STMicroelectronics LNBP8LIT

Overview

LNBP8LIT from STMicroelectronics is a monolithic linear LNB supply and control voltage regulator in IPPAK package, designed for satellite receiver front-ends to power and remotely control low-noise block down-converters (LNBs). It delivers 13 V or 18 V (typ.) regulated output with 500 mA guaranteed current, 3-state EN/VSEL logic control, external 22 kHz modulation input (EXTM), and integrated short-circuit/over-temperature protection - deployed in analog/digital DVB-S receivers.

For engineers reviewing the LNBP8LIT datasheet, LNBP8LIT pinout, LNBP8LIT application, or LNBP8LIT equivalent, this device supports remote polarization switching via voltage selection, coaxial cable-fed LNB biasing, and external tone modulation - critical for DiSEqC-compatible satellite tuner designs requiring stable 13/18 V LNB supply with AC-coupled 22 kHz signaling.

Technical Context

The LNBP8LIT implements a linear regulation architecture with dual-mode output voltage selection (13 V/18 V) controlled by a 3-state EN/VSEL pin: LOW selects 13 V, HIGH selects 18 V, and high-impedance disables output. It features an EXTM pin accepting AC-coupled 22 kHz modulation signals (400 mVPP, 10 kHz–40 kHz bandwidth) with 5.5 V/V gain, enabling band-switching commands to the LNB without internal oscillator.

Unlike LNBP9L/11L variants, LNBP8LIT lacks an integrated 22 kHz oscillator and LLC pin; it relies solely on external modulation. Its IPPAK package integrates GND-connected thermal tab, requires single 22 V min. input (VCC), and provides fixed thermal shutdown at 165 °C with 25 °C hysteresis - optimized for through-hole mounting in space-constrained satellite receiver PCBs.

Key Specifications

Pinout & Package

LNBP8LIT uses the IPPAK through-hole package (10-pin, GND-tabbed), optimized for thermal dissipation in satellite receiver chassis. Pin 1 is VCC (22–25 V input), pin 3 is OUTPUT (13/18 V LNB supply), pin 4 is GND (shared with thermal tab), pin 5 is EN/VSEL (3-state control), and pin 6 is EXTM (AC-coupled 22 kHz modulation input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LNBP8LIT, LNBP10LIT reduces thermal stress via dual-supply selection but sacrifices EXTM flexibility, while MAX2207EASA+ simplifies tone generation at the cost of less granular control and higher idle power - LNBP8LIT remains optimal for EXTM-dependent DiSEqC systems with strict thermal and footprint constraints.

Availability

LNBP8LIT is available at Aetrix Electronics and suitable for DVB-S satellite receivers, multi-LNB distribution hubs, and marine IF terminals requiring stable component supply, long-lifecycle support, and through-hole thermal reliability.

Supply support for LNBP8LIT 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, designing and manufacturing analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.

LNBP8LIT belongs to ST's LNB Power Management product line, engineered specifically for satellite receiver front-end power integrity - emphasizing robustness, thermal resilience, and DiSEqC protocol compatibility in cost-sensitive consumer and professional RF systems.

FAQ

What is the minimum input voltage required for reliable operation of LNBP8LIT?

LNBP8LIT requires a minimum 22 V DC on its VCC pin (Pin 1) to guarantee full 500 mA output capability at both 13 V and 18 V settings. Operation below 22 V may cause dropout, especially under load or elevated temperature. The absolute maximum rating allows up to 25 V, and the device includes reverse-current blocking to prevent backfeed from LNB output to VCC.

How should the EXTM pin be interfaced for proper 22 kHz modulation?

The EXTM pin (Pin 6) must be AC-coupled using a series capacitor (typically 1 µF ceramic) between the external 22 kHz source and the pin. The source must deliver 400 mVPP into 400 Ω impedance within 10–40 kHz bandwidth. Do not DC-bias EXTM - leaving it floating is safe, but driving it with unfiltered DC will disrupt regulation. Internal gain of 5.5 V/V ensures ~2.2 VPP modulation on OUTPUT.

Does LNBP8LIT support automatic polarity switching like LNBP9L/11L?

No. LNBP8LIT does not include an internal 22 kHz oscillator or TEN pin - it relies entirely on external modulation via EXTM. Polarity switching is achieved solely through EN/VSEL logic: LOW = 13 V (vertical), HIGH = 18 V (horizontal). Unlike LNBP9L/11L, it cannot generate tone autonomously, making it ideal for systems where MCU-controlled tone generation is preferred for timing precision and noise isolation.

What thermal management is required when using LNBP8LIT in continuous 500 mA operation?

At 500 mA and 23 V input, worst-case power dissipation is ~3.5 W (23 V − 13 V) × 0.5 A. With R_θJA = 35 °C/W, junction rise exceeds 120 °C without heatsinking. A minimum 25 cm² aluminum heatsink or direct chassis mount to GND-tab is mandatory. Use thermal interface material and ensure mechanical stability - the IPPAK tab is electrically GND, so insulating pads are unnecessary unless chassis is non-grounded.