STMicroelectronics LNBH26PQR

Overview

LNBH26PQR from STMicroelectronics is a dual-channel LNB supply and control IC for satellite receiver front-ends, integrating two independent 13/18 V linear regulators with programmable output voltage (15 levels), built-in 22 kHz tone generation, DiSEqC™ 2.0 bi-directional interface support, and high-efficiency step-up DC-DC converter (93% @ 0.5 A). It operates from a single 8–16 V input and delivers up to 500 mA per channel to LNB down-converters in STB, TV, and PC-card satellite receivers.

For engineers reviewing the LNBH26PQR datasheet, LNBH26PQR pinout, LNBH26PQR application, or LNBH26PQR equivalent, this IC enables compact dual-tuner designs with I²C-controlled voltage selection, real-time diagnostics (VMON, TMON, IMON, OLF, OTF), dynamic short-circuit protection, and low-power mode (LPM) for thermal optimization - all in QFN24 4×4 mm package.

Technical Context

The LNBH26PQR implements two fully independent power channels (A/B), each with a high-efficiency PWM step-up converter (VUP generation), followed by a low-dropout linear regulator (VOUT = 13/18 V), integrated 22 kHz tone generator (factory-trimmed, ±1.5% frequency accuracy), and DiSEqC™ 2.0 bi-directional data path via DETIN/DSQOUT pins. The internal LDO maintains VUP − VOUT ≈ 1 V (typ.) during tone transmission and reduces to 0.6 V (typ.) in LPM mode.

Control and monitoring occur entirely over I²C: 4 data registers configure output voltage, current limit, tone mode (EXTM/TEN), LPM, ISW (inductor current limit: 2.5 A or 4 A), COMP (boost cap ESR tuning), and EN_IMON; two status registers report 14 diagnostic bits including VMON, TMON, TDET, IMON, PDO, OLF, OTF, and PNG - all latched until cleared by register read.

Key Specifications

Pinout & Package

Supplied in QFN24 (4 × 4 mm, 0.5 mm pitch) with exposed thermal pad (EP) for enhanced PCB heat dissipation. Pin numbering follows standard counter-clockwise layout starting from top-left corner (pin 1 marked).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX2181AETL+, LNBH26PQR delivers dual-channel integration, embedded diagnostics, and lower thermal footprint; unlike LMX2531LQ1730E, it is purpose-built for LNB biasing and DiSEqC™ control - eliminating need for external tone circuitry and enabling predictive maintenance via IMON/VMON.

Availability

LNBH26PQR is available at Aetrix Electronics and suitable for STB satellite receivers, TV satellite receivers, and PC card satellite receivers requiring stable component supply, long-term lifecycle support, and traceable sourcing for CE/FCC-certified production.

Supply support for LNBH26PQR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power management, analog, MCU, and automotive ICs - with over 40 years of heritage in broadcast and consumer electronics solutions.

LNBH26PQR belongs to ST's LNB supply IC product line, engineered specifically for satellite receiver manufacturers seeking reduced BOM count, simplified thermal design, and robust DiSEqC™ interoperability in dual-tuner architectures.

FAQ

What is the maximum continuous output current per channel?

The LNBH26PQR supports up to 500 mA per channel continuously. While the current limit can be configured up to 1 A via the ISEL resistor, ST recommends limiting the combined output (IOUT_A + IOUT_B) to ≤1 A to prevent triggering overtemperature protection - especially in compact enclosures without forced airflow. Thermal validation of PCB copper area and EP soldering is required for sustained 500 mA/channel operation.

How does the LPM (low power mode) affect 22 kHz tone generation?

LPM mode disables the 22 kHz tone generator and reduces the LDO dropout voltage from 1 V to 0.6 V (typ.), cutting power dissipation by ~40% at 500 mA. To transmit DiSEqC™ commands, the LPM bit must be set to "0" before enabling the tone (TEN=1); otherwise, tone output will be suppressed. Firmware must sequence LPM=0 → TEN=1 → command transmission → TEN=0 → LPM=1 for optimal efficiency.

Can the LNBH26PQR drive a multi-switch directly?

Yes - the LNBH26PQR's 500 mA per channel output and integrated short-circuit protection make it suitable for driving inputs of passive or active multi-switches. However, for multi-switches requiring >500 mA per port or supporting >4 LNB inputs, parallel LNBH26PQR devices or external current boosting may be needed. Always verify multi-switch input impedance and surge rating compatibility with the LNBH26PQR's ±4 kV ESD tolerance.

What diagnostic functions are accessible via I²C, and how are they used in firmware?

All 14 diagnostics - including VMON (output voltage OK), TMON (tone quality), IMON (minimum load current), OLF (overload), OTF (overtemperature), and PNG (input undervoltage) - are reported as individual bits in STATUS1 and STATUS2 registers. Firmware reads these after each I²C transaction; latched bits (e.g., OLF) remain set until cleared by a subsequent register read. This enables deterministic fault logging, automatic retry logic, and user-facing error codes without analog sensing circuitry.