MAX232DWR - Dual RS-232 Transceiver 120kbps | TI
MPN: MAX232DWR ✓ ActiveMAX232DWR Overview
An RS-232 transceiver is an interface IC that connects low-voltage digital logic to the voltage-tolerant, unbalanced serial signaling defined by EIA/TIA-232. Within the product hierarchy, the MAX232 is a dual driver/receiver, an RS-232 interface transceiver, and ultimately a semiconductor for serial communications and embedded data exchange. This category is especially useful when equipment needs a compact way to bridge a TTL/CMOS UART and an RS-232 port using only a single 5 V rail.
Key features include two transmit channels, two receive channels, a maximum data rate of 120 kbit/s, and receiver input capability of ±30 V. Each receiver uses a typical input threshold of 1.3 V with 0.5 V of hysteresis. The MAX232 operates from a single 5 V supply, has a typical supply current of 8 mA, and provides ±9 V RS-232 output levels with ±2 kV ESD protection as stated on the Texas Instruments product page.
Technically, the capacitive voltage generator converts the 5 V supply into the positive and negative voltages used by the drivers. The drivers add signal conditioning to create TIA/EIA-232-F output levels, while the receivers convert incoming bipolar signals into logic-compatible levels. This integrated charge-pump approach avoids a separate negative supply rail, but the required charge-pump capacitors and their placement remain important to reliable operation.
Typical applications include industrial serial consoles, data acquisition equipment, legacy peripheral adapters, point-of-sale systems, and laboratory instrumentation. The 120 kbit/s rate supports conventional serial links while the ±30 V receiver tolerance helps protect logic-side systems when RS-232 cable noise or ground offsets exceed normal logic levels. The device is especially appropriate where a legacy RS-232 interface must coexist with a modern 5 V UART controller.
Designers should follow the manufacturer datasheet for charge-pump capacitor values, receiver input handling, unused-pin configuration, and layout recommendations. Keep the charge-pump loop compact, provide the specified bypass and flyback capacitance, and verify the connected UART voltage levels and grounding before treating the interface as RS-232 compliant.
This product page combines verified manufacturer specifications, distributor availability references, same-package replacement analysis, and practical interface-design guidance. It is intended to help engineers confirm electrical compatibility, identify genuine pin-compatible alternatives, and implement a dependable 5 V-to-RS-232 signal path without relying on packaging-only substitutions.
Drop-in alternatives for MAX232DWR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MAX232DWR (same form factor and footprint) — differing in Package, ESD Protection, Interface Standard, Product Type, Logic Compatibility.
MAX232CWE+
✅ Drop-InContact for price
View Datasheet →MAX232IDW
✅ Drop-In📋 Reference alternative (not in catalog)
ST232BDR
✅ Drop-In📋 Reference alternative (not in catalog)
HIN232IBZ
✅ Drop-In📋 Reference alternative (not in catalog)
SP232ECT-L
✅ Drop-InContact for price
View Datasheet →MAX232DWR Specifications
| Product Type | Dual RS-232 driver/receiver transceiver |
| Number of Drivers | 2 |
| Number of Receivers | 2 |
| Supply Voltage | 5 V |
| Maximum Data Rate | 120 kbit/s |
| RS-232 Output Level | ±9 V |
| Receiver Input Range | ±30 V |
| ESD Protection | ±2 kV |
| Receiver Threshold | 1.3 V typical |
| Receiver Hysteresis | 0.5 V typical |
| Supply Current | 8 mA typical |
| Interface Standard | TIA/EIA-232-F |
| V.28 Standard | ITU Recommendation V.28 |
| Package | 16-pin SOIC |
| Mounting Type | Surface mount |
MAX232DWR 16-pin soic Pin Configuration Guide
Pin configuration for MAX232DWR (16-pin soic package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for MAX232DWR.
Refer to the datasheet for full pin configuration.
Typical Applications
MAX232DWR is suitable for 6 applications: Industrial Serial Console, Data Acquisition Equipment, Legacy Peripheral Adapter, Point-of-Sale Terminal, Laboratory Test and Measurement, Telecommunications Network Equipment.
Industrial Serial Console
The MAX232DWR fits industrial serial consoles because it translates 5 V UART logic into TIA/EIA-232-F levels at up to 120 kbit/s while accepting receiver inputs up to ±30 V. Place the device between the controller UART and the DB9 or terminal connector, with the four external charge-pump capacitors placed close to the IC as directed by the manufacturer datasheet. Its 8 mA typical supply current helps limit auxiliary power demand, while ±2 kV ESD protection adds useful robustness for factory equipment. Verify the cable ground, connector shield strategy, and external surge requirements because the integrated protection is not a substitute for industrial surge protection.
Recommended
Data Acquisition Equipment
The MAX232DWR is suitable for legacy data-acquisition systems that use a 5 V controller to communicate with a PC or laboratory instrument over RS-232. Its 120 kbit/s maximum data rate supports conventional instrument-control protocols, and the receivers' ±30 V input tolerance provides margin for bipolar RS-232 signals and ground-potential differences. The transmitter produces ±9 V output levels from one 5 V rail through the integrated charge pump. Place bypass capacitance near the supply pin and route the interface away from sensitive analog inputs to prevent charge-pump and driver transitions from coupling into measurement circuitry.
Recommended
Legacy Peripheral Adapter
The MAX232DWR provides a practical way to connect a modern 5 V UART controller to a legacy RS-232 peripheral without a negative power supply. Two drivers and two receivers allow one small package to support multiple serial lines, while the 120 kbit/s rate accommodates many older printers, controllers, and service interfaces. The interface translates incoming RS-232 levels to TTL/CMOS and outgoing logic levels to ±9 V. Designers should preserve the documented charge-pump capacitor configuration, confirm logic polarity on each channel, and avoid treating TTL and RS-232 grounds as interchangeable without reviewing the complete system grounding architecture.
Recommended
Point-of-Sale Terminal
The MAX232DWR can support a 5 V embedded controller in point-of-sale equipment that must communicate with a legacy RS-232 peripheral. Its dual-channel architecture allows separate transmit and receive paths, while the 120 kbit/s rate is sufficient for many printers, scanners, and customer-display interfaces. The single 5 V supply simplifies power design, and the receiver's typical 1.3 V threshold with 0.5 V hysteresis provides noise margin for decoding the incoming bipolar signal. Keep the exposed connector away from sensitive electronics, use a common interface reference ground as appropriate, and confirm the peripheral's RS-232 voltage and timing requirements.
Recommended
Laboratory Test and Measurement
The MAX232DWR is useful in laboratory instruments that retain an RS-232 command port alongside newer USB or embedded interfaces. The 120 kbit/s limit is appropriate for configuration commands and moderate data transfers, and the ±30 V receiver tolerance helps accommodate off-nominal bipolar inputs from legacy equipment. Its ±2 kV ESD rating is useful for bench and service environments, although the integrated protection level must be matched to the actual cable exposure. Use the manufacturer's capacitor values and layout guidance, and keep the noisy charge-pump and driver paths separated from precision measurement circuitry.
Recommended
Telecommunications Network Equipment
The MAX232DWR can serve as a service or control interface on telecommunications equipment built around a 5 V UART. Its 120 kbit/s throughput supports management protocols, while two drivers and two receivers cover typical console and equipment-control paths. The integrated charge pump avoids a separate negative rail, helping compact equipment maintain a single-supply architecture. Because field-connected RS-232 ports can encounter large ground offsets and ESD events, engineers should confirm the receiver's ±30 V tolerance, implement cable-level grounding and surge protection, and reserve external protection for installations exceeding the device's specified ±2 kV ESD level.
Recommended
Recommended Products Summary
Engineering reference data for MAX232DWR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX232CWE | MAX232IDW | ST232BDR | HIN232IBZ | SP232ECT-L |
|---|---|---|---|---|---|---|
| Package | 16-SOIC | 16-SOIC | 16-SOIC | 16-SOIC | 16-SOIC | 16-SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | STMicroelectronics | Intersil | Exar |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
Key Differentiators
- Verified complete RS-232 interface performance (vs ST232BDR)
- Single-supply operation with integrated charge pump (vs HIN232IBZ)
- Two complete communication channels (vs SP232ECT-L)
Design Notes
Place the four charge-pump capacitors close to their MAX232DWR pins and keep the associated current loops compact. According to the manufacturer datasheet, incorrect capacitor values or long charge-pump loops can produce unstable driver outputs and additional noise. Route the supply bypass capacitor directly from the 5 V pin to ground, use the shortest practical ground return, and avoid routing driver outputs beneath sensitive analog inputs. Verify the physical SOIC land pattern and pin-one orientation before fabrication because the supplied excerpts do not reproduce the complete numbered pin table.
Do not substitute MAX232DWR with a narrow-SOIC MAX232DR solely because the electrical descriptions are similar. MAX232DR and MAX232DWR are listed as having identical performance profiles in the verified comparison data, but the DWR and DR ordering suffixes identify different physical package widths. Confirm the PCB drawing, land pattern, pin numbering, and exposed manufacturing rules. Also follow the datasheet instructions for unused inputs and do not assume that every RS-232-family device uses the same charge-pump capacitor connections.
Treat the MAX232DWR charge-pump and RS-232 driver outputs as potential noise sources near precision or high-speed circuitry. Maintain separation from sensor inputs, ADC channels, oscillator loops, and crystal circuits, and keep the RS-232 connector return path away from sensitive signal references. The receiver's typical 1.3 V threshold and 0.5 V hysteresis can support reliable logic conversion, but margin still depends on the actual cable, grounding, and noise environment. Validate the complete interface at the target data rate rather than relying only on individual IC specifications.
Compliance Information
The supplied verified excerpts establish TIA/EIA-232-F and ITU V.28 interface compliance but do not provide RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations. These fields remain unknown rather than being inferred.