DG403 - Dual High-Speed SPDT Analog Switch, 44V | Analog Devices
MPN: DG403 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.02 | $7.02 |
| 10 | $6.32 | $63.20 |
| 100 | $5.62 | $562.00 |
| 500 | $5.26 | $2,630.00 |
| 1,000 | $7.02 | $7,020.00 |
DG403 Overview
An analog switch is a semiconductor device that passes or blocks analog signals under digital control, acting as the solid-state equivalent of a relay contact. Within the signal-chain hierarchy, the DG403 belongs to the analog switches and multiplexers family, positioned below analog multiplexers (which route many channels) and above simple pass elements, and it is a core building block of analog front-end and signal-routing subsystems in data acquisition systems.
Key features include CMOS or TTL-level compatible logic activation, operation from single-ended supplies of +5V to +34V or split supplies from plus/minus 5V to plus/minus 17V, and a high-voltage silicon-gate process. Each of the two independent control inputs selects between two signal paths, providing the equivalent of two SPDT relay contacts with no moving parts.
The improved redesign (originally by Maxim Integrated, now Analog Devices) added guaranteed low on-resistance matching between switches and flatness over the signal range, while the epitaxial layer prevents the latch-up associated with older CMOS technologies. The ON-resistance variation with analog signal level is quite low over a plus/minus 15V analog input range, ensuring low signal distortion.
Typical applications include audio and video signal routing, precision data-acquisition channel selection, sample-and-hold circuits, and replacing electromechanical relays in industrial and instrumentation signal paths. Where two single-pole single-throw contacts are needed, the DG401 offers SPST functionality; the DG405 offers DPST.
Designers should observe supply-rail headroom: analog signal swings must remain within the supply rails, and logic inputs must meet CMOS/TTL threshold levels for correct switching.
This page synthesizes distributor pricing, family cross-references, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for DG403 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
DG403DJ+
✅ Drop-In📋 Reference alternative (not in catalog)
DG401
✅ Drop-In📋 Reference alternative (not in catalog)
DG405
✅ Drop-In📋 Reference alternative (not in catalog)
DG403DY
✅ Drop-In📋 Reference alternative (not in catalog)
DG403A
✅ Drop-In📋 Reference alternative (not in catalog)
DG403 Maximum Ratings & Electrical Characteristics
| Switch Function | Dual SPDT (2 x single-pole double-throw) |
| Number of Switches | 2 |
| Maximum Signal Voltage Range | 44 V |
| Analog Signal Handling | 30 Vp-p |
| Single Supply Range | +5 V to +34 V |
| Split Supply Range | ±5 V to ±17 V |
| On-Resistance Matching | 2 ohm max between switches |
| On-Resistance Flatness | 3 ohm max over signal range |
| Logic Compatibility | CMOS or TTL level activation |
| Process Technology | High-voltage silicon-gate CMOS, epitaxial layer (latch-up protected) |
| Package | SOIC-16 (also PDIP-16 per datasheet) |
| Mounting Type | Surface Mount |
| Analog Range Linearity | Low ON-resistance variation over ±15 V analog input range |
| Typical Relay Equivalent | 2 SPDT relay contacts, solid state |
DG403 soic-16 (also pdip-16 per datasheet) Pin Configuration Guide
Pin configuration for DG403 (soic-16 (also pdip-16 per datasheet) 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 DG403.
Refer to the datasheet for full pin configuration.
Typical Applications
DG403 is suitable for 6 applications: Data Acquisition Channel Multiplexing, Audio and Video Signal Routing, Electromechanical Relay Replacement, Sample-and-Hold and Precision Reference Switching, Industrial PLC I/O Signal Conditioning, Test and Measurement Instrument Signal Switching.
Data Acquisition Channel Multiplexing
The DG403 fits precision data-acquisition front ends where an ADC must be time-shared among multiple sensor sources. Its 44V maximum signal range and low ON-resistance variation over a ±15V analog input range ensure the switch does not introduce gain errors or distortion into high-impedance measurement paths, while the 2 ohm max Ron matching keeps channel-to-channel accuracy consistent. In a typical topology, each SPDT contact selects between a live sensor and a calibration reference, letting the system auto-zero between conversions. Because the switch is powered from the same ±15V rails as most industrial instrumentation amplifiers, no extra supply generation is needed. Designers should account for Ron in series with source impedance when calculating settling time into the ADC sample capacitor.
Recommended
Audio and Video Signal Routing
In audio and video switching, the DG403's 30Vp-p signal handling and low on-resistance flatness over the signal range directly reduce harmonic distortion, since flatness is the key parameter governing THD in CMOS switches. Each SPDT contact can select between two sources, for example routing either a playback DAC output or an external input into an amplifier stage, with CMOS/TTL-compatible logic enabling direct MCU or FPGA control. Because the improved DG403 guarantees 3 ohm max flatness, switching artifacts remain low across the full signal swing on ±15V or +34V single-supply professional audio rails. For highest-fidelity paths, place the switch into a high-impedance node with a buffer after it to minimize the impact of Ron on frequency response.
Recommended
Electromechanical Relay Replacement
The DG403 was explicitly designed to provide the equivalent of two SPDT relay contacts in solid-state form, per the Renesas/Intersil datasheet. Replacing relays eliminates contact bounce, arcing, coil power, and mechanical wear, and increases switching lifetime from tens of thousands of cycles to effectively unlimited. Its ±17V split-supply capability covers classic ±15V industrial analog systems, and the epitaxial silicon-gate process resists latch-up during inductive or transient events common in factory environments. The trade-off versus a mechanical relay is on-resistance (tens of ohms in this family) and reduced isolation, so it suits signal-level switching rather than power or safety-isolation duty. For circuits, drive the logic pins directly from a 5V controller through appropriate level shifting.
Recommended
Sample-and-Hold and Precision Reference Switching
The DG403 suits sample-and-hold front ends and reference-source selection in precision converters. Low charge injection and fast logic-controlled switching let it connect a hold capacitor to a live signal during acquisition and isolate it during hold; the 44V range accommodates ±15V measurement systems. In precision analog design, the dominant errors are Ron in series with the capacitor charge path (which lengthens acquisition time) and feedthrough in hold mode, so the switch should drive a low-impedance source and the hold node should connect to a high-input-impedance buffer such as a FET-input amplifier. Guaranteed 2 ohm max Ron matching between the two internal switches helps maintain consistent acquisition behavior in dual-channel designs.
Recommended
Industrial PLC I/O Signal Conditioning
In programmable logic controller input and output conditioning, the DG403 routes sensor signals between measurement circuits and diagnostic paths, for example switching an input between a shunt-calibration resistor and the live transducer. The wide single-supply range of +5V to +34V matches the 24V industrial bus environment, while split-supply operation to ±17V supports bipolar transducer signals. Latch-up immunity from the epitaxial CMOS process adds robustness against the wiring-fault transients typical on factory floors. Because switching is logic-controlled from the PLC's microcontroller at CMOS/TTL levels, no driver stage is required. Designers must ensure analog signals remain inside the supply rails and consider series Ron when scaling the measurement with precision resistor dividers.
Recommended
Test and Measurement Instrument Signal Switching
Bench instruments such as oscilloscope front ends, curve tracers, and automated test equipment use SPDT switches like the DG403 to select attenuation paths, calibration standards, or probe-sense nodes. The device's guaranteed on-resistance flatness over the signal range keeps insertion loss constant as input amplitude changes, important for maintaining measurement accuracy across the instrument's dynamic range. Its 30Vp-p capability covers typical ±10V instrument signal ranges, and high-speed switching supports fast autoranging between measurements. In ATE fixtures, the SOIC-16 surface-mount package supports automated assembly, and TTL-compatible control inputs simplify interface to the test controller. For higher-voltage measurement paths, series-stack multiple switches or select a rated high-voltage relay instead.
Recommended
Recommended Products Summary
Engineering reference data for DG403 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | DG403DJ+ | DG401 | DG405 |
|---|---|---|---|---|
| Package | SOIC-16 (also PDIP-16) | SOIC-16 - same | SOIC-16 - same | SOIC-16 - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Switch Configuration | Dual SPDT | Dual SPDT | Dual SPST | Dual DPST |
| Maximum Signal Voltage Range | 44 V | 44 V | 44 V | 44 V |
| Supply Range | +5V to +34V single / ±5V to ±17V split | Same family supply range | Same family supply range | Same family supply range |
| Logic Compatibility | CMOS / TTL | CMOS / TTL | CMOS / TTL | CMOS / TTL |
Key Differentiators
- Dual SPDT topology in one package (vs DG401)
- Guaranteed Ron matching and flatness on the improved generation (vs DG403DJ+ legacy equivalent)
- Wider signal range than modern small-footprint TMUX parts (vs TMUX7213 (TI))
Design Notes
Keep analog signal swings strictly within the supply rails. The DG403 supports a 44V maximum voltage range and 30Vp-p signals, but if the input exceeds the rails, the internal CMOS body diodes conduct, clamping and distorting the signal and potentially damaging the part. On split supplies this means VIN must stay between V- and V+ (for example ±15V on a ±17V supply). Add clamp diodes or series resistors on external connectors where overvoltage transients are possible, a practice emphasized in manufacturer analog-switch application guidance.
Select supplies to match your signal range: single-ended +5V to +34V or split ±5V to ±17V. For ±15V professional audio or instrumentation rails, the DG403's ±17V maximum split supply provides headroom. The series on-resistance of the switch (tens of ohms, with 2 ohm max matching guaranteed on the improved version) forms a divider with the source impedance, so keep source impedance low or buffer the switch output; this also shortens settling time when driving a sample capacitor. Estimated: a 30 ohm Ron with 1 kohm source causes roughly 3% amplitude error.
Place 0.1uF ceramic decoupling capacitors directly at each supply pin to ground to suppress logic-transition supply spikes, which can couple charge into nearby analog nodes. Route the analog signal paths away from the digital control traces to minimize crosstalk from switching edges, and use a ground plane under the SOIC-16 footprint. If substituting the legacy DG403 with the improved DG403DJ+, verify the exact package suffix (ceramic PDIP vs SOIC) before committing the land pattern.
Compliance Information
Compliance status not explicitly stated in the retrieved verified data. Verify the exact order suffix (e.g., DG403DJ+ vs legacy ceramic versions) on the Analog Devices product page for RoHS/lead-free status before ordering.
