FEB Noise Test with POL Converter Jim Kierstead

FEB Noise Test with POL Converter Jim Kierstead, Sergio Rescia, Hucheng Chen, Francesco Lanni (BNL) Mauro Citterio (INFN, Milano) Satish Dhawan (Yale) 5/26/2009 H. Chen - Brookhaven National Laboratory 1

Current LVPS System Implementation 19 voltage regulators/FEB Centralized architecture 5/26/2009 H. Chen - Brookhaven National Laboratory 2

Possible Architectures Distributed Power Architecture 280 VDC Card #3 Card #2 ni. POL Converter V 1 x VDC Main Converter Card #1 ni. POL POL Converter POL POL ni. POL Converter POL Crate V 2 x VDC (ex- LVPS) POL ni. POL Converter POL POL Card #2 Card #1 POL Converter POL LDO POL Converter LDO POL POL POL Intermediate Bus Architecture 5/26/2009 H. Chen - Brookhaven National Laboratory 3

Two Point of Load Converters • LTM 4602 – 6 A High Efficiency DC/DC μModule – – – – 5/26/2009 Complete Switch Mode Power Supply Wide Input Voltage Range: 4. 5 V to 20 V 6 A DC, 8 A Peak Output Current 0. 6 V to 5 V Output Voltage 1. 5% Output Voltage Regulation Up to 92% Efficiency Output Over Voltage Protection • IR 3841 – Integrated 8 A Synchronous Buck Regulator – – – Greater than 96% Maximum Efficiency Wide Input Voltage Range: 1. 5 V to 16 V Wide Output Voltage Range: 0. 7 V to 0. 9*Vin Continuous 8 A Load Capability Programmable Switching Frequency up to 1. 5 MHz Programmable Over Current Protection H. Chen - Brookhaven National Laboratory 4

Irradiated Noise: Test Positions • Outside FEC – Against power comb POL FEB POL 5/26/2009 L PO • Inside FEC – Proximity of preamplifier • Left and Right POL – Proximity of power comb – Proximity of manifold H. Chen - Brookhaven National Laboratory 5

Irradiated Noise: Outside FEC 5/26/2009 H. Chen - Brookhaven National Laboratory 6

Irradiate Noise: Inside FEC 5/26/2009 H. Chen - Brookhaven National Laboratory 7

Irradiated Noise: Shielding • 30 mils aluminum shielding box 5/26/2009 H. Chen - Brookhaven National Laboratory 8

Conducted Noise • Test Setup – +4 V input to 5 regulators on FEB • • • Preamplifier +3 V output SCA +3. 3 V left analog SCA +3. 3 V left digital SCA +3. 3 V right analog SCA +3. 3 V right digital – Bypass 5 regulators by short output to input – Disconnect +4 V input from LVPS – LTM 4602 3. 3 V output to supply preamplifiers and SCAs directly 5/26/2009 H. Chen - Brookhaven National Laboratory 9

Conducted Noise 5/26/2009 H. Chen - Brookhaven National Laboratory 10

Summary • Irradiated noise of POL Converters – Outside FEC: Negligible effect on coherent noise – Inside FEC: Affect coherent noise without shielding – Shielding is necessary to achieve good noise performance inside FEC • Conducted noise of POL Converters – Negligible effect on coherent noise • Ready for radiation test 5/26/2009 H. Chen - Brookhaven National Laboratory 11