Rainbow-electronics ATtiny43U Manuel d'utilisateur télécharger pdf (Page 39)

8048B–AVR–03/09

Figure 8-4. Input and Output Voltages of Boost Converter.

When input voltage V

BAT

falls below V

STOP

the converter enters Stop Mode and output voltage

begins to fall. When converter output voltage, i.e. the supply voltage of the microcontroller,

falls below V

POT

the MCU will go into reset.

Figure 8-5 illustrates how the boost converter output changes with load current. As converter

output voltage rises above the power-on threshold the microcontroller is brought on-line and cur-

rent consumption steps up to a level sufficiently high for the converter to remain in Active

Regulated Mode of operation.

Figure 8-5. Output Voltage vs. Load Current of Boost Converter.

Note: The figure is not to scale. Typically, the switching time (rising voltage) is measured in hundreds of

microseconds and idle time (falling voltage) is measured in seconds.

POT

START

BOOST

STOP

BAT

STOP STOPACTIVE

RESET ACTIVE RESET

CONVERTER:

MCU CORE:

LOAD

V/A

CCMIN

CCMAX

LOW CURRENT MODEACTIVE, REGULATED

MODE:

CCNOM

REGULATED

1 2 ... 34 35 36 37 38 39 40 41 42 43 44 ... 181 182

Pas de commentaire

Rainbow-electronics ATtiny43U Manuel d'utilisateur Page 39