STMicroelectronics LNBH29EQTR

Overview

LNBH29EQTR from STMicroelectronics is a monolithic LNB supply and control IC with integrated step-up DC-DC converter, low-drop linear post-regulator, and I²C interface - designed to deliver 13/18 V DC output and superimpose 22 kHz DiSEqC tone onto satellite dish LNBs. It supports selectable output current limit (up to 550 mA), achieves 93% typical efficiency at 0.5 A, and features ±4 kV HBM ESD tolerance on power pins for antenna-cable-connected applications.

For engineers reviewing the LNBH29EQTR datasheet, LNBH29EQTR pinout, LNBH29EQTR application, or LNBH29EQTR equivalent, this device serves as a complete single-chip solution for satellite receiver power and signaling - requiring no external tone generator, minimal passive components, and full diagnostic visibility via I²C STATUS register bits (OTF, OLF, VMON, PDO, PNG).

Technical Context

The LNBH29EQTR integrates a high-efficiency PWM step-up converter (driving internal N-MOS) followed by a low-drop linear regulator, maintaining fixed 1 V typical dropout (VUP − VOUT) to minimize thermal dissipation. Its I²C interface enables programmable output voltage (13/14/15/16/17/18 V), COMP bit selection for ceramic/electrolytic capacitor optimization, and real-time diagnostics including overtemperature (150 °C trip), dynamic short-circuit protection (90 ms ON / 900 ms OFF cycle), and input undervoltage lockout (4.7 V threshold).

Unlike standard LNB drivers, it provides dual-tone modulation paths: the LNBH29E variant (including LNBH29EQTR) uses analog EXTM pin for externally sourced 22 kHz signal injection with gain-controlled superposition (VOUT(AC) = VEXTM(AC) × GEXTM), ensuring waveform integrity even at no load - critical for DiSEqC 1.0/2.0 compliance in multi-switch systems.

Key Specifications

Pinout & Package

Package: QFN16 (4×4 mm), exposed thermal pad (Epad) - optimized for low thermal resistance (R_thJA = 40 °C/W with 4-layer PCB and thermal vias).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX2181AETL+, LNBH29EQTR integrates step-up conversion and full DiSEqC modulation capability, eliminating external power stages and enabling firmware-configurable operation; the LMX2531 is unrelated to LNB supply and must be excluded from consideration.

Availability

LNBH29EQTR 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 compliance with DiSEqC 1.x/2.0 signaling standards.

Supply support for LNBH29EQTR 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, and automotive ICs with strong focus on industrial and consumer system solutions.

The LNBH29 series belongs to ST's dedicated satellite interface product line - engineered specifically for cost-sensitive, space-constrained satellite receiver platforms demanding high integration, DiSEqC compliance, and robust field reliability.

FAQ

What is the function of the EXTM pin on LNBH29EQTR?

The EXTM pin accepts an external 22 kHz analog tone signal (−0.3 to 2 V) and injects it into the linear regulator control loop to superimpose the tone onto the VOUT DC voltage. It enables system-level tone generation - such as from a shared MCU or DSP - rather than relying on the internal generator, improving design flexibility and synchronization accuracy in multi-receiver systems.

How is output current limit configured on LNBH29EQTR?

Output current limit is set by connecting an external resistor (RSEL) between ISEL pin and GND. The relationship is IMAX(typ.) = 13915 / RSEL(kΩ); for example, a 3.6 kΩ resistor yields ~386 mA, while 2.5 kΩ gives ~550 mA. This allows precise matching to LNB load requirements without changing IC or layout.

Does LNBH29EQTR support both 13 V and 18 V LNB outputs?

Yes - output voltage is fully programmable via the I²C DATA register using three bits (bits 0–2). Valid settings include 13.0 V, 14.0 V, 15.0 V, 16.0 V, 17.0 V, and 18.0 V, allowing selection of correct polarization voltage (13 V for vertical, 18 V for horizontal) and compatibility with regional satellite standards.

What thermal management is required for LNBH29EQTR in continuous 500 mA operation?

At 500 mA output, junction temperature rise is minimized by the 1 V typical dropout and 93% boost efficiency. With QFN16 (4×4 mm) package mounted on a 4-layer PCB with thermal vias under the Epad, R_thJA is 40 °C/W - resulting in ~20 °C rise above ambient at 1 W dissipation. No heatsink is needed if ambient stays below 105 °C.