MAX3241CAI+ - 3V-5.5V RS-232 Transceiver, 1Mbps | Analog Devices
MPN: MAX3241CAI+ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $10.34 | $10.34 |
| 10 | $9.41 | $94.10 |
| 100 | $8.06 | $806.00 |
| 500 | $6.72 | $3,360.00 |
| 1,000 | $5.04 | $5,040.00 |
MAX3241CAI+ Overview
A RS-232 transceiver is a type of line driver/receiver interface IC that converts logic-level (TTL/CMOS) signals to/from the bipolar ±5V to ±15V voltage swings required by the EIA/TIA-232-E standard. It belongs to the broader category of serial interface ICs (RS-232, RS-422, RS-485, UART transceivers), which sit between a microcontroller UART and the physical cable in point-to-point or multipoint data links. Charge-pump transceivers like the MAX3241 family simplify system design by generating the required transmitter output voltages internally from a single low-voltage rail.
Key features include a 1Mbps guaranteed data rate (250kbps in the standard mode, up to 1Mbps with low-ESR capacitors), always-active extra receiver outputs for monitoring external peripherals, ±15kV ESD protection on transmitter outputs and receiver inputs (HBM), and an automatic shutdown mode that drops supply current to 1uA while keeping one receiver active. The always-on monitoring receivers (R1 and R2 extra outputs) make this part especially useful in portable and battery-powered designs that must wake the host on cable or peripheral activity.
The MAX3241 uses a low-dropout transmitter output stage that maintains true RS-232-compliant output levels (±5V minimum) even when operating from a discharged battery, together with an internal dual charge pump that generates the positive and negative supplies from a single 3.0V to 5.5V rail. Four small 0.1uF external capacitors provide the pump energy storage, reducing BOM cost and board area versus ±12V solutions.
Typical applications include battery-powered point-of-sale terminals, industrial handheld instrumentation, networking equipment (routers, switches), laptop and notebook serial ports, cellular phone data cables, and any embedded system requiring a TIA/EIA-232-E compliant UART link from a single low-voltage logic supply.
When designing with this device, place the four 0.1uF charge-pump capacitors as close as possible to the IC pins and use a low-ESR ceramic type to achieve the 1Mbps data rate. Add bulk decoupling (0.1uF + 1uF) on VCC near the device to suppress supply noise. Verify that downstream receivers tolerate the MAX3241's ±5V minimum output swing if your cable is unusually long.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for MAX3241CAI+ — 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 MAX3241CAI+ (same form factor and footprint) — differing in Data Rate, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX3241ECAI+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX3241CAI+T
✅ Drop-In📋 Reference alternative (not in catalog)
ICL3241CAZ
✅ Drop-In📋 Reference alternative (not in catalog)
ST3241EBPR
✅ Drop-In📋 Reference alternative (not in catalog)
MAX3243ECAI+
✅ Drop-In✓ In Stock
$3.43 / Unit
View Datasheet →MAX3241CAI+ Specifications
| Manufacturer | Analog Devices (Maxim Integrated) |
| Part Number | MAX3241CAI+ |
| Function | Transceiver |
| Protocol | RS-232 |
| Number of Drivers | 3 |
| Number of Receivers | 5 |
| Duplex | Full |
| Supply Voltage | 3.0 V to 5.5 V |
| Data Rate | Up to 1 Mbps |
| ESD Protection | ±15 kV (HBM, driver outputs and receiver inputs) |
| Supply Current (Shutdown) | 1 uA (with one receiver active) |
| External Capacitors | 4 x 0.1 uF |
| Operating Temperature | 0 C to +70 C (commercial, CAI suffix) |
| Package | 28-SSOP (5.30 mm body width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
MAX3241CAI+ Pin Configuration
| Pin 1 | EN — Receiver enable (active low) - high puts receivers in 3-state |
| Pin 2 | C1+ — Charge-pump capacitor 1 positive terminal |
| Pin 3 | V+ — Charge-pump generated +5.5V supply |
| Pin 4 | C1- — Charge-pump capacitor 1 negative terminal |
| Pin 5 | C2+ — Charge-pump capacitor 2 positive terminal |
| Pin 6 | C2- — Charge-pump capacitor 2 negative terminal |
| Pin 7 | V- — Charge-pump generated -5.5V supply |
| Pin 8 | R1OUT — Receiver 1 TTL/CMOS output |
| Pin 9 | R2OUT — Receiver 2 TTL/CMOS output |
| Pin 10 | R3OUT — Receiver 3 TTL/CMOS output |
| Pin 11 | R4OUT — Receiver 4 TTL/CMOS output |
| Pin 12 | R5OUT — Receiver 5 TTL/CMOS output |
| Pin 13 | R1OUTB — Always-active extra output for receiver 1 (monitor) |
| Pin 14 | R2OUTB — Always-active extra output for receiver 2 (monitor) |
| Pin 15 | FORCEON — Force ON input (active high overrides auto-shutdown) |
| Pin 16 | INVALID — Invalid signal indicator (active low when all RS-232 inputs invalid) |
| Pin 17 | GND — Ground |
| Pin 18 | T1OUT — RS-232 driver 1 output |
| Pin 19 | T2OUT — RS-232 driver 2 output |
| Pin 20 | T3OUT — RS-232 driver 3 output |
| Pin 21 | R3IN — RS-232 receiver 3 input |
| Pin 22 | R4IN — RS-232 receiver 4 input |
| Pin 23 | R5IN — RS-232 receiver 5 input |
| Pin 24 | R1IN — RS-232 receiver 1 input |
| Pin 25 | R2IN — RS-232 receiver 2 input |
| Pin 26 | VCC — +3.0V to +5.5V supply input |
| Pin 27 | T1IN — TTL/CMOS driver 1 input |
| Pin 28 | T2IN — TTL/CMOS driver 2 input |
Typical Applications
MAX3241CAI+ is suitable for 6 applications: Battery-Powered Point-of-Sale Terminals, Industrial Handheld Instrumentation, Networking Equipment Console / Management Ports, Laptop / Notebook Docking Stations, Embedded System Debug / Boot Loader Ports, Cellular / GNSS Module Data Cables.
Battery-Powered Point-of-Sale Terminals
The MAX3241CAI+ is well suited to handheld POS terminals where a 3.0V to 5.5V Li-ion supply powers the host MCU and a separate EIA/TIA-232-E link is needed for receipt printers or magnetic-stripe readers. Its 1uA shutdown current (with one receiver still active) and the always-on extra monitor outputs (R1/R2) let the terminal sleep until a peripheral asserts wake, dramatically extending battery life. The 1Mbps data rate handles legacy serial printers without bottlenecks. Place four 0.1uF X7R ceramics within 5mm of the C1+/C1-/C2+/C2- pins.
Recommended
Industrial Handheld Instrumentation
Industrial handheld multimeters, barcode scanners, and process calibrators often need a robust RS-232 link to a host PC or datalogger while running from a 3.6V Li-ion or 4xAA stack. The MAX3241CAI+ supports both rails (3.0V-5.5V) and delivers ±15kV HBM ESD on the DB-9 pins, reducing field-failure rates when cables are hot-plugged. Five receivers (vs two on MAX3232) allow simultaneous connection to multiple external sensors or to a printer plus a host. The 28-SSOP footprint fits inside compact handheld enclosures.
Recommended
Networking Equipment Console / Management Ports
Routers, switches, and small-cell base stations routinely expose an RS-232 console port for out-of-band management, even when the main logic runs at 1V or 1.8V core voltages. The MAX3241CAI+ can be powered directly from a 3.3V or 5V auxiliary rail and translates logic-level UART signals from the management MCU to true ±5V RS-232 levels for the RJ-45 console jack. The integrated dual charge pump removes the need for a bulky DC-DC converter to generate ±12V. Always-on monitor outputs can detect a console cable insertion and wake the management processor.
Recommended
Laptop / Notebook Docking Stations
Docking stations frequently expose legacy DB-9 RS-232 ports to support older peripherals (label printers, industrial bar-code readers, scientific instruments). The MAX3241CAI+ integrates 3 drivers and 5 receivers in a single 28-SSOP, which is enough to drive TX/RTS/DTR and read RX/CTS/DSR/RI/DCD plus one spare monitor line. Operating from a 3.3V or 5V dock rail and using only four 0.1uF pump capacitors, it fits small docking-station PCBs without the cost or height of a DC-DC plus discrete RS-232 solution.
Recommended
Embedded System Debug / Boot Loader Ports
Embedded Linux or RTOS development boards often include an RS-232 debug UART that remains functional across power domains and boot states. The MAX3241CAI+ operates from the same 3.3V rail as the MCU and survives cable hot-plug events thanks to integrated ±15kV HBM ESD. The 1Mbps data rate supports fast bootloader image downloads, shortening firmware-update cycles on the manufacturing line. Five receivers give developers access to multiple handshake lines plus a free monitor line for custom debug signaling.
Recommended
Cellular / GNSS Module Data Cables
Cellular modules (2G/3G/4G) and GNSS receivers frequently expose diagnostic / NMEA serial links over RS-232. The MAX3241CAI+ connects the module's CMOS UART to a PC or external logger via a true ±5V RS-232 link, all from a 3.3V or 5V single rail. Four small 0.1uF ceramic capacitors provide the charge-pump energy storage, keeping the BOM and PCB footprint compact. The integrated ±15kV ESD protects against cable discharge events common when antennas are co-located with the serial cable.
Recommended
Recommended Products Summary
Engineering reference data for MAX3241CAI+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX3241ECAI+ | MAX3241CAI+T | ICL3241CAZ | ST3241EBPR | MAX3243ECAI+ |
|---|---|---|---|---|---|---|
| Package | 28-SSOP (5.30 mm) | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same |
| Brand | Analog Devices (Maxim) | Analog Devices | Analog Devices | Renesas Electronics | STMicroelectronics | Analog Devices |
| Supply Voltage | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V |
| Drivers / Receivers | 3 / 5 | 3 / 5 | 3 / 5 | 3 / 5 | 3 / 5 | 3 / 5 |
| Data Rate | Up to 1 Mbps | Up to 1 Mbps | Up to 1 Mbps | Up to 250 kbps | Up to 400 kbps | Up to 250 kbps |
| ESD Protection | ±15 kV HBM | ±15 kV IEC 61000-4-2 | ±15 kV HBM | ±15 kV HBM | ±15 kV HBM | ±15 kV IEC 61000-4-2 |
| External Capacitors | 4 x 0.1 uF | 4 x 0.1 uF | 4 x 0.1 uF | 4 x 0.1 uF | 4 x 0.1 uF | 4 x 0.1 uF |
| Shutdown Current | 1 uA (1 receiver active) | 1 uA (1 receiver active) | 1 uA (1 receiver active) | 1 uA (1 receiver active) | 1 uA (1 receiver active) | 1 uA |
| Always-On Monitor Outputs | Yes (R1, R2 extra outputs) | Yes | Yes | Yes | No | No |
Key Differentiators
- Always-on extra receiver outputs (R1OUTB, R2OUTB) for cable/peripheral monitoring (vs MAX3243ECAI+)
- Cross-brand second-source from Renesas in same 28-SSOP package (vs ICL3241CAZ)
- Integrated ±15 kV HBM ESD on driver and receiver pins (vs ST3241EBPR)
- 3.0V to 5.5V single-supply operation eliminates ±12V DC-DC (vs Discrete RS-232 driver + DC-DC converter)
Design Notes
Place the four 0.1uF charge-pump capacitors (C1+, C1-, C2+, C2-) as close as possible to the corresponding pins and use a low-ESR ceramic type (X7R or X5R) to achieve the 1Mbps data-rate spec. Estimated: with 0.1uF X7R in 0603 at 5mm trace length, charge-pump impedance stays below 1 ohm at the pump switching frequency and supports full 1Mbps operation. Add a 0.1uF + 1uF decoupling pair on VCC (pin 26) within 2mm to suppress supply noise that could couple into the charge pump and degrade RS-232 output levels.
RS-232 cable lengths above 10 meters and data rates above 250 kbps require low-ESR capacitors AND short, parallel PCB traces between the IC and the DB-9 connector. Estimated: a 50mm differential trace pair at 1Mbps has roughly 5ns of propagation delay, which is acceptable for RS-232 timing but excessive for the on-chip charge-pump. Keep the T_OUT/R_IN traces to the connector shorter than 30mm and avoid running them parallel to clock or switching-power traces to prevent EMI-induced RS-232 errors.
Use the FORCEON pin (pin 15) high for normal operation; drive it low only if you want the auto-shutdown circuit to power down the drivers when no valid RS-232 input is detected. INVALID (pin 16) goes active low when all RS-232 receiver inputs are invalid (below +2.7V or above -2.7V), which the host MCU can use to decide whether to enter deep-sleep. This auto-shutdown plus the 1uA quiescent current (with one receiver active) is the key battery-life feature of the MAX3241 family versus MAX3232.
Do not use the non-'+' MAX3241CAI variant in new designs - it contains lead and is not RoHS-compliant. Do not exceed 5.5V on VCC or apply voltage to T_OUT/R_IN before VCC is present, as this can latch up the charge pump. The receivers are rated to survive ±25V on their inputs, but the transmitters output ±5V minimum (not ±12V), so any cable longer than 15m at high data rate will fail the TIA/EIA-232-E minimum-level compliance test. For cable runs above 15m use the MAX3232 family at 120 kbps instead.
Compliance Information
RoHS and REACH compliant per Maxim/Analog Devices product page. '+' suffix confirms lead-free. AEC-Q100 not applicable - this is a commercial-grade (0 C to +70 C) interface IC. Operating temperature is commercial grade; industrial-temperature grades would carry an E suffix (e.g., MAX3241EAI+).
