Renesas ISL6121HIBZA-T

Overview

ISL6121HIBZA-T from Intersil is a single-supply integrated current-limiting hot-swap controller with an internal 50mΩ N-channel MOSFET power switch, 2A current regulation, 12ms fault latch-off timer, and logic-level enable-high input. It provides overcurrent protection for 2.5V–5.5V systems such as Fibre Channel and industrial hot-plug power rails.

For engineers reviewing the ISL6121HIBZA-T datasheet, ISL6121HIBZA-T pinout, ISL6121HIBZA-T application, or ISL6121HIBZA-T equivalent, key selection considerations include its temperature-independent 12ms latch-off timing, soft-start voltage ramp control, active output pulldown to ≤450mV, UVLO threshold at 2.25V, and Pb-free SOIC-8 packaging compatible with SnPb and lead-free reflow.

Technical Context

The ISL6121HIBZA-T integrates a constant-current gate driver (500nA) to generate controlled voltage ramps on VOUT during turn-on and turn-off, limiting inrush current and slew rate independently of load capacitance. Its current regulation loop responds within 200µs to overcurrent events and maintains ±20% accuracy across –40°C to +85°C and 2.5V–5.5V supply range.

Unlike thermally triggered protection ICs, it uses a fixed 12ms internal timer after OC detection to initiate latch-off - eliminating thermal dependency and ensuring consistent response regardless of junction temperature or ambient conditions. Fault blanking for 12ms at startup prevents false reporting during initial capacitive charging.

Key Specifications

Pinout & Package

ISL6121HIBZA-T is housed in an 8-lead narrow-body SOIC package (JEDEC MS-012-AA / M8.15), RoHS-compliant with 100% matte tin termination, rated for –40°C to +85°C operation and compatible with standard SnPb and Pb-free reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-limiting hot-swap controller applications.

Compared with TPS2051BDR and AP2171WG-7, the ISL6121HIBZA-T delivers deterministic 12ms latch-off timing independent of temperature, built-in fault blanking, and active pulldown - making it optimal for high-reliability hot-swap systems where timing predictability and noise immunity are critical.

Availability

ISL6121HIBZA-T is available at Aetrix Electronics and suitable for Fibre Channel, industrial hot-plug backplanes, and USB port protection requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL6121HIBZA-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Intersil Corporation (now part of Renesas Electronics) designs high-performance analog and power management ICs for industrial, communications, and computing applications.

The ISL6121 product line delivers integrated hot-swap controllers targeting 2.5V–5.5V power rail protection with emphasis on deterministic fault timing, soft-start control, and minimal external component count.

FAQ

What is the current limit accuracy of the ISL6121HIBZA-T over temperature and voltage?

The ISL6121HIBZA-T maintains a nominal 2A current limit with ±20% accuracy across the full operating range of –40°C to +85°C and 2.5V to 5.5V supply voltage. This specification is confirmed in the Electrical Specifications table on page 3 of FN9004 Rev 2.00, where Ilim is specified as 1.5A (min) to 2.5A (max) under test conditions including VIN = 5V and VOUT = 3.3V.

Does the ISL6121HIBZA-T support both 3V and 5V logic levels on its ENABLE and FAULT pins?

Yes, the ISL6121HIBZA-T supports 3V and 5V logic compatibility on both ENABLE and FAULT. The ENABLE high threshold (Ven_vih) is 2.0V min at VIN = 5.5V, and FAULT output voltage is guaranteed ≤0.4V at 10mA sink current - meeting standard TTL and CMOS logic thresholds for both voltage domains as specified in the Electrical Specifications section.

How does the ISL6121HIBZA-T handle startup into heavy capacitive loads?

The ISL6121HIBZA-T uses a 500nA constant-current source to ramp the gate voltage, producing a controlled soft-start voltage ramp on VOUT. This limits inrush current and slew rate independently of load capacitance, eliminating bus droop and removing the need for external EMI filters - as detailed in the Soft Start and Figure 4 sections of FN9004 Rev 2.00.

Is the 12ms latch-off timer in the ISL6121HIBZA-T affected by junction temperature?

No, the 12ms latch-off timer in the ISL6121HIBZA-T is explicitly designed to be temperature-independent. Unlike thermal-based protection schemes, this internal timer starts upon overcurrent detection and expires after a fixed 12ms interval regardless of device temperature - a key differentiator highlighted in the Introduction and Key Feature Description sections of FN9004 Rev 2.00.

What is the maximum continuous output current the ISL6121HIBZA-T can deliver before entering current limit?

The ISL6121HIBZA-T is rated for continuous operation up to its 2A current limit threshold. Under normal conditions with adequate PCB copper and ambient temperature ≤85°C, it sustains 2A continuously; exceeding this triggers immediate current regulation. Absolute maximum ratings confirm short-circuit protection, and thermal resistance (θJA = 116°C/W) supports this performance in standard SOIC-8 layouts per page 3 of FN9004 Rev 2.00.