My Inquiry
My Account
STMicroelectronics ST232CTR
- Part No.:
- ST232CTR
- Manufacturer:
- STMicroelectronics
- Category:
- Drivers, Receivers, Transceivers
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
ST232CTR.pdf
- Description:
- IC TRANSCEIVER FULL 2/2 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,674
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
ST232CTR from STMicroelectronics is a 5 V powered dual-channel 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 0 °C to 70 °C in TSSOP16 package. It enables RS-232 communication in battery-powered portable computers and low-power modems without ±12 V supplies.
For engineers reviewing the ST232CTR datasheet, ST232CTR pinout, ST232CTR application, or ST232CTR equivalent, this page provides verified electrical parameters, terminal roles, real-world use cases, and validated alternatives for embedded serial interface design and legacy port replacement.
Technical Context
The ST232CTR integrates charge-pump voltage doublers and inverters to generate ±7.8 V RS-232 signal levels from a single 5 V supply, using only four 0.1 µF external capacitors. Its controlled slew rate (7–30 V/µs) reduces EMI while maintaining compatibility with standard RS-232 receivers.
It features TTL/CMOS-compatible inputs and outputs, with receiver input tolerance up to ±30 V and logic thresholds of 0.8 V (low) and 1.7–2.4 V (high). Propagation delay is 0.3–1 µs, and transmitter output resistance is 300 Ω, ensuring stable drive into 3–7 kΩ loads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5–5.5 V - Enables direct integration with 5 V logic rails and eliminates need for auxiliary ±12 V supplies. |
| Transmitter Output Swing | ±7.8 V (typ.) - Meets EIA/TIA-232 minimum ±5 V requirement with margin for cable loss and noise immunity. |
| Data Rate | 220 kbps (typ.) - Supports full-speed operation of standard UART peripherals including 115.2 kbps and lower baud rates. |
| Receiver Input Range | ±30 V - Withstands large common-mode transients and ESD events on RS-232 lines without damage or latch-up. |
| Supply Current (no load) | 5 mA (typ.) - Enables low-power operation in battery-powered systems such as handheld terminals and field instruments. |
| Operating Temperature | 0 °C to 70 °C - Qualified for commercial-grade industrial and consumer equipment environments. |
| Slew Rate | 7–30 V/µs - Limits high-frequency harmonics to reduce radiated emissions and improve signal integrity over long cables. |
Pinout & Package
TSSOP16 (Thin Shrink Small Outline Package, 16-pin), 4.9 × 6.4 mm body, 0.65 mm pitch, lead-free ECOPACK® compliant.
| 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 voltage output | Provides +10 V rail for transmitter driver stages; must be decoupled to GND with 0.1 µF capacitor. |
| 3 C1− | Charge pump capacitor negative terminal | Completes first charge pump loop; ties to GND during phase switching to enable voltage doubling. |
| 4 C2+ | Second charge pump capacitor positive terminal | Connects to +ve side of second 0.1 µF flying capacitor; used in inverter stage for −V generation. |
| 5 C2− | Second charge pump capacitor negative terminal | Completes inverter charge pump loop; referenced to V+ during switching to generate −V rail. |
| 6 V− | Inverted voltage output | Provides −10 V rail for transmitter drivers; requires local 0.1 µF decoupling to GND. |
| 7 T2OUT | Second transmitter output | RS-232 level output (±7.8 V) for secondary serial channel; compatible with standard DB9 pin 3 or 7. |
| 8 R2IN | Second receiver input | Accepts ±30 V RS-232 input signals; converts to TTL/CMOS logic levels for microcontroller UART RX2. |
| 9 R2OUT | Second receiver output | TTL/CMOS logic-level output (0.4 V low / ≥3.5 V high); drives MCU RX2 pin directly without level-shifting. |
| 10 T2IN | Second transmitter input | TTL/CMOS logic-level input (0.8 V low / ≥2 V high); accepts MCU TX2 signal directly. |
| 11 T1IN | First transmitter input | TTL/CMOS logic-level input for primary UART TX; compatible with 3.3 V or 5 V microcontrollers. |
| 12 R1OUT | First receiver output | TTL/CMOS logic-level output for MCU RX1; meets standard drive strength (3.2 mA sink, 1 mA source). |
| 13 R1IN | First receiver input | RS-232 input for primary channel; supports multi-drop configurations with ±30 V fault tolerance. |
| 14 T1OUT | First transmitter output | Primary RS-232 output (±7.8 V); connects to DB9 pin 2 or custom connector for host-side transmit. |
| 15 GND | Ground reference | Common return for all internal circuits and external capacitors; must be low-impedance PCB plane. |
| 16 VCC | Positive supply input | 5 V power input; requires local 0.1 µF ceramic decoupling capacitor placed within 5 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| Single 5 V supply operation | Eliminates need for ±12 V regulators or transformers, reducing BOM count and board space in portable designs. |
| Four 0.1 µF external capacitors | Minimizes footprint and cost vs. legacy RS-232 ICs requiring larger electrolytics or more components. |
| Controlled output slew rate | Reduces electromagnetic interference (EMI) and signal reflections on long RS-232 traces (>15 m). |
| ±30 V receiver input tolerance | Enables robust operation in electrically noisy industrial environments and protects against accidental miswiring. |
| Compatible with MAX232/MAX202 | Allows drop-in replacement in existing designs without layout or firmware changes. |
Applications
| Portable Computer Serial Interface | Low-Power Modem Interface |
|---|---|
|
Use Scenario: Adding RS-232 connectivity to handheld diagnostic tools powered by Li-ion batteries. IC Role / Device Role / Timing Role: Dual-channel transceiver converting UART signals between microcontroller and DB9 connector. Use Value: 5 mA quiescent current extends battery life; ±7.8 V output ensures reliable link over 10 m cables in clinic environments. |
Use Scenario: Enabling legacy RS-232 modem communication in solar-powered remote telemetry units. IC Role / Device Role / Timing Role: Level shifter and driver for bidirectional AT command exchange between MCU and modem IC. Use Value: Single 5 V supply simplifies power architecture; ±30 V input tolerance prevents damage from lightning-induced surges. |
| Industrial Multi-Drop Network | Embedded System Interface Translation |
|
Use Scenario: Connecting multiple sensors to a central PLC via daisy-chained RS-232 bus in factory automation. IC Role / Device Role / Timing Role: Receiver front-end and transmitter buffer for half-duplex multi-drop topology. Use Value: High input impedance (3–7 kΩ) minimizes loading on shared bus; controlled slew rate maintains signal integrity across 5-node chain. |
Use Scenario: Bridging 3.3 V microcontroller UART to legacy test equipment requiring RS-232 input. IC Role / Device Role / Timing Role: Bidirectional logic-to-RS-232 voltage translator with integrated charge pumps. Use Value: No external voltage converters needed; TTL/CMOS thresholds match modern MCU I/O, eliminating glue logic. |
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 220 kbps data rate and ±7.6 V output swing. | Requires through-hole assembly and larger board area; not suitable for space-constrained SMT designs. | Select when DIP mounting or legacy through-hole production is required; avoid for new compact PCBs. |
| SP3232ECA | TSSOP16 package; 3.0–5.5 V supply range; 1 µA shutdown current; ±15 kV ESD protection (IEC 61000-4-2). | Supports mixed-voltage systems and adds fail-safe ESD robustness beyond ST232CTR's ±15 kV HBM rating. | Select when operating voltage flexibility or enhanced ESD immunity is critical; verify timing compatibility with host UART. |
Compared with MAX232CPE and SP3232ECA, the ST232CTR offers optimal balance of low-cost TSSOP16 packaging, proven 5 V-only operation, and industry-standard pinout-ideal for volume commercial designs where ESD beyond HBM is not mandated.
Availability
ST232CTR is available at Aetrix Electronics and suitable for portable computing, low-power modem interfaces, and industrial multi-drop RS-232 networks requiring stable component supply and long-term manufacturability.
Supply support for ST232CTR 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, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.
The ST232CTR belongs to ST's legacy RS-232 interface product line, engineered for cost-sensitive, high-reliability serial communication in commercial-grade embedded systems with strict size and power constraints.
FAQ
What is the minimum external capacitor value supported for reliable operation?
The ST232CTR is characterized and guaranteed for stable operation with 0.1 µF ceramic capacitors on all four charge pump terminals (C1+, C1−, C2+, C2−). While the datasheet notes that 1 µF capacitors may also work, using values below 0.1 µF risks insufficient voltage regulation, reduced output swing, and failure to meet 220 kbps timing specifications under temperature variation.
Can ST232CTR operate with a 3.3 V supply?
No. The ST232CTR requires a minimum supply voltage of 4.5 V and is specified only for 4.5–5.5 V operation. At 3.3 V, the internal charge pumps cannot generate sufficient ±7.8 V RS-232 levels, resulting in non-compliant output swing (< ±3 V) and unreliable receiver detection. For 3.3 V systems, consider SP3232E or MAX3232 instead.
Is the ST232CTR pin-compatible with the MAX232?
Yes-ST232CTR uses identical pinout and function mapping to the MAX232 family (e.g., MAX232CPE, MAX232CSE). Pin 1 (C1+) through Pin 16 (VCC) serve the same roles, enabling direct PCB-level replacement in SO-16 or TSSOP16 footprints without layout modification.
Does ST232CTR include built-in ESD protection?
The ST232CTR features human-body model (HBM) ESD protection rated at ±15 kV on RS-232 pins (R1IN, R2IN, T1OUT, T2OUT), per JEDEC JS-001. It does not include IEC 61000-4-2 system-level ESD protection; external TVS diodes are recommended for applications exposed to frequent connector hot-plugging or harsh industrial environments.
ST232CTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm 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-TSSOP
ST232CTR FAQ
1.How can I place an order for ST232CTR through Aetrix?
Please submit a Request for Quotation (RFQ) for ST232CTR 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 ST232CTR reliable?
The price and inventory of ST232CTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST232CTR is usually 5 days.
3.What payment methods are accepted for ST232CTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST232CTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST232CTR?
ST232CTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST232CTR 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 ST232CTR?
For technical support, including ST232CTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST232CTR requirements.
6.How does Aetrix verify that ST232CTR is sourced from the original manufacturer or authorized distributors?
All ST232CTR 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 ST232CTR meets industry standards.
7.What is the process for return or replacement of ST232CTR?
All ST232CTR units undergo pre-shipment inspection (PSI). If there is an issue with ST232CTR, 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 ST232CTR part is unused and in its original packaging.
Return procedure for ST232CTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ST232CTR Tags
-
ATA6561-GAQW-N
Microchip Technology
-
ATA6561-GBQW-N
Microchip Technology
-
AM26LS32ACDR
Texas Instruments
-
SP485CN-L/TR
MaxLinear, Inc.
-
SP485EN-L/TR
MaxLinear, Inc.
-
SP485EEN-L/TR
MaxLinear, Inc.
-
SP485ECN-L/TR
MaxLinear, Inc.
-
THVD1400DR
Texas Instruments
-
AM26C31IDR
Texas Instruments
-
TLIN1021ADRQ1
Texas Instruments
-
MAX232IDR
Texas Instruments
-
AM26C32IDR
Texas Instruments
Tech Hub
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
Engineering guide to Raspberry Pi alternatives, covering chip-level differences, Orange Pi, ROCK, Jetson, Banana Pi, NanoPi, Compute Module, Pico, GPIO, camera, HAT compatibility, and replacement risks…
