Texas Instruments TLV1821QDCKRQ1

Overview

TLV1821QDCKRQ1 from Texas Instruments is an automotive-grade single-channel comparator with open-drain output, rail-to-rail input, 40 V supply capability, 5 µA quiescent current per channel, and 420 ns typical propagation delay. It operates from –40°C to +125°C and integrates Power-On Reset (POR) for reliable startup in HEV/EV powertrain monitoring circuits.

For engineers reviewing the TLV1821QDCKRQ1 datasheet, TLV1821QDCKRQ1 pinout, TLV1821QDCKRQ1 application, or TLV1821QDCKRQ1 equivalent, key selection considerations include its 40 V open-drain output compatibility with external pull-ups up to 40 V independent of supply voltage, AEC-Q100 Grade 1 qualification, and rail-to-rail input range extending 0.2 V beyond both supply rails.

Technical Context

The TLV1821QDCKRQ1 implements a rail-to-rail input stage with internal ESD clamps - a lower clamp to V− and a soft upper clamp to V+ via 5 kΩ resistance - enabling operation with input voltages from (V−) − 0.2 V to (V+) + 0.2 V. Its open-drain output supports logic-level translation and wired-OR configurations.

It features an integrated Power-On Reset circuit that holds the output in a known state until V+ reaches ≥1.7 V, preventing false triggering during system power-up/down. The device draws only 5 µA per channel across 2.4 V to 40 V supply range and maintains <4 mV input offset voltage over full temperature range.

Key Specifications

Pinout & Package

TLV1821QDCKRQ1 is packaged in SC-70 (DCK), a 5-pin surface-mount package measuring 1.25 mm × 2.00 mm with standard "North West" pinout orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV1821QDCKRQ1, TLV1821DBVRQ1 offers identical functionality in a more thermally robust package but occupies more PCB area, while LMV7219QMF/NOPB trades automotive qualification and 40 V capability for raw speed in narrow-voltage applications.

Availability

TLV1821QDCKRQ1 is available at Aetrix Electronics and suitable for HEV/EV battery monitoring, automotive body control modules, and instrument cluster voltage supervision requiring stable component supply across extended temperature and automotive lifecycle demands.

Supply support for TLV1821QDCKRQ1 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, with deep expertise in automotive electronics and functional safety design.

The TLV1821QDCKRQ1 belongs to TI's TLV18xx-Q1 family of AEC-Q100 qualified comparators engineered specifically for automotive powertrain, chassis, and body electronics demanding wide supply range, ultra-low power, and robust ESD performance.

FAQ

What is the maximum allowable voltage on the TLV1821QDCKRQ1 open-drain output?

The TLV1821QDCKRQ1 open-drain output supports voltages from –0.2 V to 40 V relative to V−, enabling direct connection to external pull-up supplies up to 40 V regardless of the comparator's own V+ supply voltage. This allows level translation between disparate voltage domains - for example, using a 12 V V+ supply while pulling OUT to a 24 V or 40 V bus. Exceeding 40 V risks damage per absolute maximum ratings.

Does TLV1821QDCKRQ1 require external pull-up resistors on its output?

Yes, TLV1821QDCKRQ1 requires an external pull-up resistor on the OUT pin to establish a logic-high state, as it features an open-drain output. TI recommends selecting a pull-up resistor that delivers 100 µA to 1 mA of current - typically 10 kΩ to 100 kΩ depending on supply voltage - to balance rise time, power consumption, and VOL. The TLV1821QDCKRQ1 itself does not integrate any pull-up element.

Can TLV1821QDCKRQ1 operate with input signals exceeding its supply rails?

TLV1821QDCKRQ1 supports rail-to-rail inputs with a 0.2 V overvoltage margin: inputs may range from (V−) − 0.2 V to (V+) + 0.2 V. However, the input stage includes a soft ESD clamp to V+ with 5 kΩ series resistance; TI explicitly warns against applying signals beyond this range without current limiting. For sustained overvoltage, external clamping or series resistance is required to keep input current ≤1 mA.

How does the Power-On Reset (POR) function in TLV1821QDCKRQ1 improve system reliability?

The TLV1821QDCKRQ1 incorporates an internal POR circuit that holds the output in a known state (high-impedance for open-drain) until V+ reaches ≥1.7 V. This prevents metastable or undefined output transitions during slow power ramp-up (e.g., cold-cranking) or brownout recovery, eliminating false fault assertions in safety-critical automotive subsystems such as battery disconnect units or airbag controllers.

Is TLV1821QDCKRQ1 pin-compatible with legacy comparators like TLV7211 or LMC7211?

No - TLV1821QDCKRQ1 uses the standard SC-70 "North West" pinout (OUT, V−, IN+, IN−, V+), whereas TLV7211/LMC7211 use different pin assignments. However, the pin-compatible alternative TLV1821L-Q1 (SOT-23) is explicitly designed as a drop-in replacement for those legacy parts. For TLV1821QDCKRQ1, PCB layout must follow its native DCK pinout; migration from TLV7211 requires redesign.