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Monolithic Power Systems Inc. MP8126DF-LF-Z
- Part No.:
- MP8126DF-LF-Z
- Manufacturer:
- Monolithic Power Systems Inc.
- Category:
- Special Purpose Regulators
- Package:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
MP8126DF-LF-Z.pdf
- Description:
- IC REG CONV LNB 1OUT 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,444
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Product details
Overview
MP8126DF-LF-Z from Monolithic Power Systems is a DiSEqC 1.x–compliant LNB power supply and control-voltage regulator for satellite receiver RF front-ends. It integrates a current-mode boost converter (342 kHz, internal switch) followed by a tracking linear regulator to deliver clean, low-noise 13V/18V outputs up to 550mA while compensating for coaxial cable voltage drop. It supports 22kHz tone shaping, programmable current limiting (600–1100 mA), and POK monitoring - deployed in satellite set-top boxes requiring EUTELSAT-compliant LNB biasing.
For engineers reviewing the MP8126DF-LF-Z datasheet, MP8126DF-LF-Z pinout, MP8126DF-LF-Z application, or MP8126DF-LF-Z equivalent, key selection criteria include DiSEqC 1.x signaling compliance, 1V line-drop compensation, adjustable soft-start via TCAP, 8V–14V input range, and thermal shutdown at 150°C with 20°C hysteresis.
Technical Context
The MP8126DF-LF-Z implements a two-stage regulation architecture: a fixed-frequency (342 kHz) peak-current-mode boost converter generates VBOOST, which feeds a tracking linear regulator that maintains precise VOUT (13V/18V ±1.2%) while rejecting switching noise. The boost stage operates in pulse-skipping mode at light load to improve efficiency.
DiSEqC functionality is embedded via dedicated pins: EXTM accepts 20–24 kHz input for shaped 22kHz output modulation; LINEDROP enables +1V output offset for long-cable compensation; and 13V/18V selects polarization voltage. POK provides open-drain status reporting with ±12% output window detection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 8V to 14V - supports standard satellite STB DC bus rails without external pre-regulation. |
| Output Voltage Options | 13V/14V/18V/19V - selectable via logic-level 13V/18V and LINEDROP pins for LNB polarization and cable loss compensation. |
| Max Output Current | 550mA - sufficient for dual-LNB or high-gain single-LNB operation with margin for transient loads. |
| Boost Switch RDS(on) | 500 mΩ - limits conduction loss in integrated MOSFET, enabling >85% efficiency at 500mA/19V output. |
| Line Regulation | 4–40 mV - ensures stable VOUT across full 8V–14V input range, critical for LNB gain consistency. |
| Load Regulation | 20–30 mV - maintains tight output accuracy from 10mA to 500mA, minimizing LNB bias drift under varying signal conditions. |
| POK Threshold Accuracy | ±12% - provides reliable power-good indication for system-level fault detection and safe LNB enable sequencing. |
Pinout & Package
MP8126DF-LF-Z is housed in a thermally enhanced TSSOP-16EP package with exposed pad (EP) for GND-connected heatsinking. Pin count and layout match JEDEC MO-153 ABT variant; recommended land pattern includes 5.80 mm × 3.30 mm footprint with 0.65 mm pitch and thermal vias under EP.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SGND) | Analog Ground Reference | Provides low-noise reference for COMP, TCAP, and feedback circuitry; must be star-connected to PGND near device. |
| 5 (EN) | Enable Control Input | Active-high logic input; internal pull-up not provided - requires external 100kΩ resistor to VIN for automatic startup. |
| 6 (LINEDROP) | Voltage Compensation Select | Logic-high adds +1V to nominal VOUT to counteract IR drop on long coaxial cables (>30m). |
| 8 (13V/18V) | Polarization Voltage Select | Logic-low = 13V (vertical LNB), logic-high = 18V (horizontal LNB); defines antenna polarization control path. |
| 9 (EXTM) | 22kHz Tone Input | Accepts external 22kHz square wave; internal shaper produces compliant DiSEqC tone with 50% duty cycle and 8μs edge times. |
| 10 (TCAP) | Soft-Start Timing Node | Connects external capacitor (e.g., 22nF) to set output rise time; ICHA = 7μA enables precise slew rate control. |
| 11 (ILIMIT) | Current Limit Programming | Resistor-to-GND sets output current limit (600–1100 mA); enables dynamic overload protection with 50ms on-time / 2s off-time cycling. |
| 12,13 (VOUT) | Regulated Output | High-current output pins delivering final LNB bias voltage; require low-ESR ceramic capacitors (≥22μF) close to PGND. |
Key Features
| Feature | Design Value |
|---|---|
| DiSEqC 1.x Compliance | Fully integrated 22kHz tone generation, 13V/18V polarization switching, and LINEDROP compensation - eliminates need for external DiSEqC controller IC. |
| Two-Stage Low-Noise Regulation | Boost + tracking LDO architecture isolates RF-sensitive LNB from switching noise; VBOOST ripple < 20mV ensures clean LNB bias. |
| Programmable Overcurrent Protection | External resistor sets current limit threshold (600–1100 mA); auto-retry shutdown prevents latch-up during cable shorts or LNB failure. |
| Thermal & Short-Circuit Robustness | 150°C junction shutdown with 20°C hysteresis and cycle-by-cycle boost overcurrent limiting - sustains operation under sustained overload or poor heatsinking. |
| Flexible Soft-Start & Monitoring | TCAP-based soft-start avoids inrush into coaxial cable capacitance; open-drain POK enables system-level power sequencing and fault logging. |
Applications
| Satellite Set-Top Box LNB Biasing | Dual-LNB Switching Systems |
|---|---|
Use Scenario: Powering and controlling a single LNB in consumer satellite receivers using coaxial cable for both RF signal and DC power/control. IC Role / Device Role / Timing Role: Primary LNB power supply and DiSEqC command interface - delivers regulated 13V/18V, shapes 22kHz tone, and detects polarity commands. Use Value: Eliminates discrete boost + LDO + DiSEqC IC solution; reduces BOM count by 3+ components while maintaining EUTELSAT 1.x compliance. | Use Scenario: Supporting two independent LNBs (e.g., universal LNB + legacy LNB) with independent voltage and tone control in multi-satellite installations. IC Role / Device Role / Timing Role: Dual-rail capable regulator providing separate 13V and 18V outputs via time-multiplexed DiSEqC signaling and LINEDROP toggling. Use Value: Enables single-STB control of multiple orbital positions without external multiplexers; leverages built-in 1V compensation to maintain stable bias across variable cable lengths. |
| Professional Satellite Receiver Modules | LNB Test & Calibration Equipment |
Use Scenario: High-reliability DVB-S2X receivers used in broadcast headends or commercial installations requiring extended temperature operation and long-term stability. IC Role / Device Role / Timing Role: Precision LNB bias generator with ±12% POK monitoring and thermal derating - ensures continuous LNB operation under ambient extremes (-40°C to +125°C TJ). Use Value: Maintains LNB gain flatness and noise figure stability across temperature via tight line/load regulation (≤40 mV) and low-output-impedance design. | Use Scenario: Automated test fixtures verifying LNB response to DiSEqC commands, tone injection, and voltage transients during production QA. IC Role / Device Role / Timing Role: Programmable LNB stimulus source - precisely controls VOUT, injects shaped 22kHz, and monitors POK for pass/fail validation. Use Value: Replaces bench power supplies and function generators; enables repeatable, synchronized tone/voltage sweeps with sub-100μs timing resolution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LNB power supply and DiSEqC control applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP8124DN-LF-Z | Successor device with improved efficiency (up to 92%), lower quiescent current (3.5 mA vs. 5 mA), and enhanced thermal performance (θJA = 38°C/W vs. 45°C/W). | Same pinout and DiSEqC feature set; optimized for new designs targeting higher reliability and lower standby power. | Select MP8124DN-LF-Z for new designs - it replaces MP8126DF-LF-Z with no layout change required and superior thermal margin. |
| MAX2102ETJ+ | Single-chip LNB supply with integrated 22kHz oscillator (no EXTM pin), fixed 13.5V/18.5V outputs, and lower max current (400mA). | Lacks programmable line-drop compensation and adjustable current limit; limited to basic DiSEqC 1.0 without advanced tone shaping. | Choose MAX2102ETJ+ only for cost-sensitive legacy designs where 1V compensation and 550mA drive are unnecessary. |
Compared with MP8126DF-LF-Z, MP8124DN-LF-Z offers higher efficiency and better thermal handling in identical packaging, while MAX2102ETJ+ sacrifices flexibility for integration simplicity - making MP8126DF-LF-Z optimal for field-upgradeable or long-cable installations requiring precise 1V compensation and robust 550mA delivery.
Availability
MP8126DF-LF-Z is available at Aetrix Electronics and suitable for satellite set-top box manufacturing, professional broadcast receiver development, and LNB test equipment production requiring stable component supply and long-term obsolescence management.
Supply support for MP8126DF-LF-Z 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
Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with design centers in the US, China, and Taiwan, and global distribution through authorized partners.
The MP8126 belongs to MPS's LNB Power Management product line, engineered specifically for satellite reception systems requiring DiSEqC 1.x compliance, low-noise biasing, and robust cable-length compensation - targeting set-top box, broadcast, and professional video equipment markets.
FAQ
What is the purpose of the LINEDROP pin on MP8126DF-LF-Z?
The LINEDROP pin enables 1V output voltage compensation to counteract IR drop across long coaxial cables. When driven high, it increases VOUT by exactly 1V (e.g., 13V → 14V or 18V → 19V), ensuring stable LNB bias at the antenna end for cable runs exceeding 30 meters. It must not be left floating and requires a defined logic level.
Can MP8126DF-LF-Z operate without an external inductor?
No. The MP8126DF-LF-Z requires an external power inductor for its integrated boost converter stage. The inductor (typically 10–22 μH, rated ≥750mA DC) forms the energy-transfer element between SW and PGND. Omitting it prevents VBOOST generation and causes complete functional failure - no internal inductor is integrated.
How does the EXTM pin generate the 22kHz DiSEqC tone?
The EXTM pin accepts a 20–24 kHz square-wave input; the MP8126DF-LF-Z internally shapes it into a compliant DiSEqC tone with 50% duty cycle, 0.4–0.8 Vpp amplitude, and ≤8 μs rise/fall times. If unused, EXTM must be tied to GND - leaving it floating may cause erratic tone output or false triggering.
What is the minimum recommended capacitor value for the TCAP pin?
The TCAP pin requires an external capacitor to set soft-start time; a 22 nF X7R ceramic capacitor is recommended for typical applications. With ICHA = 7 μA, this yields ~314 ms rise time (tSS ≈ 15·ICHA·CSS/k). Smaller values reduce startup time but increase inrush; larger values extend soft-start for sensitive LNBs.
Is MP8126DF-LF-Z RoHS compliant and lead-free?
Yes. The "-LF" suffix in MP8126DF-LF-Z explicitly denotes RoHS-compliant, lead-free packaging per EU Directive 2011/65/EU. All solderable terminations use matte tin plating, and the device meets MPS green status requirements for halogen-free materials and Pb-free assembly compatibility.
Why does MP8126DF-LF-Z shut down for 2 seconds during overload?
This 2-second off-time (τOFF) is part of the dynamic overload-protection circuit. After detecting sustained overcurrent for 50 ms (τON), the device shuts down to prevent thermal damage. The 2-second cooldown allows internal temperature to fall below hysteresis threshold before automatic restart - protecting both IC and downstream LNB from latch-up or burnout.
Does MP8126DF-LF-Z support DiSEqC 2.x or Unicable protocols?
No. MP8126DF-LF-Z is designed exclusively for DiSEqC 1.x (EUTELSAT specification). It lacks the bidirectional communication, data packet encoding, or frequency agility required for DiSEqC 2.x or Unicable/JESS protocols. For those standards, discrete microcontroller-based solutions or newer ICs like MPQ8124 are required.
MP8126DF-LF-Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Monolithic Power Systems Inc.
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Not For New Designs
- Applications:
- Converter, LNB
- Voltage - Input:
- 8V ~ 14V
- Number of Outputs:
- 1
- Voltage - Output:
- 13V, 14V, 18V, 19V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP-EP
MP8126DF-LF-Z FAQ
1.How can I place an order for MP8126DF-LF-Z through Aetrix?
Please submit a Request for Quotation (RFQ) for MP8126DF-LF-Z 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 MP8126DF-LF-Z reliable?
The price and inventory of MP8126DF-LF-Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP8126DF-LF-Z is usually 5 days.
3.What payment methods are accepted for MP8126DF-LF-Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP8126DF-LF-Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MP8126DF-LF-Z?
MP8126DF-LF-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MP8126DF-LF-Z 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 MP8126DF-LF-Z?
For technical support, including MP8126DF-LF-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP8126DF-LF-Z requirements.
6.How does Aetrix verify that MP8126DF-LF-Z is sourced from the original manufacturer or authorized distributors?
All MP8126DF-LF-Z 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 MP8126DF-LF-Z meets industry standards.
7.What is the process for return or replacement of MP8126DF-LF-Z?
All MP8126DF-LF-Z units undergo pre-shipment inspection (PSI). If there is an issue with MP8126DF-LF-Z, 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 MP8126DF-LF-Z part is unused and in its original packaging.
Return procedure for MP8126DF-LF-Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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