1. A complete DC/DC converter ASIC for LHC upgrades S. Michelis, F. Faccio, G. Blanchot, I. Troyano CERN PH-ESE S.Saggini University of Udine, Italy Twepp 2012, Oxford 17-21 September 2012 S. Michelis, F. Faccio, G. Blanchot, I. Troyano CERN PH-ESE S.Saggini University of Udine, Italy Twepp 2012, Oxford 17-21 September 2012 1

2. S. Michelis, Twepp 2012, Oxford Power distribution with DC-DC converters Buck Converter Specifications: Vin<=10V Vout=1.2-3.3V Iout<=3A frequency=1-3 MHz Constrains: magnetic (2T-4T) fields radiation (TID>100Mrd, fluence > 2 10 15 p/cm² ions with LET<40MeV·cm²/mg) 2 DC/DC ASIC

3. S. Michelis, Twepp 2012, Oxford aMis 5 3

4. 2.88mm 2.7 mm AMIS5 is designed in a High Voltage 0.35um technology for automotive application. This technology has been successfully tested for TID, protons and heavy ions. 4

5. S. Michelis, Twepp 2012, Oxford High Side transistors Low Side transistors Analog Linear regulators Digital Lin. Regulator capacitors Control Circuit Buffer / Drivers 5

6. S. Michelis, Twepp 2012, Oxford Two AMIS5 versions have been submitted (same dimension, same pinout) BOLL (Buffer Overcurrent=Large Low) faster turn on&off of power transistors Over-Current detection on Low Side Transistor BOSH (Buffer Overcurrent=Small High) slower turn on&off of power transistors Over-Current detection on High Side Transistor 6 Buffers

7. S. Michelis, Twepp 2012, Oxford Control Logic Input Under – Voltage Over – Temperature Buck Enable Enable Half Switch Soft start handling Power Good Soft start allows a rise time of the Vout in around 1.6ms, avoiding too high in-rush current at the start-up Vout Time 1.6ms 7

8. S. Michelis, Twepp 2012, Oxford the ASIC is OFF by default the Enable pin need to be externally controlled. AMIS5 turn on if V enable >0.7V (compatible with 1.2V logic up to 3.3V) AMIS5 Enable 0.7V Internal Enable External Pull-up Voltage (<3.3V) R Ext Power Good ENABLEPOWER GOOD Power Good: is an open drain pin. Power Good goes high if: ✓ AMIS5 is enabled, Vin>5V and it is working properly Power Good goes low (zero) when AMIS5 is supplied (Vin>5V) and if it is in one of these conditions: ‣ Start-up ‣ Over-Current limitation ‣ Over-Temperature limitation ‣ AMIS5 disabled 8

9. S. Michelis, Twepp 2012, Oxford Only 2/5th of the power transistors are operative. Higher efficiency for small load (<1A) ENABLE Half Swith 9

10. S. Michelis, Twepp 2012, Oxford Input Under – Voltage Protection time (s) 5V 4V converter off converter off converter on Vin Threshold Vin Enabler for the converter 10

11. S. Michelis, Twepp 2012, Oxford Over-Temperature Protection time (s) converter on Temperature 100°C converter on 60°C converter off 11

12. S. Michelis, Twepp 2012, Oxford Over-current protection

13. S. Michelis, Twepp 2012, Oxford AMIS5 Efficiency with Vin=10V, L=460nH, Vout=2.5V, f=1.7MHz 13

14. S. Michelis, Twepp 2012, Oxford Efficiency for different Vout 14

15. S. Michelis, Twepp 2012, Oxford Iout=0A Iout=0.5A Iout=1A Iout=1.5A Iout=2A Iout=2.5A Iout=3A @ f=1.7MHz, L=460nH Line and Load regulation Line regulation: 4mV variation with Vin=6V-12V Load regulation: 7mV variation with Iout=0A-3A 15

16. S. Michelis, Twepp 2012, Oxford Load Transient Load transient setup thanks to Cristian Fuentes

17. S. Michelis, Twepp 2012, Oxford TID tests with Vin=10V, L=460nH, Vout=2.5V, f=1.7MHz 17 pre-rad

18. S. Michelis, Twepp 2012, Oxford TID Tests at different temperature with Vin=10V, L=460nH, Vout=2.5V, f=1.7MHz 18 pre-rad

19. S. Michelis, Twepp 2012, Oxford pre-rad Line and Load regulations vs TID with Vin=10V, L=460nH, Vout=2.5V, f=1.7MHz 19

20. S. Michelis, Twepp 2012, Oxford Future plans 2.88mm 3.3 mm AMIS5_BB Test foreseen for AMIS5 Single Event and Displacement damage tests (fall 2012) BOSH version tests Tests on AMIS5 packaged in QFN32 AMIS5_BB Bump Bonded version tests and characterization (expected back in November 2012) 20

21. S. Michelis, Twepp 2012, Oxford Negative Converter 21

22. S. Michelis, Twepp 2012, Oxford Positive Converter Negative Converter Vin DC/DC VoutPhase -Vout For the time being the DC/DC converter is a commercial chip (LTC3605, the same for SM01C). It will be replaced with AMIS5 28.5 mm 13.5 mm Differential Mode noise Negative Converter Differential Mode noise Positive Converter 22 Board designed by Isaac Troyano

23. S. Michelis, Twepp 2012, Oxford Conclusions A new DC/DC converter ASIC called AMIS5 has been presented. It is a fully integrated synchronous buck converter which contains internal linear regulators, bandgaps and a control circuitry to handle signals form the protection circuitry Efficiency is high (above 80%, peak 83%-85%) Radiation effects are limited (2-4% loss of efficiency over 325Mrad and Iout=2-3A) line regulation is good (4 mV for Vin variation from 6 to 12V) load regulation is good (7 mV for Iout variation from 0 to 3A) A negative converter has been presented It allows to convert a positive input voltage to a negative voltage (e.x. Vin=7V and Vout=-2.5V). It uses a chip that has been already used for a positive convert. Only the PCB layout is changed. AMIS5 will replace the commercial component for radiation tolerance 23