ATtiny43U Atmel Corporation, ATtiny43U Datasheet - Page 43

• Manufacturer Part Number: ATtiny43U
• Manufacturer: Atmel Corporation

Specifications of ATtiny43U

• Flash (kbytes): 4 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 8 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 4
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 64
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 0.7 to 5.5
• Operating Voltage (vcc): 0.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

8.5.2
8.5.3
8.6
8.6.1
8048B–AVR–03/09
Component Selection
Switching to Full Duty Cycle Mode of Operation
Switching to Normal (Variable Duty Cycle) Mode of Operation
Inductor
To stop the boost converter, follow the below procedure:
When duty cycle control is disabled the output voltage of the boost converter will rise as fast as
possible, resulting in a minimum switching time and a maximum idle time for the converter.
To turn on Full Duty Cycle (FDC) mode, follow the below procedure:
To return duty cycle control to the boost converter, follow the below procedure:
Refer to
Low inductance increases peak currents of the inductor, creating more interference noise and
lowering the overall efficiency of the converter. Too high inductance values force the converter
into non-stable operation. The boost converter has been optimized for a certain size inductance,
L, and may not work reliably if other inductance values are used. See
nent Values” on page
The inductor must be able to tolerate the following input current:
... where
verter Efficiency vs. Load Current and VBAT Voltage” on page
The inductor must also be able to tolerate short peak currents. At steady state, i.e. when the
converter has stabilised after a constant load current has been introduced, the peak current is
calculated as follows:
1. Write 110x xxxx to the Power Reduction Register, PRR
2. Within 3 clock cycles of the above, write 10xx xxxx to PRR
3. Within 4 clock cycles of the first step, write 01xx xxxx to PRR
1. Write 110x xxxx to the Power Reduction Register, PRR
2. Within 3 clock cycles of the above, write 10xx xxxx to PRR
3. Within 4 clock cycles of the first step, write 111x xxxx to PRR
1. Write 111x xxxx to the Power Reduction Register, PRR
Figure 8-2 on page 37
η
is the efficiency of the converter at given voltages and load current. See
45.
for component placement and numbering.
I
PEAK
I
IN
=
=
V
--------------------------------
V
----------------------------------- -
CC
V
BAT
BAT
×
I
×
L
LOAD
×
T
η
S
×
D
166.
“Boost Converter Compo-
“Boost Con-
43