ATtiny43U Atmel Corporation, ATtiny43U Datasheet - Page 45

• 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

8.6.5
8.6.6
8048B–AVR–03/09
Output Capacitors
Summary
Too high resistor values may lead to Start Mode failures. See
ues” on page 45
Capacitor C
An output capacitor, C
transferred to the inductor. It is recommended to use a capacitor with high capacitance and low
Equivalent Series Resistance, ESR. A large capacitance helps to reduce the voltage ripple at
the output and a low ESR reduces voltage ripple and helps to keep the temperature of the
capacitor within limits.
The recommended capacitance at a given, steady-state load is calculated as follows:
... where T
and D is the duty cycle, calculated as shown in
The recommended ESR is calculated as follows:
A secondary output capacitor, C
The table below summarises recommended component values for a typical application.
Table 8-1.
Note:
Component
C
C
C
C
D
L
R
1
1
2
3
4
1
1
1. With these values the LPF provides a 32dB attenuation at the switching frequency of the boost
2. Application specific limits may be tighter
S
converter while permitting a supply voltage ripple of about ±200mV
2
is the switching frequency of the boost converter, V
should be located close to the device.
Boost Converter Component Values
for component recommendations and limits.
Recommended Value
C = 4.7µF
C = 100nF
C = 22µF, ESR < 100mΩ
C = 100nF
I
L = 15µH ±20%, I
R = 680Ω
R
= 1µA @ 25°C, V
3
, is required to keep the output voltage stable at times when energy is
(1)
(1)
4
, is recommended and should be placed close to the device.
MAX
C
F
OUT
= 0.5V @ 1A
= 700mA, R < 150mΩ
ESR
=
I
------------------------------------- -
LOAD
≤
“Inductor” on page
-------------- -
I
PEAK
V
V
PP
×
PP
T
S
×
D
“Boost Converter Component Val-
PP
43.
is the allowed voltage ripple
Min
100nF
15µH
10µF
1µF
(2)
Max
100nF
15µH
1kΩ
(2)
45