Texas Instruments INA203AIDR

Overview

INA203AIDR from Texas Instruments is a unidirectional current-shunt monitor IC with 20 V/V gain, dual open-drain comparators (CMP1 latched, CMP2 delay-programmable), and integrated 1.2-V reference output. It operates from 2.7 V to 18 V, supports –16 V to 80 V common-mode input range, and delivers 500-kHz bandwidth for precision shunt-based current sensing in high-side or low-side configurations - used in overcurrent protection circuits for telecom power supplies.

For engineers reviewing the INA203AIDR datasheet, INA203AIDR pinout, INA203AIDR application, or INA203AIDR equivalent, key selection criteria include its fixed 20× gain accuracy (±2% over temperature), latch/reset control on CMP1, user-adjustable delay on CMP2 via external capacitor, and SOIC-14 package compatibility with industrial-grade thermal performance (R_θJA = 84.9°C/W).

Technical Context

The INA203AIDR integrates a precision current-sense amplifier, two independent comparators, and dual internal voltage references (0.6 V for comparator thresholds, 1.2 V output). Its current-sense path features 80 dB minimum CMRR at –16 V to 80 V common-mode, ±2.5 mV max offset voltage over temperature, and 500-kHz small-signal bandwidth - enabling fast response to load transients while rejecting bus noise.

CMP1 implements a transparent/latched mode controlled by the active-low CMP1 RESET pin; CMP2 includes a programmable delay stage using an external capacitor on the CMP2 DELAY pin, with delay time t_D = 5 × C_DELAY (μF) yielding up to 0.5 s for 0.1 μF. Both comparators use open-drain outputs with 220–300 mV low-level voltage at 2.35 mA sink current.

Key Specifications

Pinout & Package

INA203AIDR is housed in a 14-pin SOIC (D) package measuring 8.65 mm × 3.91 mm, with standard JEDEC MS-012AC footprint and 1.27-mm pitch. Thermal resistance R_θJA = 84.9°C/W enables operation at full spec without forced airflow in compact PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-sense monitor applications.

Compared with INA204AIDR and INA205AIDR, the INA203AIDR offers optimal balance of gain, accuracy (±2% total error), and noise immunity for general-purpose 50–100 mV shunt designs - making it the preferred choice where robustness across varying load conditions is prioritized over maximum resolution.

Availability

INA203AIDR is available at Aetrix Electronics and suitable for telecom power supplies, automotive battery management, industrial motor drives, and server PSU redundancy requiring stable component supply across extended temperature and voltage ranges.

Supply support for INA203AIDR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision signal conditioning and power management ICs.

The INA203AIDR belongs to TI's current-shunt monitor product line, designed specifically for high-accuracy, high-common-mode current sensing in power conversion, protection, and energy metering applications - emphasizing integration, reliability, and ease of use in harsh environments.

FAQ

What is the maximum common-mode voltage the INA203AIDR can measure?

The INA203AIDR supports a common-mode input voltage range of –16 V to +80 V. This allows accurate current sensing on high-side shunts in 48-V telecom systems or negative-rail monitoring in industrial controls. The specification is guaranteed across the full –40°C to +125°C operating temperature range, with ≥80 dB common-mode rejection ratio maintained throughout.

How does the CMP1 latch function work on the INA203AIDR?

The CMP1 output on the INA203AIDR latches high upon overcurrent detection and remains asserted until the active-low CMP1 RESET pin is pulled low. Leaving CMP1 RESET open or high enables transparent operation (output follows input), while pulling it low clears the latch. This behavior is hardware-based and requires no external clock or microcontroller intervention - critical for fail-safe protection in power systems.

Can the INA203AIDR operate from a 3.3-V supply?

Yes, the INA203AIDR operates from a single supply ranging from 2.7 V to 18 V. At 3.3 V, it maintains full functionality: the 20× gain path, dual comparators, and 1.2-V reference output all remain within specification. However, the output swing is reduced to approximately 0.4 V above GND and 0.15 V below VS, so ADC interfacing must account for this limited headroom.

What is the purpose of the 1.2-V REF OUT pin on the INA203AIDR?

The 1.2-V REF OUT pin on the INA203AIDR provides a precision, temperature-stable reference voltage (1.2 V ±12 mV, 40–100 ppm/°C drift) for external circuitry. It can bias comparator thresholds, calibrate ADC references, or serve as a stable node for feedback networks - eliminating the need for discrete voltage references and reducing system cost and board space.

How is the CMP2 delay time set on the INA203AIDR?

The CMP2 delay on the INA203AIDR is set by connecting an external capacitor to the CMP2 DELAY pin. The delay time t_D (in seconds) equals 5 × C (in μF); for example, a 0.1-μF capacitor yields a 0.5-second delay. This RC-based timing provides predictable, repeatable blanking windows to suppress false trips during inrush currents or switching transients without software involvement.