Texas Instruments TLV1821QDBVRQ1

Overview

TLV1821QDBVRQ1 from Texas Instruments is an automotive-grade single-channel comparator with open-drain output, rail-to-rail input, 40V supply capability, 5μA quiescent current per channel, and 420ns typical propagation delay. It operates from –40°C to +125°C and integrates Power-On Reset (POR) for reliable startup in HEV/EV battery monitoring circuits.

For engineers reviewing the TLV1821QDBVRQ1 datasheet, TLV1821QDBVRQ1 pinout, TLV1821QDBVRQ1 application, or TLV1821QDBVRQ1 equivalent, key selection criteria include its 40V open-drain output compatibility with external pull-ups up to 40V independent of V_S, AEC-Q100 Grade 1 qualification, and rail-to-rail input range extending 200mV beyond supply rails.

Technical Context

The TLV1821QDBVRQ1 implements a dedicated open-drain output stage with no internal pull-up, enabling logic-level translation and wired-OR configurations. Its rail-to-rail input stage uses ESD clamps referenced to V– and a soft upper clamp to V+ with 5kΩ effective resistance - requiring external current limiting if inputs exceed V+ by >200mV.

Power-On Reset asserts a known output state until V+ reaches ≥1.7V, preventing false triggering during power ramp. The device draws only 5μA per channel across 2.4V–40V supply range, with input offset voltage of ±0.5mV (typ) and PSRR of 100dB, making it suitable for precision threshold detection in noisy automotive power domains.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package, 1.60mm × 2.90mm body size, with exposed thermal pad connected to V–.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV1821QDBVRQ1, TLV1821QDCKRQ1 offers identical functionality in a smaller footprint but with reduced thermal performance, while LM393BQDRQ1 trades open-drain flexibility and POR for higher speed margin and legacy compatibility - neither is pin-compatible, and both require layout revision.

Availability

TLV1821QDBVRQ1 is available at Aetrix Electronics and suitable for HEV/EV battery management, automotive body control modules, and infotainment system voltage supervision requiring stable component supply across extended temperature and automotive lifecycle requirements.

Supply support for TLV1821QDBVRQ1 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 specializing in analog and embedded processing technologies, with leadership in automotive-grade IC design and AEC-Q100 qualification infrastructure.

The TLV1821QDBVRQ1 belongs to TI's TLV18xx-Q1 family of micro-power comparators engineered specifically for automotive voltage monitoring, fault detection, and power sequencing applications demanding wide supply range and functional safety readiness.

FAQ

What is the maximum allowable voltage on the TLV1821QDBVRQ1 output pin?

The TLV1821QDBVRQ1 output pin supports –0.2V to 40V relative to V–, enabling direct connection to 40V pull-up rails independent of the comparator's supply voltage. This specification is validated per AEC-Q100 and applies across the full operating temperature range. Exceeding 40V risks permanent damage due to ESD clamp breakdown, and TI recommends using external current limiting if short-circuit risk exists above 12V pull-up.

Does TLV1821QDBVRQ1 require external pull-up resistors for proper operation?

Yes - TLV1821QDBVRQ1 has an open-drain output and requires an external pull-up resistor to define the high logic state. TI recommends values between 100kΩ and 1MΩ depending on rise-time and power trade-offs; lower values improve edge speed but increase static current. The pull-up voltage may be up to 40V and need not match V+, making TLV1821QDBVRQ1 ideal for interfacing with higher-voltage domains without level shifters.

How does the Power-On Reset (POR) function behave in TLV1821QDBVRQ1?

The TLV1821QDBVRQ1 POR circuit holds the output in a known state (high-impedance for open-drain) until V+ rises above 1.7V, then releases control to the analog comparator core. This prevents spurious outputs during cold-crank or brown-out conditions. The POR is fully integrated - no external components needed - and remains active during power-down, ensuring clean shutdown behavior critical for automotive ASIL-B–compatible systems.

Can TLV1821QDBVRQ1 inputs be driven beyond the supply rails?

TLV1821QDBVRQ1 inputs tolerate V– – 0.2V to V+ + 0.2V, but exceeding V+ by more than 0.2V activates a soft 5kΩ ESD clamp to V+. TI mandates external current limiting (≤1mA) in such cases to prevent latch-up or parametric shift. Direct connection to unregulated battery rails is safe only if clamped within this range; for overvoltage-tolerant interfaces, external diode clamping is recommended per TI's application guidance.

Is TLV1821QDBVRQ1 pin-compatible with legacy comparators like TLV7211 or LMC7211?

No - TLV1821QDBVRQ1 uses standard SOT-23-5 "North West" pinout (OUT, V–, IN+, IN–, V+), whereas TLV7211/LMC7211 use alternate pinouts. However, the pin-compatible alternative TLV1821LQDBVRQ1 is available with LMC72x1-style pin assignment (IN–, V–, IN+, OUT, V+). For drop-in replacement of legacy designs, TLV1821LQDBVRQ1 must be specified; TLV1821QDBVRQ1 requires PCB layout modification.