数字电源解决方案

Digital Power Solutions with C2000 MCU
Vieri Xue（薛超） 薛超）
Tel: 021-23073581 Mail: vieri-xue@
Content
• What is Digital Power? • Key Digital Power System Concept • TI’s Digital Power Solutions • Development Support and Tools • Demo, Q&A
•
Enables Higher Quality
– – – – – – Adaptive; efficiency across load range Flexibility Through Programmability Calibration at Final Functional Test Less Sensitive to Environment and Component Drift Better Noise Immunity Parameter Monitoring for Continual Quality Improvement
Block Diagram of Digitally Controlled Power Converter
Code execution
Analog Controller Digital Controller
Compensator PWM d(t) – + e(t)
Vin
PWM
Vref
+ –
+ –
Controller
Time Sampled Systems
Digital loop performance is fundamentally limited by three components: ADC, CPU, & PWM. Each imposes a limit on the number & complexity of control loops which can be supported.
Single or dual chip solution meets static/dynamic performance specs
Highest (32bit) CPU performance Fastest ADC, Highest PWM Duty and Frequency Resolution
– – A/D conversion delay -> Fast A/D conversion time, advanced A/D interrupt, flexible sequencing control Time it take to execute the compensation -> Fast CPU speed and high processing power, CLA, on-chip analog comparators for peak mode current control or c-b-c current limiting
Switches
(FETs)
Vramp Vramp (Compensator) 1 2
LC Network
(output filter)
Vout
Goal: maintain constant Vout regardless of change in Vin or load, within spec.
L1 L2 Vg R L1 R L2 i1 i2 Vout
+ –
R ESR + VC –
R C
Compensator PWM d (t) + – V ramp 1 + + – Vramp 2 V ref – e (t)
• It’s a discrete control system • It uses analog compensator/controller • The controller is both a PWM generator and compensator/controller
Content
• What is Digital Power? • Key Digital Power Concept • TI’s Digital Power Solutions • Development Support and Tools • Demo, Q&A
An Example Switch-Mode Power Converter
ADC Performance Limit
Sequential Sampling:
Sample "n" Clocks Convert 5 Clocks 7 Clocks Reg Write 2 Clocks 2 Clocks Max Continuous Sampling 60MHz/12 cycles = 5.0 MSPS SOC Latch & Prioritization Generate Early Interrupt Generate Late Interrupt Can Start Sampling Next Channel 40MHz/12 cycles = 3.333 MSPS Min Sample Window ~= 100nSec
• The controller block is what differentiates between a digital power system and a conventional analog power system
Why We Need Digital Power?
More and more customers want their power suppliers to go digital because it… • Reduces Costs
Large and scalable product portfolio that is 100% s/w compatible, perfect for platform choice
Content
• What is Digital Power? • Key Digital Power Concept • TI’s Digital Power Solutions • Development Support and Tools • Demo
The Block Diagram of the Example SwitchMode Power Converter
Ana PWM d(t) – + e(t)
Vin
PWM
Vref
+ –
+ –
Controller
Switches
(FETs)
Vramp Vramp (Compensator) 1 2
•
Means Higher Reliability
– Intelligent Diagnostics, Failure Prediction; Reporting Capability – Reduced Parts Count = Fewer Field Failures
Why C2000 for Digital Power Supply
Sample to Control Update Delay Critical
• • •
Sample to control update delay may or may not be the same as sampling period Minimizing this delay is critical to performance of digital power. This delay directly erodes into control loop phase margin. Key contributors to the delay are
– Development
• Tunable Platforms Lead to New Products Quicker
– Qualification
• Calibration, better noise and temperature immunity
– Manufacturing
• Reduced Board Area • Reduced Parts Count = Lower Inventory
LC Network
(output filter)
Vout
Goal: maintain constant Vout regardless of change in Vin or load, within spec.
Example Digitally Controlled Switch-Mode Power Converter
Unlock customer’s capability to innovate and differentiate Increase customer’s Reliability of digital design and no drift long-term Faster time to market because of s/w flexibility and reduced manufacturing and R&D competitiveness! cost
L1 L2 Vg R L1 R L2 i1 i2 R ESR + VC – c2 C Vsense – Vout
Code execution
+ –
R
...c 1
Set/Measure, report Voltage, Temperature, Current, faults…