MAX211EWI+ - 4/5 RS-232 Transceiver, 5V, 120kbps | ADI
MPN： MAX211EWI+ ✓ 啟用中MAX211EWI+ 概覽
An RS-232 transceiver is an interface IC that converts logic-level signals between a host or controller and a cable-based RS-232 link. Within the interface hierarchy, the MAX211EWI+ combines a charge-pump voltage converter, RS-232 line drivers, and line receivers into one mixed-signal device. This integration allows a single +5 V system to communicate with legacy RS-232 equipment without a separate negative supply or external RS-232 line-power circuit.
Key features include four RS-232 drivers, five receivers, operation above 120 kbps, integrated charge-pump circuitry, and single-supply operation from a nominal +5 V rail. The four external 0.1 µF capacitors required by the EWI+ variant simplify voltage generation but must be placed close to their designated pins to limit charge-pump switching noise. The device provides ±5 V driver levels while operating from a 5 V supply, matching the classic RS-232 electrical requirement for bipolar signaling.
The MAX211 architecture divides the transceiver into a charge-pump converter, four driver channels, and five receiver channels. Its integrated charge pump generates the positive and negative rail voltages used by the drivers. Because these rails are switched internally, PCB layout and capacitor placement materially affect radiated and conducted noise. The wide SOIC outline offers adequate lead spacing for through-hole assembly while occupying less area than a 28-pin standard SOIC.
Typical applications include industrial serial controllers, test equipment, point-of-sale terminals, instrumentation, and data-acquisition systems. Five receiver channels allow one port to monitor four incoming RS-232 lines while the fourth transmitter drives a separate link, making the device useful for console and diagnostic interfaces. The 120 kbps-plus capability is appropriate for configuration links and moderate-rate data transfers rather than modern high-speed serial protocols.
Designers should treat the external charge-pump capacitors and signal routing as critical layout elements. Keep the four 0.1 µF capacitors adjacent to their charge-pump pins, route the charge-pump output as a short and quiet net, and provide adequate bypass capacitance on the +5 V supply. Because the MAX211EWI+ is a legacy RS-232 interface rather than an EIA/TIA-422 or RS-485 transceiver, cable length, grounding, and protection-network design remain application-specific responsibilities.
This page combines manufacturer specifications, distributor references, drop-in family alternatives, and application-focused design guidance. It highlights the practical differences between temperature and packaging order codes and identifies the verification gaps that must be closed before a PCB redesign or cross-brand substitution is approved.
直接替換替代品，適用於 MAX211EWI+ — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： MAX211EWI+ （相同外形與佔位） — 差異在於 Driver Output Levels, Supply Voltage.
MAX211CWI+
✅ 直接替換聯絡詢價
查看資料表 →MAX211CWE+
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MAX211EWE+
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MAX211EWI+ 規格
| Product Type | RS-232 and V.28 transceiver |
| 供應電壓 | +5 V |
| Driver Count | 4 |
| Receiver Count | 5 |
| Maximum Data Rate | In excess of 120 kbps |
| Driver Output Levels | ±5 V EIA/TIA-232E |
| Charge Pump | Integrated |
| Required External Capacitors | 4 × 0.1 µF |
| 封裝 | 28-pin wide SOIC |
| 安裝類型 | Surface mount |
| Driver Output Voltage | ±5 V EIA/TIA-232E |
MAX211EWI+ 28-pin wide soic 腳位配置指南
MAX211EWI+（28-pin wide soic 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： MAX211EWI+.
請參閱 資料表 以查看完整腳位配置。
典型應用
MAX211EWI+ 適用於 6 應用s: Industrial Serial Controller Interface, Data-Acquisition and Test Equipment, Point-of-Sale and Peripheral Connectivity, Serial Console and Diagnostic Port, Communication and Networking Gateways, Portable Diagnostic Equipment.
Industrial Serial Controller Interface
The MAX211EWI+ fits legacy industrial controllers that need several RS-232 links but only have a +5 V rail. Its four drivers support four outgoing channels, while five receivers allow four incoming signals plus a common receive connection to be monitored. The integrated charge pump generates the bipolar driver voltage from +5 V, avoiding a separate negative supply. Operation in excess of 120 kbps supports configuration and moderate-rate command traffic. The 28-pin wide SOIC package is larger than a 16-pin MAX232DR, but its additional channels can eliminate an external transceiver and reduce board area overall.
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Data-Acquisition and Test Equipment
Laboratory instruments and data-acquisition systems can use the MAX211EWI+ to bridge a controller to RS-232 peripherals from a single +5 V supply. Four transmitter channels support command outputs, while five receivers provide flexible monitoring of status, alarm, and data lines. The ±5 V EIA/TIA-232E driver levels comply with the classic RS-232 interface expected by older instruments. Because the part is specified above 120 kbps, it handles moderate-speed configuration links and short data transfers while retaining the slower signaling convention required by legacy equipment.
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Point-of-Sale and Peripheral Connectivity
The MAX211EWI+ is useful in point-of-sale terminals and peripheral controllers that must connect several legacy RS-232 devices to a local processor. Four drivers can service separate peripherals, and five receivers provide additional status inputs without requiring multiple interface packages. Single +5 V operation simplifies system design where older RS-232 implementations used separate positive and negative supplies. The trade-off is that RS-232 remains a point-to-point, single-ended interface, so each output still requires its own return path and cable protection arrangement.
推薦
Serial Console and Diagnostic Port
A diagnostic console requiring several RS-232 lines can use the MAX211EWI+ as a multi-channel port controller. The four drivers support transmit, reset, service, and command lines, while five receiver inputs can report equipment status. Its integrated charge pump allows the port to operate from the same +5 V rail as many embedded controllers, reducing the need for a separate negative-voltage supply. Designers should still provide surge protection on externally accessible cables and route receiver inputs away from the charge-pump nets to minimize coupling.
推薦
Communication and Networking Gateways
Legacy communication gateways often need to convert older RS-232 equipment to a modern digital interface. The MAX211EWI+ provides four RS-232 transmitters and five receivers while accepting only +5 V, allowing the gateway to remain compatible with classic V.28 equipment. The >120 kbps capability is suitable for configuration and control traffic but not for high-throughput network bridging. A MAX232DR may be sufficient where only one RS-232 port is needed, whereas the MAX211EWI+ reduces package count when several isolated logical channels share the gateway.
推薦
Portable Diagnostic Equipment
Portable service tools and handheld diagnostic equipment can use the MAX211EWI+ when several legacy test ports must be supported from a +5 V supply. The integrated charge pump eliminates a separate negative rail, while the 28-pin wide SOIC package remains suitable for surface-mount assembly. Its four transmitters and five receivers cover command, trigger, ready, and status signals commonly found in test fixtures. Designers must budget capacitor placement, supply bypassing, and cable protection carefully because the RS-232 outputs are externally accessible and may be exposed to ESD or industrial transients.
推薦
工程參考資料，適用於 MAX211EWI+ — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | MAX211CWI+ | MAX211CWE+ | MAX211EWE+ |
|---|---|---|---|---|
| Package | 28-pin wide SOIC | 28-pin wide SOIC - same footprint | 28-pin wide SOIC - same footprint | 28-pin wide SOIC - same footprint |
| Brand | Analog Devices | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Driver / Receiver Configuration | 4 drivers / 5 receivers | 4 drivers / 5 receivers | 4 drivers / 5 receivers | 4 drivers / 5 receivers |
| Supply Voltage | +5 V | +5 V | +5 V | +5 V |
| Data Rate | In excess of 120 kbps | In excess of 120 kbps | In excess of 120 kbps | In excess of 120 kbps |
| External Charge-Pump Capacitors | 4 × 0.1 µF | 4 × 0.1 µF | 4 × 0.1 µF | 4 × 0.1 µF |
| RS-232 Driver Output | ±5 V EIA/TIA-232E | ±5 V EIA/TIA-232E | ±5 V EIA/TIA-232E | ±5 V EIA/TIA-232E |
| Charge-Pump Architecture | Integrated for single +5 V operation | Integrated for single +5 V operation | Integrated for single +5 V operation | Integrated for single +5 V operation |
| Temperature Grade | Industrial ordering code | Commercial ordering code | Commercial ordering code | Industrial/extended ordering code |
主要差異化特點
- Four drivers and five receivers in one interface package (對比MAX232DR)
- Industrial ordering option with same wide-SOIC electrical configuration (對比MAX211CWI+)
- Single +5 V operation with integrated charge pump (對比MAX232DR)
設計說明
Place the four mandatory 0.1 µF charge-pump capacitors directly beside their associated MAX211EWI+ pins and keep each capacitor-to-pin trace as short as practical. These capacitors are functional charge-pump components rather than optional supply bypass. Route the generated bipolar rail away from receiver inputs, and use a separate local +5 V bypass capacitor near the device so charge-pump switching current does not share the same return path with sensitive signal wiring.
Keep RS-232 driver outputs away from receiver inputs and the charge-pump section to reduce crosstalk and radiated coupling. Connect each driver channel to its intended cable-side protection network before the connector, and maintain a continuous signal-reference path to the interface connector. The wide SOIC footprint provides more lead spacing than a standard narrow SOIC, but board-area planning should account for the 28-pin package, capacitor placement, and cable-protection components.
Do not treat the MAX211EWI+ and MAX232DR as interchangeable drop-ins: their pin counts, channel counts, and footprints differ. Similarly, the MAX211EUI+ and MAX211ESE+ alternatives found in the supplied data use SSOP packages and cannot be soldered directly onto a 28-pin wide SOIC land pattern. When changing order codes, verify the complete ordering guide, temperature grade, package drawing, capacitor network, pinout, and lifecycle status rather than relying on the MAX211 family name alone.
合規資訊
The supplied verified results confirm that MAX211EWI+ is a surface-mount RS-232 transceiver but do not provide explicit RoHS, REACH, halogen-free, conflict-minerals, or AEC-Q100 statements. Compliance and automotive-grade status therefore remain unverified.
