STMicroelectronics ST232ECTR

Overview

ST232ECTR from STMicroelectronics is a dual-driver, dual-receiver RS-232 transceiver IC operating from a single 5 V supply, featuring ±15 kV HBM ESD protection on all RS-232 I/O pins, guaranteed 230 kbps data rate, and 3–30 V/µs slew rate control. It interfaces microcontrollers to legacy serial peripherals in industrial terminals and point-of-sale systems using standard RS-232 voltage levels.

For engineers reviewing the ST232ECTR datasheet, ST232ECTR pinout, ST232ECTR application, or ST232ECTR equivalent, key selection criteria include ESD robustness for field-deployed equipment, capacitor count (four 1 µF vs. 0.1 µF variants), SO16/TSSOP16 package compatibility, and compliance with EIA/TIA-232E and CCITT V.28 specifications at extended temperature (0 to 70 °C).

Technical Context

The ST232ECTR integrates charge-pump voltage converters to generate ±V_CC-derived RS-232 output voltages (±5 V to ±9 V swing) from a single 5 V rail, eliminating need for ±12 V supplies. Its receiver input resistance is 3–7 kΩ with 0.2–1 V hysteresis, enabling reliable detection of noisy RS-232 signals up to ±30 V.

Transmitter outputs drive 3 kΩ loads with short-circuit current limits of ±10 to ±60 mA and propagation delay under 2 µs; receiver propagation delay is 0.5–10 µs with TTL/CMOS-compatible outputs (V_OH ≥ 3.5 V, V_OL ≤ 0.4 V). The device supports full-duplex communication with independent T1/T2 and R1/R2 channels.

Key Specifications

Pinout & Package

ST232ECTR is available in TSSOP16 package (4.9 × 6.4 mm, 0.65 mm pitch), optimized for space-constrained PCBs. Pin numbering follows standard top-view orientation with GND at Pin 15 and V_CC at Pin 16.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RS-232 transceiver applications.

Compared with MAX232CPE and SP3232ECA-L, ST232ECTR uniquely guarantees 230 kbps performance across temperature while maintaining strict EIA/TIA-232E compliance and minimizing external component count with its 1 µF capacitor architecture.

Availability

ST232ECTR is available at Aetrix Electronics and suitable for industrial HMI terminals, point-of-sale systems, and test & measurement equipment requiring stable component supply and long-term obsolescence management.

Supply support for ST232ECTR 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 analog, MCU, power, and sensor solutions for automotive, industrial, and consumer markets.

The ST232 series belongs to ST's legacy RS-232 interface product line, engineered specifically for robust serial communication in harsh industrial and commercial environments with minimal external components.

FAQ

What is the minimum and maximum supply voltage for ST232ECTR?

The ST232ECTR operates from a single 5 V supply with a specified tolerance of ±10%, meaning the valid range is 4.5 V to 5.5 V. Absolute maximum ratings allow up to 6 V, but sustained operation outside 4.5–5.5 V may compromise ESD performance, data rate guarantee, or thermal stability per datasheet Section 2.

Can ST232ECTR replace MAX232 in existing designs?

ST232ECTR is pin-compatible with MAX232 in TSSOP16 and SO16 packages and uses identical 1 µF capacitor values, but capacitor polarity differs: C1+ and C1− connect to V+ and GND respectively, unlike MAX232's C1+ to V+ and C1− to V−. Layout review and capacitor reorientation are required before drop-in replacement.

Does ST232ECTR support automatic power-down mode?

No, ST232ECTR does not include an enable/shutdown pin or automatic power-down feature. It draws 5–10 mA quiescent current continuously when V_CC is applied. For low-power applications, consider ST3232EB or similar devices with EN pin functionality.

What is the RS-232 receiver input voltage range specification?

The ST232ECTR receiver inputs tolerate −30 V to +30 V per Table 6 in the datasheet, enabling reliable operation despite ground potential differences in industrial cabling. This range is maintained across the full 0 to 70 °C operating temperature and is independent of V_CC level.