Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of
Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI NOISE prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
|Introduction Basic Concept Tips to layout Power circuit Type of Power circuit
Basic Concept Maximum Current calculation Resistance of Copper ideal power supply & NOISE Capacitor & Inductor Power consumption Function of power circuit
ACPR (adjacent channel power ratio), AltCPR (alternatechannel power ratio), and NOISE are important performancemetrics for digital communication systems thatuse, for example, WCDMA (wideband code division multipleaccess) modulation. ACPR and AltCPR are bothmeasures of spectral regrowth. The power in the WCDMAcarrier is measured using a 5MHz measurement bandwidth;see Figure 1. In the case of ACPR, the total powerin a 3.84MHz bandwidth centered at 5MHz (the carrierspacing) away from the center of the outermost carrier ismeasured and compared to the carrier power. The resultis expressed in dBc. For AltCPR, the procedure is thesame, except we center the measurement 10MHz awayfrom the center of the outermost carrier.
Frequently, voltage reference stability and NOISE defi nemeasurement limits in instrumentation systems. In particular,reference NOISE often sets stable resolution limits.Reference voltages have decreased with the continuingdrop in system power supply voltages, making referenceNOISE increasingly important. The compressed signalprocessing range mandates a commensurate reductionin reference NOISE to maintain resolution. NOISE ultimatelytranslates into quantization uncertainty in A to D converters,introducing jitter in applications such as scales, inertialnavigation systems, infrared thermography, DVMs andmedical imaging apparatus. A new low voltage reference,the LTC6655, has only 0.3ppm (775nV) NOISE at 2.5VOUT.Figure 1 lists salient specifi cations in tabular form. Accuracyand temperature coeffi cient are characteristic ofhigh grade, low voltage references. 0.1Hz to 10Hz NOISE,particularly noteworthy, is unequalled by any low voltageelectronic reference.
Abstract: How can an interface change a happy face to a sad face? Engineers have happy faces when an interface works properly.Sad faces indicate failure somewhere. Because interfaces between microprocessors and ICs are simple—even easy—they are oftenignored until interface failure causes sad faces all around. In this article, we discuss a common SPI error that can be almostimpossible to find in a large system. Links to interface tutorial information are provided for complete information. NOISE as a systemissue and ICs to minimize its effects are also described.
This packet is a IS-95 baseband simulation for 1 data channel of 9.6 KBps rate. The simulation is written for static channel and AWGN NOISE.
The packet include:
1) Packet Builder (Viterbi Encoding, Interleaver, PN generation)
2) Modulator (RRC filter)
3) Demodulator (Matched Filter, RAKE receiver)
4) Receiver (HD or SD) (Deinterleaver, Viterbi Decoder).
You should run "Simulation.m" function that include all modules.
Random Number Generators（隨機(jī)數(shù)生成）包括gaussian random number generator、uniform random number generator、low-frequency hold generator、1/f NOISE generator等5種隨機(jī)信號(hào)生成的c源代碼
Routine mar1psd: To compute the power spectum by AR-model parameters.
Input parameters:
ip : AR model order (integer)
ep : White NOISE variance of model input (real)
ts : Sample interval in seconds (real)
a : Complex array of AR parameters a(0) to a(ip)
Output parameters:
psdr : Real array of power spectral density values
psdi : Real work array
in chapter 12
