STMicroelectronics LM239PT

Overview

LM239PT from STMicroelectronics is a low-power quad voltage comparator in TSSOP-14 package, designed for single-supply operation from +2 V to +36 V (or ±1 V to ±18 V dual supply), featuring ±1 mV typical input offset voltage, 25 nA typical input bias current, and 250 mV typical output saturation voltage at 4 mA sink current - used in precision threshold detection, window comparators, and level-shifting interfaces in industrial control and sensor signal conditioning.

For engineers reviewing the LM239PT datasheet, LM239PT pinout, LM239PT application, or LM239PT equivalent, key selection criteria include input common-mode range extending to ground on single supply, TTL/CMOS-compatible open-collector outputs, low 1.1 mA supply current independent of VCC, and guaranteed operation from –40 °C to +105 °C.

Technical Context

The LM239PT integrates four independent PNP-input comparators with rail-to-rail differential input voltage capability (±36 V) and input common-mode range spanning 0 V to (VCC – 1.5 V), enabling direct ground-referenced sensing without level-shifting. Its open-collector outputs support wired-OR logic and interface directly with TTL, CMOS, ECL, and MOS loads.

Each comparator exhibits high large-signal voltage gain (50–200 V/mV), fast 1.3 μs response time (100 mV step, 5 mV overdrive), and robust ESD protection (500 V HBM). The device operates reliably across wide supply ranges while maintaining stable bias current (<300 nA max) and low offset drift over temperature.

Key Specifications

Pinout & Package

TSSOP-14 (Thin Shrink Small Outline Package), 4.9 mm × 6.4 mm body, 0.65 mm pitch, ECOPACK® compliant, surface-mountable with exposed thermal pad option (not present in standard TSSOP14 per ST DocID2159 Rev 4).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL331IPWR and LM339DT, the LM239PT uniquely balances industrial temperature rating (–40 °C to +105 °C), quad integration in compact TSSOP-14, and proven reliability in harsh environments - making it optimal for programmable logic controllers and motor drive supervision.

Availability

LM239PT is available at Aetrix Electronics and suitable for industrial automation, sensor interface modules, and power supply monitoring systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM239PT 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, power ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The LM239 series belongs to ST's precision analog comparators product line, engineered specifically for reliable, low-drift threshold detection in resource-constrained and thermally demanding applications.

FAQ

Can LM239PT operate from a single 3.3 V supply?

Yes - the LM239PT supports single-supply operation from +2 V to +36 V. At 3.3 V, its input common-mode range spans 0 V to 1.8 V (VCC – 1.5 V), and output saturation remains ≤400 mV at 4 mA sink. Input offset voltage increases slightly (±2.5 mV typ), but remains within specification for most 3.3 V logic interfacing.

What is the maximum sink current per output?

The LM239PT output can sink up to 16 mA continuously (per comparator) with VOL ≤ 700 mV at Tamb = +105 °C. Short-term peaks up to 20 mA are permissible per absolute maximum ratings, but sustained >16 mA may cause thermal derating above 85 °C ambient due to R_thJA = 100 °C/W in TSSOP-14.

Does LM239PT require external pull-up resistors on outputs?

Yes - all four outputs are open-collector and require external pull-up resistors to a defined logic-high voltage (e.g., 3.3 V or 5 V). Typical values range from 1 kΩ (for fast rise time with heavy loads) to 10 kΩ (for low power). No internal pull-ups exist; omission results in undefined high-state behavior.

How does input overdrive affect response time?

Response time improves with higher input overdrive: 1.3 μs at 5 mV overdrive drops to 300 ns at ≥100 mV overdrive (per Figure 7). This is due to faster internal node charging; design margin should use the 1.3 μs value for worst-case 100 mV steps, as specified in Table 3.