L4947集成电路（IC）的线性+开关稳压器规格书PDF中文资料

L4947属于集成电路（IC）的线性+开关稳压器。由意法半导体集团制造生产的L4947稳压器 - 线性线性稳压器用于提供稳定的输出电压，无论负载电流、输入电压或环境因素如何变化，这些输出电压通常都要保持不变。它们的工作原理要求输入电压维持在高于所需的输出电压，而且要超出某个最小量，并且在工作时会将输入端的任何多余电压转换为热量。对于大多数应用而言，虽然这种稳压器的效率低于开关模式的稳压器，但它们通常更适合对噪声高度敏感的应用。

DESCRIPTION

The L4947/L4947R is a monolithic integrated circuit in Pentawatt package specially designed to provide a stabilized supply voltage for automotive and industrial electronic systems. Thanks to its very low voltage drop, in automotive applications the L4947/L4947R can work correctly even during the cranking phase, when the battery voltage could fall as low as 6V. Furthermore, it incorporates a complete range of protection circuits against the dangerous overvoltages always present on the battery rail of the car. The reset function makes the device particularly suited to supply microprocessor based systems : a signal is available (after an externally programmable delay) to reset the microprocessor at power-on phase ; at power-off, this signal becomes low inhibiting the microprocessor.

■ PRECISE OUTPUT VOLTAGE (5V ± 4) OVER FULL TEMPERATURE RANGE (– 40 / 125 °C)

■ VERY LOW VOLTAGE DROP (0.75Vmax) OVER FULL T RANGE

■ OUTPUT CURRENT UP TO 500mA

■ RESET FUNCTION

■ POWER-ON RESET DELAY PULSE DEFINED BY THE EXTERNAL CAPACITOR

■ + 80V LOAD DUMP PROTECTION

■ – 80V LOAD DUMP PROTECTION

■ REVERSE VOLTAGE PROTECTION

■ SHORT CIRCUIT PROTECTION AND THER MAL SHUT-DOWN (with hysteresis)

■ LOW START UP CURRENT