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Programmable Hardware Manual (PHM)
© Tibbo Technology Inc.
4.4.1.5
Power, Reset, and Mode Selection Lines
The EM510 should be powered from a stabilized DC power supply with a nominal
output voltage of 3.3V (+/- 5% tolerance). The module's current consumption is
approximately 110mA. Providing an adequate power supply is very important — a
poorly built circuit may affect the EM510's operation. We recommend that you use a
switching power regulator. One example of such a circuit is shown below.
External reset is optional — the EM510 generates a reliable power-on/brown-out
reset on its own. If the EM510 is to serve as a communications co-processor in a
larger system that has its own CPU (microcontroller) it is also OK to control the RST
line through a general-purpose I/O pin of this CPU. Reset pulses for the EM510 can
then be generated programmatically, by setting the I/O pin of the CPU to LOW and
then to HIGH.
The function of the MD line is described in
.
Power supply circuit
Many power supply circuits will work well. The one below is being used by Tibbo.
This circuit can handle input voltages in the 9-24V range.
Notes:
·
U1 (AP1501-33) is a popular power IC manufactured by Anachip (now Diodes
Incorporated,
·
C1 and C2 capacitors: Do not use SMD capacitors -- use regular through-hole
aluminum capacitors. This really helps reduce the noise produced by the power
supply.
·
This is an analog circuit, so layout matters. Apply reasonable "good layout" effort.