STMicroelectronics ST3241EBTR

Overview

ST3241EBTR from STMicroelectronics is a ±15 kV ESD-protected, 3–5.5 V, 400 kbps RS-232 transceiver with auto power-down, featuring 3 drivers, 5 receivers, dual charge-pump circuitry, and SSOP-28 package. It delivers guaranteed 6 V/µs slew rate, 250 kbps minimum data rate, and maintains true RS-232 output levels down to 3 V supply-designed for battery-powered notebook and sub-notebook serial ports.

For engineers reviewing the ST3241EBTR datasheet, ST3241EBTR pinout, ST3241EBTR application, or ST3241EBTR equivalent, key selection criteria include its auto power-down current (1 µA), wake-up-capable R2 receiver, ±8 kV IEC 1000-4-2 ESD protection on I/O pins, and guaranteed mouse drive ability in portable computing interfaces.

Technical Context

The ST3241EBTR implements a dual charge-pump architecture generating ±5.5 V rails (V+ and V−) from a single 3–5.5 V supply, enabling full RS-232 voltage swing (±5 V min) without external high-voltage sources. Its proprietary low-dropout transmitter stage ensures compliance with EIA/TIA-232 and V.28/V.24 standards across the full supply range.

Receiver R2 remains active during shutdown to support serial port wake-up; R1 and R2 each provide complementary outputs (R1OUTB/R2OUTB) for robust signal monitoring. Logic control uses active-low SHDN and EN pins with defined truth table behavior for output tri-state and receiver enable management.

Key Specifications

Pinout & Package

ST3241EBTR 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 surface-mount reflow assembly and provides thermal and mechanical stability for portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX3241ECAI+ and SP3241EEN-L, ST3241EBTR uniquely combines 1 µA auto power-down, dedicated R2OUTB wake-up output, and guaranteed 6 V/µs slew rate-making it optimal for portable computing where battery life, responsiveness, and EMI control are jointly critical.

Availability

ST3241EBTR is available at Aetrix Electronics and suitable for notebook serial interfaces, portable peripheral docking stations, battery-powered handheld terminals, and industrial field instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for ST3241EBTR 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, and interface solutions for industrial, automotive, and consumer markets.

The ST3241EBTR belongs to ST's RS-232 transceiver product line, engineered specifically for low-power, high-ESD-resilience serial communication in space-constrained portable electronics and embedded systems.

FAQ

What is the minimum external capacitor value required for ST3241EBTR at 3.3 V supply?

At 3.0–3.6 V supply, ST3241EBTR requires 0.1 µF for each of C1, C2, C3, C4, and the VCC bypass capacitor. These values ensure stable charge-pump operation and meet the 250 kbps data rate guarantee per the datasheet Table 11.

Does ST3241EBTR support true RS-232 voltage levels with a 3.3 V supply?

Yes. The dual charge-pump generates ±5.5 V rails (V+ and V−), enabling guaranteed ±5 V transmitter output swing into 3 kΩ loads-even at 3.3 V VCC. This satisfies EIA/TIA-232-F requirements for full-voltage RS-232 compliance.

How does the wake-up feature work on ST3241EBTR?

Receiver R2 remains powered and active during SHDN assertion. Its output R2OUTB stays functional and can be monitored by the host MCU to detect incoming RS-232 activity-triggering an interrupt and waking the system from low-power mode without external components.

Can ST3241EBTR replace MAX232 in existing designs?

No-ST3241EBTR is not a drop-in replacement for MAX232. It has 28 pins versus MAX232's 16, supports 3 drivers/5 receivers (vs. 2/2), and requires different capacitor values and layout. However, its SSOP-28 footprint allows redesign for enhanced channel count and lower power in new portable platforms.