S. Dhawan, O. Baker, H. Chen, R. Khanna, J. Kierstead, F. Lanni,D. Lynn, A. Mincer,

C. Musso S. Rescia, H. Smith, P. Tipton, M. Weber

Progress on DC-DC converters for SiTracker for SLHC

1

C. Musso S. Rescia, H. Smith, P. Tipton, M. Weber

Yale University, New Haven, CT USABrookhaven National Laboratory, Upton, NY USA

Rutherford Appleton Laboratory, Chilton, Didcot, UKNational Semiconductor Corp, Richardson, TX, USA

New York University, New York, NY, USA

4088 Cables10 Chip Hybrid – SCT Module

for LHC

Counting House

3.5 V

20 Chip Hybrid – Si TrModule for Hi Luminosity

Cable Resistance = 4.5 Ohms

1.5 amps

2.4 amps

X 10 DC-DCPower

Converter

20 Chip Hybrid – Si TrModule for Hi Luminosity

1.3 V

1.3 V

2.4 amps

10.25 V

12.1V

14.08 V13 V

Power Delivery with Existing SCT Cables (total = 4088)

Voltage Drop = 6.75 V

Voltage Drop = 10.8V

0.24 ampsVoltage Drop = 1.08 V

Length of Power Cables = 140 Meters

2

Power Delivery with Existing SCT Cables (total = 4088)Resistance = 4. 5 Ohms

0

10

20

30

40

50

60

70

80

90

100

3.5 V @ 1.5 amps 1.3 V @ 2.4 amps 1.3 V @ 2.4 ampswith x10 Buck

switcher. Efficiency90%

Voltage @ Load

Pow

er E

fficien

cy %

Efficiency

Agenda

§Learning from Commercial Devices§ Buck > Voltage, EMI§ Plug In Cards for ABCN2.5 Hybrids - Noise Tests @Liverpool

§ Require Radiation resistance & High Voltage operation§ Thin Oxide

3

§ Thin Oxide§ High Voltage with Thin Oxide ?§ DMOS, Drain Extension 12V @ 5 nm , 20V @ 7 nm

§ HEMPT has no Oxide – Higher Voltage ? 200 Mrads 20V

Buck Regulator Efficiency after 100 Mrad dosage

55

60

65

70

75

80P

ow

er E

ffic

ien

cy %

AfterExposure

BeforeExposure

Enpirion EN5360§ Found out at Power Technology conference 0.25 µm Lithography

§ Irradiated Stopped on St. Valentines Day 2007

4

40

45

50

0 1 2 3 4 5 6

Output Current Amps

Po

wer

Eff

icie

ncy

%

§ Irradiated Stopped on St. Valentines Day 2007§ No effects after 100 Mrads§ Noise tests at Yale, RAL & BNL.

§ 20 µm Al is good shield for Air Coils§ All other devices failed, even other part numbers from Enpirion

§ We reported @ TWEPP 2008 - IHP was foundry for EN5360§ What makes Radiation Hardness ?§ Chinese Company Devices

Controller

Power Stage Drivers

Pulse Width Controller

Synchronous Buck Converter

Power Stage-High Volts

Control Switch30 mΩ

Synch Switch20 mΩ

Error Amp 80.5

78.4

Eff

icie

ncy

(%

)

5

ControllerLow Voltage V reference

Pulse Width Controller

Buck Safety

Control Switch: Switching Loss > I2Synch Switch: Rds Loss Significant

100 ns

Synch

Control

900 ns

Control

Synch

Minimum Switch ON TimeLimits Max Frequency

500 ns 500 ns

Vout = 10%

Vout = 50%

75.2

Input Voltage (8-14 V)

Eff

icie

ncy

(%

)

Control Switch

EMI Antenna Loops

Current is switched from Q1 to Q2 with minimum Impedance change

Q2

Q1

6

Since the switching noise is generated primarily by the power stage of the supply, careful layout of the power components should take place before the small signal components are placed and routed. The basic strategy is to minimize the area of the loops created by the power components and their associated traces. In the synchronous buck converter shown above the input (source) loop #1 ideally consists of a DC current with a negligible AC ripple. Loop numbers 2 and 3 are the power switch loops. The current in these loops is composed of trapezoidal pulses with large peaks and fast edges (di/dt and dv/dt). The area of these loops will be determined primarily by how close together the power components, the inductor, and the capacitors Cin and Cout can be placed. The closer the components, the shorter the PCB traces connecting them, and therefore the smaller loop area.

Advice form a company application note

Vin = 2.5 – 17 VVout = 2.5 / 1.3 V

Enable GND

GND

RequirementsVoltage Ratio > 8For Good Efficiency Iout >3 ampsAir Coil / MagneticsRadiation Hardness

Small

Output VoltageTolerance +/- 5%

Absolute Max 10%

7

Load0.25 µm Technology Test ASIC 2.5 V @ ~ 3 amps. Actual 5 amps 0.13 µm Technology ASIC 1.3 V @ ?

Enable

Plug in Card – Power Yale Model 2151

GND

Power Good

Small Plug-in Card

Absolute Max 10%For Long Lifetime

Spiral Coils Resistance in mΩ

Top Bottom

3 Oz 57 46

10 mil Cu 19.4 17

Coupled InductorConnected in Series

Shielded Buck Inductor

Shielding Spiral – One end to GND

8

4 layersLayer1: Top Coil with no connection - ShieldLayer2: coil Connect in seriesLayer3: coil Connect in seriesLayer4: Bottom Coil with no connection- Shield

Spacing between Layer 2 & 3 = 14 mills ( 0.35 MM) Proximity EffectTop & Bottom can be more as there is no loss from these

10 mil Cu 19.4 17

Shielding Spiral – One end to GND

Power INEnable / DisablePower Good Out

9Yale University April 09, 2009 Model 2151_Max8654Yale University April 09, 2009

Power Out

Kelvin points for Vin & Vout

MAX8654 with embedded coils (#12), external coils (#17) or Renco Solenoid (#2) Vout=2.5 V

40

50

60

70

80

90

100

Eff

icie

ncy

(%

)

PCB embedded Coil

Copper Coils

Solenoid

10

0

10

20

30

40

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5Output current (amps)

Eff

icie

ncy

(%

)

MAX #12, Vin = 11.9 V MAX #17, Vin = 11.8 V MAX #2, Vin = 12.0 V

Plug In Card: DC-DC Powering 2 Different ICs 3 Different Coils

Monolithic: 14V, 8A, 1.2MHzMultichip: 16V, 8A, 1.5MHz

Coil Board # Common Power Input Noise

Mode Choke To Dc_DC Electrons rms

Solenoid Max # 2 No 881

" " " 885

Copper Coil IR # 17 No Switching 666

" " Yes " 634

11Yale Model 2151a

Embedded 3 oz Cu Etched Cu Foils 0.25 mmSolenoid without Ferrite

" " Yes Linear 664

Embedded Max 12 No Linear 686

" " Yes " 641

All Channels Trimmed

" " Yes " 648

NoiseSame with Linear or DC - DC

12

Sensor 1 cm from Coil

Shield 20 µm Al Foil NoiseNO change with Plug in cardon top

Controller : Low Voltage

Can We HaveHigh Radiation Tolerance & Higher Voltage Together ???

13

High Voltage: Switches –

LDMOS, Drain Extension, Deep Diffusion etc

>> 20 Volts HEMT GaN on Silicon, Silicon Carbide, Sapphire

Thin Gate Oxide

14

Book ‘Ionizing Radiation Effects in MOS Oxides’ Author Timothy R. Oldham

Thin oxide implies lower operating voltage

LDMOS StructureLaterally DiffusedDrain Extension

High Voltage / high FrequencyMain market. Cellular base stations

15

High performance RF LDMOS transistors with 5 nm gate oxide in a 0.25 µm SiGe:C BiCMOS technology: IHP MicroelectronicsElectron Devices Meeting, 2001. IEDM Technical Digest. International2-5 Dec. 2001 Page(s):40.4.1 - 40.4.4

16R. Sorge et al , IHP Proceedings of SIRF 2008 ConferenceHigh Voltage Complementary Epi Free LDMOS Module with 70 VPLDMOS for a 0.25 µm SiGe:C BiCMOS Platform

IBM Foundry Oxide Thickness

Lithography Process Operating Oxide

Name Voltage Thickness

nm

17

0.25 µm 6SF 2.5 5

3.3 7

0.13 µm 8RF 1.2 & 1.5 2.2

2.2 & 3.3 5.2

Company Device Process Foundry Oxide Time in Dose before Observation

Name/ Number Name Thickness Seconds Damage seen Damage Mode

Country nm

IHP ASIC custom SG25V GOD IHP, Germany 5 53 Mrad slight damage

XySemi FET 2 amps HVMOS20080720 China 7 52 Mrad minimal damage

XySemi XP2201 HVMOS20080720 China 7 In Development

XySemi XPxxxxHVMOS20080720

China 7In Development Synch Buck

Non IBM Foundry ICs

18

XySemi XP5062 China 12.3 800 44 krad loss of Vout regulation

TI

TPS54620 LBC5 0.35 µm 20 420 23 krad abrupt failure

IR IR3841 9 & 25 230 13 Krads

loss of Vout regulation

Enpirion EN5365 CMOS 0.25 µm Dongbu HiTek, Korea 5 11,500 85 krad

Increasing Input Current,

Enpirion EN5382 CMOS 0.25 µm Dongbu HiTek, Korea 5 2000 111 Krads loss of Vout regulation

Enpirion EN5360 #2 SG25V (IHP) IHP, Germany 5 22 Days 100 Mrads Minimal Damage

Enpirion EN5360 #3 SG25V (IHP) IHP, Germany 5 10 Days 48 Mrads Minimal Damage

For Higher Radiation Resistancev Oxide Thickness is predominant Effect

19

v Others Epi Free processing is Good ?v Oxide Processing is standardv ?????

From China

20

IHP PMOS TransistorVG versus ID at selected Gamma Doses

0

0.2

0.4

0.6

0.8

1

I D (m

A)

Pre-Irradiation

13 Mrad

22 Mrad

35 Mrad

53 Mrad

IHP NMOS TransistorVG versus ID at Selected Gamma Doses

0

0.5

1

1.5

2

2.5

I D (

mA

)

Pre-irradiation

13 Mrad

22 Mrad

35 Mrad

21

XY Semi (VD = 12V)2 Amp FET- HVMOS20080720 Process

00.020.040.060.08

0.10.12

0 0.5 1 1.5

Vg (Volts)

Id (A

mps

)I

0 rad

1 Mrad

5.4 Mrad

33 Mrad

52 Mrad

00 0.5 1 1.5 2 2.5

VG (Volts)

00 0.5 1 1.5 2 2.5

VG (Volts)

22

Depletion ModeNormally ON

Enhancement ModeNormally OFF

GaN for Power Switching

23

RF GaN 20 Volts & 0.1 ampv 8 pieces: Nitronex NPT 25015: GaN on Siliconü Done Gamma, Proton & Neutronsü 65 volts Oct 2009

v 2 pieces: CREE CGH40010F: GaN on siC

v 6 pieces: Eudyna EGNB010MK: GaN on siCü Done Neutrons

Gallium Nitride Devices under Tests

24

ü Done Neutrons

Switch GaNv International Rectifier GaN on Silicon

Under NDA

Gamma: @ BNLProtons: @ LansceNeutrons: @ U of Mass Lowell

Plan to Expose same device toGamma, Protons & Neutrons

Nitronex 25015 Serial # 1

0.1

0.12

25

0

0.02

0.04

0.06

0.08

-2.5 -2.3 -2.1 -1.9 -1.7 -1.5 -1.3 VGS Volts

ID A

mps 4.2 Mrad

0 rad

17.4 Mrad

Source

HEMTPulse

Generator

~ 0.070 AmpsPower SupplyV out = 20

Drain

0 to -5 V

DMMDC mV

330 2 Watts 1 Ω

Pomona Box

Reading = ~ 0.035 Amps@ 50% Duty Cycle

No change in the average current for 200 Mega rads

30 meter Coax

26

Generator0.1 – 2 MHz

50 % Duty Cycle

July 28. 2009 FET Setup for Proton Radiation Exposure @ LANSCE

.

Gate

100

0 to -5 V

Powered FETGND

50 ΩTerminator 2 Shorted

FETs

G

DS

27

IR’s basic current GaN-on-Si based device structure is a high electron mobility transistor (HEMT), based on the presence of a two dimensional electron gas (2DEG) spontaneously formed by the intimacy of a thin layer of AlGaN on a high quality GaN surface as shown in Figure 1. It is obvious that the native nature of this device structure is a HFET with a high electron mobility channel and conducts in the absence of applied voltage (normally on). Several techniques have been developed to provide a built-in modification of the 2DEG under the gated region that permits normally off behavior.

Aside from providing high quality, reliable and a low-cost CMOS compatible device manufacturing process, the GaNpowIR technology platform also delivers dramatic improvements in three basic figures of merit (FOMs), namely specific on-resistance RDS(on), RDS(on)*Qg and efficiency*density/cost.

28Intel won’t disclose any details till product is announced

ConclusionsvLearned from commercial Devices,

Companies & Power conferencesv Can get high Radiation Tolerance & Higher VoltagevHigh Frequency > Smaller Air coil > Less Materialv Goal: ~20 MHz Buck, MEM on Chip size 9 mm x 9mmvPower SOC: MEMs Air Core Inductor on Chip

29

vPower SOC: MEMs Air Core Inductor on Chipv Study Feasibility 48 / 300V Converters vIrradiation: Run @ Max operating V & I.

vLimit Power Dissipation by Switching duty cyclevOnline Monitoring during irradiation for faster resultsvYale Plug Cards can be loaned for EvaluationvCollaborators are Welcome

Working on Power Supply Is not Glamorous

30The End

Neither it on Top of the World