1. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 A novel linear-non-linear digital control for DC/DC converters DIEET – Università di Palermo Ing. Valeria BOSCAINO Ing. Giuseppe Maria DI BLASI Ing. Patrizia LIVRERI Prof. Ing. Giuseppe CAPPONI http://www.dieet.unipa.it/labep boscaino@diepa.unipa.it I&PC Division – STMicroelectronics Ing. Filippo MARINO Ing. Marco MINIERI Power Applications Lab DIEET i&p industrial & power conversion division

2. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Main features Multiphase system Digital control PWM control technique Voltage-Positioning (AVP)

3. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Four module interleaved buck converter Input Voltage: 12V Output Voltage: 1V Output Current: 0-120A Maximum Output Voltage Ripple 30mV during transient 2mV at steady state Switching frequency 250kHz/phase

4. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Single phase linear control loop Adaptive voltage positioning Current-sharing comparator

5. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Switching logic according to interleaved technique

6. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Non linear control: items Fast transient response to load changes No over- and under-shoots in regulated output voltage during transient

7. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Non linear control LINEAR CONTROL OUTPUT VOLTAGE MULTIPHASE DC/DC CONVERTER Vin=12V NON LINEAR CONTROL

8. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Non linear control action Increasing load currentDecreasing load current

9. Ischia, 21-23 giugno 2006Riunione Annuale GE 2006 Recovery time reduction by 25% up to 40%. Output voltage over- and under- shoots reduction by 50% up to 65%. Non linear control active only during a load transient Unaffected steady-state operation. Unchanged converter topology. Possible applications on any dc/dc converter topology. AVP compatible. System bandwidth independent from that of the linear control loop. Solved limit-cycle problems. Non linear action dependent only on output voltage. Easy implementation. Non linear control: main advantages