Page 133 - Microsensors, MEMS and Smart Devices - Gardner Varadhan and Awadelkarim

PROGRAMMABLE DEVICES AND ASICs 113

Figure 4.47 Three main types of ball grid array packages: (a) plastic; (b) ceramic; and (c) tape-ball

nonvolatile memory. For example, erasable programmable read-only memory (EPROM)
in which the memory is erased by UV light and its easier-to-use successor, electronically
erasable programmable read-only memory (EEPROM). In recent years, there has been a
strong move toward software programmable array devices; these components do not have
the mathematical capability of a microprocessor but are able to perform simple logical
actions. As such, they can be high-speed stand-alone chips or glue chips - that is, chips
that interface an analogue device with a microcontroller or communication chip. Examples
of these are programmable logic devices (PLDs) and PGAs that may have several thousand