Specifications

52
REGULATORY COMPLIANCE
EMI
The IS4920 consists of a 400MHz processor running a 100MHz SDRAM bus and
a camera interface capable of image transfer up to 48MHz. The IS4920 series
engine was designed to meet EN55022 Radiated Class B emission limits. Using
the system shown below, the IS4920 was able to meet these requirements with
an input voltage VIN = 3.3V and the camera interface operating at its maximum
frequency of 48MHz.
Figure 33. IS4920 EMI Test System
Components used in IS4920 EMI test system
Part Number
(Metrologic p/n)
Part Description/Function
IS4920-USB Imaging decode engine
77-77104A Imager to Decode Flex cable assembly (shielded)
77-77095A IS4920 test adapter board
52-52828 USB cable (A to B)
19-00329 12pin Host Flex cable
Given the Decoding platform architecture described above, it is follows that
harmonics of 48MHz and 100MHz were most prevalent.