STMicroelectronics LNBP20PD

Overview

LNBP20PD from STMicroelectronics is a monolithic linear voltage regulator in PowerSO-20 package, designed to power and control two LNB downconverters via coaxial cable in satellite receivers. It delivers selectable 13 V or 18 V (typ.) outputs per port, integrates a factory-trimmed 22 kHz tone oscillator (±2 kHz tolerance), supports dynamic overload protection with 4.7 µF CEXT timing, and features dual supply inputs (VCC1 ≥16 V, VCC2 ≥23 V) for optimized dissipation in analog/digital satellite receiver front-ends.

For engineers reviewing the LNBP20PD datasheet, LNBP20PD pinout, LNBP20PD application, or LNBP20PD equivalent, key selection criteria include dual-LNB port logic control (OSEL/VSEL/EN), 22 kHz tone modulation capability (ENT pin), cable length compensation (LLC), auxiliary analog modulation input (EXTM), and diagnostic open-collector overload flag (OLF).

Technical Context

The LNBP20PD implements parallel-interface LNB supply control with independent logic-selectable output ports (LNBA/LNBB), where voltage (13/14/18/19 V) and port assignment are determined by VSEL, OSEL, LLC, and EN states per truth table. Its internal dual-supply switch automatically selects VCC1 (for ≤14 V outputs) or VCC2 (for ≥18 V outputs) to minimize power loss.

Dynamic overcurrent protection operates via external capacitor CEXT (e.g., 4.7 µF sets ~1200 ms cycle), enabling automatic on/off cycling (ton ≈ toff/15) during sustained overload while maintaining thermal shutdown at 150 °C. The built-in 22 kHz oscillator starts rapidly to support DiSEqC™ burst encoding, and the MI-to-LNBA bypass switch enables slave operation in dual-receiver single-dish systems.

Key Specifications

Pinout & Package

LNBP20PD is housed in PowerSO-20 surface-mount package (15.8–16.0 mm × 13.9–14.5 mm × 3.6 mm height), with exposed die pad for thermal conduction. Pin 1 is VCC1; pin 20 is GND (internally connected to die frame). Thermal resistance junction-to-case is 2 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LNBP10SP-TR and LNBP15SP-TR, LNBP20PD provides full dual-port control, slave-mode bypass, and analog modulation - making it the only option among the three supporting professional-grade DiSEqC™-enabled dual-antenna receivers with diagnostics and coax compensation.

Availability

LNBP20PD is available at Aetrix Electronics and suitable for satellite receiver design, DiSEqC™-compliant set-top boxes, and professional LNB diagnostic equipment requiring stable component supply across production lifecycles.

Supply support for LNBP20PD 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 industrial, automotive, and consumer markets.

LNBP20PD belongs to ST's LNBP1X series of LNB power and control ICs, engineered specifically for high-reliability satellite receiver front-ends requiring integrated voltage regulation, 22 kHz tone generation, and robust fault management over long coaxial runs.

FAQ

What is the purpose of the MI (Master Input) pin on LNBP20PD?

The MI pin enables slave operation in shared-coaxial systems: when EN is LOW, an internal electronic switch connects MI to LNBA, allowing a master receiver to power and control the LNB while LNBP20PD remains in low-backward-current standby (≤3 mA). This avoids signal contention and supports multi-receiver installations on a single dish.

How does the CEXT capacitor affect overload protection behavior?

The capacitor between CEXT and GND sets the off-time (toff) of the dynamic overload protection circuit. With 4.7 µF, toff is ~1100 ms and ton is ~73 ms (toff/15), resulting in a full cycle of ~1200 ms. Larger values increase fault-hold time but reduce recovery frequency; smaller values shorten protection duration and may cause nuisance tripping under capacitive loads.

Can LNBP20PD generate DiSEqC™ Level 2.x bidirectional communication?

No. LNBP20PD supports only unidirectional DiSEqC™ 1.x tone-based signaling (22 kHz burst modulation via ENT). Bidirectional Level 2.x compliance requires external components - including a dedicated bus transceiver, level-shifting circuitry, and bidirectional data line management - as explicitly noted in the datasheet footnote (a).

What thermal management is required for continuous 500 mA operation at 18 V output?

At 500 mA and 18 V output with VCC2 = 23 V, power dissipation is ~2.5 W. With RthJC = 2 °C/W, junction-to-case rise is ~5 °C - so a modest heatsink (RthCA ≤ 20 °C/W) keeps Tj < 85 °C at 25 °C ambient. The internal 150 °C thermal shutdown provides safety margin, but sustained operation above 100 °C case temperature requires active cooling or derating.