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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Special Purpose Regulators

STMicroelectronics LNBP21PD

Name: LNBP21PD
Brand: STMicroelectronics
SKU: LNBP21PD
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LNBP21PD

Manufacturer:: STMicroelectronics

Category:: Special Purpose Regulators

Package:: 20-SOIC (0.433", 11.00mm Width) Exposed Pad

Datasheet:: LNBP21PD.pdf

Description:: IC REG CONV SAT 1OUT POWERSO-20

Quantity:: RFQ Add To RFQ list

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Product details

Overview

LNBP21PD from STMicroelectronics is a monolithic LNB power supply and control IC in PowerSO-20 package, integrating DC/DC step-up controller, linear post-regulator, 22kHz tone generator/detector, I²C interface, DiSEqC 2.x bidirectional support, and loop-through switch. It delivers regulated 13V/18V (±0.7V) output with 500–650mA current limit, 22kHz tone accuracy ±2kHz, and supports coaxial cable voltage compensation up to +1V for satellite TV receiver front-ends.

For engineers reviewing the LNBP21PD datasheet, LNBP21PD pinout, LNBP21PD application, or LNBP21PD equivalent, key selection considerations include I²C-configurable voltage selection (VSEL), pulsed vs static current limiting (PCL/ISEL), dynamic overload recovery timing (t_ON/t_OFF), thermal shutdown at 150°C, and DiSEqC 2.x signal integrity via dedicated DSQIN/DSQOUT pins with AC-coupled DETIN.

Technical Context

The LNBP21PD implements a two-stage regulation architecture: an internal 220kHz switching controller drives an external MOSFET to generate V_UP, which feeds a low-dropout linear post-regulator delivering precise 13V or 18V to the LNB. The 22kHz oscillator is factory-trimmed (20–24kHz) and modulated via DSQIN for DiSEqC encoding or enabled statically via TEN bit.

DiSEqC 2.x bidirectionality is achieved through hardware-assisted tone detection: DETIN accepts AC-coupled 22kHz carrier (0.2–1.5V_PP) and extracts PWK data routed to open-drain DSQOUT; simultaneous tone generation and detection enables full-duplex command/response without external logic. Loop-through operation (EN=0) closes LT1–LT2 switch (900mA rated) to pass master-controlled power while disabling local regulation.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	13V or 18V (typ.), adjustable +1V via LLC bit for coax voltage drop compensation
Output Current Limit	500–650mA (ISEL=0) or 400–550mA (ISEL=1); SOA-type short-circuit protection
22kHz Tone Accuracy	20–24kHz (typ. 22kHz), factory-trimmed, duty cycle 40–60%, rise/fall time 5–15µs
Thermal Protection	Shuts down step-up & linear regulators at T_J ≥150°C; resumes at 140°C (15°C hysteresis)
I²C Interface	Standard-mode (≤500kHz), 7-bit address (4 options via ADDR pin), 6-bit writable system register
Dynamic Overload Recovery	t_OFF = 900ms, t_ON = 90ms (t_ON = t_OFF/10), full cycle ~990ms with internal timer
ESD Rating	4kV HBM on power and I/O pins (VCC, VUP, OUT, LT1, LT2, DSQIN, DETIN, DSQOUT)

Pinout & Package

LNBP21PD is housed in PowerSO-20 package (20-pin, exposed thermal pad, R_thj-case = 2°C/W), optimized for high-power satellite LNB supply applications requiring efficient thermal dissipation.

Pin/Terminal	Circuit Role	Design Meaning
VCC	Primary Supply Input	8–15V DC input; powers internal logic, I²C, and gate driver; requires 220µF + 470nF bypass
GATE	External MOSFET Driver Output	Drives gate of external N-channel MOSFET in boost converter stage; ±400mA peak drive capability
SENSE	Current Sense Input	Connects to sense resistor (e.g., 0.1Ω); triggers current limiting when V_SENSE ≥200mV
VUP	Step-up Converter Output	Intermediate rail fed to linear regulator; dynamically adjusted to minimize dropout and power loss
OUT	LNB Power Output	Regulated 13/18V output with LLC compensation; connects directly to LNB via coaxial cable
SDA / SCL	I²C Data / Clock	Bidirectional I²C interface (open-drain SDA, push-pull SCL); compatible with 3.3V/5V µCs
DSQIN	DiSEqC Encoding Input	Accepts PWK-encoded DiSEqC commands (0/1 logic levels); disabled when TEN=1
DETIN	Tone Detection Input	AC-coupled 22kHz carrier input (0.2–1.5V_PP); enables bidirectional DiSEqC 2.x
DSQOUT	DiSEqC Decoding Output	Open-drain output reporting detected tone (LOW = tone present); connects to µC GPIO
LT1 / LT2	Loop-through Switch Terminals	Internally shorted when EN=0; passes master-supplied power (≤900mA); no current limiting applied
ADDR	I²C Address Selection	Sets one of four I²C addresses (0001000–0001011) by applying 0/1.5/2.5/4V

Key Features

Feature	Design Value
Integrated DiSEqC 2.x Transceiver	Dedicated DSQIN/DSQOUT/DETIN pins enable full-duplex 22kHz tone modulation and demodulation without external components
Coaxial Cable Compensation	LLC bit adds +1V to selected output voltage (13V→14V or 18V→19V) to offset voltage drop over long coax runs
Configurable Overcurrent Protection	Selectable static clamp (ISEL=1) or pulsed limiting (PCL=0) with 900ms off-time and automatic recovery cycling
Low-Power Standby Mode	EN=0 disables all regulators, opens loop-through switch, reduces supply current to 2.5–5mA
Factory-Trimmed 22kHz Oscillator	22kHz ±2kHz accuracy eliminates need for external crystal or calibration; supports DiSEqC 1.x and 2.x standards

Applications

Direct Broadcast Satellite (DBS) Receiver

Digital Satellite TV Set-Top Box

Use Scenario: Single-tuner STB receiving signals from multiple orbital positions via DiSEqC-switched LNB array.

IC Role / Device Role / Timing Role: Primary LNB power controller and DiSEqC protocol engine; generates 22kHz tone, decodes return data, regulates 13/18V supply.

Use Value: Enables seamless switching between satellites using standardized DiSEqC 2.x commands while maintaining stable LNB bias under varying cable lengths and temperatures.

Use Scenario: Multi-tuner PVR STB with independent LNB control per tuner, supporting simultaneous recording and playback.

IC Role / Device Role / Timing Role: Dual-role IC: supplies regulated power to each LNB and handles bidirectional DiSEqC communication for position selection and diagnostics.

Use Value: Reduces BOM count by integrating boost controller, linear regulator, tone generator, detector, and I²C interface-eliminating discrete transistors, op-amps, and crystals.

PC-Based Satellite TV Tuner Card

Integrated Satellite TV Module for Smart TVs

Use Scenario: Low-profile PCIe or USB satellite tuner card for Windows/Linux PCs requiring compact, thermally efficient design.

IC Role / Device Role / Timing Role: Compact LNB interface IC with PowerSO-20 thermal pad enabling conduction cooling; supports hot-plug DiSEqC initialization via I²C.

Use Value: Delivers 650mA output current in <10mm² footprint with R_thj-case = 2°C/W, enabling fanless operation in space-constrained tuner cards.

Use Scenario: Embedded satellite tuner module inside 4K UHD smart TV, sharing main SoC's 3.3V/5V rails and I²C bus.

IC Role / Device Role / Timing Role: I²C-configurable LNB supply with address pin flexibility (4 options) avoids bus conflicts in multi-peripheral SoC designs.

Use Value: Simplifies firmware integration via standardized 6-bit system register; diagnostic bits (OLF/OTF) report overcurrent/overtemperature events to host without polling sensors.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
LNBP22PD	Higher output current (800mA vs 650mA), improved thermal resistance (1.5°C/W), same pinout and register map	Required for multiswitch-fed systems with >6 LNBs or long (>50m) coax runs demanding higher sustained current	Drop-in upgrade where thermal headroom or current margin is critical; identical firmware compatibility
MAX2181AETG+	Analog Devices part; integrates LNB bias, 22kHz tone, and I²C but lacks DiSEqC detector (DETIN/DSQOUT) and loop-through	Suitable only for unidirectional DiSEqC 1.x or non-DiSEqC LNBs; cannot support DiSEqC 2.x return-channel diagnostics	Select only for cost-sensitive single-LNB designs without bidirectional command/response requirements

Compared with LNBP21PD, LNBP22PD offers superior thermal performance and current capacity for high-density installations, while MAX2181AETG+ sacrifices DiSEqC 2.x bidirectionality for lower system cost in legacy-only deployments.

Availability

LNBP21PD is available at Aetrix Electronics and suitable for satellite TV set-top boxes, PC-based DVB-S tuners, and integrated smart TV satellite modules requiring stable component supply, long-lifecycle availability, and ESD-hardened LNB interface solutions.

Supply support for LNBP21PD 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 analog, power, microcontrollers, and automotive ICs with broad industrial and consumer reach.

The LNBP series targets satellite reception infrastructure, designed specifically to consolidate LNB power regulation, DiSEqC protocol handling, and thermal protection into a single monolithic IC for STB and tuner manufacturers.

FAQ

What is the function of the EXTM pin on LNBP21PD?

The EXTM pin provides an analog modulation input for custom LNB control signals beyond standard DiSEqC. It accepts AC-coupled modulation sources (≤400mV_PP, 10Hz–40kHz) with 260Ω input impedance. When active, it modulates the OUT voltage with 6× gain; unused, it may be left floating. No external DC bias is required due to internal AC coupling.

How does the loop-through function operate during standby mode?

When the EN bit is LOW, the LNBP21PD disables its internal regulators and closes the internal LT1–LT2 switch, allowing external master-supplied power (e.g., from another STB) to pass through. This mode supports slave operation in multiswitch configurations. The switch handles up to 900mA, but external current limiting is required since internal protection is inactive.

Can LNBP21PD support both DiSEqC 1.x and 2.x protocols?

Yes - DiSEqC 1.x is supported via DSQIN-driven tone modulation with TEN=1 or DSQIN logic control. DiSEqC 2.x bidirectional operation requires simultaneous use of DSQIN (encoding), DETIN (AC-coupled to coax), and DSQOUT (decoding), enabling full command/response exchange. External LR termination on OUT is mandatory for 2.x compliance to meet 15Ω source impedance at 22kHz.

What happens during undervoltage lockout (UVLO) on LNBP21PD?

When VCC drops below 6.7V (typ.), the UVLO circuit disables all internal blocks including I²C interface, regulators, and oscillators. The System Register resets to zero, halting communication and output regulation. Operation resumes only after VCC exceeds 7.3V (500mV hysteresis), ensuring clean power-on reset without spurious I²C activity or output glitches.

LNBP21PD Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 20-SOIC (0.433", 11.00mm Width) Exposed Pad

Packaging:: Tube

Product Status:: Obsolete

Applications:: Converter, Analog and Digital Satellite STB Receivers/SatTV

Voltage - Input:: 8V ~ 15V

Number of Outputs:: 1

Voltage - Output:: 13V, 18V

Operating Temperature:: 0°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: PowerSO-20

LNBP21PD FAQ

1.How can I place an order for LNBP21PD through Aetrix?

Please submit a Request for Quotation (RFQ) for LNBP21PD on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LNBP21PD reliable?

The price and inventory of LNBP21PD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LNBP21PD is usually 5 days.

3.What payment methods are accepted for LNBP21PD?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LNBP21PD transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LNBP21PD?

LNBP21PD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LNBP21PD order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LNBP21PD?

For technical support, including LNBP21PD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LNBP21PD requirements.

6.How does Aetrix verify that LNBP21PD is sourced from the original manufacturer or authorized distributors?

All LNBP21PD products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LNBP21PD meets industry standards.

7.What is the process for return or replacement of LNBP21PD?

All LNBP21PD units undergo pre-shipment inspection (PSI). If there is an issue with LNBP21PD, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LNBP21PD part is unused and in its original packaging.

Return procedure for LNBP21PD:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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