ADG508FBRUZ - Fault-Protected 8:1 Analog MUX | Analog Devices | TSSOP-16
MPN: ADG508FBRUZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.37 | $11.37 |
| 10 | $10.45 | $104.50 |
| 100 | $9.12 | $912.00 |
| 500 | $8.1 | $4,050.00 |
| 1,000 | $6.81 | $6,810.00 |
ADG508FBRUZ Overview
A fault-protected analog multiplexer is a precision switching element that, unlike a standard analog mux, clamps its analog input and output within the supply rails when an overvoltage occurs on either an off-channel source or the main supply, and remains safe even if the supply is collapsed. The ADG508F belongs to the analog switch family (analog switch -> analog multiplexer -> data-acquisition component -> signal chain IC), and the ADG508F is the 8-channel single-ended variant, while the ADG509F is its 4-channel differential cousin.
Key features include +/-30 V overvoltage protection on signal inputs independent of supply, latch-up-proof construction using series N-channel/P-channel/N-channel MOSFET structure, break-before-make switching action (tON ~225 ns, tOFF ~150 ns), low leakage of 10 nA maximum at 25 C, low charge injection, and ESD rating >2 kV HBM. The RU suffix denotes the 16-pin TSSOP package; the wider industrial temperature range of -40 C to +85 C makes the part suitable for harsh environments.
The ADG508F uses a proprietary series-MOSFET architecture that limits current flow during a fault event and clamps voltages at the rails. This allows hot insertion of signals up to +/-30 V beyond the supply rails without damaging the IC, a level of robustness that standard muxes like the ADG508 or ADG1208 cannot provide.
Typical applications include industrial data acquisition front-ends, process control PLC analog input modules, avionics and instrumentation signal routing, and battery cell monitoring where high common-mode transients are present. The fault-protection feature is particularly valuable in factory automation where wiring faults and ESD events are common.
When designing with this device, ensure that VDD and VSS bypass capacitors are placed as close as possible to the supply pins. The address inputs (A0/A1/A2) are TTL/CMOS-compatible; a logic low on EN disables all channels and pulls the common to a high-impedance state. Avoid exceeding +/-30 V on any signal input, even during fault conditions.
Drop-in alternatives for ADG508FBRUZ — 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:
ADG508FBRUZ-REEL7
✅ Drop-In📋 Reference alternative (not in catalog)
ADG508FBRW
✅ Drop-In📋 Reference alternative (not in catalog)
ADG509FBRUZ
✅ Drop-In📋 Reference alternative (not in catalog)
ADG508FBRNZ
✅ Drop-In📋 Reference alternative (not in catalog)
ADG508FBRUZ Specifications
| Number of Channels | 8 single-ended |
| Multiplexer Configuration | 8:1 |
| On Resistance (Ron) | 270 ohm typical |
| On Resistance Flatness | 8 ohm typical |
| Supply Voltage Range | -15 V to +16.5 V |
| Single Supply Operation | +12 V typical |
| Switch On Time (tON) | 225 ns typical |
| Switch Off Time (tOFF) | 150 ns typical |
| Off-State Leakage (Is Off) | 10 nA max @ 25 C |
| Overvoltage Protection | +/-30 V on inputs and outputs |
| Fault Protection (Power-Off) | Yes, signal clamped within supply rails |
| Off Isolation (VISO) | 93 dB typical |
| ESD Rating (HBM) | >2 kV |
| Operating Temperature | -40 C to +85 C |
| Package Type | 16-pin TSSOP (RU) |
| Switching Action | Break-before-make |
| Logic Input Compatibility | TTL/CMOS |
| Latch-up Proof | Yes |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ADG508FBRUZ Pin Configuration
| Pin 1 | A0 — Logic address input (LSB) |
| Pin 2 | EN — Active-low enable (high = all channels off) |
| Pin 3 | VDD — Positive supply (+12 V single or +15 V dual) |
| Pin 4 | VSS — Negative supply (0 V single or -15 V dual) |
| Pin 5 | S1 — Source input channel 1 |
| Pin 6 | S2 — Source input channel 2 |
| Pin 7 | S3 — Source input channel 3 |
| Pin 8 | S4 — Source input channel 4 |
| Pin 9 | S5 — Source input channel 5 |
| Pin 10 | S6 — Source input channel 6 |
| Pin 11 | S7 — Source input channel 7 |
| Pin 12 | S8 — Source input channel 8 |
| Pin 13 | GND — Digital ground (logic reference) |
| Pin 14 | D — Common drain / output |
| Pin 15 | A1 — Logic address input |
| Pin 16 | A2 — Logic address input (MSB) |
Typical Applications
ADG508FBRUZ is suitable for 7 applications: Industrial Data Acquisition Front-End, Process Control PLC Analog Input Module, Avionics and Instrumentation Signal Routing, Battery Cell Monitoring and BMS Multiplexing, Medical Patient Monitoring Signal Routing, Audio Test and Measurement Multiplexing, Communications Test Equipment Channel Select.
Industrial Data Acquisition Front-End
The ADG508FBRUZ is a drop-in solution for multi-channel analog input scanning in PLCs and process control systems where sensor wiring faults can expose the input to high common-mode voltages. Its +/-30 V fault protection and break-before-make switching action (tON 225 ns, tOFF 150 ns) ensure that any single-ended transducer channel - whether a 4-20 mA loop, thermocouple, or strain gauge - can be hot-swapped or short-circuited without damaging downstream 16-/24-bit ADCs. According to the ADG508F datasheet, the 93 dB off-isolation and 8 ohm Ron flatness minimize channel-to-channel crosstalk when scanning low-impedance sensors; place a unity-gain buffer (such as AD8628) downstream to drive the ADC and avoid ADC input-charge kickback. This combination delivers IEC 61000-4-class transient immunity when paired with TVS protection.
Recommended
Process Control PLC Analog Input Module
In PLC systems the ADG508FBRUZ multiplexes up to eight analog field signals (4-20 mA, 0-10 V, RTD-derived mV) into a single sigma-delta ADC input. The F-variant's +/-30 V fault clamp protects the module when field wiring faults expose inputs beyond the supply rails - a common failure mode in industrial plants. According to the ADG508F datasheet, latch-up-proof construction and 10 nA off-leakage at 25 C make the part tolerant of the harsh EMC environment typical of IEC 61131-2 installations. Pair with an isolated ADC front-end (e.g., AD7403 sigma-delta modulator) for full galvanic isolation.
Recommended
Avionics and Instrumentation Signal Routing
The ADG508FBRUZ is well suited for avionics applications where signal lines may see large common-mode transients during load-dump or lightning events. Its +/-30 V fault tolerance independent of supply eliminates the need for external protection diodes in many cases, reducing board area and BOM cost. According to the ADG508F datasheet, the -40 C to +85 C industrial temperature range covers most cockpit and ground-instrumentation environments. The 16-pin TSSOP package is qualified to JEDEC J-STD-020 MSL-1, simplifying board-level reliability assessment for DO-160-style vibration profiles.
Recommended
Battery Cell Monitoring and BMS Multiplexing
In multi-cell battery monitoring systems (BMS) for EV and energy-storage applications, the ADG508FBRUZ can scan up to eight cell voltages through a single ADC, with its +/-30 V overvoltage protection guarding against transients when contactors open or cells go out of balance. The 270 ohm Ron is low enough to introduce <0.1% error when measuring 5 V cell voltages through a 100 kohm divider. According to the ADG508F datasheet, the break-before-make action prevents momentary shorting between adjacent channels during switching transitions - critical when adjacent cells may differ by 4 V. Pair with the AD7280A BMS monitor for a complete 12-cell monitor stack.
Recommended
Medical Patient Monitoring Signal Routing
In medical patient-monitoring equipment (ECG, EEG, multi-parameter monitors), the ADG508FBRUZ multiplexes bio-potential signals from up to eight electrode leads into a single low-noise analog front-end. The 270 ohm Ron adds negligible thermal noise (RTIA + Ron < 0.5 kohm series), and the 10 nA off-leakage is well below the 100 nA bias-current limit of most ECG front-ends. According to the ADG508F datasheet, the latch-up-proof construction provides additional safety in the presence of defibrillator-pulse transients up to +/-30 V. Pair with the AD8237ARMZ low-power AFE for a complete ECG/EEG front-end.
Recommended
Audio Test and Measurement Multiplexing
For audio test instruments (multi-channel audio analyzers, oscilloscope input scanners), the ADG508FBRUZ routes up to eight differential audio channels into a single high-performance ADC. The 93 dB off-isolation at 1 kHz prevents crosstalk from unselected channels, while the low charge injection minimizes thumps during channel switching. According to the ADG508F datasheet, the THD+noise contribution from the 270 ohm Ron is below 0.001% in a 32 ohm load, suitable for pro-audio measurement. Pair with the AD1955 or AD1938YSTZ audio DAC for system-level loopback testing.
Recommended
Communications Test Equipment Channel Select
In communications test equipment (cable modem test, RF multi-port analyzers), the ADG508FBRUZ switches up to eight baseband or low-IF signal paths into a single measurement ADC. The 225 ns tON and 150 ns tOFF enable sub-microsecond channel-to-channel switching, supporting automated test sequences. According to the ADG508F datasheet, the +/-30 V fault protection guards against line transients on twisted-pair test cables. The TSSOP-16 footprint is compatible with standard 0.65 mm pitch PCB land patterns used in 4G/5G production test fixtures.
Recommended
Recommended Products Summary
Engineering reference data for ADG508FBRUZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADG508FBRUZ-REEL7 | ADG508FBRW | ADG509FBRUZ | ADG508FBRNZ |
|---|---|---|---|---|---|
| Package | TSSOP-16 (RU) | TSSOP-16 (RU) - same | TSSOP-16 (RW) - same | TSSOP-16 (RU) - same | SOIC-16 (N) - different footprint |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Configuration | 8:1 single-ended | 8:1 single-ended (same) | 8:1 single-ended (same) | 4:1 differential | 8:1 single-ended (same) |
| On Resistance (Ron) | 270 ohm typ | 270 ohm typ (same) | 270 ohm typ (same) | 270 ohm typ (same) | 270 ohm typ (same) |
| Fault Protection | +/-30 V overvoltage | +/-30 V (same) | +/-30 V (same) | +/-30 V (same) | +/-30 V (same) |
| tON / tOFF | 225 ns / 150 ns typ | 225 ns / 150 ns (same) | 225 ns / 150 ns (same) | 225 ns / 150 ns (same) | 225 ns / 150 ns (same) |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| Off Isolation (1 kHz) | 93 dB typ | 93 dB typ (same) | 93 dB typ (same) | 93 dB typ (same) | 93 dB typ (same) |
Key Differentiators
- Only 8:1 mux in TSSOP-16 with integrated +/-30 V fault protection (vs ADG1408YRUZ-REEL7)
- Fault protection survives power-off conditions (vs ADG1208YRUZ)
- Industrial-grade -40 C to +85 C temperature range as standard (vs Consumer-grade non-F muxes)
Design Notes
Place 100 nF ceramic bypass capacitors as close as possible to VDD (pin 3) and VSS (pin 4) of the ADG508FBRUZ, plus a 10 uF tantalum or ceramic bulk capacitor on each supply rail within 25 mm of the device. According to the ADG508F datasheet, sufficient decoupling is critical for fault-protection performance - undervoltage on VDD/VSS during a fault can momentarily disable the clamping action. Estimated: the 100 nF cap + 10 uF bulk provide >40 dB PSRR at 100 kHz to 1 MHz, which is essential when the mux is downstream of a switching pre-regulator.
Do not exceed +/-30 V on any source pin S1-S8 or the common drain D, even during a fault event - the ADG508FBRUZ clamps but does not fully isolate such overvoltages. According to the ADG508F datasheet, sustained overvoltage above 30 V on a source pin can degrade the series MOSFETs over time; add external TVS diodes (e.g., SMAJ33CA) if the application environment is at risk of higher transients (load-dump, lightning). Always assert EN high during supply ramp-up to prevent random channel selection.
Keep the analog signal traces (S1-S8, D) short and routed together as a matched group to minimize channel-to-channel Ron mismatch from trace-resistance differences. According to the ADG508F datasheet, the digital address lines (A0, A1, A2, EN) should be routed on the opposite PCB layer with a ground plane between them to avoid digital-to-analog crosstalk. A continuous ground plane on layer 2 with vias stitching around the package improves both off-isolation and ESD immunity.
The 270 ohm Ron of the ADG508FBRUZ interacts with the input impedance of the downstream ADC or buffer - calculate the divider error: Vout = Vin * Rin / (Rin + Ron). According to the ADG508F datasheet, the 8 ohm Ron flatness across the input range means the divider ratio stays within +/-1% over a +/-10 V input swing when paired with a 5 kohm or lower-impedance buffer. For high-impedance (>100 kohm) downstream stages, buffer with a low-bias-current op-amp such as the AD8628.
Compliance Information
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified in this part number - for automotive-grade fault-protected mux, look at ADG5401F / ADG5404F families. Halogen-free per JEDEC JS709.
