Rad-hardened 12V-input point of load switching regulator
Intersil claims it has the first radiation hardened 12V input point-of-load (POL) synchronous buck switching regulator capable of operating over an input voltage range of 3.0 to 13.2V for aerospace and satellite power applications. The ISL70003SEH synchronous buck switching regulator is a highly integrated single-chip power management solution that increases power system efficiency and improves thermal performance while reducing the number of required external components. The regulator offers robust reliability and accuracy to support the most demanding POL voltage tolerance requirements and to withstand low-dose rate and high-dose rate ionising radiation found in harsh environments.
The continued increase in satellite complexity, with more low and high voltage rail requirements and increased computing power demands, presents a number of new challenges to system designers who must balance demands for increased system efficiency and improved thermal performance while ensuring fail-proof operation under extreme conditions.
Intersil’s new ISL70003SEH switching regulator helps to address these design issues by delivering efficiency through the integration of upper and lower switching MOSFETs and an advanced packaging technique that eliminates the need for an external heat sink. Synchronous rectification topology allows for seamless switching between MOSFETs which dramatically improves efficiency and thermal management, reducing power loss. The ISL70003SEH uses voltage mode control architecture with feed-forward, and switches at a selectable frequency of 500 kHz or 300 kHz. Loop compensation is externally adjustable to allow for an optimum balance between stability and output dynamic performance.
The high level of integration allows one part to work on both high and low voltage rails so designers can use the same part across many applications, minimising both qualification and design time. The ISL70003SEH switching regulator also integrates a buffer amplifier for use in double data rate (DDR) power applications, which minimises the number of discrete components to save board space, reduce the overall weight of the satellite and reduce system cost.
This reliable and accurate power management solution achieves the ±5% voltage accuracy required by FPGAs, ASICs, microprocessors and microcontrollers in space applications. With superior radiation hardness, the ISL70003SEH achieves a ±1% reference voltage variation over line, temperature and radiation. The ISL70003SEH’s excellent single event transient (SET) response effectively minimises output voltage variation and increases accuracy, resulting in ±3% SET performance. In addition, the switching regulator’s 14.7V absolute maximum rating in the heavy ion environment at a linear energy transfer (LET) of 86 MeV•cm2/mg provides an adequate de-rating margin for 12V applications, which improves system reliability.
Features and Specifications
• Operates over an input voltage of 3.0 to 13.2V
• Externally adjustable output voltage from 0.6V to ~90% of the input voltage
• Continuous output load current capability is 6A for Tj ≤+125°C and 3A for Tj ≤ +150°C
• Peak efficiency up to 95% with integrated MOSFETs and available heat sink package for thermal management
• 3A current sinking capability and buffer amplifier supports emerging DDR memory power requirements
• Wafer-by-wafer high dose (100 krad(Si)) and low dose rate (50 krad(Si)) radiation guarantee
Intersil; www.intersil.com/products/ISL70003SEH – for the evaluation board; www.intersil.com/en/tools/reference-designs/isl70003sehev1z.html