MAX4851HETE - Quad SPST Over-Rail Switch | Analog Devices
料号： MAX4851HETE ✓ 量产中MAX4851HETE 概述
An analog switch is a semiconductor device that routes an electrical signal between external terminals under digital control. The SPST designation means each of the four channels has one signal path, while the quad configuration integrates four switches into one package. In the device hierarchy, MAX4851HETE belongs to the analog-switch, interface-IC, and semiconductor categories. This integration allows one controller to manage several independently switched signal lines on a compact circuit board.
Over-rail signal handling is the principal functional distinction of the MAX4851 family. This characteristic allows the switched signal to extend beyond the nominal supply-voltage range, which is useful when a source can present a voltage above or below the switch’s normal operating rails. The 2 V to 5.5 V operating range also supports both lower-voltage and conventional 5 V system environments. The compact 16-pin TQFN package reduces PCB area compared with larger switch packages.
The MAX4851HETE is designed for signal routing where rapid transitions and channel isolation matter. Its 100 ns turn-on and 60 ns turn-off times provide substantially faster switching than many mechanical relay implementations. The 80 dB isolation specification helps reduce unwanted coupling between channels, while the 4.5 ohm on resistance suits applications where moderate insertion resistance is acceptable. These characteristics position the device between low-cost mechanical relays and more specialized high-performance switch networks.
Typical uses include test and measurement signal routing, industrial control interfaces, communication-line switching, instrumentation multiplexing, and embedded systems that must route external signals under firmware control. It can also support over-rail input conditioning when the controlling system has a different voltage domain. The extended -40°C to +85°C range makes it appropriate for industrial equipment where room-temperature commercial components would be insufficient.
Designers should verify every signal’s absolute maximum voltage, logic threshold, and permitted over-rail condition before routing it through the switch. Input and ground connections should have low impedance paths, while unused control pins should be driven to a defined state. Because on resistance contributes insertion loss and consumes power, sensitive high-frequency or precision analog paths should be checked for bandwidth and attenuation rather than relying only on nominal transition time.
This product page combines the MAX4851 family specifications, package details, sourcing information, and engineering guidance with same-package replacement analysis. It also highlights the practical distinction between fast semiconductor switching, over-rail operation, channel isolation, and the trade-offs associated with the device’s 4.5 ohm on resistance.
直接替换替代料： MAX4851HETE ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： MAX4851HETE （相同外形与封装尺寸） ——差异在于 Package, Switch Configuration.
MAX4851EETE
✅ 直接替换📋 参考替代料（不在目录中）
MAX4853HETE
✅ 直接替换联系询价
查看数据手册 →MAX4853EETE
✅ 直接替换📋 参考替代料（不在目录中）
MAX4851HETE 最大额定值与电气特性
| Product Type | Quad SPST analog switch with over-rail signal handling |
| Number of Switch Channels | 4 channels |
| Switch Configuration | SPST |
| Supply Voltage Range | 2 V to 5.5 V |
| On Resistance | 4.5 ohm |
| Switch Resistance Family | 3.5 ohm / 7 ohm |
| Turn-On Time | 100 ns |
| Turn-Off Time | 60 ns |
| Isolation | 80 dB |
| 工作温度范围 | -40°C to +85°C |
| 封装 | 16-pin TQFN, 3 mm × 3 mm |
| 引脚数量 | 16 pins |
| 安装类型 | Surface mount |
| Device Marking | +ABX |
| Signal Handling | Over-rail signal handling |
MAX4851HETE 16-pin tqfn, 3 mm × 3 mm 引脚配置指南
MAX4851HETE（16-pin tqfn, 3 mm × 3 mm 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： MAX4851HETE.
请参阅 数据手册 以查看完整引脚配置。
典型应用
MAX4851HETE 适用于 6 应用s: Industrial Test and Measurement Signal Routing, Communication-Line Switching, Embedded Control and Peripheral Switching, Instrumentation Signal Multiplexing, Data Acquisition Front Ends, Security and Surveillance Control.
Industrial Test and Measurement Signal Routing
The MAX4851HETE fits laboratory and industrial test systems that must route several instrument signals under software control. Its four SPST channels provide a compact alternative to a bank of slower mechanical relays, while 100 ns turn-on and 60 ns turn-off times shorten the interval between routing commands. The stated 80 dB isolation helps separate routed channels, and operation from -40°C to +85°C supports industrial equipment. Engineers should verify the input bandwidth, signal-level limits, and control truth table before connecting external sources.
推荐
Communication-Line Switching
MAX4851HETE can route communication or control lines in equipment where compactness and fast operation are important. Over-rail signal handling is valuable when a connected peripheral can present a voltage outside the switch’s normal 2 V to 5.5 V supply range. Four independently controlled channels reduce component count, and the 3 mm by 3 mm TQFN preserves board area. The 4.5 ohm on resistance must be acceptable for the signal being routed, while the 80 dB isolation specification should be checked against crosstalk requirements.
推荐
Embedded Control and Peripheral Switching
The MAX4851HETE is appropriate for embedded systems that need to connect or disconnect external lines under MCU or FPGA control. Its 60 ns turn-off and 100 ns turn-on times permit fast switching, while four channels provide convenient integration in a 16-pin TQFN. The 2 V minimum supply supports integration with suitable low-voltage logic systems, but control thresholds must be checked against the selected MCU or FPGA. For long external lines, add protection appropriate to the environment and validate the complete signal path for ringing.
推荐
Instrumentation Signal Multiplexing
A MAX4851HETE-based design can multiplex several instrumentation signals through a compact analog-routing network. The four SPST channels provide independent control paths, and the 80 dB isolation figure supports designs requiring meaningful separation between channels. The 4.5 ohm on resistance adds attenuation, so precision measurements may require a lower-resistance switch or an appropriate buffer. Keep trace lengths short, use a stable ground reference, and verify that switching transients do not corrupt the measurement window.
推荐
Data Acquisition Front Ends
The MAX4851HETE can implement controlled signal selection in data-acquisition front ends where multiple sensor or test channels must reach a common processing chain. Its fast switching behavior allows channel changes with less delay than electromechanical relays, and the small TQFN footprint supports compact multi-channel boards. Four channels can be expanded for larger systems, although off-state leakage, bandwidth, and charge injection should be checked against the sensor impedance and acquisition timing. The manufacturer data sheet supplies the authoritative electrical limits.
推荐
Security and Surveillance Control
MAX4851HETE is suitable for surveillance equipment that switches or isolates video-related control or sensor lines. Its compact 16-pin TQFN package preserves PCB area in camera and controller assemblies, while four channels permit coordinated routing. The over-rail feature helps accommodate signal levels that may differ from the logic supply. Actual video analog paths normally require very low capacitance and higher bandwidth, so the device is better suited to control, monitoring, or auxiliary lines than high-definition video conductors. Protection against external transients remains essential.
推荐
推荐产品汇总
工程参考数据： MAX4851HETE ——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 | MAX4851EETE | MAX4853HETE | MAX4853EETE |
|---|---|---|---|---|
| Package | 16-pin TQFN, 3 mm × 3 mm | 16-pin TQFN, 3 mm × 3 mm | 16-pin TQFN, 3 mm × 3 mm | 16-pin TQFN, 3 mm × 3 mm |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Switch Configuration | Quad SPST | Quad SPST | Quad SPST | Quad SPST |
| Number of Channels | 4 channels | 4 channels | 4 channels | 4 channels |
| On Resistance | 4.5 ohm | 3.5 ohm / 7 ohm family | 3.5 ohm / 7 ohm family | 3.5 ohm / 7 ohm family |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C |
| Signal Handling | Over-rail signal handling | Over-rail signal handling | Over-rail signal handling | Over-rail signal handling |
关键差异点
- Compact four-channel over-rail switching （对比 MAX4851EETE)
- Fast complementary switching response （对比 MAX4853HETE)
- Extended industrial temperature capability （对比 MAX4853EETE)
设计说明
Do not assume that over-rail handling removes all absolute-maximum limits. Confirm the permitted signal excursion, supply state, and control-pin level for every operating mode in the Analog Devices data sheet. The MAX4851HETE operates from 2 V to 5.5 V and supports over-rail signal handling, but transient duration, polarity, and fault-current behavior can still constrain a design. Apply appropriate external protection when long cables or inductive loads can introduce large excursions.
Place input and output decoupling capacitors close to the 16-pin TQFN power and ground connections, and use a low-impedance ground plane beneath the device. Follow the manufacturer’s exposed-pad land pattern and assembly recommendations for the TQFN package. Keep switched-signal traces short and separate from control and clock routing where possible. Because the stated 4.5 ohm on resistance creates attenuation, precision and high-frequency paths should be evaluated for bandwidth rather than only insertion resistance.
Account for switch capacitance, off-state leakage, and charge injection when the switched source has a high impedance or when measurement timing is critical. The published 100 ns turn-on and 60 ns turn-off times describe switching speed, not the settling time of the complete analog path. Establish an acquisition dead time after each switching command and compare the resulting error with the converter’s resolution. For high-speed signals, validate bandwidth and crosstalk using the actual board layout.
Estimate the average supply current from the device quiescent current, control-state current, and the dynamic current required by the switched paths. The MAX4851HETE uses a 2 V to 5.5 V supply, so the chosen regulator must maintain the required voltage during switching transients. Decouple the supply locally and avoid routing return current through sensitive analog paths. The precise power-consumption figures should be taken from the manufacturer data sheet under the intended control and signal conditions.
合规信息
No definitive environmental or material-compliance statement was identified in the manufacturer page snippet or distributor specifications. Confirm the current declarations with Analog Devices before using the part in a compliance-controlled design.
