This reference design is a 28V output, 12A synchronous buck converter for space missions operating from a 50V to 150V input range. Primary applications include stepping down voltages from solar panels and 120VDC power distribution buses. The TPS7H5006-SEP pulse width modulation (PWM) controller controls the power stage using voltage-mode control. The OPA4H199-SEP senses the sense resistor voltage which enables the output short-circuit protection. The adjustable dead time of the TPS7H6005-SEP allows the timing of the switching MOSFETs to be optimized and results in over 95% efficiency with a 100V input and over 96% efficiency with a 50V input. A 12V self-biasing circuit is included to power the control circuits directly from the output. If an external 12V bias is provided, the self-biasing circuit can be removed, and results in higher efficiency.

• Rad-tolerant: TPS7H5006-SEP TID 50krad (Si), TPS7H6005-SEP 50krad (Si), OPA4H199-SEP 30krad (Si) SEL, SEB, SEGR immune up to 43MeV-cm²/mg
• Pin-to-pin radiation hardened options: TPS7H5002-SP TID 100krad (Si), TPS7H6005-SP 100krad (Si), OPA4H199-SP 100krad (Si) SEL, SEB, SEGR immune up to 75MeV-cm²/mg
• Space-grade Gallium nitride field effect transistor (GaN FET) based
• > 95% efficiency at 100V_IN
• Overcurrent and short-circuit protection
• Synchronizable
• Optional self-bias circuit (higher efficiency with external bias)

• Satellite electrical power system (EPS)

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