Always follow TI’s setup and application instructions, including use of all interface components within their recommended electrical rated voltage and power limits. Always use electrical safety precautions to help ensure the user's personal safety and the safety of those working around the user. Contact TI’s Product Information Center TI's Product Information Center for further information.

Save all warnings and instructions for future reference.

Failure to follow warnings and instructions can result in personal injury, property damage, or death due to electrical shock, burn hazards, or both.

The term TI HV EVM refers to an electronic device typically provided as an open-framed, unenclosed printed-circuit board assembly. It is intended strictly for use in development laboratory environments, solely for qualified professional users that have training, expertise, and knowledge of electrical safety risks in development and application of high-voltage electrical circuits. Any other use, application, or both, are strictly prohibited by Texas Instruments. If the user is not suitably qualified, the user should immediately stop from further use of the HV EVM.

• Work Area Safety:
  • Maintain a clean and orderly work area.
  • Qualified observer or observers must be present any time circuits are energized.
  • Effective barriers and signage must be present in the area where the TI HV EVM and its interface electronics are energized, indicating operation of accessible high voltages can be present, for the purpose of protecting inadvertent access.
  • All interface circuits, power supplies, evaluation modules, instruments, meters, scopes, and other related apparatus used in a development environment exceeding 50-V_RMS/75-VDC must be electrically located within a protected Emergency Power Off (EPO) protected power strip.
  • Use a stable and non-conductive work surface.
  • Use adequately insulated clamps and wires to attach measurement probes and instruments. No freehand testing whenever possible.
• Electrical Safety:

  As a precautionary measure, it is always a good engineering practice to assume that the entire EVM may have fully accessible and active high voltages.

  • De-energize the TI HV EVM and all its inputs, outputs, and electrical loads before performing any electrical or other diagnostic measurements. Confirm that TI HV EVM power has been safely de-energized.
  • With the EVM confirmed de-energized, proceed with required electrical circuit configurations, wiring, measurement equipment hook-ups, and other application needs, while still assuming the EVM circuit and measuring instruments are electrically live.
  • When EVM readiness is complete, energize the EVM as intended.
  WARNING: WARNING: While the EVM is energized, never touch the EVM or its electrical circuits as they could be at high voltages capable of causing electrical shock hazard.
  
• Personal Safety:
  • Wear personal protective equipment, for example, latex gloves, safety glasses with side shields, or both, or protect the EVM in an adequate lucent plastic box with interlocks from accidental touch.
• Limitation for Safe Use:
  • EVMs are not to be used as all or part of a production unit.

Safety and Precautions

The EVM is designed for professionals who have received the appropriate technical training, and is designed to operate from an AC power supply or a high-voltage DC supply. Please read this user's guide and the safety-related documents that come with the EVM package before operating this EVM.

CAUTION:

Do not leave the EVM powered when unattended.

WARNING:

Hot surface! Contact may cause burns. Do not touch!

WARNING:

High Voltage! Electric shock is possible when connecting board to live wire. Board should be handled with care by a professional. For safety, use of isolated test equipment with overvoltage and overcurrent protection is highly recommended.

The LMR38020QEVM is configured to deliver 5 V and 2 A at a switching frequency of 400 kHz.

• Tightly regulated output voltage of 5 V with 1.5% setpoint accuracy
• Wide input voltage operating range of 4.2 V to 80 V
• 98% maximum duty cycle
• PFM operation to improve efficiency at light load
• Spread spectrum option for reduced EMI
• PWRGD signal indicates output regulation
• Supports start-up with pre-biased output
• Programmable system UVLO through precision enable
• Fully assembled, tested, and proven PCB layout

1. Connect the voltage supply between VIN and GND connectors using short wires.
2. Connect the load of the converter between VOUT and GND connectors using short wires.
3. Set the supply voltage (V_IN) at an appropriate level between 6 V to 80 V. Set the current limit of the supply to an appropriate level as well.
4. Turn on the power supply. The EVM powers up and provides V_OUT = 5 V.
5. Monitor the output voltage while increasing the load current to 2-A maximum.

See Figure 2-1 for the location of the connectors.

Figure 2-1 LMR38020QEVM Top View

WARNING:

Hot surface! Contact may cause burns. Do not touch!