DG401DY+ - Dual 45Ω High-Speed SPST Switch | Analog Devices
MPN: DG401DY+ ✓ ActiveDG401DY+ Overview
An analog switch is an integrated semiconductor device that connects or disects signal paths under digital control. The DG401 belongs to the monolithic CMOS analog-switch hierarchy, which also includes multiplexers and demultiplexers. Unlike a mechanical relay, it changes connection state electronically and enables compact, repeatable routing of low-voltage analog signals in instrumentation, communications, and industrial control equipment.
Key characteristics include two independent SPST switch circuits, 45 Ω maximum analog on resistance, and switching time below 150 ns. According to the Analog Devices DG401 product page, the redesigned DG401, DG403, and DG405 families also feature guaranteed low on-resistance matching between switches of 2 Ω maximum and guaranteed on-resistance flatness over the signal range of 3 Ω maximum. The typical on resistance is 20 Ω.
The DG401DY+ uses TTL- and CMOS-compatible digital inputs, allowing its control signals to be driven by a broad range of digital logic families. Its monolithic CMOS implementation provides consistent bidirectional analog conduction when a switch is closed. The normally-open topology keeps each switched node disconnected during the off state, which helps prevent unintended signal paths in test systems and measurement circuits.
Typical uses include automated test equipment, sample-and-measurement systems, instrumentation signal routing, communications equipment, and industrial control modules. Its dual-channel organization reduces the number of packages required when two independently controlled signal paths are needed. The 16-pin SOIC format supports conventional surface-mount assembly and is convenient for designs that require multiple switch functions without using a large connectorized relay.
When designing around the DG401DY+, place the device close to the routed signal nodes to minimize PCB-trace resistance and capacitance. Check the absolute maximum signal and supply ratings in the manufacturer datasheet, particularly for bipolar analog signals, and use a defined control state during power transitions to prevent unwanted switching. Treat the 45 Ω maximum on resistance as a signal-loss term when calculating attenuation and bandwidth.
This page combines the manufacturer specifications, sourcing guidance, pin-package details, and practical comparison information to support faster component selection. It also distinguishes true same-footprint drop-in choices from related DG401-family variants and highlights the electrical trade-offs engineers should review before replacing an installed switch.
Drop-in alternatives for DG401DY+ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
DG401DY
✅ Drop-In📋 Reference alternative (not in catalog)
DG401DY-E3
✅ Drop-In📋 Reference alternative (not in catalog)
DG401DY+ Maximum Ratings & Electrical Characteristics
| Product Type | Dual high-speed analog switch IC |
| Number of Circuits | 2 circuits |
| Multiplexer Configuration | 1:1 |
| Switch Architecture | Dual SPST normally open |
| Maximum On Resistance | 45 ohm |
| Typical On Resistance | 20 ohm |
| On-Resistance Matching Between Switches | 2 ohm maximum |
| On-Resistance Flatness Over Signal Range | 3 ohm maximum |
| Switch-On Time | Less than 150 ns |
| Logic Compatibility | TTL and CMOS compatible |
| Technology | Monolithic CMOS |
| Package | 16-pin SOIC |
| Mounting Type | Surface mount |
| Temperature Grade | Industrial |
| Lifecycle Status | Production |
DG401DY+ 16-pin soic Pin Configuration Guide
Pin configuration for DG401DY+ (16-pin soic package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for DG401DY+.
Refer to the datasheet for full pin configuration.
Typical Applications
DG401DY+ is suitable for 6 applications: Automated Test Equipment Signal Routing, Sample-and-Hold Signal Selection, Instrumentation Signal Multiplexing, Communications Receive-Path Switching, Industrial Control Signal Isolation, Battery-Powered Sensor Interface.
Automated Test Equipment Signal Routing
The DG401DY+ fits automated test equipment because two independently controlled SPST channels can route a DUT connection without using mechanical relays. Its switch-on time below 150 ns supports rapid test sequencing, while the 45 Ω maximum on resistance must be included in the accuracy budget for low-amplitude measurements. TTL- and CMOS-compatible control inputs simplify integration with the test controller. Place the device near the fixture connector to limit trace resistance, and verify that every signal and supply condition remains within the datasheet limits.
Sample-and-Hold Signal Selection
The DG401DY+ can select or disconnect an analog sample path in a sample-and-measurement system because each normally-open SPST channel provides controlled isolation when the switch is off. The 20 Ω typical and 45 Ω maximum on resistance should be compared with the source impedance and acquisition capacitor to determine settling error. Fast operation below 150 ns is valuable when multiple measurements are acquired in rapid succession. The control signals should have clean transitions, and the layout should minimize capacitance across switched nodes.
Instrumentation Signal Multiplexing
The DG401DY+ is useful in instrumentation modules that must connect two analog sources or measurement paths under digital supervision. Its dual 1:1 configuration reduces package count while preserving independent control of both channels. Maximum channel resistance of 45 Ω can affect source loading, so buffer high-impedance sensors when accuracy or settling time is critical. Use the monolithic CMOS device's low on resistance as part of the overall error budget, and maintain short, guarded routing between the switch and the measurement front end.
Communications Receive-Path Switching
The DG401DY+ can support receive-path routing in communications equipment when the signals remain within the switch's specified voltage range. Its TTL- and CMOS-compatible inputs allow control from common digital logic, and the sub-150 ns turn-on behavior supports fast channel selection. The 45 Ω maximum on resistance introduces attenuation and may limit system gain at high frequencies, so the complete receiver path must be simulated with the actual source impedance. Keep return routing short to minimize crosstalk and susceptibility to external interference.
Industrial Control Signal Isolation
The DG401DY+ can disconnect low-voltage control or diagnostic signals in industrial modules because its normally-open topology leaves switched paths open in the inactive state. The dual-channel arrangement provides two separately commanded isolation points within one 16-pin SOIC. Designers should use the channel-specific on-resistance and switching-time limits when calculating fault-detection timing. Control-state defaults should prevent unintended paths during startup, and the device must remain within its documented supply and analog-signal ratings.
Battery-Powered Sensor Interface
The DG401DY+ can route sensor signals in compact battery-powered electronics when two controlled analog paths are required and switching speed is important. The monolithic CMOS implementation and 16-pin SOIC package support board-level integration, while operation below 150 ns enables rapid range or source selection. Designers should assess off-state behavior and leakage against the sensor source impedance because those effects can dominate low-current measurements. Control circuitry should remain in a defined state during sleep transitions to prevent unintended sensor loading.
Engineering reference data for DG401DY+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | DG401DY | DG401DY-E3 |
|---|---|---|---|
| Manufacturer | Analog Devices | Vishay Intertechnology | Vishay Intertechnology |
| Package | 16-SOIC | 16-SOIC | 16-SOIC |
| Number of Circuits | 2 circuits | 2 circuits | 2 circuits |
| Multiplexer Configuration | 1:1 | 1:1 | 1:1 |
| Maximum On Resistance | 45 ohm | 45 ohm | 45 ohm |
| Switch-On Time | Less than 150 ns | Less than 150 ns | Less than 150 ns |
| Logic Compatibility | TTL and CMOS compatible | TTL and CMOS compatible | TTL and CMOS compatible |
| Technology | Monolithic CMOS | Monolithic CMOS | Monolithic CMOS |
Key Differentiators
- Two independently controlled channels in one package (vs DG401DY)
- Matched switching characteristics within the DG401 family (vs DG401DY-E3)
- Fast electronic control with compact surface-mount packaging (vs DG401DY)
Design Notes
Treat the closed-channel resistance as part of the signal path. At the 45 Ω maximum on resistance, a 1 V signal produces a voltage drop of up to 45 mV at 1 mA before considering source impedance. Compare this loss with the receiver's input range, and use a lower-resistance switch or an input buffer when the measurement cannot tolerate the error.
Route switched analog nodes directly between the DG401DY+ pins and their destination, with a continuous ground reference beneath the trace. Keep the logic-control traces away from high-impedance analog nodes, and place any input or bypass capacitors at the associated supply pin. Short traces reduce parasitic capacitance that can slow switching and contribute to crosstalk.
Do not assume that matching package outlines establish electrical interchangeability. Before fitting DG401DY or DG401DY-E3 to a DG401DY+ footprint, compare control polarity, supply requirements, maximum analog signal voltage, off leakage, and break-before-make behavior in the manufacturer datasheets. Validate the assembled board with the intended signal amplitude and control sequence.
Define the logic state of both control inputs during power-up and power-down so the switched paths do not connect unintentionally. Confirm that the selected supply arrangement keeps every control input within its permitted logic range. Because the device is not a power semiconductor, safe operating area data is not applicable; thermal design should instead follow the package and total power-dissipation limits in the manufacturer documentation.
Compliance Information
The Analog Devices product page identifies DG401 as a production family, but the available listings do not provide explicit RoHS, REACH, lead-free, halogen-free, or conflict-minerals declarations.