A8298: Single LNB Supply and Control Voltage Regulator

Intended for analog and digital satellite receivers, this single low noise block converter regulator (LNBR) is a monolithic linear and switching voltage regulator, specifically designed to provide the power and the interface signals to an LNB down converter via coaxial cable. The A8298 requires few external components, with the boost switch and compensation circuitry integrated inside of the device. A high switching frequency is chosen to minimize the size of the passive filtering components, further assisting in cost reduction. The high levels of component integration ensure extremely low noise and ripple figures.

The A8298 has been designed for high efficiency, utilizing the Allegro® advanced BCD process. The integrated boost switch has been optimized to minimize both switching and static losses. To further enhance efficiency, the voltage drop across the tracking regulator has been minimized.

For DiSEqC™ communications, a tone control pin is provided to gate the internally-generated 22 kHz tone on-and-off.

A comprehensive set of fault registers are provided, which comply with all the common standards, including: overcurrent, thermal shutdown, undervoltage, and power not good.

The device uses a 2-wire bidirectional serial interface, compatible with the I2C™ standard, that operates up to 400 kHz.

The A8298 is supplied in a lead (Pb) free package.

Arrow Electronics (Distributor, Allegro & Sanken Semiconductors)
25 Hub Drive
Melville, NY 11747
Phone: 1-800-777-2776 for local distributor
Web: www.arrow.com

If this is not your local representative, find your local sales rep here.

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  • Integrated boost MOSFET, current sensing, and compensation
  • Stable with low-profile ceramic boost capacitors
  • Adjustable LNB output current limit from 250 to 950 mA
    • Covers wide array of application requirements
    • Minimizes component sizing to fit each application
    • For startup, reconfiguration, and continuous output
      (maximum value depends on PCB thermal design)
  • Boost peak current limit scales with LNB current limit setting
  • 8 programmable LNB output voltage (DAC) levels
  • LNB overcurrent limiter with shutdown timer
  • Static LNB overcurrent limiter with shutdown timer
  • Tracking boost converter minimizes power dissipation
  • LNB transition times configurable by external capacitor
  • Push-pull LNB output stage maintains 13→18 V and 18→13 V transition times, even with highly capacitive loads
  • Built-in 22 kHz tone oscillator facilitates DiSEqC™ tone encoding, even at no-load
  • Tone generation does not require additional external components
  • Diagnostic features: PNG, TDET
  • Dynamic tone detect amplitude and frequency thresholds
  • Extensive protection features: UVLO, OCP, TSD, CPOK
  • 2-wire I2C-compatible interface

The A8298 is supplied in a 20 contact MLP/QFN (suffix ES) lead (Pb) free package.

ES QFN 20-lead

Click the image to view larger
Product Image Functional Block Diagram

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check
Distributor Stock
A8298SESTR-T 20-lead QFN -20°C to 85°C Yes View Data Discontinued Contact your
local sales rep
Check Stock
APEK8298SES-01-T DEMO BOARD -20°C to 85°C No -- Contact your
local sales rep
Check Stock

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.

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