IC Voltage Regulators Information

IC voltage regulators are three-terminal devices that provide a constant DC output voltage that is independent of the input voltage, output load current, and temperature. There are three types of IC voltage regulators: IC linear voltage regulators, IC switching voltage regulators, and DC/DC converter chips. IC linear voltage regulators use an active pass element to reduce the input voltage to a regulated output voltage. By contrast, IC switching voltage regulators store energy in an inductor, transformer, or capacitor and then use this storage device to transfer energy from the input to the output in discrete packets over a low-resistance switch. DC/DC converter chips, a third type of IC voltage regulators, also provide a regulated DC voltage output from a different, unregulated input voltage. In addition, DC/DC converters are provide noise isolation regulate power buses. For each type of IC voltage regulator, the output voltage can be fixed or adjusted to a value within a specified range.

Performance specifications for IC voltage regulators include regulated output voltage, output current, dropout voltage, quiescent current, and operating temperature. The regulated output voltage (V_olt) represents minimum and maximum amounts in continuous mode (DC). The output current (I_OUT) is measured under specified conditions. Dropout voltage (V_D) is the minimum voltage drop across the regulator that maintains output voltage regulation. IC voltage regulators that operate with small dropout voltages dissipate less internal power, but have relatively high efficiencies. Measured in amperes (A) during the idling state, the quiescent current never makes it to the load. Instead, it flows from the battery to power the regulator itself. The operating temperature is a full-required range.

IC voltage regulators are available with a variety of features. Some devices have more than one output or channel. Others have an internal circuit to control the amount of current produced, or an error flag for monitoring outputs that drop below a nominal value. Reverse voltage protection prevents damage in applications where users can accidentally reverse battery polarity. Thermal shutdown protection turns off IC voltage regulators when the temperature exceeds a predefined limit. Shutdown (inhibit) pins are used to disable regulator outputs. 

IC voltage regulators are available in a variety of IC package types. Dual in-line packages (DIP) can be made of ceramic (CIP) or plastic (PDIP). Quad flat packages (QFPs) contain a large number of fine, flexible, gull wing shaped leads. SC-70, one of the smallest available IC packages, is well-suited for applications where space is extremely limited. Small outline (SO) packages are available with 8, 14, or 20 pins. Transistor outline (TO) packages are commonly available. TO-92 is a single in-line package used for low power devices. TO-220 is suitable for high power, medium-current, and fast-switching products. TO-263 is the surface-mount version of the TO-220 package. Other IC packages for IC voltage regulators include shrink small outline package (SSOP), small outline integrated circuit (SOIC), small outline package (SOP), small outline J-lead (SOJ), discrete package (DPAK), and power package (PPAK).