ST662A ST Microelectronics, ST662A Datasheet - Page 5

• Manufacturer Part Number: ST662A
• Description: DC-DC CONVERTER
• Manufacturer: ST Microelectronics

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 V
closed so that C1 and C2 capacitors are placed in series one to each other, and both are in series with
V
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 V
shows the transition time of the shut down pin when the V
this input are CMOS compatible Applying a logic high at this input, the V
the V
transition time of the shut down pin when the V
Figure 10 : Operating Principle Circuit
Figure 11 : Exiting Shutdown
NOTE: V
IN
. The sum of V
OUT
CC
= 5 V, I
will reach the V
OUT
= 200 µA
C1
and V
I
value by D1. In this condition I
C2
and V
I
is applied to the capacitor C4. This works as voltage triple. An
CC
. When it is held low the output voltage rises to +12V. Fig.11
SHDN
goes from 0V to 5V.
Figure 12 : Entering Shutdown
NOTE: V
SHDN
CC
CC
will be. low as 1µA. The fig.12 shows the
CC
= 5 V, I
goes from 5V to 0V. Input logic levels of
voltage. After S1 will be opened and S2
OUT
OUT
= 200 µA
oscillator will be blocked and
ST662A
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