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Home > Products > Integrated Circuits (ICs) > Interface > Drivers, Receivers, Transceivers

STMicroelectronics ST232BDR

Name: ST232BDR
Brand: STMicroelectronics
SKU: ST232BDR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ST232BDR

Manufacturer:: STMicroelectronics

Category:: Drivers, Receivers, Transceivers

Package:: 16-SOIC (0.154", 3.90mm Width)

Datasheet:: ST232BDR.pdf

Description:: IC TRANSCEIVER FULL 2/2 16SO

Quantity:: RFQ Add To RFQ list

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Inventory:5,777

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Product details

Overview

ST232BDR from STMicroelectronics is a dual-transmitter/dual-receiver RS-232 interface IC operating from a single 5 V supply, delivering ±7.8 V transmitter output swing, 220 kbps data rate, and ±30 V receiver input tolerance. It replaces legacy ±12 V RS-232 transceivers in battery-powered modems and portable computing interfaces.

For engineers reviewing the ST232BDR datasheet, ST232BDR pinout, ST232BDR application, or ST232BDR equivalent, key selection criteria include its industrial temperature range (–40 °C to +85 °C), SO-16 package with tape-and-reel delivery (2500 units/reel), controlled slew rate for EMI reduction, and compatibility with MAX232/MAX202 designs.

Technical Context

The ST232BDR integrates two charge-pump voltage doublers and inverters to generate ±V_CC-derived RS-232 voltage levels from a single 5 V rail, using only four 0.1 µF external capacitors. Its transmitter outputs feature slew-rate limiting to reduce electromagnetic interference during signal transitions.

Receiver inputs meet EIA/TIA-232 and V.28 standards with ±30 V fault tolerance and 0.5 V hysteresis for noise immunity. Logic-level I/O (TTL/CMOS compatible) interfaces directly with microcontrollers and UARTs without level-shifting circuitry.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage	4.5 V to 5.5 V - Enables direct connection to standard 5 V logic rails without regulation overhead.
Transmitter Output Swing	±7.8 V (typ.) - Meets RS-232 minimum ±5 V requirement with margin for cable loss and noise.
Data Rate	220 kbps (typ.) - Supports high-speed serial communication in modem and industrial control links.
Receiver Input Range	±30 V - Withstands large ground potential differences and transient surges in multi-drop networks.
Slew Rate	7–30 V/µs - Limits edge speed to suppress radiated emissions while maintaining signal integrity.
Operating Temperature	–40 °C to +85 °C - Qualified for industrial environments including factory automation and outdoor telemetry.
Supply Current (no load)	5 mA (typ.) - Enables low-power operation in battery-backed portable systems.

Pinout & Package

ST232BDR is housed in a 16-pin SOIC (SO-16) package with 1.27 mm pitch, JEDEC MS-012 compliant, RoHS-compliant and ECOPACK® certified. Dimensions: 9.8–10.0 mm × 5.8–6.2 mm × 1.75 mm height.

Pin/Terminal	Circuit Role	Design Meaning
1 C1+	Charge pump capacitor positive terminal	Connects to + terminal of first 0.1 µF flying capacitor for voltage doubling.
2 V+	Doubled supply voltage output	Provides +2×V_CC (~10 V) to transmitter drivers; must not be externally driven.
3 C1−	Charge pump capacitor negative terminal	Completes first charge pump loop; connects to GND side of C1.
4 C2+	Second charge pump capacitor positive terminal	Connects to + terminal of second 0.1 µF flying capacitor for voltage inversion.
5 C2−	Second charge pump capacitor negative terminal	Completes second charge pump loop; connects to V+ node.
6 V−	Inverted supply voltage output	Provides –V_CC (~–5 V) to transmitter drivers; must not be externally driven.
7 T2OUT	Second transmitter output	RS-232-level output (±7.8 V) for secondary serial channel (e.g., RTS/CTS).
8 R2IN	Second receiver input	Accepts ±30 V RS-232 signals; converts to TTL/CMOS logic for secondary input (e.g., DSR/DCD).
9 R2OUT	Second receiver output	TTL/CMOS logic-level output corresponding to R2IN; drives MCU input pins directly.
10 T2IN	Second transmitter input	TTL/CMOS logic input (0.8 V / 2.0 V thresholds) for secondary transmit path.
11 T1IN	First transmitter input	TTL/CMOS logic input for primary transmit path (e.g., TXD from UART).
12 R1OUT	First receiver output	TTL/CMOS logic output for primary receive path (e.g., RXD to UART).
13 R1IN	First receiver input	RS-232 input for primary channel (e.g., RXD from DB9 connector); ±30 V tolerant.
14 T1OUT	First transmitter output	Primary RS-232 output (±7.8 V) for main serial channel (e.g., TXD to DB9).
15 GND	Analog and digital ground reference	Common return for all internal circuits and external capacitors; requires low-impedance PCB connection.
16 VCC	Positive supply input	Single 5 V power source; decoupling capacitor (0.1 µF) required between VCC and GND.

Key Features

Feature	Design Value
Single 5 V supply operation	Eliminates need for ±12 V supplies, reducing BOM count and board space in portable and embedded systems.
Four external 0.1 µF capacitors	Minimizes external component count and cost versus older RS-232 ICs requiring larger electrolytics or more caps.
Controlled output slew rate	Reduces EMI generation by limiting dV/dt on RS-232 lines-critical for CE/FCC compliance in compact enclosures.
±30 V receiver input tolerance	Enables robust operation in electrically noisy industrial settings and long-cable multi-drop RS-232 networks.
MAX232/MAX202 compatibility	Pin- and function-compatible drop-in replacement, enabling legacy design upgrades without PCB rework.

Applications

Portable Computing Interface

Low-Power Modem

Use Scenario: Serial communication between ARM-based tablet SoC and external GPS module via DB9 connector.

IC Role / Device Role / Timing Role: Dual-channel RS-232 transceiver converting TTL UART signals to full-voltage RS-232 levels.

Use Value: Single 5 V supply eliminates need for isolated DC-DC converter; ±7.8 V swing ensures reliable link over 15 m cable at 115.2 kbps.

Use Scenario: Battery-operated cellular modem interfacing with microcontroller over RS-232 for AT command control.

IC Role / Device Role / Timing Role: Level translator and driver for bidirectional AT command exchange and status reporting.

Use Value: 5 mA no-load current extends battery life; ±30 V input tolerance prevents latch-up during antenna coupling events.

Industrial Multi-Drop Network

Interface Translation Module

Use Scenario: Central PLC communicating with up to 8 remote sensors via shared RS-232 bus with termination resistors.

IC Role / Device Role / Timing Role: Robust RS-232 receiver/transmitter with high common-mode rejection for multi-node bus operation.

Use Value: Receiver hysteresis (0.5 V typ.) rejects line noise; slew-rate control prevents signal reflections on unterminated stubs.

Use Scenario: USB-to-RS-232 adapter PCB where FT232RL USB UART outputs TTL and must drive legacy equipment.

IC Role / Device Role / Timing Role: Bidirectional voltage-level shifter translating 3.3 V/5 V logic to ±7.8 V RS-232 and vice versa.

Use Value: TTL/CMOS input thresholds (0.8 V low / 2.0 V high) ensure compatibility with both 3.3 V and 5 V host controllers.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MAX232CPE+	0 to +70 °C rating; requires five 1 µF capacitors; higher quiescent current (8 mA typ.)	Not rated for industrial temperature range; unsuitable for extended ambient deployments	Select when cost sensitivity outweighs temperature or power requirements and legacy 1 µF cap footprint exists.
SP3232EBCY-L	–40 °C to +85 °C; 3.0–5.5 V supply; 1 µA shutdown current; uses four 0.1 µF caps	Includes enable/shutdown pin and lower supply voltage flexibility but lacks MAX232 pinout alignment	Select when ultra-low standby power or 3.3 V system integration is required and PCB layout allows pin remapping.

Compared with MAX232CPE+, ST232BDR offers wider temperature range and lower supply count; compared with SP3232EBCY-L, it provides exact MAX232 pin compatibility and simpler enable-free operation for drop-in replacements.

Availability

ST232BDR is available at Aetrix Electronics and suitable for industrial automation, portable computing, and telecom infrastructure requiring stable component supply across extended temperature conditions and long production lifecycles.

Supply support for ST232BDR 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, mixed-signal, power, and microcontroller solutions for industrial, automotive, and consumer markets.

The ST232BDR belongs to ST's legacy RS-232 interface product line, engineered specifically to replace ±12 V transceivers with single-supply operation while maintaining full EIA/TIA-232 compliance and interoperability.

FAQ

What is the minimum external capacitor value supported for reliable operation?

The ST232BDR is characterized and guaranteed for stable operation with 0.1 µF ceramic capacitors on all four charge-pump terminals (C1+, C1−, C2+, C2−). Using smaller values risks insufficient voltage conversion efficiency and reduced output swing under load, especially at temperature extremes or high data rates.

Can ST232BDR drive standard RS-232 loads over 50 feet of cable?

Yes - with its ±7.8 V output swing and 300 Ω transmitter output resistance, the ST232BDR meets RS-232 specifications for driving up to 50 ft (15 m) of standard 24 AWG twisted-pair cable at 115.2 kbps, provided proper termination and grounding practices are followed per EIA/TIA-232.

Is the SO-16 package of ST232BDR lead-free and RoHS compliant?

Yes - the ST232BDR SO-16 package carries ST's ECOPACK® designation, indicating lead-free second-level interconnects, RoHS compliance, and adherence to JEDEC JESD97 marking standards. The inner reel box label confirms Pb-free status and soldering profile limits.

Does ST232BDR require external pull-up or pull-down resistors on logic inputs?

No - the T1IN, T2IN, and all other logic inputs have built-in biasing and defined TTL/CMOS-compatible thresholds (0.8 V low, 2.0 V high). External resistors are unnecessary unless specific noise immunity or fail-safe idle-state requirements dictate otherwise per system-level design.

ST232BDR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 16-SOIC (0.154", 3.90mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Transceiver

Protocol:: RS232

Number of Drivers/Receivers:: 2/2

Duplex:: Full

Receiver Hysteresis:: 500 mV

Data Rate:: 220Kbps

Voltage - Supply:: 4.5V ~ 5.5V

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 16-SO

ST232BDR FAQ

1.How can I place an order for ST232BDR through Aetrix?

Please submit a Request for Quotation (RFQ) for ST232BDR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for ST232BDR reliable?

The price and inventory of ST232BDR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST232BDR is usually 5 days.

3.What payment methods are accepted for ST232BDR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST232BDR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ST232BDR?

ST232BDR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ST232BDR order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for ST232BDR?

For technical support, including ST232BDR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST232BDR requirements.

6.How does Aetrix verify that ST232BDR is sourced from the original manufacturer or authorized distributors?

All ST232BDR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ST232BDR meets industry standards.

7.What is the process for return or replacement of ST232BDR?

All ST232BDR units undergo pre-shipment inspection (PSI). If there is an issue with ST232BDR, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The ST232BDR part is unused and in its original packaging.

Return procedure for ST232BDR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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