MAX3238EAI+ - 3-5.5V RS-232 Transceiver with AutoShutdown Plus | ADI
料号： MAX3238EAI+ ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $5.27 | $5.27 |
| 10 | $4.78 | $47.80 |
| 100 | $4.12 | $412.00 |
| 500 | $3.55 | $1,775.00 |
| 1,000 | $3.08 | $3,080.00 |
MAX3238EAI+ 概述
An RS-232 transceiver is a line driver/receiver IC that translates logic-level UART signals (0V/3.3V or 0V/5V) into the +-5V to +-15V swing defined by the EIA/TIA-232 standard, providing the voltage translation and noise immunity required to communicate with PCs, modems, and legacy industrial equipment over cables up to 15 meters. The MAX3238EAI+ belongs to the multi-channel RS-232 transceiver category (part of the larger UART-to-RS232 interface transceiver hierarchy) within the wired communication IC market.
Key features include 1 uA AutoShutdown Plus supply current, 250 kbps guaranteed data rate, integrated charge-pump requiring only four 0.1 uF capacitors, and compatibility with EIA/TIA-232 and V.28/V.24 standards. The IC also provides INVALID logic output to signal when receivers are out of range, plus FORCEON and FORCEOFF pins for manual shutdown control. The MAX3238EAI+ is the non-ESD version; the MAX3238E variant adds +/-15 kV IEC 61000-4-2 air-gap ESD protection on transceiver pins.
The architecture pairs a switched-capacitor DC-DC converter (charge pump) that doubles and inverts the supply, with five RS-232 drivers and three RS-232 receivers. Compared with the older MAX232 family, the MAX3238EAI+ adds the AutoShutdown Plus feature, reducing quiescent current from typical 1 mA to 1 uA when no valid RS-232 signal is present - critical for battery-powered portable equipment.
Typical applications include notebook and sub-notebook computers, PDAs, hand-held terminals, battery-powered point-of-sale equipment, and any portable system that needs an EIA/TIA-232 serial port running directly from a 3.3V or 5V battery.
When designing with this part, place the four charge-pump capacitors as close to the IC as possible, use 0.1 uF ceramic with X7R or better dielectric, and tie unused driver inputs to GND through 100 kohm resistors to prevent supply-current oscillation.
This page synthesizes distributor pricing, validated drop-in alternatives (MAX3238E family variants and TI MAX3238E), and practical design notes that complement the manufacturer datasheet.
直接替换替代料： MAX3238EAI+ ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
MAX3238ECAI+
✅ 直接替换📋 参考替代料（不在目录中）
MAX3238ECAI+T
✅ 直接替换📋 参考替代料（不在目录中）
MAX3238EAI+T
✅ 直接替换📋 参考替代料（不在目录中）
MAX3238E
✅ 直接替换📋 参考替代料（不在目录中）
MAX3238E
✅ 直接替换📋 参考替代料（不在目录中）
MAX3238EAI+ 规格参数
| 电源电压 | +3.0 V to +5.5 V |
| Supply Current (AutoShutdown Plus) | 1 uA typical |
| 数据速率 | Up to 250 kbps |
| Drivers / Receivers | 5 / 3 |
| Logic Compatibility | 3.3 V and 5 V UART |
| RS-232 Standards | EIA/TIA-232, V.28, V.24 |
| Charge Pump Capacitors | 4 x 0.1 uF external |
| 工作温度 | -40 to +85 C (E suffix) |
| 封装 | 28-pin SSOP |
| 安装类型 | Surface Mount |
| MSL 等级 | 1 (unlimited floor life) |
| RoHS 状态 | Compliant |
| Lead-Free / Halogen-Free | Yes |
| ForceOn / ForceOff Pins | Yes |
| INVALID Output | Yes |
MAX3238EAI+ 引脚配置
| 引脚 1 | C1+ — Charge-pump capacitor 1 positive terminal |
| 引脚 2 | V+ — Charge-pump generated +5.5V supply |
| 引脚 3 | C1- — Charge-pump capacitor 1 negative terminal |
| 引脚 4 | C2+ — Charge-pump capacitor 2 positive terminal |
| 引脚 5 | C2- — Charge-pump capacitor 2 negative terminal |
| 引脚 6 | V- — Charge-pump generated -5.5V supply |
| 引脚 7 | T1OUT — RS-232 driver 1 output |
| 引脚 8 | T2OUT — RS-232 driver 2 output |
| 引脚 9 | T3OUT — RS-232 driver 3 output |
| 引脚 10 | T4OUT — RS-232 driver 4 output |
| 引脚 11 | T5OUT — RS-232 driver 5 output |
| 引脚 12 | R1IN — RS-232 receiver 1 input |
| 引脚 13 | R2IN — RS-232 receiver 2 input |
| 引脚 14 | R3IN — RS-232 receiver 3 input |
| 引脚 15 | R4IN — RS-232 receiver 4 input |
| 引脚 16 | R5IN — RS-232 receiver 5 input |
| 引脚 17 | FORCEON — Force-on logic input (active high) |
| 引脚 18 | FORCEOFF — Force-off logic input (active low) |
| 引脚 19 | INVALID — Invalid-signal logic output |
| 引脚 20 | R1OUT — RS-232 receiver 1 logic output |
| 引脚 21 | R2OUT — RS-232 receiver 2 logic output |
| 引脚 22 | R3OUT — RS-232 receiver 3 logic output |
| 引脚 23 | R4OUT — RS-232 receiver 4 logic output |
| 引脚 24 | R5OUT — RS-232 receiver 5 logic output |
| 引脚 25 | GND — Ground |
| 引脚 26 | VCC — +3.0V to +5.5V supply |
| 引脚 27 | T1IN — RS-232 driver 1 logic input |
| 引脚 28 | T2IN — RS-232 driver 2 logic input |
典型应用
MAX3238EAI+ 适用于 6 应用s: Notebook / Sub-notebook Serial Port, PDA and Hand-Held Terminal, Battery-Powered Point-of-Sale (POS) Terminal, Industrial Modem / Serial Backhaul, Embedded Debug / Development Serial Console, Medical Device Serial Interface (Patient Monitor / Infusion Pump).
Notebook / Sub-notebook Serial Port
The MAX3238EAI+ integrates the full DB-9 EIA/TIA-232 port (5 drivers + 3 receivers) plus 1 uA AutoShutdown Plus standby, making it ideal for battery-powered notebooks and sub-notebooks. Operating from a single +3.0V to +5.5V rail, it interfaces the internal UART (TD, RD, RTS, CTS, DTR, RI) to an external DB-9 connector without a separate +-12V supply. The four 0.1 uF charge-pump capacitors generate the +/-5.5V RS-232 swing, and 250 kbps covers all legacy COM-port baud rates including 115.2 k and 230.4 k with margin.
推荐
PDA and Hand-Held Terminal
The MAX3238EAI+'s 1 uA AutoShutdown Plus supply current makes it well suited for PDAs, hand-held data terminals, and bar-code scanners running from 3.3V Li-ion cells. The IC automatically drops into 1 uA standby when no valid RS-232 signal is present on the receiver inputs and wakes on the first edge transition, preserving battery life across weeks of standby. The 5/3 channel count covers DTR/RTS handshaking plus ring-indicator wake on PDA cradles, and the 28-SSOP footprint fits underneath a DB-9 connector.
推荐
Battery-Powered Point-of-Sale (POS) Terminal
Portable POS terminals that connect to legacy receipt printers and barcode scanners over RS-232 benefit from the MAX3238EAI+'s 1 uA standby. The wide 3.0V to 5.5V supply range supports direct 1-cell Li-ion or 4-cell NiMH operation, and the integrated charge pump removes the need for a boost converter. The 5 drivers / 3 receivers support both data and hardware-flow control (RTS/CTS) needed by older POS peripherals, while 250 kbps handles modern printers without throttling throughput.
推荐
Industrial Modem / Serial Backhaul
Industrial modems, environmental sensors, and SCADA RTUs that communicate with legacy EIA/TIA-232 instrumentation use the MAX3238EAI+ as a logic-to-RS-232 level translator. The 5/3 channel count exposes TD, RD, RTS, CTS and DTR/DSR for full hardware-flow control against older industrial equipment, and the 28-SSOP package withstands -40C to +85C industrial ambient. The 0.1 uF ceramic charge-pump capacitors operate reliably across industrial temperature extremes when X7R dielectric is specified.
推荐
Embedded Debug / Development Serial Console
Embedded Linux boards, industrial gateways, and SoC evaluation kits often expose a 3.3V UART as a debug console that engineers connect to a PC COM port for terminal output. The MAX3238EAI+ bridges the 3.3V UART TX/RX pins to the +-5V RS-232 swing expected by legacy PCs and USB-to-serial dongles. With 1 uA standby and 250 kbps, it handles 115.2 kbaud Linux console logs without dropping characters, and the 28-SSOP footprint fits in the small PCB area available on SoM carriers.
推荐
Medical Device Serial Interface (Patient Monitor / Infusion Pump)
Patient-side medical equipment such as infusion pumps, vital-sign monitors, and bedside terminals use the MAX3238EAI+ to communicate with hospital IT systems over EIA/TIA-232. The 3.0V to 5.5V supply works from either battery packs or regulated 5V rails, and the 1 uA AutoShutdown Plus standby preserves battery life during patient transport. The industrial -40C to +85C temperature grade accommodates hospital HVAC variations, and the 28-SSOP footprint simplifies sterilization and conformal-coating processes.
推荐
推荐产品汇总
工程参考数据： MAX3238EAI+ ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | MAX3238ECAI+ | MAX3238ECAI+T | MAX3238EAI+T | MAX3238E | MAX3238E (TI) |
|---|---|---|---|---|---|---|
| Package | 28-SSOP | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments |
| 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 |
| Data Rate | 250 kbps | 250 kbps | 250 kbps | 250 kbps | 250 kbps | 250 kbps |
| Drivers / Receivers | 5 / 3 | 5 / 3 | 5 / 3 | 5 / 3 | 5 / 3 | 5 / 3 |
| Shutdown Current | 1 uA (AutoShutdown Plus) | 1 uA (AutoShutdown Plus) | 1 uA (AutoShutdown Plus) | 1 uA (AutoShutdown Plus) | 1 uA (AutoShutdown Plus) | 1 uA (AutoShutdown) |
| ESD Protection (RS-232 pins) | Not specified (non-E version) | Not specified | Not specified | Not specified | +/-15 kV HBM | +/-15 kV HBM / +/-8 kV IEC contact |
| Operating Temperature | -40C to +85C | 0C to +70C | 0C to +70C | -40C to +85C | -40C to +85C | -40C to +85C |
| RoHS / Lead-Free | Compliant | Compliant | Compliant | Compliant | Compliant | Compliant |
关键差异点
- 1 uA AutoShutdown Plus standby current vs 1 mA typical for MAX3232 （对比 MAX3232E)
- 5 drivers / 3 receivers vs MAX3232's 2 / 2 （对比 MAX3232E)
- INVALID logic signal for cable-disconnect detection （对比 MAX3241E)
- Single 3.0V to 5.5V supply with no +-12V rail required （对比 MAX232 (legacy))
设计说明
Place the four 0.1 uF charge-pump capacitors (C1+, C1-, C2+, C2-) within 2-3 mm of their respective IC pins per the Analog Devices datasheet. Use X7R (or better) ceramic dielectric to maintain capacitance across the -40C to +85C industrial temperature range. Y5V or Z5U ceramics lose 50%+ capacitance at cold temperatures and can cause RS-232 level compliance failures. Keep charge-pump traces short to minimize ripple on V+ and V- that couples into RS-232 output edges.
Tie unused RS-232 driver logic inputs (T_IN) to GND through 100 kohm resistors when not driven by the host UART. Floating driver inputs can oscillate, drawing extra supply current and injecting noise into the charge pump. Also ensure any unused RS-232 receiver inputs (R_IN) are left open or connected to a defined logic level - never tie an R_IN to ground, as EIA/TIA-232 receivers expect RS-232-level signals on their inputs.
Estimated: at 250 kbps with a 5 m unshielded cable, the MAX3238EAI+'s RS-232 driver slew rate produces edge rise times around 100 ns - well below the EIA/TIA-232 4 V/us minimum and tolerant of typical cable capacitance up to 2,500 pF. For cables longer than 10 m or in noisy industrial environments, add a series ferrite bead on each RS-232 output and a 100 ohm termination at the receiver input to suppress ringing.
The MAX3238EAI+ draws 1 uA in AutoShutdown Plus shutdown, but the host MCU must drive FORCEOFF high or let it idle high to enable the 1 uA mode. Per the Analog Devices datasheet, leaving FORCEOFF floating defaults the part to always-on operation, consuming the full active supply current. For battery-powered designs, gate VCC through a load switch and drive FORCEOFF from the MCU so the IC powers down completely when the serial port is unused.
合规信息
RoHS and lead-free per Analog Devices (formerly Maxim Integrated) product page. The + suffix in MAX3238EAI+ denotes RoHS-compliant lead-free packaging. AEC-Q100 not applicable for this RS-232 interface IC (not an automotive-qualified part).