INA2181A4IDSQR - 26V Dual Current Sense Amp 200V/V | TI
MPN: INA2181A4IDSQR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.31 | $0.31 |
| 10 | $0.28 | $2.80 |
| 100 | $0.24 | $24.00 |
| 500 | $0.21 | $105.00 |
| 1,000 | $0.18 | $180.00 |
INA2181A4IDSQR Overview
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.
Drop-in alternatives for INA2181A4IDSQR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with INA2181A4IDSQR (same form factor and footprint) — differing in Package, Output Type, Common-Mode Voltage Range, Channels, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
INA2181A3IDSQR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
INA2181A2IDSQR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
INA2181A1IDSQR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$0.55 / Unit
View Datasheet →INA2181A4IDSQR Maximum Ratings & Electrical Characteristics
| Product Type | Current Sense Amplifier (Current-Shunt Monitor) |
| Channels | 2 |
| Gain (A4 option) | 200 V/V, fixed |
| Bandwidth | 350 kHz |
| Common-Mode Voltage Range | -0.2 V to +26 V |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Output Type | Rail-to-Rail, voltage output, bidirectional |
| Sensing Topology | High-side or low-side |
| Operating Temperature Range | -40 C to +125 C |
| Package | 10-WSON (DSQ), 2 mm x 2 mm |
| Mounting Type | Surface Mount |
| MSL Rating | MSL 1 - 260 C - UNLIM |
| RoHS Status | RoHS & Green compliant |
| REACH Compliance | Unknown - see compliance_info |
| Automotive Qualification | Not AEC-Q100 (see INA2181-Q1 variants) |
INA2181A4IDSQR 10-wson (dsq), 2 mm x 2 mm Pin Configuration Guide
Pin configuration for INA2181A4IDSQR (10-wson (dsq), 2 mm x 2 mm package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for INA2181A4IDSQR.
Refer to the datasheet for full pin configuration.
Typical Applications
INA2181A4IDSQR is suitable for 6 applications: Battery Charge/Discharge Monitoring, 24 V Industrial Rail Monitoring, Motor Control DC Bus Current Sensing, Server and Telecom Board Power Telemetry, Portable and IoT Device Power Management, Automotive-Adjacent 12 V Bus Monitoring (Non-Q1 Applications).
Battery Charge/Discharge Monitoring
The INA2181A4IDSQR fits battery telemetry because its -0.2 V to +26 V common-mode range measures battery bus voltage directly while its 200 V/V gain amplifies millivolt-level shunt drops to ADC-friendly levels. The bidirectional REF pin offsets the rail-to-rail output mid-scale (e.g., 1.65 V on a 3.3 V supply) so charge current appears above offset and discharge below, allowing a single ADC input to resolve both directions. The dual channels let one device monitor charge and discharge shunts separately for higher resolution. With 350 kHz bandwidth, fast inrush and fault currents are captured, supporting protection firmware in portable, UPS, and battery-backup designs.
Recommended
24 V Industrial Rail Monitoring
Industrial PLC and factory automation systems run 24 V rails that a 5 V microcontroller cannot sense directly. The INA2181A4IDSQR solves this because its common-mode range extends to +26 V independent of its own 2.7-5.5 V supply, so the high-side shunt on a 24 V bus is measured safely and its output is ground-referenced for the controller. The 200 V/V gain suits low-ohm shunts (2-10 milliohm) typical on power distribution boards, keeping insertion loss minimal. The dual channel monitors two buses (e.g., 24 V input and 5 V logic rail) with one 2 mm x 2 mm WSON device, cutting BOM cost and board area in cost-optimized industrial designs.
Recommended
Motor Control DC Bus Current Sensing
In BLDC and PMSM servo drives, DC bus overcurrent detection demands both speed and voltage tolerance. The INA2181A4IDSQR delivers 350 kHz bandwidth, fast enough for protection loops responding within microseconds of a stall or short, while the +26 V common-mode limit covers 12 V and 24 V drive buses. The high 200 V/V gain enables small shunts that limit power loss in the bus path. The bidirectional output with REF offset captures regenerative braking currents flowing back into the supply. The dual channels can independently monitor the bus and a leg current, or two motor phases, within a single footprint compatible with space-constrained drive PCBs.
Recommended
Server and Telecom Board Power Telemetry
Datacenter and telecom line cards require per-rail current telemetry for power budgeting and thermal management. The INA2181A4IDSQR monitors shunts on -48 V-derived intermediate buses up to 26 V common-mode and on 12 V distribution rails, feeding host-management ADCs with a rail-to-rail output. The dual-channel WSON 2 mm x 2 mm footprint integrates two monitors into the area of one, easing dense power-tree layouts. Its cost-optimized design suits high-volume boards where per-point telemetry cost must stay low. The 200 V/V gain pairs with 1-5 milliohm shunts so full-load drops stay in the tens of millivolts, preserving efficiency on multi-amp rails.
Recommended
Portable and IoT Device Power Management
Battery-powered consumer and IoT products need accurate current telemetry to extend runtime and detect faults, at minimal cost and area. The INA2181A4IDSQR operates from a 2.7 V supply, compatible with single-cell Li-ion and 3.3 V systems, and its 200 V/V gain resolves microamp-to-amp dynamic ranges using small shunts with the REF offset trick for bidirectional measurement. Its MSL 1 rating and compact WSON-10 package simplify assembly on dense two-sided boards. The dual channels can separately monitor system load and charger current, enabling charge-termination algorithms and short-circuit logging in firmware. The rail-to-rail output preserves ADC resolution at light loads where telemetry accuracy matters most.
Recommended
Automotive-Adjacent 12 V Bus Monitoring (Non-Q1 Applications)
Twelve-volt accessory and auxiliary buses in trucks, agricultural equipment, and off-highway vehicles fall within the INA2181A4IDSQR's +26 V common-mode limit, allowing high-side shunt monitoring of loads such as pumps, fans, and heaters. The 350 kHz bandwidth catches wire-harness fault transients, while the 200 V/V gain with low-value shunts keeps sense-path losses negligible. Designers must note the standard part is not AEC-Q100 qualified; for true automotive programs, TI's INA2181-Q1 variants (e.g., INA2181A4QDGSRQ1 family naming) carry the qualification, with the gain-suffix convention retained. The dual channel supports monitoring both a load branch and its return path for plausibility checks.
Recommended
Recommended Products Summary
Engineering reference data for INA2181A4IDSQR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | INA2181A3IDSQR | INA2181A2IDSQR | INA2181A1IDSQR |
|---|---|---|---|---|
| Package | 10-WSON (DSQ), 2 mm x 2 mm | 10-WSON (DSQ) - same | 10-WSON (DSQ) - same | 10-WSON (DSQ) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Fixed Gain | 200 V/V | 100 V/V | 50 V/V | 20 V/V |
| Channels | 2 | 2 | 2 | 2 |
| Bandwidth | 350 kHz | 350 kHz | 350 kHz | 350 kHz |
| Common-Mode Range | -0.2 V to +26 V | -0.2 V to +26 V | -0.2 V to +26 V | -0.2 V to +26 V |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Automotive Grade (Q1) | No | No (Q1 variants exist) | No (Q1 variants exist) | No (Q1 variants exist) |
Key Differentiators
- Highest gain in the dual-channel INAx181 family (vs INA2181A3IDSQR)
- Dual-channel density in 2 mm x 2 mm (vs INA181A4 (single-channel, different package))
- Cost-optimized positioning (vs INA2181A1IDSQR)
Design Notes
Kelvin-connect the shunt resistor: route the IN+ and IN- traces directly to the shunt terminals, not to shared current-carrying copper. With 200 V/V gain, every milliohm of parasitic trace resistance adds gain error, and asymmetric routing adds offset. Keep the differential pair short and symmetric, and guard the sense lines from switching-node aggressors. The exposed die-attach pad of the WSON (DSQ) package should be soldered to a grounded pad per the TI INAx181 datasheet layout section for thermal and mechanical reliability.
The REF pin sets the bidirectional zero-current output level. Do not drive it directly from a resistor divider with high impedance - the REF pin current creates a gain-dependent offset error. Buffer the divider with an op amp (e.g., a low-offset op amp) or use a precision reference. Estimated: on a 3.3 V rail with REF at 1.65 V, the 200 V/V gain gives +/-8.25 mV full-scale input swing, i.e., with a 5 milliohm shunt about +/-1.65 A bidirectional range before clipping.
Select the gain variant before finalizing the shunt: the A4 200 V/V gain amplifies input offset twenty-fold relative to the A1, so accuracy targets at light load may force a lower-gain variant on the same footprint. Also verify the common-mode rating of 26 V against worst-case bus transients - automotive load-dump on a 12 V rail can exceed it, which is a reason to use the INA2181-Q1 family with appropriate absolute maximums for those environments. Confirm the DSQ pin table, since the DGS package pinout differs.
Compliance Information
RoHS & Green compliant per TI compliance data referenced by distributor listings; MSL 1 - 260 C - UNLIM. Not AEC-Q100 qualified - use INA2181-Q1 variants for automotive. REACH status should be confirmed on the TI product folder.
