High-precision bidirectional current monitors

Diodes Incorporated have announced a series of bidirectional current monitors based on a high-stability zero-drift architecture. These devices are capable of accurately measuring very low sense voltages across a wide range of common-mode voltages. Key applications include laptop PCs, battery chargers, industrial servos, servers, power supply racks in server farms, and robotic systems.

Consisting of six different variants, the DIODES ZXCT199 series of current monitor devices each feature a precision chopper stabilized op-amp for high accuracy operation.Their low offset voltage enables current sensing with maximum drops across shunts as low as 10mV full-scale. This allows high currents to be measured via inexpensive, low-value shunt resistor components.

The ZXCT199 series are voltage output type devices, and are available in three fixed voltage gain options in 50V/V, 100V/V, and 200V/V. These devices can measure voltages across shunts at common-mode voltages from -0.1V to 26V, independent of the supply voltage.

The new current sensors from Diodes have an operational temperature range of -40°C to 125°C, exhibiting minimal gain error across this. For the A and B versions, the maximum gain error over temperature is ±1.0%, while for the C version, it is ±0.8%. Their offset voltage levels are a maximum of ±150μV for the A version, ±100μV for the B version, and an ultra-low ±80μV for the highest precision C version. All variants can be powered via a 2.7V to 26V supply, giving them greater application flexibility. A maximum supply current of just 100μA is drawn.

The ZXCT199A, ZXCT199B and ZXCT199C are available at $0.21, $0.23 and $0.25 respectively in 1000 piece quantities.