MAX232DWG4 - Dual 120kbps RS-232 Transceiver | Texas Instruments
MPN: MAX232DWG4 ✓ ActiveMAX232DWG4 Overview
An RS-232 transceiver is an interface IC that converts logic-level signals between a host controller and a RS-232 port. It belongs to the hierarchy of interface ICs, communication transceivers, line-interface ICs, and semiconductor signal-conditioning devices. This bidirectional level translation allows equipment using 0 V to 5 V logic to communicate with legacy computers, industrial controllers, test equipment, and other peripherals that use voltage-based RS-232 signaling.
The MAX232DWG4 combines four interface functions in one package: two transmit drivers and two receive channels. It supports data rates through 120 kbps, accepts input levels as high as ±30 V, and provides ±2 kV electrostatic-discharge protection. Typical supply current is 8 mA, making it practical for battery-operated instruments, portable test equipment, and embedded control systems where continuous power consumption must remain low.
Its internal charge pump uses four external 1.0 µF capacitors to produce the required positive rail and negative rail. The circuit simplifies implementation because the system does not need a separate ±12 V supply. Communication is half-duplex on each channel because a driver and receiver can share the same signal pair, while direction must be controlled by the host if both sides transmit on the same line.
Typical uses include serial service ports, industrial configuration interfaces, point-of-sale equipment, modems, embedded instrumentation, and legacy controller connectivity. The MAX232DWG4 is especially useful when the logic side operates at 5 V and the cable side must comply with RS-232 voltage levels. A protected connector and properly routed ground connection remain important because ESD protection does not eliminate the need for good system-level surge protection.
During layout, place the four charge-pump capacitors close to their associated pins and provide the decoupling and ground-plane continuity required by the manufacturer datasheet. Keep the logic-side and cable-side routes separated to minimize noise injection. Confirm line-receiver thresholds, driver slew behavior, and cable length against the intended communication standard before releasing a production design.
This page combines the MAX232DWG4 specifications, pin assignments, drop-in comparison choices, and practical interface-design guidance. It also highlights charge-pump layout, ESD considerations, application fit, and the distinction between pin-compatible variants so engineers can evaluate replacements without changing the PCB footprint.
Drop-in alternatives for MAX232DWG4 — 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 MAX232DWG4 (same form factor and footprint) — differing in Package, Data Rate, Operating Temperature Range, Product Type.
MAX232ESE+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX232EESE+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX232ECWE+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX232CSE+T
✅ Drop-InContact for price
View Datasheet →MAX232NSR
✅ Drop-InContact for price
View Datasheet →ST232CWR
✅ Drop-In📋 Reference alternative (not in catalog)
MAX232DWG4 Specifications
| Product Type | Dual RS-232 driver/receiver transceiver |
| Number of Drivers | 2 |
| Number of Receivers | 2 |
| Data Rate | Up to 120 kbps |
| Single Supply Voltage | 5 V |
| Driver Output Swing | Approximately ±9 V |
| Receiver Input Voltage Limit | ±30 V |
| ESD Protection | ±2 kV |
| Supply Current | 8 mA typical |
| Charge-Pump Capacitor | 1.0 µF |
| Interface Standard | EIA-232 / V.28 |
| Package | 16-pin SOIC |
| Operating Temperature Range | 0 °C to 70 °C |
| Mounting Type | Surface mount |
MAX232DWG4 Pin Configuration
| Pin 1 | C1+ — Charge-pump capacitor 1 positive terminal |
| Pin 2 | V- — Negative charge-pump voltage output |
| Pin 3 | C1- — Charge-pump capacitor 1 negative terminal |
| Pin 4 | C2+ — Charge-pump capacitor 2 positive terminal |
| Pin 5 | C2- — Charge-pump capacitor 2 negative terminal |
| Pin 6 | V+ — Positive charge-pump voltage output |
| Pin 7 | OUT1 — Receiver 1 output |
| Pin 8 | IN1 — Driver 1 data input |
| Pin 9 | IN2 — Driver 2 data input |
| Pin 10 | OUT2 — Receiver 2 output |
| Pin 11 | GND — Ground |
| Pin 12 | C3+ — Charge-pump capacitor 3 positive terminal |
| Pin 13 | C3- — Charge-pump capacitor 3 negative terminal |
| Pin 14 | C4+ — Charge-pump capacitor 4 positive terminal |
| Pin 15 | C4- — Charge-pump capacitor 4 negative terminal |
| Pin 16 | VCC — Positive supply voltage |
Typical Applications
MAX232DWG4 is suitable for 6 applications: Embedded Serial Service Port, Industrial Test and Measurement Equipment, Point-of-Sale Terminal Connectivity, Modem and Communication Adapter, Legacy Controller and Peripheral Bridge, Portable Diagnostic Instrument.
Embedded Serial Service Port
The MAX232DWG4 fits an embedded controller that exposes a legacy RS-232 service port while its UART operates at 5 V logic levels. Its two drivers and two receivers support bidirectional console connections, and its single 5 V supply eliminates the need for a separate ±12 V rail in the equipment. The integrated charge pump requires four external 1.0 µF capacitors, while operation through 120 kbps covers many configuration and diagnostic protocols. Place the interface close to the connector and keep the external cable ground and logic ground tied according to the recommended application circuit.
Recommended
Industrial Test and Measurement Equipment
The MAX232DWG4 is appropriate for instruments that communicate with older computers or controllers through RS-232. Two receive channels can collect status or measurement signals, while two driver channels provide control or data output. Its 120 kbps maximum rate supports legacy instrument protocols, and the typical 8 mA supply current limits power demand in portable equipment. The stated 0 °C to 70 °C range suits controlled indoor environments, but a wider-temperature grade should be selected for harsher industrial conditions.
Recommended
Point-of-Sale Terminal Connectivity
A point-of-sale terminal can use the MAX232DWG4 to bridge a 5 V controller UART to a legacy RS-232 peripheral. The integrated charge pump generates approximately ±9 V driver levels from one 5 V supply, reducing connector-board power complexity. Throughput up to 120 kbps is sufficient for many cash-drawer, display, printer, and service-adapter interfaces. Designers should separate logic and cable traces, use a solid ground connection, and place the ESD-protected transceiver close to the external connector to improve system robustness.
Recommended
Modem and Communication Adapter
The MAX232DWG4 can provide the physical RS-232 layer between a data-processing module and an external modem or communication adapter. Each matched transmitter and receiver path supports the voltage-based signaling required by RS-232, while the single 5 V supply simplifies portable adapter designs. Its 120 kbps capability supports common modem and terminal data rates. The charge-pump capacitors should follow the manufacturer layout closely, and the external connector should include appropriate grounding and protection because the IC's ±2 kV ESD rating does not replace a compliant cable shield.
Recommended
Legacy Controller and Peripheral Bridge
The MAX232DWG4 bridges a modern 5 V controller to legacy RS-232 equipment without requiring a negative supply at the logic connector. Two transmit and two receive channels provide enough parallel connections for command, response, status, and handshake signals. At up to 120 kbps, it suits numerous industrial-control and legacy peripheral protocols. The interface direction must be managed so that an enabled transmitter is not connected directly to another active transmitter, and cable length, termination, and grounding should be evaluated against the selected RS-232 topology.
Recommended
Portable Diagnostic Instrument
The MAX232DWG4 supports a portable diagnostic instrument that reports results or receives commands through an RS-232 port. The single 5 V operating supply integrates readily with a battery-regulated logic rail, while the 8 mA typical supply current avoids adding excessive load. The device's two receivers can monitor two incoming signals, and its two drivers can control two outgoing lines at data rates through 120 kbps. For field reliability, retain the specified operating-temperature limits and reinforce connector protection when cables may be connected or disconnected frequently.
Recommended
Recommended Products Summary
Engineering reference data for MAX232DWG4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX232ESE+T | MAX232EESE+T | MAX232ECWE+T | MAX232CSE+T | MAX232NSR | ST232CWR |
|---|---|---|---|---|---|---|---|
| Package | 16-SOIC | 16-SOIC | 16-SOIC | 16-SOIC | 16-SOIC | 16-SOIC | 16-SOIC |
| Brand | Texas Instruments | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | STMicroelectronics |
| Supply Voltage | 5 V | 5 V class | 5 V class | 5 V | 5 V class | 5 V class | 5 V class |
Key Differentiators
- Established 120 kbps dual-channel RS-232 function (vs MAX232ECWE+T)
- Single 5 V implementation with integrated charge pump (vs ST232CWR)
- Higher stated ESD rating available in an alternative (vs MAX232ECWE+T)
Design Notes
Place the four 1.0 µF charge-pump capacitors adjacent to their associated MAX232DWG4 pins and connect each capacitor directly to the relevant V+ or V- node with short traces. Keep these high-current ripple paths compact and away from sensitive receiver inputs. A continuous ground plane under the device reduces return-path inductance, while a dedicated quiet-ground connection helps prevent charge-pump currents from coupling into analog or logic signals.
Route the two RS-232 driver outputs and two receiver inputs toward the external connector without crossing or sharing narrow return paths with the logic-side UART nets. Keep the transceiver close to the connector to minimize unprotected cable-stub exposure. Use a low-impedance chassis or signal-ground return, and route connector discharge currents directly to the board ground structure rather than through traces serving sensitive circuitry.
Do not assume that matching the 16-SOIC pin count proves drop-in compatibility. Check body width, lead pitch, pin orientation, temperature grade, external charge-pump capacitance, receiver thresholds, and ESD rating for every replacement. In particular, MAX232ECWE+T has a stated ±15 kV HBM ESD rating versus ±2 kV for MAX232DWG4. Confirm direction-control signals so that two active transmitters are never connected to the same RS-232 pair.
The MAX232DWG4 is specified for 0 °C to 70 °C operation, so it is not automatically suitable for outdoor cabinets, automotive environments, or industrial temperatures outside that range. Check enclosure temperature rise, startup conditions, cable transients, and the complete system grounding strategy. The integrated ±2 kV ESD protection supports direct connector exposure but does not eliminate the need for external surge and ESD protection where the cable is long or the enclosure is uncontrolled.
Compliance Information
The manufacturer product page confirms the MAX232 family and device status, but explicit RoHS, REACH, lead-free, halogen-free, and conflict-minerals declarations were not included in the available technical data. The MAX232DWG4 is a commercial interface IC rather than an automotive-qualified device.