ST662A datasheet(5/13 Pages) STMICROELECTRONICS

номер детали	ST662A

подробное описание детали	DC-DC CONVERTER FROM 5V TO 12V, 0.03A FOR FLASH MEMORY PROGRAMMING SUPPLY

PDF	13 Pages

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производитель	STMICROELECTRONICS [STMicroelectronics]

домашняя страница	http://www.st.com

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ST662A

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DESCRIPTION

The ST662 is an IC developed to provide a 12V regulated output 30mA from voltage input as low as 4.75

without any inductors. It is useful for a wide range of applications and its performances makes it ideal for

flash memory programming supply.

An evaluation kit is provided to facilitate the application. This include a single-side demo board designed

for surface-mount components.The operating principle of ST662 (see fig. 10) is to charge C1 and C2

capacitor by closing the S1 switch (while S2 is opened) at the VCC voltage. After S1 will be opened and S2

closed so that C1 and C2 capacitors are placed in series one to each other, and both are in series with

VIN.The sum of VC1 and VC2 and VI is applied to the capacitor C4. This works as voltage triple. An

amplifier error checks the output voltage and blocks the oscillator if the output voltage is greater than 12V.

The shutdown pin is internally pulled to VCC. When it is held low the output voltage rises to +12V. Fig.11

shows the transition time of the shut down pin when the VSHDN goes from 5V to 0V. Input logic levels of

this input are CMOS compatible Applying a logic high at this input, the VOUT oscillator will be blocked and

the VOUT will reach the VI value by D1. In this condition ICC will be. low as 1µA. The fig.12 shows the

transition time of the shut down pin when the VSHDN goes from 0V to 5V.

Figure 10 : Operating Principle Circuit

Figure 11 : Exiting Shutdown

Figure 12 : Entering Shutdown

NOTE: VCC =5V, IOUT = 200 µA

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