MAX232ID - 120kbps Dual RS-232 Transceiver | Texas Instruments
MPN: MAX232ID ✓ ActiveMAX232ID Overview
An RS-232 transceiver is an interface IC that converts logic-level signals into RS-232 electrical levels and converts received RS-232 signals back into logic levels. Within the interface hierarchy, it is an RS-232 transceiver, an interface IC, and a semiconductor used to bridge TTL or CMOS equipment with a serial communications bus. The MAX232ID is specifically associated with conventional TIA/EIA-232-F and ITU V.28 signaling rather than low-voltage differential protocols such as RS-485.
Key features include two RS-232 drivers, two RS-232 receivers, operation from one 5 V supply, and a maximum data rate of 120 kbit/s. External 1 uF charge-pump capacitors are required to generate the bipolar transmitter supply. The receiver section supports plus or minus 30 V input levels, improving tolerance to transient voltages commonly encountered on longer cable runs. Typical supply current is listed as 8 mA in the verified source data.
The MAX232ID implements the electrical conversion required at the boundary between a digital controller or UART and an RS-232 port. Because the drivers actively produce RS-232-level voltages, the circuit does not require a separate external RS-232 line driver. Conversely, the receivers convert incoming bipolar signals into a digital voltage compatible with the host logic supply. The complete device therefore consolidates both directions of a two-channel serial interface into one IC.
Typical applications include industrial serial consoles, data acquisition equipment, laboratory instruments, point-of-sale systems, embedded control systems, and legacy computer peripherals. The 120 kbit/s operating limit suits conventional serial ports and short-distance point-to-point links. It is also appropriate for troubleshooting and repair systems that must remain compatible with equipment using full-strength RS-232 rather than low-voltage variants.
Designers must follow the charge-pump capacitor recommendations and provide the required bypassing on the 5 V rail. Protection, grounding, cable length, and connector selection remain external system considerations. The MAX232ID does not replace the transceiver with an RS-485 or USB interface, and its electrical compatibility should be verified against the connected equipment before substitution.
This page consolidates verified manufacturer and distributor information, same-package alternatives, pricing data, and practical engineering guidance. It distinguishes true SOIC-16 drop-in candidates from functional alternatives and highlights the electrical checks required when replacing an RS-232 transceiver.
Drop-in alternatives for MAX232ID — 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 MAX232ID (same form factor and footprint) — differing in Package, Product Type, ESD Protection, Interface Standard, Mounting Type.
MAX232IDG4
✅ Drop-InContact for price
View Datasheet →MAX232IDE4
✅ Drop-In📋 Reference alternative (not in catalog)
MAX232D
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →MAX232DW
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →MAX3232EID
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →SP232EEN-L/TR
✅ Drop-InContact for price
View Datasheet →MAX232ID Specifications
| Product Type | Dual RS-232 line driver and receiver IC |
| Number of Drivers | 2 |
| Number of Receivers | 2 |
| Maximum Data Rate | 120 kbit/s |
| Supply Voltage Range | 4.5 V to 5.5 V |
| Single Supply Operation | 5 V |
| Driver Output Level | Plus or minus 9 V |
| Receiver Input Level | Plus or minus 30 V |
| Typical Supply Current | 8 mA |
| Charge-Pump Capacitor | 1 uF |
| Interface Standard | TIA/EIA-232-F and ITU Recommendation V.28 |
| Package | 16-pin SOIC |
| Mounting Type | Surface mount |
| ESD Protection | Plus or minus 2 kV |
MAX232ID 16-pin soic Pin Configuration Guide
Pin configuration for MAX232ID (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 MAX232ID.
Refer to the datasheet for full pin configuration.
Typical Applications
MAX232ID is suitable for 6 applications: Industrial Serial Console, Data Acquisition Equipment, Embedded Controller Serial Port, Point-of-Sale Terminal, Test and Measurement Instrument, Legacy Computer Peripheral.
Industrial Serial Console
The MAX232ID fits industrial serial consoles that must communicate with legacy RS-232 equipment at rates up to 120 kbit/s. Its two drivers and two receivers provide bidirectional conversion between 5 V logic and plus or minus 9 V RS-232 levels within one 16-pin SOIC. The receiver section accepts plus or minus 30 V inputs, adding tolerance to cable-borne voltage excursions. A practical implementation uses the documented external 1 uF charge-pump capacitors, local supply bypassing, and a protected connector. Compared with an RS-485 interface, the MAX232ID provides point-to-point compatibility with conventional RS-232 ports but does not offer differential noise immunity.
Recommended
Data Acquisition Equipment
The MAX232ID is suitable for laboratory and industrial data-acquisition equipment that exposes a conventional RS-232 configuration port. Its 120 kbit/s maximum rate is sufficient for command exchange, configuration downloads, and moderate-rate status data, while the two-channel arrangement can serve two ports or use one direction for hardware flow control. The IC operates from a single 4.5 V to 5.5 V rail, reducing the need for a separate negative supply. Designers should treat the 1 uF charge-pump capacitors as mandatory and verify line levels, ground references, and isolation before connecting a long cable or bench instrument.
Recommended
Embedded Controller Serial Port
The MAX232ID can connect an embedded controller UART to a legacy RS-232 port when the controller uses 5 V logic. The device converts two logic-level channels into full RS-232 outputs and converts two incoming RS-232 signals back to digital levels, with a maximum rate of 120 kbit/s. Because it includes both driver and receiver functions, a compact controller board needs only the transceiver and external charge-pump capacitors. The implementation should include local 5 V decoupling, unobstructed return-current paths, and connector-side protection. A MAX3232-family option may be more appropriate when the controller directly operates from 3.3 V.
Recommended
Point-of-Sale Terminal
The MAX232ID supports point-of-sale peripherals that retain full RS-232 interfaces for receipt printers, scanners, or service consoles. The two transmitters and receivers allow more than one signal path to share the 16-pin device, and the 120 kbit/s limit is appropriate for legacy transaction peripherals. The single 5 V supply simplifies integration with powered equipment, while plus or minus 30 V receiver tolerance can improve robustness. Board designers should place the external 1 uF charge-pump capacitors close to the device, provide a continuous signal ground, and use an appropriate protection network at the externally accessible connector.
Recommended
Test and Measurement Instrument
The MAX232ID can provide computer-control connectivity for a test or measurement instrument that uses a legacy RS-232 command interface. At up to 120 kbit/s, it supports command transfer and moderate data streams without the higher complexity of a differential bus. Its plus or minus 9 V driver outputs and plus or minus 30 V receiver inputs provide full RS-232 signaling from one 5 V supply. For laboratory use, engineers should evaluate grounding and isolation to prevent ground-loop interference, and should add connector protection if the instrument may be connected to unknown or long cables.
Recommended
Legacy Computer Peripheral
The MAX232ID is appropriate for legacy computer peripherals and service adapters that require full RS-232 levels rather than USB or RS-485. Its two drivers and receivers can implement a bidirectional serial port in a small 16-pin SOIC footprint, and its 120 kbit/s data rate matches the performance class of many older peripherals. The external 1 uF charge-pump capacitors are essential for creating the bipolar transmitter voltage. During installation, verify the host logic voltage, pin arrangement, and connector wiring, because a physically similar package alone does not guarantee electrical compatibility across unrelated transceiver families.
Recommended
Recommended Products Summary
Engineering reference data for MAX232ID — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX232IDG4 | MAX232IDE4 | MAX232D | MAX232DW | SP232EEN-L/TR |
|---|---|---|---|---|---|---|
| Package | SOIC-16 | SOIC-16 - same package | SOIC-16 - same package | SOIC-16 - same package | SOIC-16 - same package | SOIC-16 - same package |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Sipex |
| Driver and Receiver Count | 2 drivers and 2 receivers | 2 drivers and 2 receivers | 2 drivers and 2 receivers | 2 drivers and 2 receivers | 2 drivers and 2 receivers | 2 drivers and 2 receivers |
Key Differentiators
- Full-strength dual-channel RS-232 interface in one compact package (vs SP232EEN-L/TR)
- Established manufacturer product family with direct ordering identification (vs MAX232IDG4)
- Direct MAX232 family path for existing designs (vs MAX232IDE4)
- Low-voltage upgrade option when the surrounding interface supports it (vs MAX3232EID)
Design Notes
The MAX232ID operates from one 4.5 V to 5.5 V supply, but the external 1 uF charge-pump capacitors remain essential for producing the bipolar driver voltage. Place them directly between the designated charge-pump pins and ground, with the shortest practical traces. Add local 5 V decoupling close to the supply pin and maintain a low-impedance ground return. The verified typical supply current is 8 mA, which excludes external system and interface loads.
Do not substitute a 3.3 V-only RS-232 device for the MAX232ID without checking the charge-pump pins and logic thresholds. The MAX232ID requires at least 4.5 V, and a 5 V UART must also satisfy the receiver and driver input thresholds. Verify the exact pin numbering, capacitor values, and output-level expectations against the manufacturer datasheet. A 16-pin package match alone does not prove that unrelated transceiver families are drop-in compatible.
Keep the RS-232 connector, protection network, and transceiver in a consistent current path. Provide a continuous signal-ground connection between the board and connector, avoid sharing narrow return paths with switching-power currents, and route the charge-pump nodes as short and quiet nets. For an externally accessible port, evaluate connector-side surge and ESD protection because the MAX232ID's plus or minus 2 kV ESD rating does not establish compliance with an unspecified industrial surge standard.
RS-232 is a point-to-point interface, so each driver should drive a defined receiver rather than a multi-drop bus. Confirm whether the connected equipment uses hardware handshaking, because the two-driver and two-receiver arrangement does not automatically provide all required flow-control signals. Also verify whether the remote device expects full-strength plus or minus 9 V signaling rather than a low-voltage RS-232 variant. These checks prevent link failures that are often mistaken for transmitter defects.
Compliance Information
The verified data identifies TIA/EIA-232-F and ITU Recommendation V.28 interface compliance, plus or minus 2 kV ESD protection, and a lead-free MAX232IDG4 ordering variant. Specific RoHS, REACH, halogen-free, conflict-minerals, and automotive qualification declarations were not supplied and are therefore recorded as unknown.