2013-10-08
PRODUCT MANUAL PPC3-G-6.5-359
5
POWER SUPPLY
The power supply and how it is connected to the Single Board Computer (SBC) is very important.
Avoid Electrostatic Discharge (ESD)
Only handle the SBC and other bare electronics when electrostatic discharge
(ESD) protection is in place. Having a wrist strap and a fully grounded
workstation is the minimum ESD protection required before the ESD seal on
the product bag is broken.
Power Supply Budget
Evaluate your power supply budget. It is usually good practice to budget 2X
the typical power requirement for all of your devices.
Zero-Load Power Supply
Use a zero-load power supply whenever possible. A zero-load power supply
does not require a minimum power load to regulate. If a zero-load power
supply is not appropriate for your application, then verify that the single board
computer’s typical load is not lower than the power supply’s minimum load. If
the single board computer does not draw enough power to meet the power
supply’s minimum load, then the power supply will not regulate properly and
can cause damage to the SBC.
Use Proper Power Connections (Voltage)
When verifying the voltage, you should always measure it at the power
connector on the SBC. Measuring at the power supply does not account for
voltage drop through the wire and connectors.
The single board computer re5V (±5%) to operate. Verify the power
connections. Incorrect voltages can cause catastrophic damage.
Populate all of the +5V and ground connections. Most single board computers
will have multiple power and ground pins, and all of them should be populated.
The more copper connecting the power supply to the single board computer
the better.
Adjusting Voltage
If you have a power supply that will allow you to adjust the voltage, it is a good
idea to set the voltage at the power connector of the SBC to 5.1V. The SBC
can tolerate up to 5.25V, so setting your power supply to provide 5.1V is safe
and allows for a small amount of voltage drop that will occur over time as the
power supply ages and the connector contacts oxidize.
Power Harness
Minimize the length of the power harness. This will reduce the amount of
voltage drop between the power supply and the single board computer.
Gauge Wire
Use the largest gauge wire that you can. Most connector manufacturers have
a maximum gauge wire they recommend for their pins. Try going one size
larger; it usually works and the extra copper will help your system perform
properly over time.
