Electronics Weekly Electronics Design & Components Tech News
The note, AN005, picks a radiation-specified current-mode PWM controller from Texas Instruments (TPS7H5001-SP) as a source of PWM waveforms.
Each TPS7H5001-SP can produce two pairs of upper and lower PWMs for a total of two phases, and TPS7H5001-SP has a mode that allows two ICs to be used in parallel to produce four pairs of upper and lower PWMs correctly timed for a four-phase dc-dc converter. “All the necessary dead times and phase-shifts are performed within the ICs,” said EPC.
In the app note, these are connected to four radiation-specified EPC modules, either:
- FBS-GAM02-P-R50, a 50Vdc 10A module that includes two GaN transistors forming a half-bridge.
- FBS-GAM02P-R-PSE, a similar module, but designed to drive external GaN transistors.
In each case, level-shifting and anti-shoot-though circuits are included within the module, and they produce up to 40A in the integrated hemt module case, or 200A (pictured) when the external hemt modules are used.
The note includes some LTspice modelling of a 40A 12 to 0.96V converter optimised to run at 200kHz, and another with smaller passive components for 500kHz.
At loads between 15 and and 40A “it can be seen that at 200kHz operation that the efficiency never drops below 90.5%, and never drops below 84.5% for 500kHz operation,” according to EPC.
Find AN005 here – it is more concept than reference design
