing 

High Side

• Detects load shorts
• No ground path resistance

• More expensive than low side sensing
• No ground path resistance
Low Side Sensing

Low Side

• Simple Implementation
• Inexpensive

• Cannot detect load shorts
• Resistance in ground path
Key Applications


• 12V-48V DC-DC Converters (High Side Current Sensing)
• Electric Oil Pump, 3 Phase Motor (Low Side Current Sensing)
• HEV Inverter, 3 Phase Motor (Low Side Current Sensing)
• E-bike, 3 Phase Motor (Low Side Current Sensing)
• Solenoid/Glow Plug Control - Diesel (High Side Current Sensing)
• Gasoline Direct Injection (Low Side Current Sensing)

Body Control & Safety

• Electric Parking Brake (Low Side Current Sensing)
• Electronic Power Steering (Low Side Current Sensing)
• Active Suspension (Signal Conditioning)
• Next Gen. PM Emissions Sensors (Precision Signal Conditioning)
• Rearview Mirror Dimming (Driving Electro-chromatic Element)

Multimedia & Infotainment

• "Qi" Wireless Charging (High Side Current Sensing)
• Microphone Pre Amplifier (Low Noise Op-Amp)


• SMPS Controller Feedback Loop (High Side Current Sensing)
• Rear Dimming Light (RDL) (Low Side Current Sensing)

NCS199 & NCS21x Current Sense Amplifiers

The NCS199 and NCS21x devices are voltage output current shunt monitors that measure voltage across shunts at common-mode voltages from -0.3 V to 26 V, independent of supply voltage. Multiple fixed gains are available: 50 V/V, 75 V/V, 100 V/V, 200 V/V, 500 V/V, or 1000 V/V. The low offset of the zero-draft architecture enables current sensing with maximum drops across the shunt as low as 10 mV full-scale. The devices cab operate from a single +2.7 V to +26 V power supply, drawing a maximum of 100 µA of supply current. All versions are specified over the extended operating temperature range (–40° C to +125° C).
• Low offset drift 
• Wide common mode input range       -0.3 V to 26 V
• Supply Voltage range from 2.7 V       to 26 V
• Low offset voltage of ±60 µV,             ±100 µV, and ±150 µV Max
• ±1% and ±1.5 % Accuracy for              NCS21x & NCS199 respectively
• High Precision Current Sensing
• High-Side Current Sensing for             High Voltage Systems
• Flexible System Supply Voltage
• Low Value Current Sense                     Resistors for Better Power                   Efficiency
• Temperature Sensitive                         Applications
Part Numbers Available from RS Gain (V/V) Gain Error Max (%) GBW Typ (MHz) VIOMax (mV) VIO Drift (µV/°C)
NCS210SQT2G 200 ±1.0 0.040 ±0.060 0.6
NCS211SQT2G 500 ±1.0 0.025 ±0.060 0.6
NCS214SQT2G 100 ±1.0 0.060 ±0.060 0.6
NCS199A1SQT2G 50 ±1.5 0.100 ±0.150 2.0
NCS199A2SQT2G 100 ±1.5 0.060 ±0.150 0.6
NCS199A3SQT2G 200 ±1.5 0.040 ±0.150 0.6
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