资 源 简 介
The Philips Semiconductors 74F “Light Load” product line is a highperformance, TTL bus compaTIble series of very low input biascurrent (±20mA), buffer/driver, transceiver, register, mulTIplexer andarithmeTIc MSI funcTIons. The patented “Light Load”, ±20mA NPNinput structure, shown in Figure 1, combined with a unique inputspeed-up circuit (also patented) makes this product line ideal forinterfacing with all MOS devices, without any speed degradation.When compared to the IIL of standard FAST inputs of 600mA (largerfor some other logic families) this “Light Load” input shows a30:1 reduction in IIL loading (600mA/20mA).These devices were specifically designed to meet the requirementsof buffering low output drive MOS VLSI/LSI devices from therigorous loading environment PC board/motherboard buses andsystem backplanes. The “Light Load” inputs and improved speedperformance make this product line ideal for interfacing to low outputdrive capability, slower MOS CPU, peripherals and semi-customchips used in most state-of-the-art logic designs today. Using these“Light Load” input bus products, MOS chip outputs will only have todrive the small amount of distributed PC trace capacitance andinductance loading. The MOS device output drive capability is notwasted on drivers/transceivers with large DC input current driverequirements.See Table 1 for a complete listing of the part numbers and functionsof the “Light Load” product line.
