STMicroelectronics ST3222ECPR

Overview

ST3222ECPR from STMicroelectronics is a ±15 kV ESD-protected, 3–5.5 V low-power RS-232 transceiver IC with two drivers and two receivers, 250 Kbps guaranteed data rate, 6 V/µs minimum slew rate, and 300 µA supply current. It enables robust serial communication in battery-powered portable systems such as handheld computers and printers.

For engineers reviewing the ST3222ECPR datasheet, ST3222ECPR pinout, ST3222ECPR application, or ST3222ECPR equivalent, key selection criteria include ESD robustness (±15 kV HBM), shutdown current (1 µA), dual-receiver monitoring capability in shutdown, charge-pump capacitor count (4 × 0.1 µF), and SSOP20 package compatibility with space-constrained PCB layouts.

Technical Context

The ST3222ECPR integrates a dual charge pump to generate ±5.4 V RS-232 output levels from a single 3–5.5 V supply, eliminating need for external high-voltage supplies. Its proprietary low-dropout transmitter stage ensures full compliance with EIA/TIA-232 down to 3 V.

It supports independent receiver enable (EN) and active-low shutdown (SHDN), enabling selective power gating: receivers remain operational in shutdown mode (1 mA total current), allowing modem status monitoring without waking the host system.

Key Specifications

Pinout & Package

ST3222ECPR is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch, optimized for high-density portable PCBs and RoHS-compliant reflow assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX3222CPE+ and SP3222ECA-L, ST3222ECPR uniquely delivers verified ±8 kV IEC 61000-4-2 contact discharge protection alongside 250 Kbps performance and SSOP20 packaging - making it the only choice for CE-compliant, high-speed, space-constrained portable designs.

Availability

ST3222ECPR is available at Aetrix Electronics and suitable for notebook computers, handheld test equipment, and battery-powered printers requiring stable component supply, long-term lifecycle support, and RoHS-compliant SSOP20 packaging.

Supply support for ST3222ECPR 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 devices, and sensors for automotive, industrial, and consumer markets.

The ST3222E product line targets low-power, ESD-hardened RS-232 interfaces for portable and battery-operated equipment - emphasizing single-supply operation, minimal external components, and regulatory-compliant transient protection.

FAQ

What is the minimum number of external capacitors required for ST3222ECPR operation?

The ST3222ECPR requires exactly four 0.1 µF ceramic capacitors (C1+, C1−, C2+, C2−) to operate its dual charge pump from a 3–5.5 V supply. No additional bypass or timing capacitors are needed - this minimal BOM enables compact PCB layouts in space-constrained portable designs.

Can ST3222ECPR receivers remain active while transmitters are disabled?

Yes. When SHDN = high, transmitters and charge pump enter 1 µA shutdown, but receivers continue operating with full ±25 V input tolerance and CMOS-level outputs. This enables modem status monitoring (e.g., DCD detection) without waking the host processor - a key feature for battery life optimization.

Does ST3222ECPR meet IEC 61000-4-2 ESD requirements for industrial equipment certification?

Yes. The ST3222ECPR is rated for ±8 kV contact discharge per IEC 61000-4-2 and ±15 kV air discharge per HBM. This dual-rating satisfies EN 61000-4-2 Level 3 requirements for industrial equipment, eliminating need for external ESD protection components in certified designs.

What is the maximum recommended trace length for ST3222ECPR RS-232 outputs driving a 3 kΩ load?

At 250 Kbps with 6 V/µs slew rate, ST3222ECPR maintains signal integrity up to 15 m on standard twisted-pair cable per EIA/TIA-232-F. For PCB traces, keep driver-to-connector paths under 10 cm with controlled impedance (≈100 Ω differential) to avoid reflections that degrade rise/fall times below specification.