Monolithic Power Systems, Inc. · NASDAQ:MPWR
Monolithic Power Systems — Technical Presentation
15 slides from Monolithic Power Systems's technical presentation
Slide 1: Optimize Switch-Mode Power Modules to Achieve Ultra-Low (μV) Ripple and Noise
Optimize Switch-Mode Power Modules to Achieve Ultra-Low (μV) Ripple and Noise Ao Sun -- Monolithic Power Systems Xin Zhao -- Monolithic Power Systems George Stathakis -- Monolithic Power Systems 3092 1 of 15
Slide 2: Background
Background • The growing bandwidth of wireless networks and data centers demand for power regulators with high power density, fast load transient response, and high efficiency. • High-performance RF data converters, e.g. Xilinx Zynq UltraScale+ RFSoCs which provides a comprehensive RF signal chain,
Slide 3: Output Voltage Ripple with Forced CCM Operation
Output Voltage Ripple with Forced CCM Operation Figure 1. Low Noise Filter Design 3 of 15
Slide 4: Why use second stage inductive filter?
Why use second stage inductive filter? • As more capacitors are placed on the output plane, the distance from the additional capacitor to the output pin of the power module increases. • Consequently, more parasitic inductance is involved in the output capacitor that is farther away from the power mo
Slide 5: Why use second stage inductive filter?
Why use second stage inductive filter? Output voltage ripple with one 22uF output capacitor 4mV Peak-to-Peak • Additional output capacitor becomes less effective 4x22uF output capacitor 5x22uF output capacitor 2mV Peak-to-Peak 1.7mV Peak-to-Peak Fig. 3 Output Voltage Ripple of the MPM3833C with (a)
Slide 6: Design of the Second Stage Filter
Design of the Second Stage Filter Buck Converter Circuit 2nd Stage Filter Figure 4. Second Stage LC Filter with Parallel Damping Branch [1] 6 of 15 [1] https://www.monolithicpower.com/cn/passive-filter-design-concept-of-buck-regulators-for-ultra-low-noise-applications
Slide 7: Damping of the LC filter
Damping of the LC filter • At load transient, the resonance between the filtering inductor and bypassing capacitor may amplify the output ripple and create undesired ringing. • To avoid undesired ringing at load transient, the second stage LC filter resonance must be properly damped. Figure 5. Secon
Slide 8: Damping of the LC filter
Damping of the LC filter Figure 6. Step Response of (a) Underdamped LC Filter and (b) Overdamped LC filter • RDamp needs to satisfy 8 of 15
Slide 9: Design Specification for ADC rails
Design Specification for ADC rails Rail Name VIN VOUT IOUT Target Ripple Magnitude ADC_AVCC 5V 0.925V 2A 0.4mV DAC_AVCC 5V 0.925V 3.5V 0.4mV ADC_AVCCAUX 5V 1.8V 2A 5.5mV DAC_AVCCAUX 5V 1.8V 2A 1mV ADC_AVTT 5V 2.5V/3V 2A 5mV 9 of 15
Slide 10: Traditional Solution – LDO Approach
Traditional Solution – LDO Approach Vin=5V+/-5% ADC_AVCC LDO • High Loss 0.925V/2A • Noise target achieved ADC_AVCCAUX LDO 1.8V/2A LDO DAC_AVCC 0.925V/3.5A DAC_AVCCAUX LDO 1.8V/2A DAC_AVTT LDO 2.5/3.0V/2A 10 of 15
Slide 11: Switch Mode Power Module + Passive Filter Solution
Switch Mode Power Module + Passive Filter Solution Figure 7. MPS EVREF0102 Power Module 11 of 15
Slide 12: Same Noise Performance as LDO Solution
Same Noise Performance as LDO Solution Figure 8. MPS EVREF0102 Power Module Noise Figure 9. MPM3833C Efficiency VS. Output Current Spread Spectrum Same noise performance 4X more efficient than LDO 12 of 15
Slide 13: Passive Filter Design Example MPM3833C
Passive Filter Design Example MPM3833C Converter Circuit 2nd Stage Filter VIN VOUT IOUT Target Ripple Magnitude 5V 0.925V 2A 20uV 13 of 15
Slide 14: Passive Filter Design Example
Passive Filter Design Example MPM3833C Converter Circuit 2nd Stage Filter VIN VOUT IOUT Target Ripple Magnitude 5V 0.925V 2A 20uV STEP 4. In this use case, more output capacitors are used to achieve better load transient performance. The required damping resistance can be calculated ᵃ 1 = 100ᵆᵃ + 47
Slide 15: Thank You
Thank You 15 of 15