User's Manual

Heat Dissipation Requirements
14 IM4 Module Integration Guide
Heat Dissipation Requirements
In most usage scenarios, the IM4 uses a maximum of 6.0W of power from
its host device. Since its RF transmit power is 1W, the IM4 must dissipate
up to 5.0W of heat.
Normally, the host dissipates this heat. However, under high ambient
temperature conditions or in a high duty cycle application, this heat may
need to be conducted outside the host to prevent the IM4 from entering
Overtemperature mode.
The IM4 has a built-in Overtemperature mode that provides sufficient
protection against very high temperatures. When the IM4 enters
Overtemperature mode, the card shuts down until cool enough to resume
operating.
The IM4 transfers heat to the back side (non-label side) of its case. Any
heat transfer mechanism (such as moving air, a metal heatsink, or a heat
pipe) applied to this surface will help this dissipate the heat.
Ideally, the optimum temperature for the IM4 is below 65°C (149°F).
Power Requirements
The PC card slot must be able to supply enough current for the IM4 in RF
ON mode. There are three current modes: idle (quiescent), digital only, and
RF ON. Each mode requires a different current draw.
Use the following table when calculating DC power requirements for your
laptop computer.
The RF ON mode corresponds to the highest current mode when the
reader is communicating with a tag. The IM4 will not stay in Digital Only
mode for any significant length of time before it switches to RF ON mode.
The amount of time that the IM4 is in RF ON mode is mostly affected by
the number of RFID tags in the reading range.
Note: Most laptop PC card slots cannot supply enough current to support
the IM4 in RF ON mode.
Current Mode Current Draw Status
RF ON 1100 mA Communicating with tags
Digital Only 200 mA Fully ready state ready to execute a command
Idle 3 mA No activity (quiescent)
?
?
TBD
TBD
TBD
11
11
_
11
11
11
11
11
11
11
_
_
m-PCI
mini-PCI
mini-PCI slot.
IM11