STMicroelectronics ST3241ECDR

Overview

ST3241ECDR 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 supply voltages. Designed for battery-powered portable systems including notebooks and handheld peripherals.

For engineers reviewing the ST3241ECDR datasheet, ST3241ECDR pinout, ST3241ECDR application, or ST3241ECDR equivalent, key selection criteria include ESD robustness (±15 kV HBM), ultra-low 1 µA shutdown current, guaranteed mouse drive capability, 0.1 µF capacitor requirement, and wake-up-enabled R2 receiver.

Technical Context

The ST3241ECDR integrates a dual charge-pump circuit 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 voltage ranges.

Receiver R2 remains active during auto power-down to support serial port wake-up functionality; R1 and R2 each provide complementary outputs (R1OUTB/R2OUTB) for continuous monitoring. Logic inputs (SHDN, EN) operate with TTL/CMOS-compatible thresholds and sub-1 µA leakage.

Key Specifications

Pinout & Package

ST3241ECDR is housed in a 28-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch, JEDEC MO-153 compliant, RoHS-compliant ECOPACK® grade. Dimensions: 10.2 mm × 7.8 mm × 1.75 mm (L × W × H).

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, ST3241ECDR uniquely combines 3-Tx/5-Rx channel count, 1 µA shutdown, and R2OUTB wake-up output - making it optimal for full-featured, battery-sensitive notebook and handheld serial ports.

Availability

ST3241ECDR is available at Aetrix Electronics and suitable for notebook computers, handheld terminals, industrial printers, and POS peripheral adapters requiring stable component supply and long-term lifecycle support.

Supply support for ST3241ECDR 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, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The ST3241E series belongs to ST's high-reliability RS-232 interface portfolio, engineered specifically for portable and battery-constrained systems needing ESD resilience, low-power operation, and full serial port functionality.

FAQ

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

The ST3241ECDR guarantees ±5 V output swing and full EIA/TIA-232 compliance down to VCC = 3.0 V, verified across –40 °C to 85 °C with 0.1 µF external capacitors. This enables direct use with 3.3 V microcontrollers and single-cell Li-ion systems without voltage boosting.

How does the auto power-down feature interact with the wake-up function?

When SHDN is asserted low, the device enters auto power-down mode drawing 1 µA, but receiver R2 remains fully active and its R2OUTB output stays functional. This allows detection of valid RS-232 start bits on R2IN to assert an interrupt and wake the host system - no external components needed.

Can ST3241ECDR drive standard RS-232 loads without external components?

Yes - the ST3241ECDR drives standard 3 kΩ RS-232 loads directly with guaranteed ±5 V output swing and 6 V/µs slew rate. Only four 0.1 µF charge-pump capacitors and a 0.1 µF VCC bypass capacitor are required; no resistors, inductors, or additional regulators are needed.

Is the SSOP-28 package lead-free and RoHS-compliant?

Yes - ST3241ECDR is supplied in an ECOPACK®-compliant SSOP-28 package meeting RoHS Directive 2011/65/EU and REACH SVHC requirements. The package uses matte tin (Sn) lead finish and is rated for lead-free reflow soldering per J-STD-020.