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Allegro MicroSystems A8303SESTR-T-1
- Part No.:
- A8303SESTR-T-1
- Manufacturer:
- Allegro MicroSystems
- Category:
- Voltage Regulators - Linear + Switching
- Package:
- 20-WFQFN Exposed Pad
- Datasheet:
-
A8303SESTR-T-1.pdf
- Description:
- IC REG SGL BST/LNR 352KHZ 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,251
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Product details
Overview
A8303SESTR-T-1 from Allegro MicroSystems is a discontinued single LNB supply and control voltage regulator IC designed for analog/digital satellite receivers. It integrates a tracking boost converter (352 kHz), linear regulator, 22 kHz tone generator/detector, I²C interface (400 kHz), and comprehensive fault monitoring (OCP, TSD, UVLO, PNG). It delivers programmable LNB output voltages (e.g., 11.667 V, 13.667 V, 19.000 V) with adjustable current limit (250–950 mA) to power and control low-noise block downconverters over coaxial cable.
For engineers reviewing the A8303SESTR-T-1 datasheet, A8303SESTR-T-1 pinout, A8303SESTR-T-1 application, or A8303SESTR-T-1 equivalent, this page provides verified technical context, validated pin functions, confirmed LNB-specific specifications (ripple ≤15 mVPP, ΔVREG = 600–1000 mV), real-world DiSEqC™ tone performance (20–24 kHz, 400–900 mVPP), and two documented alternative regulators for legacy satellite receiver redesigns.
Technical Context
The A8303SESTR-T-1 implements a current-mode tracking boost converter (352 kHz typical) that regulates BOOST voltage to within 800 mV of the LNB output setpoint, minimizing linear regulator dissipation. Its integrated boost MOSFET (RDS(on) = 300 mΩ) and internal compensation eliminate external loop components.
It features bidirectional 22 kHz tone handling: internally generated tone (gated by TONECTRL) with 5–15 µs edge times, and adaptive tone detection (TDO open-drain output, TDET status bit) with dynamic amplitude/frequency thresholds-tighter during transmit (TONECTRL = 1), wider during receive (TONECTRL = 0) to accommodate coaxial signal degradation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Accuracy | ±2% - Ensures stable LNB biasing across global standards (e.g., 13.667 V EU, 11.667 V JP). |
| LNB Output Ripple & Noise | 15 mVPP (20 MHz BW) - Meets stringent satellite receiver EMI requirements without additional filtering. |
| Boost Switching Frequency | 352 kHz typical - Enables use of small, low-profile ceramic boost inductors (15 µH) and capacitors. |
| Linear Regulator Drop | 600–1000 mV - Minimizes power loss when VIN exceeds LNB voltage, critical for thermal management. |
| I²C Interface Speed | 400 kHz - Supports fast configuration and real-time status reads (fault registers, PNG, TDET) in set-top box firmware. |
| Tone Detection Delay | 1.5 cycles typical - Enables rapid DiSEqC™ command response (<100 µs at 22 kHz) for antenna positioning. |
| Thermal Resistance | RθJA = 37 °C/W (4-layer PCB) - Defines maximum continuous load (e.g., 700 mA @ 85°C ambient) before thermal shutdown. |
Pinout & Package
Package: 20-contact MLP/QFN (ES), 4 mm × 4 mm × 0.75 mm, exposed thermal pad (connected to GND).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BOOST (20) | Tracking supply to linear regulator | Delivers regulated voltage to LNB stage; must be filtered externally to meet ripple spec. |
| LNB (2) | LNB output voltage terminal | Provides programmable 13–19.667 V DC to satellite dish; includes slew rate control via TCAP. |
| ISET (12) | External resistor connection for current limit | Sets LNB output current limit (250–950 mA) using RSET; enables design flexibility across LNB types. |
| TONECTRL (10) | 22 kHz tone enable/disable control | Direct logic-level gate for DiSEqC™ tone transmission; configures tone detector thresholds. |
| TDI (4) / TDO (5) | Tone input / tone detect output | TDI accepts AC-coupled 22 kHz from coax; TDO asserts low when tone detected (open-drain). |
| SCL/SDA (7/8) | I²C clock/data interface | Configures DAC voltage, reads fault status (OCP, TSD, PNG), and monitors tone detection (TDET). |
| VIN (15) | Main supply input (10–16 V) | Power source for boost converter and internal circuitry; includes UVLO (8.35 V typ) and hysteresis. |
| GND / GNDLX (14/17) | Signal ground / boost switch ground | Separate grounds minimize noise coupling between analog (LNB) and switching (boost) sections. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated boost MOSFET + current sensing | Eliminates external high-side switch and sense resistor, reducing BOM count and layout area. |
| 8-programmable LNB output voltages (DAC) | Supports regional standards (EU 13.667 V, JP 11.667 V, global 19.000 V) without hardware change. |
| Adaptive 22 kHz tone detection | Adjusts amplitude/frequency thresholds based on TONECTRL state-ensures robust DiSEqC™ operation over long coax runs. |
| LNB overcurrent limiter with 45 ms shutdown timer | Protects against sustained shorts while allowing inrush current during LNB startup (≤45 ms). |
| Push-pull LNB output stage | Maintains controlled 13↔18 V transition times (10 ms rise, 25 ms fall) even with 100 µF load capacitance. |
Applications
| Digital Satellite Set-Top Box | Multi-Switch Distribution System |
|---|---|
|
Use Scenario: Powering and controlling a single LNB in consumer-grade DVB-S/S2 receivers with DiSEqC™ 1.0/1.1 support. IC Role / Device Role / Timing Role: Primary LNB power regulator and 22 kHz tone interface; manages voltage selection, tone gating, and fault reporting via I²C. Use Value: Enables compact, low-noise LNB supply with <15 mVPP ripple and sub-100 µs tone response-critical for reliable channel locking and dish positioning. |
Use Scenario: Driving one port of a multi-switch (e.g., 4×1, 8×1) in communal TV installations where multiple LNBs feed a single receiver. IC Role / Device Role / Timing Role: Provides isolated, programmable LNB voltage per port; prevents cross-talk via independent slew rate control and OCP protection. Use Value: Ensures stable 13/18 V switching across ports without interference-even when adjacent outputs are shorted or misconfigured. |
| Professional Satellite Modulator | Legacy Broadcast Monitoring Equipment |
|
Use Scenario: Supplying LNBs in professional modulators used for satellite uplink testing and signal analysis. IC Role / Device Role / Timing Role: High-accuracy LNB regulator with diagnostic visibility (PNG, TDET, OCP bits) for remote system health monitoring. Use Value: Delivers ±2% output accuracy and real-time fault flags-enabling automated diagnostics and reducing field service time. |
Use Scenario: Replacing obsolete LNB regulators in aging broadcast monitoring receivers deployed in headend facilities. IC Role / Device Role / Timing Role: Drop-in compatible LNB controller supporting legacy DiSEqC™ commands and existing I²C firmware interfaces. Use Value: Extends service life of installed base equipment with minimal redesign-leveraging identical pinout and register map as A8303/A8303-1 family. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LNB supply and control applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX2100AETM+ | Fixed 13/18 V outputs only; no programmable DAC; requires external tone generator; 2-wire serial interface (non-I²C). | Lacks Japanese 11.667 V support and adaptive tone detection; suitable for basic DiSEqC™ 1.0 systems without advanced diagnostics. | Select when cost sensitivity outweighs need for voltage flexibility and integrated tone features. |
| STV0900 | Integrated dual-LNB controller; supports two independent outputs; higher integration but larger QFN48 package. | Designed for multi-LNB receivers (e.g., twin-tuner PVRs); not pin-compatible; requires full schematic revision. | Choose for new dual-LNB designs requiring simultaneous 13/18 V control-not for A8303SESTR-T-1 replacement. |
Compared with A8303SESTR-T-1, MAX2100AETM+ offers lower BOM cost but sacrifices programmability and integrated tone handling, while STV0900 provides dual-output capability at the expense of footprint and redesign effort-neither is pin-compatible, making them functional alternatives rather than drop-in replacements.
Availability
A8303SESTR-T-1 is available at Aetrix Electronics and suitable for digital satellite set-top boxes, multi-switch distribution systems, professional satellite modulators, and legacy broadcast monitoring equipment requiring stable component supply despite its discontinued status.
Supply support for A8303SESTR-T-1 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
Allegro MicroSystems is a U.S.-based designer of high-performance magnetic sensing and power ICs, specializing in automotive, industrial, and communications applications since 1989.
The A8303SESTR-T-1 belongs to Allegro's satellite LNB power management product line, engineered specifically for low-noise, high-efficiency coaxial power delivery and DiSEqC™ control in digital satellite reception systems.
FAQ
What is the primary function of the A8303SESTR-T-1 in satellite receiver systems?
The A8303SESTR-T-1 serves as a single-channel LNB supply and control IC, delivering regulated DC voltage (11.667–19.667 V) and 22 kHz tone signaling over coaxial cable to low-noise block downconverters. It integrates a tracking boost converter, linear regulator, tone generator/detector, and I²C interface-enabling complete LNB power management and DiSEqC™ communication in devices like set-top boxes and modulators. The A8303SESTR-T-1 replaces discrete solutions with high integration and low noise.
Is the A8303SESTR-T-1 still in production, and what does "discontinued" mean for design-in?
No, the A8303SESTR-T-1 is officially discontinued-Allegro ceased production as of December 28, 2019, and no new samples are available. "Discontinued" means it should not be selected for new designs; however, Aetrix Electronics maintains inventory for legacy support, repair, and end-of-life fulfillment. Customers designing new products must evaluate alternatives like MAX2100AETM+ or STV0900, as the A8303SESTR-T-1 has no direct pin-compatible successor.
How does the A8303SESTR-T-1 implement DiSEqC™ tone generation and detection?
The A8303SESTR-T-1 generates a precise 22 kHz tone internally (20–24 kHz guaranteed) and gates it via the TONECTRL pin. For detection, it uses the TDI pin to accept AC-coupled tone signals from coax and asserts TDO low when present. Critically, its tone detector dynamically adjusts amplitude/frequency thresholds: tighter during transmit (TONECTRL = 1) to ensure clean tone output, wider during receive (TONECTRL = 0) to tolerate degraded signals over long cables. This behavior is confirmed in the Electrical Characteristics table and functional description of the A8303SESTR-T-1 datasheet.
What are the key thermal limitations affecting A8303SESTR-T-1 performance?
The A8303SESTR-T-1 has a junction temperature limit of 150°C and thermal shutdown at 165°C (with 20°C hysteresis). Its RθJA is 37°C/W on a 4-layer JEDEC board, meaning power dissipation must be managed carefully-especially when VIN exceeds LNB voltage, as the linear regulator drops up to 1000 mV. At 700 mA load and 85°C ambient, thermal design (exposed pad grounding, copper area) directly determines maximum continuous operation. Exceeding limits triggers TSD fault, latching OCP until reset via I²C or power cycle-verified in the Protection section of the A8303SESTR-T-1 documentation.
Can the A8303SESTR-T-1 support Japanese market LNB requirements?
Yes-the A8303SESTR-T-1 variant (denoted by "-1" suffix) includes a dedicated 11.667 V output setting explicitly to meet Japanese regulatory and LNB compatibility requirements, as stated in the Features and Benefits section. This voltage is selectable via the VSEL2/1/0 DAC inputs and is distinct from the standard 13.667 V (EU) and 19.000 V (global) settings. The A8303SESTR-T-1 datasheet confirms this in Table 3b (Selection Guide) and electrical specs, ensuring compliance for JIS-certified satellite receivers.
A8303SESTR-T-1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 20-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Topology:
- Step-Up (Boost) (1), Linear (LDO) (1)
- Number of Outputs:
- 1
- Frequency - Switching:
- 352kHz
- Voltage/Current - Output 1:
- -
- Voltage/Current - Output 2:
- -
- Voltage/Current - Output 3:
- -
- w/LED Driver:
- No
- w/Supervisor:
- No
- w/Sequencer:
- No
- Voltage - Supply:
- 30V
- Operating Temperature:
- -20°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QFN-EP (4x4)
A8303SESTR-T-1 FAQ
1.How can I place an order for A8303SESTR-T-1 through Aetrix?
Please submit a Request for Quotation (RFQ) for A8303SESTR-T-1 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 A8303SESTR-T-1 reliable?
The price and inventory of A8303SESTR-T-1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A8303SESTR-T-1 is usually 5 days.
3.What payment methods are accepted for A8303SESTR-T-1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A8303SESTR-T-1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A8303SESTR-T-1?
A8303SESTR-T-1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A8303SESTR-T-1 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 A8303SESTR-T-1?
For technical support, including A8303SESTR-T-1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A8303SESTR-T-1 requirements.
6.How does Aetrix verify that A8303SESTR-T-1 is sourced from the original manufacturer or authorized distributors?
All A8303SESTR-T-1 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 A8303SESTR-T-1 meets industry standards.
7.What is the process for return or replacement of A8303SESTR-T-1?
All A8303SESTR-T-1 units undergo pre-shipment inspection (PSI). If there is an issue with A8303SESTR-T-1, 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 A8303SESTR-T-1 part is unused and in its original packaging.
Return procedure for A8303SESTR-T-1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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