The ZXCT21xQ Series: Automotive-Compliant Current Shunt Monitors Enable High-Precision Voltage Sensing in Electric Vehicles

Diodes Incorporated introduced the ZXCT21xQ series, a collection of highly precise current shunt monitors specifically designed for electric vehicles (EVs) allowing the measurement of small sense voltages across a broad common-mode voltage range.

The ZXCT21xQ family possesses a zero-drift core with low offset voltage (±30μV) and gain error (±0.5% and ±0.8%), typically ±100nV/°C. This exceptional performance enables accurate current sensing across the shunt, even with minimal voltage drops as low as 10mV (full-scale). Consequently, small-value sense resistors can be utilized to achieve high-precision monitoring of large-magnitude currents, thereby reducing power losses during measurement. Additionally, the devices have a low quiescent current consumption of up to 100μA, maximizing power efficiency.

With a rail-to-rail common-mode sense voltage range of 0-26V, independent of the supply voltage, the ZXCT21xQ series allows for high-side and low-side precision current measurement. The REF pin facilitates bi-directional current flow measurement. The family offers six voltage gain options (50V/V, 75V/V, 100V/V, 200V/V, 500V/V, and 1000V/V), and operates reliably within a temperature range of -40°C to +125°C.

Features

• Automotive AEC-Q100 Grade 1
• Supply Voltage Range: 2.7V to 26V
• Temperature Range: -40°C to +125°C
• Wide Common-Mode Range: -0.3V to 26V
• Support Shunt Drops of 10mV Full-Scale
• Low Offset Voltage: ±30μV (max)
• Quiescent Current: 100μA (max)
• Low Gain Error Drift: 10ppm/°C (max)
• Rail-to-Rail Output Capacity
• Package: 6-pin SOT363

Applications

Current sensing of load/rail currents in brushless DC (BLDC) motor controllers, e-compressors, high-power DC-DC converters, on-board chargers (OBC), battery management systems (BMS), ADAS power supplies, and wireless phone chargers.

Availability and Pricing 

The ZXCT21xQ series is now available at prices ranging from $0.321 to $0.451 per unit in quantities of 1,000.