Power Supply - Spectrum Digital TMS320VC5509A EVM PLUS Technical Reference

Spectrum Digital, Inc

1.6 Power Supply

The EVM PLUS operates from a single +5V external power supply connected to the
main power input (J5). Internally, the +5V input is converted into +1.6V and +3.3V.
The +1.6V supply is used for the DSP core while the +3.3V supply is used for the DSP's
I/O buffers and all other chips on the board. The power connector is a 2.5mm.
barrel-type plug.
The core voltage on the EVM PLUS is selectable based on the output of GPIO5 and
GPIO6 or CPLD control registers. If GPIO5 and GPIO6 are high or configured as an
input the core voltage will remain at +1.6V. If GPIO5 and GPIO6 are driven low the
voltage will drop to +1.2V. The table below shows the 3 core voltage levels available on
the VC5509 EVM PLUS.
There are three power test points on the EVM PLUS at JP2, JP3 and JP6. All board
current passes through JP2 (the +5V supply). All DSP core current passes through
JP3. JP6 allows measurement of DSP I/O pins. To measure the current passing
connect the pins with a voltage measuring device. A current shunt is also supplied to
amplify this voltage. This allows voltage meters to more accurately track current
changes.
The EVM PLUS also provides +3.3V for the daughter card. It is also possible to
provide the daughter card with +12V and -12V when the external power connector is
used.
1-8
Table 2: Core Voltage Level Select
GPIO6 GPIO5
0 0
0 1
1 0
1 1
TMS320VC5509A EVM PLUS Technical Reference
Core Voltage
Selected
1.2V
1.4V
1.4V
1.6V