Renesas ISL6422BERZ

Overview

ISL6422BERZ from Renesas (formerly Intersil) is a dual-output LNB supply and control voltage regulator IC for satellite set-top box designs, integrating two current-mode boost PWMs, two low-noise linear regulators, 22kHz tone generation, DiSEqC modulation/decoding, and full I²C interface. It delivers up to 750mA per channel at selectable 13.3V/14.3V/18.3V/19.3V outputs with ±2% regulation accuracy and supports simultaneous dual-tuner operation with independent enable, fault reporting, and cable-length compensation.

For engineers reviewing the ISL6422BERZ datasheet, ISL6422BERZ pinout, ISL6422BERZ application, or ISL6422BERZ equivalent, this page provides verified technical context, validated pin functions, confirmed dual-channel LNB power architecture, real-world DiSEqC timing behavior, and two production-validated alternative parts with documented functional differences.

Technical Context

The ISL6422BERZ implements a dual-channel architecture where each channel combines a current-mode boost PWM (operating at 440kHz typical) feeding a low-dropout linear post-regulator, enabling precise output voltage control while minimizing thermal dissipation. The 22kHz tone oscillator is factory-trimmed (20–24kHz range) and supports both internal generation and external DiSEqC envelope modulation via EXTM1/EXTM2 pins.

I²C control (400kHz fast-mode compatible, slave address 000100XX) manages all functions including VTOP/VBOT bit-selectable output voltages, dynamic/static current limiting (programmable thresholds from 270mA to 990mA), overtemperature shutdown (150°C trip), and diagnostic flag reporting (OLF, BCF, OTF, OUVF). Each channel features independent soft-start, backward current protection (28V back-bias capability), and open-drain FLT interrupt signaling.

Key Specifications

Pinout & Package

ISL6422BERZ is packaged in a RoHS-compliant 40-lead 6×6 mm QFN (L40.6x6) with exposed thermal pad. Pin functions are validated per FN6486 Rev 2.00 datasheet and match the top-view QFN pinout on Page 2.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LNB supply and control applications.

Compared with MAX2102ETJ+ and LMX2531LQ1730E, the ISL6422BERZ uniquely integrates dual-channel boost+linear regulation, factory-trimmed 22kHz tone generation, full DiSEqC transceiver functionality, and I²C-based diagnostics - making it the only single-chip solution qualified for advanced dual-tuner satellite STB designs requiring compact layout and robust field diagnostics.

Availability

ISL6422BERZ is available at Aetrix Electronics and suitable for satellite set-top box manufacturing, dual-tuner PVR development, and professional broadcast monitoring equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for ISL6422BERZ 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 maintains full technical and supply chain responsibility for legacy Intersil analog power products including the ISL6422B family.

The ISL6422B product line was designed specifically for high-efficiency, space-constrained satellite receiver power architectures - delivering integrated LNB supply, DiSEqC control, and intelligent fault management in a single QFN package.

FAQ

What is the maximum continuous output current per channel for the ISL6422BERZ?

The ISL6422BERZ delivers up to 750mA per channel continuously under specified operating conditions (−20°C to +85°C ambient, with appropriate PCB thermal design). Derating curves on Page 8 of FN6486 confirm 750mA is maintained up to 80°C ambient for the QFN package. This rating applies independently to both VOUT1 and VOUT2, enabling true dual-tuner operation without current sharing limitations.

Does the ISL6422BERZ support both 13V and 18V LNB output modes, and how are they selected?

Yes, the ISL6422BERZ supports four output voltage levels: 13.3V, 14.3V, 18.3V, and 19.3V per channel. Selection is achieved either via I²C register bits (VTOP1/2 and VBOT1/2) or hardware pin control using SELVTOP1/2 in conjunction with VSPEN1/2 bits. Table 1 on Page 11 of FN6486 defines exact mapping - for example, SELVTOP1 = 0 and VBOT1 = 0 yields 13.3V, while SELVTOP1 = 1 and VTOP1 = 1 yields 19.3V.

How does the ISL6422BERZ implement DiSEqC communication without external components?

The ISL6422BERZ integrates a factory-trimmed 22kHz tone oscillator, tone decoder (TDIN1/TDIN2), tone detector outputs (TDOUT1/TDOUT2), and EXTM1/EXTM2 modulation inputs - forming a complete DiSEqC transceiver. When ENT1/2 = HIGH, it generates continuous 22kHz tone; when ENT1/2 = LOW and MSEL1/2 = LOW, EXTM1/2 modulates the internal tone. No external crystal, op-amps, or comparators are required for standard DiSEqC 1.0/1.1/2.0 operation.

What fault conditions trigger the FLT pin on the ISL6422BERZ, and how is root cause identified?

The FLT pin asserts low on overtemperature (>150°C), overcurrent (dynamic or static limit exceeded), undervoltage lockout (VCC < 7.5V), or I²C bus reset. Root cause is identified by reading the status registers (SR1 and SR5) via I²C - which report individual flags: OLF1/2 (overload), BCF1/2 (backward current), OTF (overtemperature), and OUVF1/2 (output undervoltage). This eliminates guesswork during system debug.

Is the ISL6422BERZ pin-compatible with earlier ISL6422 variants such as ISL6422BEVEZ?

No, the ISL6422BERZ (40-lead QFN) is not pin-compatible with the discontinued ISL6422BEVEZ (38-lead EPTSSOP). Pin counts, layouts, and thermal pad configurations differ significantly - as shown in the top-view diagrams on Page 2 of FN6486. Migration requires PCB redesign. Renesas explicitly recommends ISL6422BERZ as the replacement part but confirms no mechanical or electrical pin-to-pin compatibility exists.