New Picor hot swap controller ensures safe, continuous system operation with advanced digital thermal emulation

The Cool-Swap PI2211’s programmable True-SOA feature ensures safe, reliable operation at both the system and MOSFET level during both circuit card insertion and steady state operation. The True-SOA feature provides MOSFET protection in the most ideal way possible by emulating the transient thermal performance of the specific MOSFET in use. By emulating MOSFET thermal behavior and digitally calculating the MOSFET junction temperature rise using the MOSFET manufacturers’ transient thermal impedance data, the Cool-Swap PI2211 can adapt its control, start-up and thermal cycling to the specific user-selected external N-channel MOSFET requirements, ensuring safe operating limits regardless of load and line conditions. Typical industry practice attempts this level of protection by simple timer-based constant power limiting which does not allow for MOSFET optimization and forces designers to oversize the MOSFET, increasing board area use and cost.

The Picor Cool-Swap PI2211, with its Glitch-Catcher voltage suppression technology, also mitigates the need for large external protection components by diminishing transient overshoot events and maintaining compliance with the specified voltage ratings. During a circuit breaker event, the PI2211’s internal Glitch-Catcher voltage suppression circuit controls the MOSFET to act as an active snubber, passing potentially high inductive bus energy through the MOSFET to limit overvoltage exposure. By shunting the energy through the MOSFET to the low impedance load, the PI2211 not only eliminates the need for external protection components but further reduces overall cost and total solution size.

Picor’s Cool-Swap PI2211 with True-SOA and Glitch-Catcher technology provides the highest level of reliability to hot swap and circuit breaker applications within base station power distribution systems, server backplane systems and other ‘live board’ applications. Digital emulation of a MOSFET’s transient thermal performance ensures the best protection approach to hot swap control without increasing cost or design complexity.

The PI2211 is available now and priced at $1.49 in OEM quantity.

Key points:
• IC supports live card insertion and removal, adds transient-suppression function
• Ensures external power MOSFET switches always operate within safe limits
• Circuit-breaker mode diverts damaging power transients in steady-state operation
• Operates with power rails in +0.9 to +14V range, protecting boards and backplane
• Provides designers with a single-chip solution to multiple power-protection issues