LT1342CG - 5V RS-232 Transceiver | Analog Devices
MPN： LT1342CG ✗ 停產LT1342CG 概覽
An RS-232 transceiver is an interface IC that combines line drivers and receivers for serial data transmission over the RS-232 standard. The LT1342 belongs to the broader line-driver/receiver and interface-IC hierarchy, converting between digital logic levels and RS-232 signal levels. Its 3 V logic interface allows connection to modern low-voltage digital systems while the RS-232 side operates from a 5 V supply.
The verified product information identifies three drivers, five receivers, 0.2 µF charge-pump capacitors, 1 µA shutdown supply current, low-power driver disable, and ESD protection exceeding ±10 kV. The device also operates above 120 kbaud with heavy capacitive loads, supports 250 kBaud operation for 1000 pF, and is pin compatible with the LT1137A. These features make it suitable for compact serial links where low supply current and direct 3 V logic interfacing are important.
The LT1342CG is packaged as a 28-pin SSOP from Linear Technology, now part of Analog Devices. The “G” package code and SSOP form factor are identified in distributor and cross-reference results. The device also supports shutdown, allowing drivers and receivers to assume high-impedance states and reducing supply current to near zero. This is useful for portable equipment where system power conservation and bus isolation affect battery life.
Typical applications include notebook computers, palmtop computers, and other equipment requiring an RS-232 port with a 3 V host logic connection. The 0.2 µF charge-pump capacitors help reduce external capacitor size, while the driver-disable function allows individual transmitters to be placed into a low-power state. The device is intended for systems where EIA RS-232 compliance, low supply current, and compact packaging are priorities.
When laying out a board, place the charge-pump capacitors close to their associated pins and preserve the verified package pin assignments. Confirm the interface voltage levels, baud rate, capacitive loading, and shutdown-control polarity in the system specification. The LT1342CG is an interface IC rather than a power semiconductor, so a safe-operating-area specification does not apply.
This product page combines verified Analog Devices and distributor information with interface-specific application guidance, design cautions, and selection criteria to support practical RS-232 design decisions.
直接替換替代品，適用於 LT1342CG — 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。
LT1137A
✅ 直接替換📋 參考替代品（不在目錄中）
LT1342CG 規格
| Device Type | RS-232 transceiver |
| Number of Drivers | 3 |
| Number of Receivers | 5 |
| 供應電壓 | 5 V |
| Logic Supply Voltage | 3 V |
| Logic Interface | 3 V logic interface |
| Charge-Pump Capacitors | 0.2 µF |
| Shutdown Supply Current | 1 µA |
| 資料速率 | In excess of 120 kbaud |
| Operation at 2500 pF Load | 120 kbaud |
| Operation at 1000 pF Load | 250 kbaud |
| ESD Protection | Over ±10 kV |
| Driver Disable | Low-power driver disable |
| Shutdown Behavior | Drivers and receivers assume high-impedance states |
| Pin Compatibility | Pin compatible with LT1137A |
| 封裝 | 28-pin SSOP |
| Package Code | SSOP |
| Terminal Count | 28 terminals |
| 安裝類型 | Surface mount |
| Interface Standard | EIA RS-232 |
| Applications | Notebook computers and palmtop computers |
LT1342CG ssop 腳位配置指南
LT1342CG（ssop 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： LT1342CG.
請參閱 資料表 以查看完整腳位配置。
典型應用
LT1342CG 適用於 6 應用s: Notebook Computer Serial Port, Palmtop Computer Interface, Portable RS-232 Data Link, Embedded Equipment Configuration Port, Instrument Serial Communication, Industrial Control Module.
Notebook Computer Serial Port
The LT1342CG fits a notebook computer interface requiring an RS-232 driver and receiver stage alongside a 3 V host logic domain. Its three drivers and five receivers provide multiple serial-line functions in one 28-pin SSOP. The verified information identifies notebook computers as an intended application, while the 3 V logic interface allows connection to suitable low-voltage logic without an additional level-shifting stage. Keep the charge-pump capacitors close to the device and verify the actual cable length and baud rate during system validation.
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Palmtop Computer Interface
The LT1342CG is suitable for compact palmtop equipment that needs an RS-232 connection while conserving board area and power. Its 28-pin SSOP package combines three drivers and five receivers, and the verified feature list includes 1 µA shutdown supply current for low-power operation. The 3 V logic side can connect to compatible digital circuits, while the RS-232 side operates from 5 V. Validate the transceiver’s driver-disable and shutdown states to prevent unnecessary current draw when the serial port is idle.
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Portable RS-232 Data Link
For portable equipment, the LT1342CG provides an RS-232 line interface with explicit power-management controls. Shutdown places drivers and receivers in high-impedance states, and the verified 1 µA shutdown supply current can reduce current consumption when the port is not active. The device also offers a low-power driver-disable function for transmitters that are not in use. The design must still account for the 5 V RS-232 supply and the 3 V logic supply, including sequencing requirements across the complete system.
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Embedded Equipment Configuration Port
The LT1342CG can provide a wired configuration or service connection for embedded equipment that uses a 3 V control logic domain and an RS-232 service port. Multiple drivers and receivers allow the system to support several signal directions or diagnostic functions in one device. The verified operating data indicates operation above 120 kbaud and defined performance at capacitive loads, but the actual usable rate depends on cable length, termination, noise, and firmware timing. Confirm signal polarity and shutdown behavior in the service-port specification.
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Instrument Serial Communication
The LT1342CG is appropriate for test and measurement equipment requiring a short-distance RS-232 control or data link with a modern 3 V logic interface. Its 5 V RS-232 supply and 3 V logic interface separate external line-level signaling from the host-side digital domain. The transceiver’s specified 250 kBaud capability at 1000 pF can help when the connected load is light, although real cable capacitance and protection-network loading must be included in system validation. Use the official datasheet for pin and charge-pump layout details.
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Industrial Control Module
The LT1342CG can serve as the RS-232 interface in a small industrial control module where a 3 V microcontroller or logic device must communicate with a legacy RS-232 peripheral. Its three drivers and five receivers provide a useful mix of transmit and receive channels in one package. The manufacturer identifies notebook and palmtop applications, while the electrical feature set supports broader point-to-point serial links. Before deployment, verify industrial temperature requirements, surge protection, isolation strategy, and cable grounding because those requirements are not established by the supplied snippets.
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推薦產品摘要
工程參考資料，適用於 LT1342CG — 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 | LT1137A |
|---|---|---|
| Device Type | RS-232 transceiver | RS-232 transceiver family member |
| Package | 28-pin SSOP | 28-pin SSOP |
| Brand | Analog Devices | Linear Technology |
| Pin Compatibility | Pin compatible with LT1137A | Pin-compatible reference |
主要差異化特點
- Direct 3 V logic integration (對比LT1137A)
- Power-conscious shutdown behavior (對比LT1137A)
- Specified high-speed capacitive-load operation (對比LT1137A)
設計說明
Place the verified 0.2 µF charge-pump capacitors close to the associated LT1342CG pins and keep their return paths short. Follow the manufacturer datasheet layout for capacitor placement and grounding. Because the device uses a 5 V RS-232 supply and a 3 V logic supply, keep noisy RS-232 driver-current paths away from sensitive logic routing and preserve the recommended ground reference.
Treat the 5 V RS-232 supply and 3 V logic supply as separate rails that require correct sequencing and adequate decoupling. The verified shutdown specification is 1 µA supply current, so a design that expects low standby consumption should also verify that the external supply and pull networks do not add significant leakage. Check whether the host or peripheral requires the transceiver to remain powered during reset.
Do not assume that a matching SSOP package alone guarantees a drop-in replacement. The verified LT1342CG data identifies a 3 V logic interface, 5 V RS-232 supply, 3 drivers, 5 receivers, and particular charge-pump capacitors. Compare every pin, supply level, enable polarity, shutdown behavior, and external capacitor connection in the official datasheet before replacing the part or changing an existing PCB.
合規資訊
The supplied verified results do not state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. The LT1342CG is an interface IC, not a power semiconductor, so a safe-operating-area specification is not applicable.