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STMicroelectronics ST232CD
- Part No.:
- ST232CD
- Manufacturer:
- STMicroelectronics
- Category:
- Drivers, Receivers, Transceivers
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ST232CD.pdf
- Description:
- IC TRANSCEIVER FULL 2/2 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:1,380
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Product details
Overview
ST232CD from STMicroelectronics is a 5 V-powered dual RS-232 transceiver IC with 2 drivers and 2 receivers, compliant with EIA/TIA-232 and V.28 standards. It delivers ±7.8 V transmitter output swing, supports 220 kbps data rate, draws 5 mA supply current at no load, and operates from –40 °C to 85 °C. It enables RS-232 communication in battery-powered portable computers and low-power modems using only four 0.1 µF external capacitors.
For engineers reviewing the ST232CD datasheet, ST232CD pinout, ST232CD application, or ST232CD equivalent, key selection considerations include its single-supply operation, controlled slew rate for EMI reduction, ±30 V receiver input tolerance, and compatibility with MAX232/MAX202 in space-constrained SO-16 designs.
Technical Context
The ST232CD integrates on-chip charge pumps to generate ±VCC-derived voltages (V+ and V−) from a single 5 V rail, eliminating need for ±12 V supplies. Its dual transmitter/receiver channels support full-duplex asynchronous serial communication with TTL/CMOS logic-level interfacing on the digital side and RS-232 voltage-level signaling on the bus side.
It features controlled output slew rate (7–30 V/µs) to limit electromagnetic interference, TTL-compatible input thresholds (0.8 V low / 2.0 V high), and robust ±30 V receiver input range with 5 kΩ typical input resistance - enabling reliable operation in electrically noisy industrial environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5–5.5 V - Enables direct integration into 5 V logic systems without level-shifting or auxiliary rails. |
| Transmitter Output Swing | ±7.8 V (typ.) - Meets RS-232 minimum ±5 V requirement with margin for cable loss and noise immunity. |
| Data Rate | 220 kbps (typ.) - Supports standard UART baud rates up to 115.2 kbps with timing margin for jitter and propagation delay. |
| Receiver Input Range | ±30 V - Withstands large common-mode transients and ESD events on RS-232 lines without latch-up. |
| Supply Current (no load) | 5 mA (typ.) - Enables low-power operation in battery-backed or portable applications. |
| Operating Temperature | –40 °C to +85 °C - Qualified for industrial-grade deployment in extended ambient conditions. |
| Slew Rate | 7–30 V/µs - Limits high-frequency spectral content to reduce radiated emissions per FCC/CE requirements. |
Pinout & Package
ST232CD is housed in a 16-pin SOIC (SO-16) package with 1.27 mm pitch, 10.0–10.65 mm width, and 9.8–10.5 mm length - optimized for automated PCB assembly and board space efficiency.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 C1+ | Charge pump capacitor positive terminal | Connects to +ve side of first 0.1 µF flying capacitor; critical for V+ generation stability. |
| 2 V+ | Doubled voltage output | Provides ~+10 V rail for transmitter outputs; must be decoupled to GND near IC. |
| 3 C1− | Charge pump capacitor negative terminal | Completes first charge pump loop; ties to GND during phase switching. |
| 4 C2+ | Second charge pump capacitor positive terminal | Connects to +ve side of second 0.1 µF flying capacitor; enables V− generation. |
| 5 C2− | Second charge pump capacitor negative terminal | Completes second charge pump loop; referenced to V+ during inversion phase. |
| 6 V− | Inverted voltage output | Provides ~–10 V rail for transmitter outputs; requires local 0.1 µF bypass to GND. |
| 7 T2OUT | Second transmitter output | RS-232-level output (±7.8 V) for channel 2; drives DTE/DCE interface lines like RTS/CTS. |
| 8 R2IN | Second receiver input | Accepts RS-232 signals up to ±30 V; includes hysteresis for noise rejection on RXD/DCD lines. |
| 9 R2OUT | Second receiver output | TTL/CMOS logic-level output (0.4 V low / ≥3.5 V high); interfaces directly to UART RX pin. |
| 10 T2IN | Second transmitter input | TTL/CMOS logic-level input (0.8 V low / 2.0 V high); accepts UART TX signal directly. |
| 11 T1IN | First transmitter input | Primary TTL/CMOS input for UART TX path; compatible with 3.3 V or 5 V logic families. |
| 12 R1OUT | First receiver output | Primary TTL/CMOS output driving UART RX; specified for 3.2 mA sink / 1 mA source capability. |
| 13 R1IN | First receiver input | Main RS-232 input (e.g., RxD line); features 0.5 V hysteresis to suppress contact bounce or line noise. |
| 14 T1OUT | First transmitter output | Main RS-232 output (e.g., TxD line); delivers ±7.8 V swing into 3 kΩ load per EIA-232 spec. |
| 15 GND | Signal ground reference | Common return for all internal circuitry and external capacitors; must be low-impedance plane. |
| 16 VCC | Positive supply input | 5 V power input; requires 0.1 µF ceramic bypass capacitor placed within 5 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| Single 5 V supply operation | Eliminates need for ±12 V rails - reduces BOM count, board area, and power conversion losses. |
| Four 0.1 µF external capacitors | Minimizes external component count and footprint vs. legacy RS-232 ICs requiring larger electrolytics. |
| Controlled output slew rate | 7–30 V/µs limits edge-induced EMI, easing EMC compliance in compact enclosures and mixed-signal systems. |
| ±30 V receiver input tolerance | Withstands cable discharge events and ground potential differences without protection diodes or clamps. |
| MAX232/MAX202 pin-to-pin compatibility | Enables drop-in replacement in existing designs - no layout or firmware changes required. |
Applications
| Portable Computers | Low-Power Modems |
|---|---|
|
Use Scenario: Serial debug port and peripheral interface in handheld terminals and ruggedized laptops. IC Role / Device Role / Timing Role: Dual-channel RS-232 level translator between 3.3 V/5 V UART and external DB9 connectors. Use Value: Single-supply operation extends battery life; ±7.8 V output ensures interoperability with legacy peripherals over 15 m cables. |
Use Scenario: Data communication interface in battery-operated DSL/cable modems and IoT gateways. IC Role / Device Role / Timing Role: Full-duplex RS-232 transceiver handling AT command exchange and firmware updates. Use Value: 5 mA quiescent current minimizes standby drain; 220 kbps supports fast configuration and diagnostics. |
| Interface Translation | Battery-Powered RS-232 Systems |
|
Use Scenario: Protocol bridge between microcontroller UARTs and industrial RS-232 field devices (PLCs, sensors). IC Role / Device Role / Timing Role: Signal-level converter with ±30 V input tolerance for noisy factory floor wiring. Use Value: Robust input stage eliminates need for external TVS diodes; hysteresis prevents false triggering on long lines. |
Use Scenario: Embedded telemetry unit in remote environmental monitoring stations powered by Li-ion cells. IC Role / Device Role / Timing Role: Low-quiescent RS-232 interface enabling periodic sensor data upload via serial radio link. Use Value: 5 mA supply current allows >1 year operation on 2000 mAh battery; SO-16 package fits compact PCB layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-channel RS-232 transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX232CPE+ | DIP-16 package; higher 10 mA supply current; same ±7.8 V output swing and 220 kbps rating. | Preferred for through-hole prototyping or legacy DIP-based systems; not suitable for surface-mount volume production. | Select when manual assembly or socket-based testing is required; avoid for automated SMT lines. |
| SP3232EEN-L | Wider 3.0–5.5 V supply range; lower 1 mA supply current; identical SO-16 footprint and pinout. | Better suited for mixed-voltage systems (e.g., 3.3 V MCU + 5 V RS-232); enhanced ESD rating (±15 kV HBM). | Choose for new designs requiring lower power or tighter supply flexibility; pin-compatible upgrade path. |
Compared with MAX232CPE+, ST232CD offers superior SMT manufacturability and lower quiescent draw; versus SP3232EEN-L, it trades wider supply range for guaranteed industrial temperature operation and proven field reliability in legacy infrastructure.
Availability
ST232CD is available at Aetrix Electronics and suitable for portable computing, industrial interface translation, and battery-powered RS-232 systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for ST232CD 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 sensing solutions for industrial, automotive, and consumer markets.
The ST232CD belongs to ST's legacy RS-232 transceiver product line, engineered specifically for cost-sensitive, space-constrained industrial and portable applications requiring robust single-supply serial communication.
FAQ
What external components are required for ST232CD operation?
The ST232CD requires exactly four 0.1 µF ceramic capacitors (C1–C4) for internal charge pump operation - no inductors, transformers, or additional regulators needed. These capacitors connect between pins C1+/C1−, C2+/C2−, V+, and V−. Placement within 5 mm of the IC and use of X7R dielectric are recommended for stable voltage doubling and inversion.
Can ST232CD operate from a 3.3 V supply?
No - ST232CD is specified only for 4.5–5.5 V operation. Attempting 3.3 V supply will result in insufficient V+ and V− generation, causing degraded output swing (<±5 V), increased bit error rate, and possible failure to meet EIA-232 compliance. For 3.3 V systems, consider SP3232EEN-L or MAX3232.
Is ST232CD RoHS-compliant and lead-free?
Yes - ST232CD is manufactured in ST's ECOPACK®-compliant SO-16 package with lead-free second-level interconnects, meeting RoHS Directive 2011/65/EU and JEDEC JESD97 standards. The device marking includes the "E" suffix per ST's eco-labeling convention, and Pb-free soldering profiles are documented in ST's package mechanical data sheets.
How does ST232CD handle ESD on RS-232 lines?
ST232CD incorporates on-die ESD protection on all RS-232 pins (R1IN, R2IN, T1OUT, T2OUT), rated to ±15 kV HBM per IEC 61000-4-2 Level 4. Its ±30 V receiver input range provides inherent tolerance to transient overvoltage, reducing need for external TVS diodes in most industrial installations - though external protection is still advised for high-risk environments.
ST232CD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- 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:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
ST232CD FAQ
1.How can I place an order for ST232CD through Aetrix?
Please submit a Request for Quotation (RFQ) for ST232CD 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 ST232CD reliable?
The price and inventory of ST232CD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST232CD is usually 5 days.
3.What payment methods are accepted for ST232CD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST232CD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST232CD?
ST232CD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST232CD 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 ST232CD?
For technical support, including ST232CD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST232CD requirements.
6.How does Aetrix verify that ST232CD is sourced from the original manufacturer or authorized distributors?
All ST232CD 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 ST232CD meets industry standards.
7.What is the process for return or replacement of ST232CD?
All ST232CD units undergo pre-shipment inspection (PSI). If there is an issue with ST232CD, 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 ST232CD part is unused and in its original packaging.
Return procedure for ST232CD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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