Renesas ISL8702AIBZ

Overview

ISL8702AIBZ from Renesas (formerly Intersil) is a quad-channel, adjustable power supply sequencer with integrated under/overvoltage monitoring for distributed rail supervision. It delivers four programmable enable outputs (ENABLE_A–D), supports 3.3V–24V input bias, provides UV/OV fault detection with 1.21V typical threshold, and features SEQ_EN-controlled on/off sequencing - used in FPGA, DSP, and multi-rail embedded systems requiring precise power-up/down timing.

For engineers reviewing the ISL8702AIBZ datasheet, ISL8702AIBZ pinout, ISL8702AIBZ application, or ISL8702AIBZ equivalent, this device enables robust voltage compliance validation, daisy-chainable sequencing up to >4 rails, and resistor- and capacitor-programmable delays (e.g., 3.5–240 ms between ENABLE outputs) without external logic or microcontroller intervention.

Technical Context

The ISL8702AIBZ implements a deterministic A→B→C→D sequencing order triggered by either auto-start (TIME capacitor charging) or external SEQ_EN assertion. Its internal 2.6µA TIME pin current source and 2.0V threshold comparator generate the initial delay, while TB/TC/TD pins each control subsequent inter-output delays via external resistors forming RC-based timing counters.

Voltage monitoring uses dedicated UV and OV pins with 104mV hysteresis and ±10nA input leakage; FAULT output asserts low when VIN falls outside the programmed window. All four ENABLE outputs are open-drain, active-high, and pull low below 1V VIN - ensuring fail-safe behavior during brown-out conditions.

Key Specifications

Pinout & Package

ISL8702AIBZ is housed in a 14-lead narrow-body SOIC package (JEDEC MS-012, package drawing M14.15), optimized for surface-mount assembly and thermal performance in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power supply sequencing applications.

Compared with TPS65023RSLR and MAX16054ATL+, the ISL8702AIBZ uniquely combines adjustable UV/OV monitoring, fully programmable inter-output delays via external resistors, and bidirectional SEQ_EN-triggered sequencing - making it optimal for complex, multi-rail systems demanding precision, adaptability, and fault resilience.

Availability

ISL8702AIBZ is available at Aetrix Electronics and suitable for FPGA power sequencing, DSP subsystem timing, and industrial PLC backplane control requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ISL8702AIBZ 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

Renesas Electronics Corporation acquired Intersil in 2017 and continues to manufacture and support its high-performance analog and power management portfolio.

The ISL8702AIBZ belongs to the ISL870XA family of voltage-monitoring sequencers designed specifically for reliable, component-minimized power-up/down control in FPGA, DSP, and multi-rail embedded systems.

FAQ

What is the primary function of the ISL8702AIBZ in a power system?

The ISL8702AIBZ functions as a quad-channel, resistor- and capacitor-programmable power supply sequencer with integrated under/overvoltage monitoring. It ensures correct turn-on and turn-off order of multiple voltage rails - such as FPGA core, I/O, and auxiliary supplies - while continuously validating input rail compliance. Its design eliminates reliance on microcontrollers or complex logic for sequencing, making ISL8702AIBZ ideal for deterministic, fail-safe power management in high-reliability systems.

How does the ISL8702AIBZ handle undervoltage and overvoltage events?

The ISL8702AIBZ uses dedicated UV and OV pins with 1.21V typical threshold and 104mV hysteresis to monitor a distributed voltage rail. When the monitored voltage falls below UV or rises above OV, the FAULT output transitions high (open-drain, pulled externally), and all four ENABLE outputs are immediately forced low. This response occurs within 30µs, providing rapid fault signaling and preventing downstream circuitry from operating outside safe voltage limits - a critical safeguard in ISL8702AIBZ deployments.

Can the ISL8702AIBZ perform controlled power-down sequencing?

Yes - the ISL8702AIBZ supports bidirectional sequencing via its SEQ_EN input. When SEQ_EN is asserted high, it initiates standard A→B→C→D power-up. When SEQ_EN is deasserted, ISL8702AIBZ executes reverse-order power-down: D→C→B→A. Each inter-stage delay during shutdown is independently set by the same RTB, RTC, and RTD resistors used for power-up, ensuring symmetrical, predictable timing in both directions - a capability not found in most fixed-sequence alternatives.

What external components are required to configure the ISL8702AIBZ?

The ISL8702AIBZ requires minimal external components: one capacitor on the TIME pin (e.g., 10nF for ~8ms delay to ENABLE_A), three timing resistors (RTB, RTC, RTD) for inter-output delays, two divider resistors (Ru, Rm, Rl) for UV/OV threshold setting, a 1µF VIN decoupling capacitor, and pull-up resistors for ENABLE and FAULT outputs. No external clock, microcontroller, or additional logic is needed - the entire sequencing and monitoring functionality is self-contained within ISL8702AIBZ and these passive elements.

Is the ISL8702AIBZ pin-compatible with other members of the ISL870XA family?

No - while ISL8702AIBZ shares the same 14-lead SOIC package and pinout layout with ISL8700A, ISL8701A, ISL8703A, ISL8704A, and ISL8705A, functional pin assignments differ. For example, ISL8702AIBZ uses pin 9 as SEQ_EN, whereas ISL8704A uses it as SEQ_EN#, and ISL8700A/ISL8701A leave it unconnected. Similarly, ENABLE polarity (active-high vs. active-low) varies across variants. Therefore, ISL8702AIBZ is not a drop-in replacement for other ISL870XA parts without board-level verification and potential schematic updates.