Comparison of two dual +-V output converter circuist: LT1930 vs LT8335

Question

Hi, 
 I am studying on dual ouput converter based on SEPIC topology. I find from datasheets that both LT1930 and LT8335 could create a symmetrical dual output. Please see.

The pictures show clear that there are 2 kinds of circuts to create dual +-V outputs. 
 1, consists of 1 inductor and 4 Schottky diodes. 
 2, consists of 3 inductors (coupled) and 2 Schottky diodes. 
 My questions are: 
 Is the 2 circuits equivalent? 
 If they are quite different, what's the exact differences about their efficiency and output current capacity? 
 Is there a simple sign via which I could easily judged which kind of ICs should use which circuit? 
 Thank you very much! 
 Best Regards.

ADIApproved · Accepted Answer

Hi, 
 The 2 circuits are not the same with the other one. The LT1930 diagram you have shown is a boost converter that can output a positive and negative output rail while the LT8335 is designed to configure with a SEPIC for the positive rail and a Cuk for the negative rail. If you need both positive and negative rail output for your converter and looking for the functionality of a SEPIC converter that has the capability of stepping-up or down a voltage supply, the LT8335 diagram you have shown exhibits this property since the LT1930, although has the capability of being configured on a SEPIC topology, does not have an example for +- rails example. 
 
 Regards, 
 Siglo)

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Comparison of two dual +-V output converter circuist: LT1930 vs LT8335