Designed for use in analog and digital satellite receivers, this single low-noise downconversion is convertedVoltage regulator(LNBR) is a monolithic linear/switching regulator designed to pass power and interface signals over coaxial cable to an LNB buck converter. The A8298 has a boost switch and compensation circuit integrated into the device, requiring only a few external components. A higher switching frequency is chosen to minimize the size of the passive filter element, further reducing costs. The high level of component integration ensures extremely low noise and pulsation patterns.
A8298Designed to achieve high efficiency by leveraging Allegro's® advanced BCD processes. The integrated boost switch is optimized to minimize switching and static losses. To further improve efficiency, voltage drops during the tracking regulator have been minimized.
For DiSEqC™ communication, a tone control pin is provided to gate an internally generated 22kHz tone switch.
The device provides a comprehensive set of fault registers that meet all common criteria, including overcurrent, thermal shutdown, undervoltage, and poor power supply.
The device uses a 2-wire bidirectional serial interface, is compatible with I2C™ standards, and operates at frequencies up to 400 kHz.
The A8298 is available in a lead-free (Pb) package.
- Integrated boost MOSFETs, current sensing, and compensation
- Stable operation with ultra-thin ceramic boost capacitors
- Continuously delivers up to 550 mA
- Provides up to 700 mA for reconfiguration
- Adjustable LNB output current limit from 300 to 800 mA
- The boost peak current limit level is set by LNB current limit
- 8-Level Programmable LNB Output Voltage (DAC)
- LNB overcurrent limiter with shutdown timer
- Track boost converters to reduce power consumption
- LNB transient time configurable by an external capacitor
- The push-pull LNB output stage maintains 13→18 volt and 18→13 volt transient times, even with high capacitive loads.
- A built-in 22 kHz tone oscillator facilitates DiSEqC™ tone encoding, even when there is no load
- No additional external components are required to produce tones
- Diagnostic features: PNG, TDET
- Dynamic tone detection amplitude and frequency thresholds
- Extensive protection functions: UVLO, OCP, TSD, CPOK
- Two-wire I2C compatible interface