Allegro | Product | A8298 Single LNB Supply and Control Voltage Regulator Page 1 of 2 Home / Products / Part Numbers / A8298 A8298 Single LNB Supply and Control Voltage Regulator Contact Allegro Marketing for datasheet. Features • • • • • • • • • • • • • • • • • • Integrated boost MOSFET, current sensing, and compensation Stable with low-profile ceramic boost capacitors Higher voltage ratings support increased surge Supplies up to 550 mA continuously Supplies up to 700 mA for reconfiguration Adjustable LNB output current limit from 300 to 800 mA Boost peak current limit scales with LNB current limit setting 8 programmable LNB output voltage (DAC) levels 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 Description 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. Functional Block Diagram Complete Part Numbers Part Number A8298SESTR-T Package Type 20-lead QFN APEK8298SES-01-T DEMO BOARD RoHS Part Composition/ Temperature Comments Compliant RoHS Data Samples/Demo Yes view data -20 °C to 85 °C new Contact Local Sales Representative or check distributor stock No -- -20 °C to 85 °C new Contact Local Sales Representative Distributor Stock All Check Stock Allegro's products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the failure of that life support device or system, or to affect the safety or effectiveness of that device or system. http://www.allegromicro.com/en/Products/Part_Numbers/8298/ 10/4/2011 Allegro | Product | A8298 Single LNB Supply and Control Voltage Regulator Page 2 of 2 Copyright © 2011 Allegro MicroSystems, Inc. • 115 Northeast Cutoff, Worcester, MA 01606 USA • Phone: 1.508.853.5000 • Fax: 1.508.853.7895 http://www.allegromicro.com/en/Products/Part_Numbers/8298/ 10/4/2011