VSC7155VU-02 - 8-Bit I/O Expander IC Interface Controller | Analog Devices
MPN: VSC7155VU-02 ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $13.2 | $132.00 |
| 100 | $11.85 | $1,185.00 |
| 500 | $10.4 | $5,200.00 |
| 1,000 | $9.25 | $9,250.00 |
VSC7155VU-02 Overview
An I/O expander (also called a GPIO expander or port expander) is a peripheral IC that communicates with a host processor over a serial bus (typically I2C, SPI, or SMBus) and presents multiple parallel GPIO pins to the outside world. Conceptually it belongs to the broader hierarchy: GPIO expander -> parallel I/O controller -> interface IC -> mixed-signal IC -> semiconductor. Compared to in-line shift registers, an I/O expander integrates direction control, pull-ups, interrupt generation, and sometimes debounce, reducing host firmware overhead and PCB area.
The VSC7155VU-02 provides a parallel I/O expansion function intended for telecom line-card, industrial control, and instrumentation backplane designs where board real estate for the host controller is constrained. It is supplied in a surface-mount package and operates from standard logic supply rails, making it compatible with +3.3 V and +5 V digital sections. Its integration into the Analog Devices portfolio preserves second-source availability for designs that were originally qualified against the Vitesse datasheet.
Typical applications include central-office line cards and DSLAM line interfaces, industrial PLC digital I/O modules, telecommunications backplane control, redundant array of independent disks (RAID) controller cards, and legacy VME/cPCI chassis management. The expander approach offloads housekeeping I/O from the main processor, freeing CPU cycles for the actual line-coding or signal-processing workload.
When designing with the VSC7155VU-02, observe the host-bus timing budget for read/write cycles and ensure that any interrupt-capable inputs are pulled to a defined logic level at power-up to avoid spurious interrupt events. Decoupling should follow the manufacturer datasheet recommendation, typically a 100 nF ceramic capacitor adjacent to each supply pin.
This page synthesizes distributor pricing, parameter summaries, and drop-in alternative guidance not found in the original Vitesse datasheet, helping engineers qualify the part for new designs and resolve long-term supply questions for legacy boards.
Drop-in alternatives for VSC7155VU-02 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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Request AlternativesVSC7155VU-02 Specifications
| Product Type | I/O Expander |
| Function | IC Interface Controller |
| Manufacturer | Analog Devices Inc. / Maxim Integrated (formerly Vitesse Semiconductor) |
| Mounting Type | Surface Mount |
| Logic Family | CMOS digital interface controller |
VSC7155VU-02 standard Pin Configuration Guide
Pin configuration for VSC7155VU-02 (standard 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 VSC7155VU-02.
Refer to the datasheet for full pin configuration.
Typical Applications
VSC7155VU-02 is suitable for 6 applications: Telecom Line-Card I/O Expansion, Industrial PLC Digital I/O Modules, Backplane Management and Chassis Control, RAID Controller and Storage Backplane Cards, Test and Measurement Instrumentation Front Panel, Legacy VME/cPCI Board Reproduction.
Telecom Line-Card I/O Expansion
The VSC7155VU-02 fits telecom line-card designs because it expands the host processor's GPIO count without consuming additional board area, allowing line-interface chips to expose alarm, LED, and craft-port signals to a centralized controller. With 8+ parallel I/O lines it can drive per-port status LEDs, relays, and alarm inputs over a single host bus, reducing pin count on the main ASIC. Designers value its parallel write/read access for deterministic update latency in TDM backplanes.
Recommended
Industrial PLC Digital I/O Modules
In PLC and distributed I/O modules the VSC7155VU-02 acts as a per-slot digital expander so the backplane controller can monitor and drive dozens of field-side discretes. Its parallel host interface lets the PLC CPU poll all field inputs in a single read cycle, simplifying deterministic scan-time software. The CMOS logic levels interface cleanly to 24V field-side opto-isolators through external buffers.
Recommended
Backplane Management and Chassis Control
The VSC7155VU-02 is well suited for cPCI, VME, and ATCA chassis management cards where it exposes IPMI-style signals - fan tachometer, presence detect, LED indicators, and board-ID strapping - to the shelf manager. Its compact SMD package fits behind dense backplane connectors and its parallel interface minimizes shelf-manager firmware overhead. Designers can dedicate one VSC7155VU-02 per slot to keep wiring harnesses flat.
Recommended
RAID Controller and Storage Backplane Cards
RAID HBAs and SAS/SATA expander cards use the VSC7155VU-02 to drive drive-activity LEDs, fault indicators, and presence pins across multiple drive bays. Because each LED is independently controllable, the storage processor can flash only the affected bay without taxing its native GPIO. The parallel write path ensures all LEDs in a multi-drive enclosure update within a single host cycle.
Recommended
Test and Measurement Instrumentation Front Panel
Bench instruments such as oscilloscopes, logic analyzers, and modular data-acquisition systems use the VSC7155VU-02 to read front-panel pushbuttons, rotary-encoder switches, and LED status bars through a single host interface. The expander's deterministic read cycle keeps user-input latency bounded, which is critical for tactile UI responsiveness. Its small SMD footprint preserves front-panel board area for the display and BNC connectors.
Recommended
Legacy VME/cPCI Board Reproduction
The VSC7155VU-02 remains the part of record for legacy VMEbus and cPCI boards where the original Vitesse BOM must be matched for FAA, military, or long-life-cycle programs. Because the artwork, BOM, and qualification artifacts already cite the Vitesse part, dropping in a modern GPIO expander would invalidate re-qualification. The VSC7155VU-02 preserves form, fit, and function for these long-life programs even as broader market production winds down.
Recommended
Recommended Products Summary
Engineering reference data for VSC7155VU-02 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX7317AEE | MAX7318AEE |
|---|---|---|---|
| Brand | Analog Devices / Maxim (formerly Vitesse) | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated |
| Lifecycle Status | NRND | Active | Active |
| Mounting Type | Surface Mount | Surface Mount | Surface Mount |
| Approx. Unit Price (USD, qty-1) | 14.50 | 3.50 (approx.) | 4.10 (approx.) |
Key Differentiators
- Original Vitesse design preserved in the Analog Devices portfolio (vs MAX7317AEE)
- NRND part with limited remaining inventory (vs MAX7318AEE)
- Same-vendor portfolio cross-reference (vs MAX7317AEE)
Design Notes
Because the VSC7155VU-02 is in NRND status, do not start a new design with this part. Treat any new procurement as a lifetime-buy or last-time-buy action, and qualify a modern GPIO expander (e.g. MAX7317, PCA9555, MCP23017) in parallel so that a second source is ready when NRND stock is exhausted.
Place a 100 nF decoupling capacitor as close as physically possible to each VSC7155VU-02 supply pin, and add a bulk 10 uF tantalum or ceramic capacitor on the same supply rail within 25 mm of the part. Because the device sits on a parallel host bus, route the host data and strobe lines together with matched lengths to avoid skew-induced false writes during read-modify-write cycles.
Estimated: if the VSC7155VU-02 is placed more than 50 mm from the host controller on a backplane, insert a 33 ohm series-termination resistor at the driver end of each host-bus line to dampen reflections on the parallel bus. For point-to-point host wiring under 50 mm, termination is generally unnecessary.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status are not published in the available distributor data as of 2026-10-15 and are marked unknown. AEC-Q100 is not applicable because the VSC7155VU-02 is an industrial / telecom interface controller.
