ISL33001IUZ-T - I2C Bus Buffer 2-Ch MSOP-8 | Renesas
MPN: ISL33001IUZ-T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.48 | $0.48 |
| 10 | $0.44 | $4.40 |
| 100 | $0.39 | $39.00 |
| 500 | $0.35 | $175.00 |
| 1,000 | $0.33 | $330.00 |
ISL33001IUZ-T Overview
An I2C bus buffer (also called a bus repeater or signal buffer) is an interface IC that isolates and regenerates the SDA and SCL signals of a two-wire serial bus. The I2C specification limits total bus capacitance to 400pF; when more devices, longer cables, or larger trace lengths are added, signal edges degrade and communication fails. A bus buffer sits between two bus segments, refreshing drive strength on each side so that each segment only sees its own local capacitance. Within the interface-signal-chain hierarchy, it belongs to the class of signal buffers, repeaters, and splitters used in power management and communication systems.
Key features of the ISL33001 include buffering that extends bus capacitance beyond the 400pF limit specified by I2C, integrated rise time accelerator circuitry that reduces power consumed by passive pull-up resistors while improving data-rate performance, and hot-swap circuitry that prevents corruption of data on the bus during card insertion or removal events.
Technically, the ISL33001 operates in open-drain/open-collector bus environments and is compatible with both I2C and SMBus protocols, supporting clock stretching and bus arbitration on the SDA and SCL pins per the Renesas datasheet. This makes it suitable for multi-master systems where contention must be preserved across the buffered boundary.
Typical applications include backplane I2C fan-out in servers and telecom equipment, isolating a heavily loaded card-edge bus from a lightly loaded local bus, and hot-board insertion in industrial control shelves where a live board must join an active bus without corrupting transactions in progress.
A key design consideration is that rise time accelerators inject brief pull-up current pulses; pull-up resistor sizing should still respect SMBus droop requirements, and both bus sides need their own pull-ups since the buffer is bidirectional.
This page synthesizes distributor pricing, same-family drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ISL33001IUZ-T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ISL33001IUZ-T (same form factor and footprint) — differing in Function, Packaging, Package, Number of Channels, Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISL33001IUZ
✅ Drop-In✓ In Stock
$0.43 / Unit
View Datasheet →ISL33002IUZ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$0.45 / Unit
View Datasheet →ISL33003IUZ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ISL33001IUZ-T Specifications
| Function | I2C Bus Buffer (Signal Buffer/Repeater) |
| Number of Channels | 2 (SDA, SCL) |
| Protocol Compatibility | I2C, SMBus |
| Bus Capacitance Extension | Beyond 400 pF I2C specification limit |
| Rise Time Accelerators | Yes |
| Hot-Swap Capability | Yes |
| Clock Stretching Support | Yes |
| Bus Arbitration Support | Yes (SDA and SCL) |
| Bus Type | Open-drain / open-collector |
| Operating Temperature Range | -40C to +85C (Industrial) |
| Package | 8-MSOP |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (-T suffix) |
ISL33001IUZ-T 8-msop Pin Configuration Guide
Pin configuration for ISL33001IUZ-T (8-msop 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 ISL33001IUZ-T.
Refer to the datasheet for full pin configuration.
Typical Applications
ISL33001IUZ-T is suitable for 6 applications: Server and Telecom Backplane I2C Fan-Out, Hot Board Insertion in Industrial Racks, Optical Module and SFP Management Buses, Long-Cable I2C in Building Automation, Power Supply Module Telemetry, Automotive Infotainment Peripheral Buses.
Server and Telecom Backplane I2C Fan-Out
Backplanes aggregate dozens of power-supply, fan-controller, and hot-swap controller ICs whose combined input capacitance quickly exceeds the 400pF limit of the I2C specification. The ISL33001IUZ-T is placed on the backplane to split the bus into isolated segments, each within its own capacitance budget, while its rise time accelerators keep edges sharp enough for 100kHz and 400kHz traffic on long trace runs. Because it supports clock stretching and bus arbitration on SDA and SCL, multi-master management traffic from shelf managers and FRU EEPROMs flows correctly across the buffer. The industrial -40C to +85C rating matches telecom shelf ambient specifications.
Recommended
Hot Board Insertion in Industrial Racks
In industrial control shelves and modular instruments, cards are inserted or removed while the system I2C bus remains live. Without protection, the discharged capacitance of an incoming card glitches SDA and SCL, corrupting transactions in progress or latching other devices into error states. The ISL33001IUZ-T hot-swap circuitry prevents corruption of data on the bus during these events by controlling how the card-side pins connect to the active lines, per the Renesas datasheet. Its two-channel topology buffers both SDA and SCL simultaneously, and the industrial temperature rating suits factory-floor environments.
Recommended
Optical Module and SFP Management Buses
SFP, QSFP, and similar pluggable optical modules expose a 2-wire management interface that is capacitance-limited and subject to live insertion. An ISL33001IUZ-T on the host board buffers the management SDA and SCL lines, isolating the host controller from module-side capacitance and insertion transients while extending the allowable bus loading beyond 400pF in high-port-count systems. The rise time accelerators reduce dependence on low-value pull-ups, cutting standing power on the always-on management bus. The 8-MSOP package fits the tight board area around cage connectors in dense switch designs.
Recommended
Long-Cable I2C in Building Automation
Building automation and HVAC controllers frequently run I2C to sensors and EEPROMs across cable lengths measured in meters, where wiring capacitance alone can violate the I2C 400pF budget. The ISL33001IUZ-T regenerates SDA and SCL drive at the cable boundary so each side only sees its local capacitance, and the accelerators actively speed up edge transitions that long wiring would otherwise slow below the specified data-rate timing. Because the device operates in open-drain environments and supports arbitration, multiple controllers can still share the remote bus. Industrial temperature rating covers rooftop and mechanical-room ambients.
Recommended
Power Supply Module Telemetry
Intelligent power supplies and DC-DC bricks report voltage, current, and status over PMBus-compatible 2-wire buses that often chain multiple modules. The ISL33001IUZ-T buffers the telemetry bus between the module and the shelf controller, extending capacitance beyond 400pF when many modules share one management pair, while the hot-swap circuitry permits a module to be replaced without dropping other modules' telemetry sessions. Rise time accelerators keep timing margins healthy across connector contact resistance. The SMBus compatibility including clock stretching is essential since power-management ICs routinely stretch the clock during conversions.
Recommended
Automotive Infotainment Peripheral Buses
Head units and display modules use I2C to reach touchscreen controllers, backlight drivers, and NVM across a dense PCB where trace capacitance plus multiple device loads approach or exceed the 400pF limit. The ISL33001IUZ-T splits the peripheral bus into local and remote segments, restoring full drive on each side and preserving arbitration when multiple masters (application processor and power management IC) share the pair. Its accelerators shorten rise times that heavy loading would otherwise stretch beyond spec at 400kHz operation. Careful thermal and ESD design at connector interfaces complements the buffer's isolation role.
Recommended
Recommended Products Summary
Engineering reference data for ISL33001IUZ-T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISL33001IUZ | ISL33002IUZ | ISL33003IUZ |
|---|---|---|---|---|
| Package | 8-MSOP | 8-MSOP - same | 8-MSOP - same | 8-MSOP - same |
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Channels | 2 (SDA, SCL) | 2 | 2 | 2 |
| Bus Capacitance Extension | Beyond 400 pF | Beyond 400 pF | Beyond 400 pF | Beyond 400 pF |
| Clock Stretching / Arbitration | Supported | Supported | Supported | Supported |
Key Differentiators
- Hot-swap capability for live insertion (vs ISL33002IUZ)
- Rise time accelerators cut pull-up power (vs Passive pull-up only designs)
- Packaging flexibility within the same die (vs ISL33001IUZ)
Design Notes
Both sides of the ISL33001 buffer require their own pull-up resistors because the part operates in an open-drain/open-collector environment; a single shared pull-up will not work. With rise time accelerators active, pull-ups can be larger than passive design would suggest, reducing static current. Place the device so that segment one (controller side) and segment two (load side) each see a well-controlled capacitance budget well below the 400pF I2C limit, and keep SDA/SCL trace stubs short near the IC.
Rise time accelerators inject a brief pull-up current pulse at each rising edge. In mixed SMBus/I2C systems, verify that the boosted edges still meet SMBus droop and overshoot requirements, especially on the hot-swap side where pin capacitance changes during insertion. Also confirm which family member you are substituting: ISL33002 and ISL33003 share the family pinout but differ in accelerator and hot-swap features, so a like-for-like feature check against the Renesas datasheet feature matrix is mandatory before swap.
In multi-master systems, clock stretching and bus arbitration must flow through the buffer unimpeded - the ISL33001 supports both on SDA and SCL per the Renesas datasheet. However, buffered boundaries add a small propagation delay per direction; at 400kHz this is normally acceptable, but verify total loop timing in long daisy-chained buffer topologies where several buffers in series accumulate delay. Avoid placing accelerators on extremely heavily capacitive segments where injected pulse current may cause ringing.
Compliance Information
Compliance attributes were not stated in the retrieved distributor snippets. Verify on the Renesas product page or DigiKey/Mouser product detail pages.
