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VersaKit-30xx
2.1
Power Supply Requirement
The VersaKit-30xx development board is powered via either the Versa JTAG USB (VJTAG-USB) board or an external
power supply connected to PJ1. The VJTAG-USB provides up to about 110mA of power to the devboard or target board.
The development board consumes from 30 to 40mA, leaving approximately 70mA for prototype development
If your prototype's total power consumption is more than 70mA, we recommend using the external power supply shipped
with the VersaKit-30xx. This should be connected to PJ1 on the devboard and can supply up to 300mA.
Note: If the external power supply is connected to PJ1, remove the JP1 jumper on the VJTAG-USB board.
If you need to use another power source, ensure that it respects the following parameters:
Table 1. Development board power supply specifications
Nominal input Voltage
Maximum input voltage
Current
Plug Type
Warning: Many commercially-available wall-mount DC power adapters exceed their output voltage rating when in low
load condition. If you do not plan to use the power supply provided with the kit, verify that the specifications on the one
you choose meets the requirements above before using it with the development board.
Ensure that the input voltage supplied to the devboard PWR-IN input is always below 11 volts.
2.2
VersaKit-30xx Devboard: Onboard Power Supply Configuration Regulators & JP1 Jumper
The VersaKit-30xx devboard includes a 3.3V low drop-out linear regulator to power the VRS51L3074 (through the JP1
jumper) and the RS-232 transceiver. This regulator provides up to 250mA of power and includes a thermal shutdown
feature.
To facilitate use of the devboard as a prototyping platform, access to the 3.3V regulator output and ground access are
available via two 4x2 header footprints located on each side of the prototyping area.
The development board also features an auxiliary LM2937 regulator footprint, which is powered by a DC power input and
whose output is accessible on the H6 4x2 header footprint. The R9 resistor provides a path from the U4 output and H6
VDD to the Reg102-3.3 regulator output.
Heat from the regulators is dissipated through the devboard PCB. As such, the area on the PCB around the regulators
may become hot when the regulators are operating.
Warning: It is mandatory to remove resistor R9 when installing a regulator in position U4.
Please refer to the development board schematics at the end of this document for more details about regulator
configuration.
2.3
_______________________________________________________________________________________________
www.ramtron.com
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Figure 3: JP1 jumper of the VJTAG-USB board
6VDC
11V DC
200mA+
2.1mm Female Plug (Center
positive)
page 4 of 28
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