ISL33001IUZ - I2C Bus Buffer, Hot-Swap 2-Ch | Renesas
MPN: ISL33001IUZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.72 | $0.72 |
| 10 | $0.62 | $6.20 |
| 100 | $0.52 | $52.00 |
| 500 | $0.47 | $235.00 |
| 1,000 | $0.43 | $430.00 |
ISL33001IUZ Overview
An I2C bus buffer (also called a bus repeater or signal buffer) is an interface IC that sits between an I2C controller segment and a heavily loaded peripheral segment. The I2C specification limits total bus capacitance to 400 pF, which restricts the number of devices, trace length, and pull-up resistance a system can support. A bus buffer regenerates the SDA and SCL edges, segmenting the bus so each side only sees its own local capacitance, allowing much larger backplanes, card cages, and cable runs.
Key features of the ISL33001 include two independent buffered channels (SDA and SCL), rise-time accelerator circuitry that drives rising edges actively to reduce power dissipated in passive pull-up resistors and enable faster data rates, and integrated hot-swap circuitry that prevents SDA/SCL corruption when a board is inserted into or removed from a live backplane. The device supports standard and fast-mode I2C operation with level-tolerant I/O structure.
Architecturally, the buffer uses a dual-direction translator between the controller-side and card-side pins: a low level on either side propagates to the other, while levels are re-driven with controlled rise times. This bidirectional, transparent behavior requires no mode control in typical single-controller systems. The hot-swap input stage holds the local bus pins low or high-impedance during power ramp until VCC stabilizes, avoiding spurious start or stop conditions during card insertion.
Typical applications include server and telecom backplanes, I2C fan controllers, optical-module management (SFP/QSFP style management buses), battery-management and hot-pluggable card rails, and long cable runs between chassis in industrial systems.
Design consideration: rise-time accelerators pull up only during edges; ensure adequate static pull-up resistance on the far side of the buffer for DC low-level sinks, and keep the EN/enable pin controlled during power sequencing to avoid bus glitches.
This page synthesizes distributor pricing, drop-in family alternatives (ISL33002/ISL33003), and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ISL33001IUZ — 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 (same form factor and footprint) — differing in Function, Package, Channels, Packaging.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISL33002IUZ
✅ Drop-In✓ In Stock
$0.45 / Unit
View Datasheet →ISL33003IUZ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ISL33001IUZ Maximum Ratings & Electrical Characteristics
| Function | 2-channel I2C bus buffer with rise-time accelerator and hot-swap |
| Channels | 2 (SDA, SCL) |
| Bus Capacitance Extension | Beyond 400 pF I2C specification limit |
| Hot-Swap Support | Yes |
| Rise-Time Accelerator | Yes |
| Package | 8-MSOP |
| Operating Temperature | -40C to +85C (industrial) |
| Mounting Type | Surface Mount |
| Packaging Option | ISL33001IUZ (tube), ISL33001IUZ-T (tape and reel) |
ISL33001IUZ 8-msop Pin Configuration Guide
Pin configuration for ISL33001IUZ (8-msop package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ISL33001IUZ.
Refer to the datasheet for full pin configuration.
Typical Applications
ISL33001IUZ is suitable for 6 applications: Telecom and Server Backplanes, Optical Module Management Buses (SFP/QSFP), Industrial Cable Runs Between Chassis, Hot-Pluggable Card Rails and Fan Trays, Battery Management Systems, Test and Measurement Instrumentation.
Telecom and Server Backplanes
In telecom shelves and server chassis, dozens of line cards share a single I2C management bus, quickly exceeding the 400 pF capacitance limit defined by the I2C specification. The ISL33001IUZ segments the bus at each card slot: its two buffered channels regenerate SDA and SCL edges so each segment only sees its local capacitance, while the hot-swap circuitry prevents spurious start/stop conditions when a card is inserted into a live backplane. The rise-time accelerator actively drives rising edges, allowing smaller pull-up resistors on long backplane traces without the DC power penalty of low-value passive pull-ups. Place one buffer per slot connector, and keep the enable pin controlled by card-detect logic so the bus remains quiescent until VCC has fully ramped.
Recommended
Optical Module Management Buses (SFP/QSFP)
SFP, QSFP, and similar pluggable optical modules expose a 2-wire management interface that is hot-plugged by design, and a host cage may carry several modules on shared clock and data lines. The ISL33001IUZ is well matched here: its hot-swap input stage holds the module-side pins from corrupting the bus during insertion, and its rise-time accelerator restores edge rates degraded by module and cable capacitance. Buffering at the cage isolates the module segment from the host segment, so total capacitance per segment stays comfortably within the I2C specification even with multiple cages. The industrial -40C to +85C rating of the IUZ grade covers telecom outdoor and central-office temperature requirements.
Recommended
Industrial Cable Runs Between Chassis
When I2C must cross cables between cabinets - for sensors, enclosures, or remote I/O - cable capacitance typically swamps the 400 pF budget and slow edges cause data errors at fast-mode rates. The ISL33001IUZ placed at each cable end regenerates clean SDA/SCL edges, and its rise-time accelerator compensates the heavy RC loading without the power cost of very low pull-up resistors across long cable runs. In a typical deployment, one buffer per cable end segments the system so each segment independently meets the I2C specification. The dual-direction transparent architecture needs no direction-control signal, which suits multi-controller or arbitration-capable I2C topologies used in distributed industrial control.
Recommended
Hot-Pluggable Card Rails and Fan Trays
Fan trays, power shelves, and other field-replaceable units are inserted while the system management bus is active. Un-buffered I2C pin electronics on such units can glitch the shared bus, causing bus lockups elsewhere in the shelf. The ISL33001IUZ's hot-swap circuitry holds its pins from corrupting SDA/SCL until the card's supply has stabilized, eliminating this failure mode. Its 2-channel structure matches exactly the SCL/SDA pair of a 2-wire fan-control or PMBus-adjacent interface, and the rise-time accelerator maintains signal integrity on the high-capacitance fan-control wiring looms typical of dense shelves. The industrial temperature grade supports equipment specified from -40C to +85C ambient.
Recommended
Battery Management Systems
Battery packs and battery-management units are frequently removable and communicate over I2C or SMBus with the host charger and fuel-gauge electronics. The ISL33001IUZ provides the hot-swap protection needed at the pack connector - preventing start/stop corruption during insertion - while buffering the bus so that the pack's internal gauge, protection IC, and EEPROM loads do not exceed the I2C capacitance limit together with the host segment. The rise-time accelerator helps maintain fast-mode timing on pack-internal wiring, which is often unshielded and moderately capacitive. Designers should verify that the ISL33001 supply domain matches the pack-side logic level before layout.
Recommended
Test and Measurement Instrumentation
Instrument mainframes with plug-in measurement modules use I2C for module identification, calibration-memory access, and housekeeping. Module count and internal wiring push these buses beyond the 400 pF I2C limit, and modules are inserted during operation. The ISL33001IUZ addresses both problems: one device per module slot provides capacitive segmentation and live-insertion protection, and the rise-time accelerator preserves edge rates on the long internal ribbon wiring. The 8-pin MSOP fits easily on dense module edge-card layouts, and the industrial temperature grade aligns with typical instrument environmental specifications from -40C to +85C.
Recommended
Recommended Products Summary
Engineering reference data for ISL33001IUZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISL33002IUZ | ISL33003IUZ |
|---|---|---|---|
| Package | 8-MSOP | 8-MSOP - same | 8-MSOP - same |
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Channels | 2 (SDA, SCL) | 2 (SDA, SCL) | 2 (SDA, SCL) |
| Hot-Swap | Yes | Yes | Yes |
| Rise-Time Accelerator | Yes | Yes | Yes |
| Bus Capacitance Extension | Beyond 400 pF | Beyond 400 pF | Beyond 400 pF |
| Operating Temperature | -40C to +85C | -40C to +85C (I grade) | -40C to +85C (I grade) |
| Voltage/Level Configuration | Fixed-voltage member of ISL33001/02/03 family | Family variant - see shared datasheet selection table | Family variant - see shared datasheet selection table |
Key Differentiators
- Integrated hot-swap protection (vs PCA9306DCTR)
- Rise-time accelerator reduces pull-up power (vs TCA9517DR)
- Compact 8-MSOP footprint (vs ISL33001IBZ)
Design Notes
The ISL33001 family members (ISL33001/02/03) share one datasheet but differ in voltage-level configuration. Before substituting ISL33002 or ISL33003 on an existing ISL33001 footprint, verify the supply and I/O voltage arrangement of your design against the family selection table in the Renesas datasheet - a same-package swap with the wrong level configuration will fail at the system level even though the buffer function is identical.
Place the buffer close to the bus segment boundary (slot connector or cable entry) so that the segmented capacitances stay on their intended sides. Keep pull-up resistors on each segment sized for that segment's local capacitance - do not rely on the rise-time accelerator to fix a globally under-pulled bus, since the accelerator only assists during edges and the DC low-level sink capability of each side must still meet I2C VOL requirements per the datasheet electrical characteristics.
Sequence the enable/control input with the local supply: the hot-swap circuitry protects the bus during power ramp only if the device's own VCC ramps cleanly. Add a local 0.1 uF ceramic decoupling capacitor directly at the supply pin. Estimated: at typical I2C bus idle levels the static current draw is small, but confirm the exact quiescent-current figure from the manufacturer datasheet electrical table before doing battery-budget calculations.
Compliance Information
Compliance status not stated in the provided web data; verify RoHS/REACH status on the Renesas product page or distributor compliance documents before order release.
