Texas Instruments LM94021BIMGX

Overview

LM94021BIMGX from Texas Instruments is a precision analog-output CMOS temperature sensor with four selectable gain settings (−5.5, −8.2, −10.9, −13.6 mV/°C), ±1.5°C accuracy from +20°C to +40°C, and operation from 1.5V to 5.5V supply across −50°C to +150°C. It delivers inverse-temperature voltage output for battery-powered thermal monitoring in automotive ECUs and portable electronics.

For engineers reviewing the LM94021BIMGX datasheet, LM94021BIMGX pinout, LM94021BIMGX application, or LM94021BIMGX equivalent, key selection factors include gain-select logic compatibility, SC70-5 package footprint constraints, low-quiescent-current operation under 1.5V, and verified accuracy over extended automotive temperature ranges.

Technical Context

The LM94021BIMGX implements a CMOS-based bandgap-derived analog temperature-to-voltage transducer with digitally controlled gain via two logic inputs (GS1/GS0). Its output is inherently inverse to temperature and exhibits parabolic nonlinearity compensated by factory-characterized transfer tables.

Gain selection directly sets the slope of the V_OUT vs. T curve without requiring external resistors; GS1 and GS0 accept rail-tied or actively driven logic signals. The device includes short-circuit protected output, load regulation ≤1.6 mV at 100 µA sink, and self-heating error <0.021°C under typical conditions.

Key Specifications

Pinout & Package

LM94021BIMGX uses the 5-pin SC70 (DCK) package with exposed pad not connected internally. Thermal performance relies on GND pin (Pin 2) as primary heat path; die backside is bonded directly to this pin.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog temperature sensor applications.

Compared with LM20BIM7/NOPB and TSYS01B, the LM94021BIMGX uniquely balances analog simplicity, wide supply range, programmable sensitivity, and AEC-Q100-compatible temperature coverage-making it optimal for resource-constrained embedded systems requiring field-configurable thermal response.

Availability

LM94021BIMGX is available at Aetrix Electronics and suitable for automotive cabin control, battery pack monitoring, and industrial motor protection requiring stable component supply and long-term lifecycle assurance.

Supply support for LM94021BIMGX 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 delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM94021 product line delivers precision analog temperature sensing with digitally selectable gain for applications demanding flexible resolution, ultra-low power, and extended temperature operation without digital interface complexity.

FAQ

What is the minimum supply voltage required for full-range operation of the LM94021BIMGX?

The LM94021BIMGX operates across its full −50°C to +150°C range with a minimum supply voltage of 1.5V when configured in the lowest gain mode (GS1 = 0, GS0 = 0, −5.5 mV/°C). At higher gains, minimum VDD increases to 1.9V (GS0 = 1) or 2.4V (GS1 = 1) to maintain output headroom. This behavior is explicitly specified in the Accuracy Characteristics table of the LM94021BIMGX datasheet.

How does the LM94021BIMGX achieve ±1.5°C accuracy over +20°C to +40°C?

The LM94021BIMGX achieves ±1.5°C accuracy in the +20°C to +40°C range through factory trimming of its bandgap reference and gain stages, combined with parabolic error compensation implemented in its internal circuitry. This specification is guaranteed under 1.5V–5.5V supply and applies specifically to the GS1/GS0 = 00 configuration per the Electrical Characteristics table. The LM94021BIMGX transfer table provides measured mV outputs at 1°C intervals to support software correction if tighter tolerance is required.

Can the LM94021BIMGX be used without an external bypass capacitor?

Yes, the LM94021BIMGX requires no external bypass capacitor because it draws only 9 µA quiescent current with negligible transient demand. TI's bench testing confirms stable operation even with bypass capacitance located up to 6 inches from the device. This simplifies layout and reduces BOM count-particularly valuable in space-constrained applications like wireless transceivers where the LM94021BIMGX is commonly deployed.

What is the thermal resistance (θ_JA) of the LM94021BIMGX in its SC70 package?

The LM94021BIMGX in the SC70 (DCK) package has a junction-to-ambient thermal resistance (θ_JA) of 415°C/W, measured in still air without a heatsink. This value is critical for calculating self-heating error using the formula T_J = T_A + θ_JA × (V_DD × I_Q + (V_DD − V_OUT) × I_L). For example, at 30°C ambient, 5V supply, and 2 µA load, self-heating is just 0.021°C-well within the LM94021BIMGX's accuracy budget.

Is the LM94021BIMGX pin-compatible with the LM20 temperature sensor?

Yes, the LM94021BIMGX is footprint-compatible with the LM20 in the SC70-5 package: both share identical pinout (GS0-GND-OUT-VDD-GS1 for LM94021BIMGX vs. GND-OUT-VDD-GS0-GS1 for LM20), but pin functions differ. While mechanical placement aligns, electrical connections require PCB trace rework-LM94021BIMGX places GND on Pin 2 and GS0 on Pin 1, whereas LM20 places GND on Pin 1. Always verify layout against the LM94021BIMGX connection diagram before substitution.