Texas Instruments LM211P

Overview

LM211P from Texas Instruments is a single high-speed voltage comparator with open-collector output, designed for precision level detection in industrial and embedded systems. It delivers 165 ns response time, supports ±15 V or single 5-V supply operation, and drives loads up to 50 V at 50 mA - used in zero-crossing detectors, peak detectors, and oscillator circuits.

For engineers reviewing the LM211P datasheet, LM211P pinout, LM211P application, or LM211P equivalent, key selection considerations include its –40°C to +85°C operating range, strobe-enabled disable function, BALANCE/BAL/STRB offset trimming capability, and compatibility with TTL/MOS logic interfaces.

Technical Context

The LM211P employs a PNP input stage enabling rail-to-rail common-mode input down to VCC–, followed by high-gain amplification and an isolated-emitter NPN open-collector output stage. Its differential input structure supports precise voltage comparison with low input bias current (≤300 nA) and low input offset current (≤70 nA).

Strobe functionality allows active-low disabling of the output regardless of input differential, while BALANCE and BAL/STRB pins support external offset nulling. The output can sink up to 50 mA and interface directly with ground-, VCC+-, or VCC–-referenced loads - enabling flexible level-shifting and wire-OR configurations.

Key Specifications

Pinout & Package

LM211P uses an 8-pin PDIP package (9.81 mm × 6.35 mm) with through-hole mounting. All pins are electrically defined per TI SLCS007K Rev K; no NC (no-connect) pins present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM311P and LM2903P, the LM211P uniquely combines industrial temperature range (–40°C to +85°C), strobe control, offset trimming, and 165 ns speed - making it the only option among the three for precision, synchronized, high-speed comparator applications in harsh environments.

Availability

LM211P is available at Aetrix Electronics and suitable for industrial control systems, building automation, and white goods requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM211P 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 over 50 years of innovation in precision analog ICs and industrial-grade components.

The LM211P belongs to TI's legacy high-speed comparator family, engineered specifically for robust voltage comparison in noisy, wide-supply, and thermally demanding environments - including motor drives, power supplies, and safety-critical subsystems.

FAQ

What is the maximum supply voltage for LM211P?

The LM211P supports a total supply voltage (VCC+ − VCC−) up to 30 V, with individual rail limits of +18 V on VCC+ and –18 V on VCC−. Absolute maximum ratings prohibit exceeding ±18 V on either supply pin - operation beyond these stresses risks permanent damage. For reliable long-term use, TI recommends staying within the recommended 3.5 V to 30 V range.

Does LM211P support single-supply operation?

Yes, the LM211P supports true single-supply operation down to 3.5 V total supply. When VCC− is grounded, the device operates from a 3.5–30 V positive supply. Its PNP input stage allows the common-mode input range to extend to within 1.5 V of VCC−, enabling accurate comparison near ground - critical for sensor interfacing and low-voltage logic translation.

How does the BAL/STRB pin function in LM211P?

The BAL/STRB pin on the LM211P serves dual roles: as a strobe input (active-low) to force the COL OUT into high-impedance state, and as a balance control node when used with external resistors for offset trimming. To strobe, drive with –3 mA to –5 mA current; never short directly to ground. For balancing, connect a 10-kΩ potentiometer between VCC+ and VCC− with wiper to BAL/STRB.

Can LM211P drive a relay directly?

Yes, the LM211P COL OUT pin can directly drive small relays rated ≤50 V and ≤50 mA coil current. With a 5-V supply and appropriate pullup, it sinks sufficient current to activate common 5 V/12 V signal relays. For higher-power relays, use an external transistor buffer. Always include a flyback diode across the relay coil to protect the LM211P output from inductive kickback.

What is the purpose of the EMIT OUT pin on LM211P?

The EMIT OUT pin provides an emitter-follower output referenced to VCC−, offering low-impedance buffering and level-shifting capability independent of the COL OUT. It enables driving loads tied to VCC−, ground, or floating references - useful in isolated feedback paths, analog multiplexing, or generating complementary logic levels. Unlike COL OUT, EMIT OUT cannot be wire-OR'd but offers faster rise times in certain configurations.