A8281

• LNB Selection and Standby function
• Built-In Tone Oscillator Factory Trimmed to 22 kHz, Facilitates
• DiSEqC^TM (a trademark of EUTELSAT) Encoding
• Tracking Switch-Mode Power Converter for Lowest Dissipation
• Externally Adjustable Short-Circuit Protection
• LNB Short-Circuit Protection and Diagnostics
• Auxiliary Modulation Input
• Cable Length Compensation (A8282SLB only)
• Internal Over-Temperature Protection
• Reverse-Current protection

Description

Intended for analog and digital satellite receivers, these low-noise block converter regulators (LNBRs) A8281 are monolithic linear and switching voltage regulators specifically designed to provide the power and interface signals to the LNB down converter via the coaxial cable. If the device A8281 is in standby mode (EN terminal low), the regulator output is disabled, allowing the antenna down converters to be supplied or controlled by other satellite receivers sharing the same coaxial cable. In this mode, the device will limit the output reverse current.

The A8281SLB output is set to 13 or 18-V by the VSEL terminal. It is supplied in a 16-lead SOIC package with internally-fused leads for enhanced thermal dissipation. The fused leads are at ground potential and need no electrical isolation.

The A8282SLB output is set to 12, 13, 18, or 20-V by the VSEL terminals. Additionally, it is possible to increase the selected voltage by 1-V to compensate for the voltage drop in the coaxial cable (LLC terminal high). It is supplied in a 24-lead SOIC package with internallyfused leads for enhanced thermal dissipation. The fused leads are at ground potential and need no electrical isolation The A8282SLB is an improved version of the A8283SLB, without a bypass switch.The lead (Pb) free version has 100 % matte tin leadframe plating.