Jimmy Chang

• In charge of Power supply Unit(PSU) design quality of all CMs (Delta, Liteon, AEI, Flextronics)
• In charge of Power supply Unit(PSU) design quality of all ODMs (Chicony, Acbel, Belpower, Murata, Greatwall, Meanwell)
• Coordinated Multiple projects, defined scope and managed milestones

- Edge server for 5G application for Telecom
- Compute server for Cloud service for MSFT/META/AWS
- GPU server for AI training/inference for Intel/AMD/AWS
- Tank server for immersion cooling for MSFT

• Provided guidance in data analysis, inspection, problem-solving to function team
• Define validation flow to prevent potential bugs in system application
• Analyzed RFQ from customers and develop PSU solutions
• Review technology roadmaps from vendors to define strategic partnership for company5

• Huawei stylus with HPP2.0 (Huawei Pen Protocol 2.0)

- Powered by 1.5V AAAA battery with 2.5V & 20V boost converter

- 15uA power consumption design for six months battery life

- Take care of PCB placement and layout review

- On-site support (China) to solve ESD issue

• Huawei stylus with HPP3.0 (Huawei Pen Protocol 3.0)

- Powered by 120mAh Li-Battery with 40V boost topology and 1.8V buck converter

- Design deep sleep mode to achieve 1uA ultra low power consumption

- Take care of Bluetooth Low Energy(BLE) hardware design, antenna , PCB placement and layout review

- Design Battery management system(BMS), include modeling, gauging, charing, protection.

- Design test fixture for Tip pressure calibration by servo motor

- On-site support (China) for prototype testing

• Huawei stylus with HPP4.0 (Huawei Pen Protocol 4.0)

- Dual power sources, 20mAh Li-Battery or 3F Supercapacitor

- Dual power tree design, type C charging or NFC wireless charging

- 100MHz Radio Frequency(RF) front end circuit design for signal conditioning

- On-site support (Japan) for prototype testing

• HP & Dell stylus with MPP2.0 (Microsoft Pen Protocol 2.0)

- Powered by 20mAh Li-Battery with 2.5V & 20V boost converter

- Design EVK for add-on features verification

- On-site support (Hsinchu) to pass Microsoft HLK testing
- Release guideline about Troubleshooting to improve productivity

• Worked flexible hours across night, weekend and holiday shifts.

• 70W embedded power for Juniper Networks

- Flyback topology and full analog control

- Achieve complicated and tough design for -40C~85C temperature requirement

- Solve EMC issues and pass 6kV surge test

• 750W/550W/45W power for Lenovo's Grantley platform

- CCM PFC + PSFB topology and full digital control

- Study firmware control algorithm and help firmware engineer to solve related issues.

- Common PCB design for cost reduction

• 130W power for Hewlett Packart enterprice(HPE) Networking

- DCM PFC + flyback topology and full digital control

- Apply SIMetrix simulation and Mathcad calculation to find optimal design in design proposal stage

- Firstly introduce Freescale MCU in design for cost reduction

• 800W/550W power both for Lenovo and Quanta Computer

- CCM PFC + LLC topology and full digital control

- Common circuit design for both clients to meet tight schedule

- In charge of firmware design for PFC control

- Design for production at prototype stage, minimize trial run and development cost

- Assign daily tasks properly to team members for solving issues in time

• 250W power for Cisco

- CCM PFC + LLC topology and hybrid control

- Design for extra low cost to achieve 20% BOM cost reduction

- Design for 15% parts count reduction

- Design new development&verification process to minimize cost. Three trial runs from prototype to mass production at factory

• 3200W rack power for Cisco

- Interleaved PFC + PSFB topology and hybrid control

- Dispatched to work in Nanjing. lead 7 EE (Nanjing) + 1 FW (Beijing) + 1 EE (Taipei)

- Guide colleague to solve issues, like EMC, thermal, timing control, protection, performance.

- chase down all defects which delay development for years

- Accomplish 3 trial runs at factory to converge problems within 6 months

• 0.7kW~ 5kW Servo motor driver

- introduce specific encoder communication for high accuracy

- develop S-type position control technique, theoretical derivation, CPLD programming for high response of position control

- Patent: High-accuracy motor speed calculation method of servo driver (Patent No: M429919)

• 40kW Elevator motor driver

- slim driver platform for OTIS Elevator Company

- complete energy re-generation technique for energy recovery

- complete initial position detection for pre-torque appling

- develop hardware&firmware compensator for noise suppression to enhance performance.

• 200kW General-purpose motor driver

- customized pressure control for injection-molding motor drive

- universal motor driver with Integrated PMSM&IM driver technique

- Develop sensor-less control technique for marketability

• Photovoltaic(PV) inverter

- 20kW high-power PV inverter design

- 200W micro PV inverter prototyping & field testing

- Prepare research proposals and Identified schedule and budget