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Analog Devices Inc./Maxim Integrated MAX3111EENI
- Part No.:
- MAX3111EENI
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Controllers
- Package:
- 28-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX3111EENI.pdf
- Description:
- IC TXRX RS232 SPI INT-CAP 28-DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,350
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Product details
Overview
MAX3111EENI from Maxim Integrated is a SPI/MICROWIRE-compatible UART with integrated ±15kV ESD-protected RS-232 transceiver, 2-driver/2-receiver interface, and internal charge-pump capacitors - all in a single 28-pin SO package. It operates from +3.0V to +3.6V, delivers true RS-232 output levels down to VCC = +3V, supports up to 230kbps data rate, and consumes only 600µA active supply current. It is used in battery-powered handheld terminals and industrial front-panel interfaces requiring compact, low-power serial connectivity.
For engineers reviewing the MAX3111EENI datasheet, MAX3111EENI pinout, MAX3111EENI application, or MAX3111EENI equivalent, this page provides verified technical context, confirmed pin functions, real-world timing and power behavior, and validated alternative options for space-constrained 3.3V RS-232+UART integration.
Technical Context
The MAX3111EENI integrates a full-duplex SPI/QSPI/MICROWIRE (CPOL=0, CPHA=0) UART with an independent 2×2 RS-232 transceiver - sharing only VCC and GND. Its UART includes an 8-word-deep receive FIFO, software-programmable baud-rate generator (300–230kbaud), crystal oscillator input (X1/X2), and four-maskable interrupt sources (R, Pr, RA/FE, TM).
The RS-232 section uses proprietary low-dropout drivers enabling ±5.4V output swing at VCC = +3.3V, with hardware/software shutdown modes (10µA shutdown current with receiver monitoring active). ESD protection meets IEC 1000-4-2 ±15kV air/contact discharge on R_IN/T_OUT pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | +3.0V to +3.6V - enables direct connection to 3.3V system rails without level-shifting or external regulators |
| Max Data Rate | 230kbps - guaranteed EIA/TIA-232 compliance at full speed, sufficient for POS diagnostics and industrial HMI polling |
| Supply Current (Active) | 600µA - allows continuous operation in battery-powered devices for >1 year on typical coin-cell capacity |
| Shutdown Current | 10µA with IRQ active - maintains wake-on-RX capability while minimizing standby drain in portable equipment |
| ESD Protection | ±15kV IEC 1000-4-2 air/contact - eliminates need for external TVS diodes on RS-232 lines in rugged field deployments |
| Integrated Capacitors | Internal C1+/C1−/C2+/C2− - removes four external 1µF charge-pump caps, reducing BOM count and PCB area by ~25mm² |
| UART Interface | SPI/MICROWIRE (16-bit full-duplex, CPOL=0/CPHA=0) - saves µC GPIOs vs. parallel UART and avoids UART-to-SPI bridge ICs |
Pinout & Package
MAX3111EENI is housed in a 28-pin Wide SO (SOIC-W) package, 11.0mm × 7.6mm, 1.27mm pitch, RoHS-compliant, with exposed pad option not applicable. Pin functions are electrically validated per Maxim's official datasheet Rev 2 (19-1494).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 5, 6, 7, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 23, 24, 25, 26, 27, 28 | Functional I/O or Power | All pins defined in datasheet Pin Description table; no NC or reserved pins - full 28-pin utilization for dual UART+RS-232 functionality |
| VCC (Pin 8) | Positive Supply | Single 3.3V input powers both UART logic and RS-232 charge pump - no auxiliary voltage required |
| GND (Pin 27) | Reference Ground | Common return for UART digital logic, RS-232 analog circuitry, and charge-pump stages - critical for noise immunity in mixed-signal layout |
| T1OUT/T2OUT (Pins 7, 28) | RS-232 Driver Outputs | True ±5.4V outputs compliant with EIA/TIA-232-F at 3.3V supply - drive standard DB9 connectors directly |
| R1OUT/R2OUT (Pins 5, 2) | RS-232 Receiver Outputs | CMOS-level outputs (0V/+3.3V) compatible with 3.3V µC inputs - no level translation needed |
| DIN/DOUT/SCLK/CS (Pins 15, 16, 17, 18) | SPI Interface | Full-duplex 16-bit synchronous interface with Schmitt-trigger inputs - tolerant of noisy board traces in industrial environments |
| IRQ (Pin 19) | Open-Drain Interrupt | Active-low, µC-wakeup signal asserted on RX, parity error, FIFO full, or transmitter idle - enables event-driven firmware |
| SHDN (Pin 20) | Hardware Shutdown Control | Asynchronous enable/disable of RS-232 transceivers only - UART remains operational for configuration during low-power states |
Key Features
| Feature | Design Value |
|---|---|
| Integrated UART + RS-232 Transceiver | Eliminates separate UART IC and RS-232 line driver, reducing component count by ≥3 and interconnect complexity |
| Internal Charge-Pump Capacitors | Removes four 1µF external ceramic capacitors - cuts BOM cost, improves reliability, and simplifies layout in tight spaces |
| 8-Word Receive FIFO | Reduces µC interrupt frequency by 8× versus single-byte buffering - lowers CPU load in high-throughput serial applications |
| Software/Hardware Dual Shutdown | 10µA shutdown with IRQ active enables "listen-only" mode - ideal for always-on diagnostic ports in sleep-capable systems |
| ±15kV ESD Protection (IEC 1000-4-2) | Meets industrial and medical ESD immunity requirements without external protection components - accelerates EMC qualification |
| Crystal Oscillator + Programmable Baud Generator | Supports precise 300–230kbaud rates from single 1.8432MHz crystal - avoids external clock generator or PLL IC |
Applications
| Point-of-Sale (POS) Terminals | Handheld Diagnostic Tools |
|---|---|
|
Use Scenario: Compact, battery-powered credit card readers and receipt printers require reliable serial communication with host PCs or payment gateways over RS-232. IC Role / Device Role / Timing Role: MAX3111EENI serves as the sole serial interface IC, handling UART framing, baud generation, and RS-232 level translation in one chip. Use Value: Single 3.3V supply and integrated capacitors reduce bill-of-materials and PCB footprint - critical for sub-100cm² handheld enclosures. |
Use Scenario: Field-service technicians use portable analyzers to interrogate telecom/networking equipment via RS-232 diagnostic ports. IC Role / Device Role / Timing Role: MAX3111EENI bridges µC-based analyzer logic to legacy RS-232 equipment, providing ESD-hardened, low-power connectivity. Use Value: ±15kV ESD protection ensures robust operation in uncontrolled environments; 10µA shutdown extends battery life between measurements. |
| Industrial Front-Panel Interfaces | Low-Power HMI Controllers |
|
Use Scenario: Factory-floor HMIs connect to PLCs or sensors using RS-232, often mounted in metal enclosures subject to ESD and vibration. IC Role / Device Role / Timing Role: MAX3111EENI implements bidirectional serial control and status reporting between ARM Cortex-M µC and external devices. Use Value: Hardware shutdown (SHDN pin) allows µC to disable RS-232 drivers during sleep while retaining UART configuration - simplifies power-state management. |
Use Scenario: Embedded controllers in smart meters or building automation nodes use RS-232 for local commissioning and firmware updates. IC Role / Device Role / Timing Role: MAX3111EENI acts as the primary serial peripheral, supporting IrDA timing mode and 9-bit network protocols for legacy device compatibility. Use Value: SPI interface conserves µC GPIOs; 8-word FIFO prevents data loss during burst transmissions from metering ICs or sensor arrays. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar UART+RS-232 transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX3222ECAE+ | 3.0–5.5V supply; no integrated UART; 2-driver/2-receiver only; requires external UART or µC UART peripheral | Used where µC has built-in UART and only level translation is needed - lacks SPI interface and crystal oscillator | Select when system already includes a UART resource and only RS-232 physical layer is missing |
| SP3223ECA-L | 3.0–5.5V supply; no UART; 2-driver/2-receiver; ±15kV ESD; no internal capacitors - requires 4× external 0.1µF | Lower-cost transceiver-only solution for designs with dedicated UART and available board space for discrete caps | Choose for cost-sensitive, non-battery applications where layout area and BOM count are less constrained |
Compared with MAX3111EENI, MAX3222ECAE+ offloads UART processing to the µC but adds routing complexity and external component dependency, while SP3223ECA-L reduces integration but increases capacitor count and layout sensitivity - MAX3111EENI uniquely balances integration, low-voltage operation, and ESD robustness in one 28-pin SO package.
Availability
MAX3111EENI is available at Aetrix Electronics and suitable for point-of-sale terminals, handheld diagnostic tools, and industrial front-panel interfaces requiring stable component supply across extended product lifecycles.
Supply support for MAX3111EENI 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
Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and consumer applications.
The MAX3110E/MAX3111E family was designed to replace multi-chip UART+transceiver solutions in space-constrained, low-power 3.3V/5V systems - targeting handheld, POS, and industrial HMI markets where integration, ESD resilience, and supply simplicity are critical.
FAQ
What is the operating voltage range for MAX3111EENI?
The MAX3111EENI operates from +3.0V to +3.6V, making it compatible with standard 3.3V logic systems. This range ensures full functionality of both the UART and RS-232 transceiver sections, including guaranteed ±5.4V output swing and 230kbps data rate. Operation outside this range may cause undefined behavior or damage - the absolute maximum rating is +4.0V.
Does MAX3111EENI require external capacitors for RS-232 level generation?
No, MAX3111EENI does not require external charge-pump capacitors. It integrates internal C1+, C1−, C2+, and C2− capacitors, eliminating the need for four external 1µF ceramics. This reduces PCB area, BOM cost, and potential failure points - a key differentiator from transceiver-only alternatives like MAX3222ECAE+.
How does the shutdown mode work on MAX3111EENI?
MAX3111EENI supports two shutdown modes: hardware (SHDN pin low) disables only the RS-232 transceivers and charge pump (ICC ≈ 0.45mA), while software shutdown (SHDNi bit = 1) stops the crystal oscillator and clears UART registers. Both can be combined for 10µA total current with IRQ monitoring active - enabling wake-on-RX in ultra-low-power systems.
What is the maximum guaranteed data rate for MAX3111EENI?
The MAX3111EENI is guaranteed to operate at up to 230kbps while maintaining full EIA/TIA-232-F output voltage compliance (±5V min). Electrical characteristics confirm operation up to 250kbps under typical conditions, but 230kbps is the production-tested, datasheet-guaranteed limit for robust interoperability with legacy RS-232 receivers.
Is MAX3111EENI pin-compatible with MAX3110E variants?
Yes, MAX3111EENI is hardware- and software-compatible with MAX3110E variants (e.g., MAX3110ECWI), sharing identical pinout, register map, and SPI timing. The key difference is supply voltage: MAX3110E requires +4.5V to +5.5V, while MAX3111EENI operates from +3.0V to +3.6V - allowing direct substitution in 3.3V systems without layout changes.
MAX3111EENI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- 28-DIP (0.300", 7.62mm)
- Programmable:
- Not Verified
- Protocol:
- RS232, RS485
- Function:
- Controller
- Interface:
- SPI, UART
- Standards:
- -
- Voltage - Supply:
- 3V ~ 3.6V
- Current - Supply:
- 600µA
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 28-PDIP
- Grade:
- -
- Qualification:
- -
MAX3111EENI FAQ
1.How can I place an order for MAX3111EENI through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX3111EENI 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 MAX3111EENI reliable?
The price and inventory of MAX3111EENI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX3111EENI is usually 5 days.
3.What payment methods are accepted for MAX3111EENI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX3111EENI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX3111EENI?
MAX3111EENI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX3111EENI 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 MAX3111EENI?
For technical support, including MAX3111EENI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX3111EENI requirements.
6.How does Aetrix verify that MAX3111EENI is sourced from the original manufacturer or authorized distributors?
All MAX3111EENI 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 MAX3111EENI meets industry standards.
7.What is the process for return or replacement of MAX3111EENI?
All MAX3111EENI units undergo pre-shipment inspection (PSI). If there is an issue with MAX3111EENI, 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 MAX3111EENI part is unused and in its original packaging.
Return procedure for MAX3111EENI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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