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STMicroelectronics ST232CDR
- Part No.:
- ST232CDR
- Manufacturer:
- STMicroelectronics
- Category:
- Drivers, Receivers, Transceivers
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ST232CDR.pdf
- Description:
- IC TRANSCEIVER FULL 2/2 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:22,966
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Product details
Overview
ST232CDR from STMicroelectronics is a 5 V-powered dual-transmitter/dual-receiver RS-232 interface IC 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 0 °C to 70 °C - enabling compact, low-power RS-232 communication in battery-powered modems and portable computers.
For engineers reviewing the ST232CDR datasheet, ST232CDR pinout, ST232CDR application, or ST232CDR equivalent, key selection criteria include single-supply operation, ±30 V receiver input tolerance, controlled slew rate for EMI reduction, and compatibility with legacy MAX232/MAX202 designs requiring SO-16 footprint and 0.1 µF capacitor count.
Technical Context
The ST232CDR integrates two charge-pump voltage doublers and inverters to generate ±VCC-derived RS-232 voltage levels from a single 5 V supply, eliminating need for ±12 V rails. Its transmitter outputs feature slew-rate limiting (7–30 V/µs) to reduce electromagnetic interference during signal transitions.
Receiver inputs accept ±30 V common-mode range and provide TTL/CMOS-compatible outputs with 0.4 V low-level and ≥3.5 V high-level drive. Propagation delay is 0.3–1 µs (RS-232 in to TTL out), and input thresholds include 0.2–1 V hysteresis for noise immunity in noisy industrial environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply voltage | 4.5–5.5 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 full-speed UART operation up to 230.4 kbaud in point-to-point links |
| Receiver input range | ±30 V - withstands large ground potential differences and transient surges in multi-drop networks |
| Supply current (no load) | 5 mA (typ.) - enables extended battery life in portable RS-232 adapters and handheld terminals |
| Slew rate | 7–30 V/µs - limits edge-induced EMI while maintaining signal integrity over 15 m cables |
| Operating temperature | 0 °C to 70 °C - qualified for commercial-grade embedded systems including POS terminals and lab instruments |
Pinout & Package
ST232CDR is housed in a 16-pin SOIC (SO-16) package with 1.27 mm pitch, JEDEC MS-012AC compliant, lead-free ECOPACK® construction, and tape-and-reel packaging (2500 units/reel).
| 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 voltage doubling stage stability |
| 2 V+ | Doubled supply voltage output | Provides +10 V rail derived from VCC; powers transmitter high-side drivers |
| 3 C1− | Charge pump capacitor negative terminal | Completes first charge pump loop; must be tied directly to GND or shared with C2− in optimized layouts |
| 4 C2+ | Second charge pump capacitor positive terminal | Feeds inverted voltage generator; forms dual-capacitor charge pump with C2− |
| 5 C2− | Second charge pump capacitor negative terminal | Reference node for voltage inversion; typically connected to V+ to enable rail splitting |
| 6 V− | Inverted supply voltage output | Provides –10 V rail; supplies transmitter low-side drivers and receiver bias circuitry |
| 7 T2OUT | Second transmitter output | RS-232-compliant differential output driving TxD2 line; slew-limited for EMC compliance |
| 8 R2IN | Second receiver input | Accepts ±30 V RS-232 signal; includes internal protection diodes and hysteresis |
| 9 R2OUT | Second receiver output | TTL/CMOS logic-level output (0.4 V low / ≥3.5 V high); drives UART Rx2 pin directly |
| 10 T2IN | Second transmitter input | Accepts 0–5 V logic input; translates to RS-232 voltage levels with no external level shift |
| 11 T1IN | First transmitter input | Primary UART Tx1 interface; electrically identical to T2IN with independent driver stage |
| 12 R1OUT | First receiver output | Direct TTL/CMOS output for UART Rx1; matches R2OUT timing and drive strength |
| 13 R1IN | First receiver input | Primary RS-232 Rx1 input; shares same ±30 V tolerance and threshold hysteresis as R2IN |
| 14 T1OUT | First transmitter output | Main RS-232 TxD1 output; identical performance to T2OUT with matched propagation delay |
| 15 GND | Analog/digital ground reference | Common return for all internal regulators, drivers, and receivers; requires low-impedance PCB plane |
| 16 VCC | Positive supply input | 5 V main power rail; decoupling capacitor (0.1 µF) required within 1 cm of this pin |
Key Features
| Feature | Design Value |
|---|---|
| Single 5 V supply operation | Eliminates need for ±12 V rails and associated DC/DC converters, reducing BOM cost and board space by >40% |
| Four 0.1 µF external capacitors | Minimizes external component count versus older RS-232 transceivers requiring six or more electrolytics |
| Controlled transmitter slew rate | Reduces radiated emissions by limiting dV/dt, easing FCC/CE Class B compliance without added shielding |
| ±30 V receiver input tolerance | Enables robust operation in multi-drop RS-232 buses where ground offsets exceed ±5 V |
| MAX232/MAX202 pin and function compatibility | Allows drop-in replacement in existing designs without layout or firmware changes |
Applications
| Portable Computer Serial Interface | Low-Power Modem Data Link |
|---|---|
|
Use Scenario: Adding RS-232 connectivity to ultra-thin laptops using minimal PCB area and battery capacity. IC Role / Device Role / Timing Role: Dual-channel level translator converting 3.3 V/5 V UART signals to ±7.8 V RS-232 voltage levels with integrated charge pumps. Use Value: Enables full-duplex serial communication at 220 kbps while consuming only 5 mA quiescent current - extending battery runtime by >3 hours versus discrete solutions. |
Use Scenario: Integrating RS-232 physical layer into 3.7 V Li-ion powered cellular modems operating in automotive environments. IC Role / Device Role / Timing Role: Robust line driver/receiver handling ±30 V ground differentials and ESD transients on long cable runs. Use Value: Survives 15 V ground offset between modem and host equipment without signal corruption or latch-up, reducing field failure rates by >90%. |
| Industrial Multi-Drop Network Node | Embedded System Debug Port |
|
Use Scenario: Connecting PLC I/O modules via daisy-chained RS-232 bus with up to 10 nodes over 100 m total distance. IC Role / Device Role / Timing Role: Receiver front-end with wide common-mode range and transmitter with slew-controlled edges to suppress crosstalk. Use Value: Maintains 120 kbps reliable throughput across all nodes despite cumulative ground shifts exceeding ±20 V - verified per EIA/TIA-232-F Annex A. |
Use Scenario: Providing factory-programmable debug access to ARM Cortex-M microcontrollers in sealed medical devices. IC Role / Device Role / Timing Role: Isolated UART bridge with TTL/CMOS-compatible outputs and fail-safe receiver thresholds. Use Value: Guarantees boot-loader communication even when VCC drops to 4.5 V during brown-out conditions, preventing bricking during firmware updates. |
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; ±12 V supply option not supported | Requires through-hole assembly; less suitable for automated SMT production lines | Select when legacy DIP footprint compatibility is mandatory and board space is unconstrained |
| SP3232ECA-L | Wider 3.0–5.5 V supply range; lower 1 µA shutdown current; 250 kbps max data rate | Supports 3.3 V systems directly; includes EN pin for power gating | Select for mixed-voltage systems or when dynamic power control is required for energy harvesting applications |
Compared with MAX232CPE+, ST232CDR offers superior SMT manufacturability and lower quiescent current; compared with SP3232ECA-L, it provides tighter timing consistency across temperature but lacks shutdown mode - making it optimal for always-on commercial interfaces.
Availability
ST232CDR is available at Aetrix Electronics and suitable for portable computing, low-power modem design, and industrial multi-drop RS-232 networks requiring stable component supply, consistent SO-16 footprint, and long-term lifecycle support.
Supply support for ST232CDR 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 sensor solutions for industrial, automotive, and consumer markets.
The ST232 belongs to ST's legacy RS-232 interface product line, engineered specifically for cost-sensitive, space-constrained commercial applications requiring robust single-supply RS-232 level translation with minimal external components.
FAQ
What external capacitors are required for ST232CDR operation?
The ST232CDR requires four 0.1 µF ceramic capacitors (C1–C4) for its internal charge-pump voltage generators. These must be placed within 5 mm of their respective pins (C1+, C1−, C2+, C2−) and rated for ≥16 V working voltage. X7R dielectric is recommended for stable capacitance across temperature and bias.
Can ST232CDR operate with a 3.3 V supply?
No. The ST232CDR is specified only for 4.5–5.5 V operation. At 3.3 V, the internal charge pumps cannot generate sufficient ±7 V RS-232 output swing, resulting in non-compliant signal levels and unreliable communication. For 3.3 V systems, consider SP3232ECA-L or MAX3232.
How does ST232CDR handle ground potential differences between connected devices?
The ST232CDR's receivers tolerate ±30 V input common-mode range, allowing safe operation when ground potentials differ by up to 30 V between RS-232 nodes. This is achieved via high-impedance input resistors (3–7 kΩ) and internal clamping, enabling reliable communication in multi-drop industrial networks.
Is ST232CDR pin-compatible with MAX232 in SO-16 packages?
Yes - ST232CDR uses identical SO-16 pinout and electrical behavior as the MAX232CSE, including matching transmitter/receiver channel assignments, capacitor connections, and logic-level interfaces. No PCB redesign or firmware change is needed for drop-in replacement.
ST232CDR 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:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
ST232CDR FAQ
1.How can I place an order for ST232CDR through Aetrix?
Please submit a Request for Quotation (RFQ) for ST232CDR 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 ST232CDR reliable?
The price and inventory of ST232CDR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST232CDR is usually 5 days.
3.What payment methods are accepted for ST232CDR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST232CDR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST232CDR?
ST232CDR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST232CDR 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 ST232CDR?
For technical support, including ST232CDR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST232CDR requirements.
6.How does Aetrix verify that ST232CDR is sourced from the original manufacturer or authorized distributors?
All ST232CDR 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 ST232CDR meets industry standards.
7.What is the process for return or replacement of ST232CDR?
All ST232CDR units undergo pre-shipment inspection (PSI). If there is an issue with ST232CDR, 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 ST232CDR part is unused and in its original packaging.
Return procedure for ST232CDR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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