Texas Instruments TMP101NA/3KG4

Overview

TMP101NA/3KG4 from Texas Instruments is a digital temperature sensor IC with I²C/SMBus interface, integrated ΔΣ ADC and on-chip thermal diode sensing element. It delivers ±1°C typical accuracy from –55°C to 125°C, 9–12-bit user-selectable resolution (down to 0.0625°C), and operates from 2.7 V to 5.5 V. It serves as a direct NTC/PTC thermistor replacement in thermal protection circuits for power supplies, battery management, and embedded peripherals.

For engineers reviewing the TMP101NA/3KG4 datasheet, TMP101NA/3KG4 pinout, TMP101NA/3KG4 application, or TMP101NA/3KG4 equivalent, this page provides verified functional specifications, SOT-23 package mapping, ALERT pin behavior, SMBus Alert protocol support, and validated alternative options for thermal monitoring designs requiring low quiescent current (45 µA active, 0.1 µA shutdown) and bus-addressable multi-sensor configurations.

Technical Context

The TMP101NA/3KG4 implements an on-die thermal diode sensed by a 12-bit delta-sigma ADC, with conversion time ranging from 320 ms (12-bit) to 40 ms (9-bit). Its digital core supports I²C fast-mode (400 kHz) and high-speed mode (2 MHz), with open-drain SDA and SCL pins requiring external pullups.

It features one address pin (ADD0) enabling up to three devices per bus, plus a dedicated open-drain ALERT output that asserts when temperature exceeds THIGH or falls below TLOW-fully compliant with SMBus Alert protocol. Shutdown mode reduces current to 0.1 µA while retaining I²C address latching capability.

Key Specifications

Pinout & Package

Package: 6-pin SOT-23 (DBV), body size 2.90 mm × 1.60 mm, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM75BIMM/NOPB and MAX31820MUA+, the TMP101NA/3KG4 uniquely combines I²C/SMBus Alert interrupt capability, sub-degree resolution, ultra-low shutdown current, and industrial-grade temperature range - making it the optimal choice for power-constrained, interrupt-driven thermal protection in compact electronics.

Availability

TMP101NA/3KG4 is available at Aetrix Electronics and suitable for power-supply thermal monitoring, notebook battery management, and industrial motor drive control requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for TMP101NA/3KG4 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 sensing and low-power interface solutions.

The TMP101NA/3KG4 belongs to TI's TMP10x digital temperature sensor family, designed specifically for replacing thermistors in space-constrained, low-power thermal protection applications across computing, industrial, and communications systems.

FAQ

What is the absolute maximum supply voltage for the TMP101NA/3KG4?

The TMP101NA/3KG4 has an absolute maximum supply voltage (V+) rating of 7.5 V. Exceeding this value may cause permanent damage. For reliable operation, maintain V+ within the recommended 2.7 V to 5.5 V range. The device's internal ESD protection and regulator circuitry are optimized for this window, and operation above 5.5 V voids parametric guarantees including accuracy and quiescent current.

Does the TMP101NA/3KG4 require external components for basic temperature measurement?

No, the TMP101NA/3KG4 requires no external passive components for core functionality. Only two external 4.7-kΩ pullup resistors on SDA and SCL are mandatory for I²C communication. A 0.1-µF ceramic decoupling capacitor on V+ is strongly recommended but not strictly required for short-duration lab evaluation. The on-die thermal diode and ΔΣ ADC eliminate need for thermistors, op-amps, or calibration circuitry.

How does the ALERT pin on the TMP101NA/3KG4 behave in Comparator Mode versus Interrupt Mode?

In Comparator Mode (TM = 0), the ALERT pin latches LOW when temperature crosses THIGH and remains asserted until temperature drops below TLOW. In Interrupt Mode (TM = 1), ALERT pulses LOW only during the condition and clears automatically after SMBus Alert command acknowledgment. Both modes use the same THIGH/TLOW registers, but TM selection determines persistence and bus protocol interaction - critical for deterministic thermal fault handling in safety-aware systems.

Can the TMP101NA/3KG4 be used alongside TMP100 devices on the same I²C bus?

Yes, TMP101NA/3KG4 and TMP100 devices can coexist on the same I²C bus because their default slave addresses differ: TMP101NA/3KG4 defaults to 1001000b (0x48) when ADD0 = GND, while TMP100 uses 1001000b only when ADD0 = GND and ADD1 = GND. Address collisions are avoidable by configuring ADD0 on TMP101NA/3KG4 to float or V+, yielding 1001001b (0x49) or 1001010b (0x4A), ensuring up to 11 total devices (8 TMP100 + 3 TMP101) on one bus.

What is the conversion time for the TMP101NA/3KG4 at 12-bit resolution?

At 12-bit resolution, the TMP101NA/3KG4 requires 320 ms to 600 ms per conversion, depending on supply voltage and temperature. At V+ = 5 V and TA = 25°C, typical conversion time is 320 ms. This interval is fixed per resolution setting and independent of I²C bus speed - the device performs the ADC conversion autonomously and asserts ALERT or updates the Temperature Register upon completion, regardless of bus activity.