STMicroelectronics ST3241EBDR

Overview

ST3241EBDR from STMicroelectronics is a ±15 kV ESD-protected, 3–5.5 V, 400 kbps RS-232 transceiver with auto power-down, featuring 3 drivers and 5 receivers in SSOP-28 package. It delivers guaranteed 6 V/µs slew rate, 250 kbps minimum data rate, and true RS-232 output levels from low-voltage supply - designed for battery-powered portable computing interfaces.

For engineers reviewing the ST3241EBDR datasheet, ST3241EBDR pinout, ST3241EBDR application, or ST3241EBDR equivalent, key selection criteria include ESD robustness (±15 kV HBM), ultra-low 1 µA shutdown current, wake-up-capable R2 receiver, dual charge-pump architecture, and guaranteed mouse drive ability in space-constrained systems.

Technical Context

The ST3241EBDR implements a dual charge-pump voltage converter to generate ±5.5 V rails from a single 3–5.5 V supply, enabling full RS-232 compliance without external high-voltage sources. Its proprietary low-dropout transmitter stage maintains ±5 V output swing into 3 kΩ loads across temperature and supply variation.

Receiver R2 remains active during auto power-down to detect incoming wake-up signals, while R1OUTB and R2OUTB provide always-on complementary outputs. Logic control uses active-low SHDN and EN pins with defined truth table behavior for precise port management in portable host systems.

Key Specifications

Pinout & Package

ST3241EBDR is housed in a 28-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch, 10.2 mm × 7.8 mm body size, and ECOPACK® environmental compliance. The package supports automated surface-mount assembly and thermal performance suitable for portable equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX3241CSE+ and SP3241ECA-L, ST3241EBDR uniquely combines 1 µA shutdown, always-active R2 wake-up, and ±8 kV IEC contact discharge in a single SSOP-28 package - making it optimal for portable systems requiring certified ESD resilience and zero-latency wake-up.

Availability

ST3241EBDR is available at Aetrix Electronics and suitable for notebook serial interfaces, battery-powered handheld terminals, industrial printers, and POS peripheral adapters requiring stable component supply and long-term lifecycle support.

Supply support for ST3241EBDR 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 ST3241E series belongs to ST's RS-232 interface product line, engineered specifically for portable and battery-operated computing devices needing high ESD immunity, minimal quiescent power, and full RS-232 voltage compliance from low-voltage supplies.

FAQ

What is the minimum supply voltage required for guaranteed RS-232 output levels?

The ST3241EBDR guarantees ±5 V transmitter output swing and full EIA/TIA-232 compliance down to 3.0 V supply. At VCC = 3.0 V, the dual charge pump still generates sufficient ±5.5 V rails to meet RS-232 voltage thresholds under load, verified across –40°C to +85°C.

How does the auto power-down function detect idle conditions?

Auto power-down activates when all five receiver inputs (R1IN–R5IN) remain within the invalid RS-232 range (–3 V to +3 V) for more than 30 µs. This condition is monitored continuously; assertion of any valid RS-232 signal (>±3 V) exits shutdown within 10 µs, restoring full operation.

Can ST3241EBDR drive standard RS-232 cables up to 15 meters?

Yes - with its 6–30 V/µs slew rate and ±5 V output swing into 3 kΩ, the ST3241EBDR meets EIA/TIA-232-F specifications for driving up to 50 ft (≈15 m) of standard 24 AWG twisted-pair cable at 250 kbps, provided proper termination and grounding practices are followed per ANSI/TIA-561.

Is external capacitor polarity critical for C1+/C1– and C2+/C2– connections?

Yes - C1+ and C1– must connect to V+ and GND respectively; C2+ and C2– must connect to GND and V– respectively. Reversing either pair disables the charge pump, resulting in no RS-232 output voltage and potential latch-up. Ceramic 0.1 µF X7R capacitors are recommended for stability and low ESR.