Texas Instruments LM211D

Overview

LM211D from STMicroelectronics is a precision voltage comparator with strobe functionality, designed for high-speed level detection in industrial control and power supply monitoring circuits. It features ±30 V differential input voltage range, 150 nA maximum input current, 20 nA maximum offset current, 50 mA output sink capability, and operates from +5 V to ±15 V supplies.

For engineers reviewing the LM211D datasheet, LM211D pinout, LM211D application, or LM211D equivalent, key selection criteria include input bias current stability over temperature, strobe-enabled output disable, wide common-mode input range (–14.5 V to +13.8 V), and TTL/RTL/MOS-compatible open-collector output capable of switching up to +50 V.

Technical Context

The LM211D implements a bipolar transistor-based comparator core with internal strobe-controlled output transistor enable/disable logic. Its input stage uses matched PNP transistors to achieve low input bias current (≤150 nA) and low offset current (≤20 nA), enabling accurate DC-coupled comparisons in high-impedance sensor interfaces.

It supports single-supply (+5 V) and dual-supply (±15 V) operation, with rail-to-rail input common-mode range extending to within 1.5 V of either supply rail. The open-collector output delivers 50 mA sink current and withstands up to +50 V external pull-up, allowing direct interfacing with logic families and higher-voltage loads without level-shifting circuitry.

Key Specifications

Pinout & Package

LM211D is housed in an SO-8 plastic micropackage (ECOPACK® compliant), with standard 1.27 mm pitch, 5.0 mm × 4.0 mm body size, and 1.35–1.75 mm height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM311D, LM211D offers extended temperature support (–40°C to +105°C) essential for industrial deployment; versus TLV3011DBVR, it provides strobe control and +50 V output capability critical for factory automation and power electronics, at the cost of higher supply voltage and quiescent current.

Availability

LM211D is available at Aetrix Electronics and suitable for industrial control systems, power supply monitoring, and sensor interface designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM211D 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, analog ICs, power management devices, and sensors for industrial, automotive, and consumer markets.

The LM211 series belongs to ST's precision analog comparators product line, engineered for robust performance in harsh environments where reliability, wide supply flexibility, and high-voltage interoperability are mandatory.

FAQ

What is the function of the strobe pin (Pin 1) on the LM211D?

The strobe pin (Pin 1) is an active-low enable input that places the open-collector output in high-impedance state when pulled low (requiring ≥3 mA sink current). When high (open or pulled up), normal comparator operation resumes. This allows synchronized blanking of output transitions during critical timing intervals, such as ADC conversion windows or PWM dead-time periods.

Can the LM211D operate from a single +5 V supply?

Yes, the LM211D is fully specified for single +5 V operation per ST's datasheet (DocID4848 Rev 5, Table 3). Input common-mode range extends from –14.5 V to +13.8 V relative to V–, so with V– = 0 V and V+ = +5 V, usable input range is 0 V to +3.5 V. Output remains compatible with TTL/CMOS logic when pulled up to +5 V.

Does the LM211D have internal offset null capability?

No. Pins 5 and 8 are labeled "Offset Null" in the SO-8 pinout diagram but are internally unconnected (NC) in the LM211D. ST confirms these pins serve no function and must be left floating or tied to ground - they cannot be used to trim input offset voltage, unlike older metal-can versions of the LM311.

What is the maximum output voltage the LM211D can switch?

The LM211D output transistor can withstand up to +50 V between collector (output pin) and emitter (V– pin), as specified in Table 2 (Absolute Maximum Ratings). This allows direct connection to external pull-up voltages up to +50 V, enabling interface with 24 V industrial controls, relay coils, and optocouplers without additional level-shifting components.