Download HSM550 Technical Reference

HSM/550 Technical Reference - July 13, 1999 - © Systronix®, Inc.
HSM/550 HARDWARE
Controller or ICE Pod Installation
A PLCC68 part has one chamferred corner which must be aligned with the matching socket corner.
Device leads are relatively fragile so be careful to line up the part in the socket precisely before
pressing it in place. Refer to the schematics and the Dallas data sheets for processor pinout details
and signal names.
If you are using an In Circuit Emulator (ICE), turn off the board and ICE power. Insert the ICE pod,
then turn on the ICE and board power at the same time. We recommend using a power strip to do
this. If you power one and not the other, you could cause CMOS components in the ICE or the board
to latch up, possibly destructively. We’ve seen this erase PLDs and damage the ICE. That’s when we
started using a power strip to turn both the board and the ICE on and off simultaneously.
Power Supply
The power input jack is 5.5 x 2.5 mm, with center terminal positive and the sleeve negative. The
voltage regulator will accept supplies up to an absolute maximum of 24 VDC.. Power supply input
voltages above 6 VDC are acceptable, and up to a point (about 9V DC) will make the regulator more
efficient. The regulator will simply shut down if it is short-circuited or overheats. The regulator will
start to drop out at about 5.5 volts typical. Reset circuitry puts the board in a safe reset state if VCC
drops to 4.5 volts.
If you provide your own power supply be sure it is a DC voltage of at least 6 volts. Some wall cube
power supplies are actually AC transformers and may damage the board. HSM/550 ships with a 12
VDC 1000 mA power cube. With an input voltage of 7 VDC, HSM/550 draws 180 mA typical, and
with 6 VDC input, 210 mA. Current use is lower at higher input voltages because of the power
conversion of the switching regulator (Power = Voltage X Current).
If you will be driving the board from a 12 VDC vehicle electrical system, the input voltage will
typically be 13.8 VDC. HSM/550 includes reverse-polarity and overvoltage protection. The
overvoltage typically clamps at 24 VDC.
HSM/550 is designed to be operated from a 6 volt or greater battery. All the on-board circuitry is
relatively efficient. The DS87C550 has numerous power conservation modes. We may offer a special
low-power version with ‘zero-power’ PLDs, let us know if you’re interested in this.
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