Texas Instruments TMP708AQDBVRQ1

Overview

TMP708AQDBVRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-grade resistor-programmable temperature switch in SOT-23 package, featuring ±0.5°C typical threshold accuracy, 40 μA typical quiescent current, pin-selectable 10°C/30°C hysteresis, and open-drain active-low output for microprocessor overtemperature protection.

For engineers reviewing the TMP708AQDBVRQ1 datasheet, TMP708AQDBVRQ1 pinout, TMP708AQDBVRQ1 application, or TMP708AQDBVRQ1 equivalent, key selection considerations include trip-point programmability via external R_SET, automotive-grade thermal reliability (–40°C to 125°C), low-power operation, and hysteresis configuration logic on HYST pin.

Technical Context

The TMP708AQDBVRQ1 integrates dual temperature-dependent voltage references (one positive tempco, one negative tempco) and a comparator to determine trip point; the SET pin voltage-set by external R_SET-controls the positive reference level across 0°C to 125°C range.

Hysteresis is digitally selected via HYST pin logic level: V_CC yields 10°C hysteresis, GND yields 30°C; this prevents output oscillation near threshold and defines untrip temperature offset. The OT pin implements an NFET open-drain stage with 12 mA sink capability at 0.3 V.

Key Specifications

Pinout & Package

Package: 5-pin SOT-23 (DBV), body size 2.90 mm × 1.60 mm, 1.45 mm max height, moisture sensitivity level MSL-2 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMP708AQDBVRQ1, LM57BISD-5/NOPB adds analog telemetry but lacks resistor-programmability and has higher ICC, while MAX6505UTT+T offers lower power and smaller footprint but forfeits adjustable trip points - making TMP708AQDBVRQ1 optimal for automotive designs requiring field-configurable, AEC-Q100-compliant thermal shutdown.

Availability

TMP708AQDBVRQ1 is available at Aetrix Electronics and suitable for automotive powertrain control, ADAS thermal supervision, and infotainment system protection requiring stable component supply across extended product lifecycles.

Supply support for TMP708AQDBVRQ1 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for automotive, industrial, and personal electronics markets.

The TMP708-Q1 product line delivers AEC-Q100-qualified, resistor-programmable temperature switches optimized for automotive thermal management where precision, reliability, and hardware-level fault response are mandatory.

FAQ

What is the recommended external resistor tolerance for accurate trip-point setting on the TMP708AQDBVRQ1?

The TMP708AQDBVRQ1 datasheet specifies use of a 1% tolerance resistor between SET and GND to achieve the stated ±0.5°C typical threshold accuracy. Using a resistor with worse tolerance (e.g., 5%) directly degrades trip-point repeatability and may exceed the ±3.5°C maximum error band. The TMP708AQDBVRQ1's internal architecture relies on precise ratio-matching between references, so external R_SET tolerance is a dominant contributor to overall accuracy.

Can the HYST pin of the TMP708AQDBVRQ1 be left floating or tied through a resistor?

No - the HYST pin of the TMP708AQDBVRQ1 must be hard-connected either to V_CC (for 10°C hysteresis) or GND (for 30°C hysteresis). The datasheet explicitly warns that floating or resistively biased states cause abnormal supply currents or device malfunction. This requirement stems from the internal hysteresis control logic, which interprets intermediate voltages as undefined states; therefore, the TMP708AQDBVRQ1 design mandates direct rail connection for reliable operation.

What is the minimum pullup resistor value required for the OT pin of the TMP708AQDBVRQ1?

The TMP708AQDBVRQ1 OT pin requires an external pullup resistor to V_CC, with TI recommending ≥10 kΩ to minimize internal power dissipation. While larger values (up to 470 kΩ) are acceptable for ultra-low-power designs, using <10 kΩ increases current draw during output assertion and risks exceeding the 12 mA sink rating under worst-case V_OT = 0.3 V conditions. Therefore, the minimum recommended value is 10 kΩ, and the TMP708AQDBVRQ1's output stage is rated for reliable sinking up to 12 mA.

Does the TMP708AQDBVRQ1 require a bypass capacitor, and where should it be placed?

Yes - the TMP708AQDBVRQ1 requires a 0.1 μF ceramic bypass capacitor placed as close as possible to the V_CC pin, with short, low-inductance traces to GND. This is mandated in Section 8.1 and Figure 7 of the datasheet to suppress supply noise that could induce trip-point errors. Noise on V_CC directly modulates internal reference voltages; without proper decoupling, the TMP708AQDBVRQ1 may exhibit false trips or delayed response. The capacitor must be X7R or better dielectric and located within 2 mm of the V_CC/GND pins.

How does the TMP708AQDBVRQ1 achieve its ±0.5°C typical threshold accuracy?

The TMP708AQDBVRQ1 achieves ±0.5°C typical threshold accuracy through matched on-die temperature-dependent voltage references (one positive tempco, one negative tempco) and precision comparator design. Its accuracy is specified over 60°C–100°C and depends critically on 1% external R_SET tolerance and proper PCB layout (e.g., thermal isolation from self-heating sources). The TMP708AQDBVRQ1's internal trimming and AEC-Q100 qualification ensure this performance is maintained across automotive temperature and lifetime stress conditions.