MRF208

The MRF208 was designed for RF signal switching and tuning. As a function of the forward bias current the forward resistance (rf) can be adjusted over a wide range. A long carrier life time offers low signal distortion for signals over 10 MHz up to 3 GHz. Typical applications for this PIN Diodes are switches and attenuators in wireless, mobile and TV-systems.

MRF208 Write-only control and status Read multiple command for data transfer Up to 4 host clients control and status queues Physical or logical clients C Enables peer-to-peer architecture Descriptor-based buffer chaining Scatter/gather DMA Endian neutral Non-word (byte) aligned host buffer addresses Automatically detects presence of Tx data or Rx free buffers Virtual FIFOs (PCI bursts treated as single address) Hardware indication of BOM Allows isolation of system resources Status queue interrupt delay.Some care must be used in interpreting the numbers in this table. Philips Semiconductors feels strongly that the specifications set forth in a data sheet should reflect as accurately as possible the operation of the part in an actual system.

This MRF208 frequently causes problems because of the noise present at the test head of automated test equipment. Parametric tests, such as those used for the output levels under the VIH and VIL conditions are done fairly slowly, on the order of milliseconds, and any noise present at the inputs has settled out before the outputs are measured. (This is not the case with clocked or enabled parts and poor or moderate fixturing may induce oscillations or severe ground bounce if noise is present.) But in functionality testing, the outputs are examined much faster, before the noise on the inputs is settled out and the part has assumed its final and correct output state. Since these are unloaded outputs, having faster edge rates, this causes more noise, If the outputs are loaded, the 50pF per output pin can cause substantial ground bounce. Thus VIH and VIL should never be used in testing the functionality of any TTL part including FAST. For these types of tests input voltages of +4.5V and 0.0V should be used for the High and Low states respectively.