![]() ![]() Thus we normally do not know the value of Most vendors do not specify output characteristics because they are difficult to measure in production. , that results, we find that a buffer is capable of sourcing and sinking far more than the specified , of an output buffer, using a voltage supply, and measure the output current, Is negative) through a pull-down resistor, (c) Pull-up transistor M1 (M2 is off) sources (from VDD) current (b) Pull-down transistor M2 (M1 is off) sinks (to GND) a current = 4.0 V for a technology-without referring to the current values at which these are measured-strictly this is incorrect. Similarly, when the output is 4 V, the buffer can CMOS logic inputs that may be connected to the pad draw minute amounts of current, but bipolar TTL inputs can require several milliamperes. No more than 8 mA if the load requires it. The Xilinx XC5200 specifications show that the output buffer can force the output pad to 0.4 V or lower and Input currents, if there are any, are positive if they flow into the inputs. , is positive if it flows into the output. As an example, values for the Xilinx XC5200 are as follows Data books typically specify the output characteristics at two points, A Shows a CMOS complementary output buffer used in many FPGA I/O cells and its DC characteristics. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |