CI amplificadores

INA2181

INA2181 - 26V Dual-Channel Current Sense Amp | Texas Instruments

The Texas Instruments INA2181 is a 26V, dual-channel, bi-directional, 350kHz voltage-output current sense amplifier designed for cost-optimized low- and high-side current sensing. It integrates two independent current-sense amplifier channels in a single 10-pin VSSOP or WSON package, each providing a voltage output proportional to the voltage drop across an external shunt resistor. A current sense amplifier (also called a current-shunt monitor) is a specialized difference amplifier that extracts a small differential voltage developed across a shunt resistor riding on a large common-mode voltage, and translates it to a ground-referenced output. Within the power-management IC hierarchy, current sense amplifiers sit alongside fuel gauges and monitors as essential building blocks of power supervision, telemetry, and protection subsystems. Key features include a wide input common-mode range of -0.2V to 26V independent of the supply voltage, four factory-calibrated gain options (A1 = 20 V/V, A2 = 50 V/V, A3 = 100 V/V, A4 = 200 V/V), and a 350kHz bandwidth that supports fast transient monitoring and cycle-by-cycle current protection. A shared reference (REF) pin allows bi-directional current measurement by offsetting the output for both charging and discharging directions. The device operates from a 2.7V to 5.5V supply over an extended temperature range of -40C to +125C. Architecturally, the INA2181 belongs to the INA181 (INAx181) family, which also includes the single-channel INA181 (SOT-23/SC70) and quad-channel INA4181 (TSSOP-20). This dual-channel integration halves solution size and cost in applications that monitor two rails or both ends of a battery. Typical applications include battery charging and discharging monitoring, power supply and DC-DC converter current telemetry, motor control current feedback, load management, and industrial automation. The 350kHz bandwidth and fast 1us settling make it suitable for peak-current limit implementations in power converters. When designing, select the shunt resistor so the full-scale shunt voltage stays within the 10mV-to-100mV optimal range for your gain option, and use a Kelvin (4-wire) connection to the shunt to preserve accuracy. The REF pin must be driven from a low-impedance source to avoid gain error.

INA2181A4IDSQR

INA2181A4IDSQR - 26V Dual Current Sense Amp 200V/V | TI

The Texas Instruments INA2181A4IDSQR is a 26V, dual-channel, bi-directional current sense amplifier (current-shunt monitor) with a fixed gain of 200 V/V, 350 kHz bandwidth, rail-to-rail output, and supply operation from 2.7 V to 5.5 V, housed in a 10-pin WSON (DSQ) package measuring 2 mm x 2 mm. The A4 suffix denotes the 200 V/V gain option, the highest gain in the INAx181 family. A current sense amplifier is a special-purpose difference amplifier that measures the small voltage drop across a shunt resistor and converts it to a ground-referenced output signal. Within the power management IC hierarchy, current-shunt monitors sit alongside voltage regulators and supervisors as essential elements of power monitoring, protection, and telemetry subsystems in both high-side and low-side topologies. Key features of the INA2181A4 include common-mode voltage sensing from -0.2 V to +26 V independent of the supply voltage, which allows a 3.3 V or 5 V microcontroller to supervise a 24 V industrial rail directly. The dual-channel architecture monitors two shunts with a single IC, saving board area and BOM cost in cost-optimized designs. The 350 kHz bandwidth supports fast load-transient and short-circuit detection loops, and the rail-to-rail output maximizes ADC dynamic range on low supply rails. Technically, the INA2181 family uses a precision frontend that rejects the high common-mode voltage, amplifying only the differential shunt signal. The bidirectional REF pin allows the output to be offset so that charging and discharging currents can be distinguished by the monitoring ADC. The 200 V/V gain of the A4 version is optimized for small shunt resistors, minimizing insertion loss and power dissipation in the sense element. Typical applications include battery charging and discharging telemetry in portable and battery-backup systems, motor control DC bus monitoring, server and telecom board-level power telemetry, and 24 V industrial PLC input rails. The dual channel suits push-pull converters and dual-rail systems. Design consideration: with a 200 V/V gain, input offset is amplified twenty-fold, so shunt value and layout symmetry drive accuracy; Kelvin-connect the shunt and consider the REF pin buffering. The compact 2 mm x 2 mm WSON requires careful thermal pad soldering for the exposed die-attach pad. This page synthesizes distributor pricing, same-family drop-in alternatives, and practical design notes not found in the manufacturer datasheet.