ATTINY461-20SU Atmel, ATTINY461-20SU Datasheet - Page 96

• Manufacturer Part Number: ATTINY461-20SU
• Description: IC MCU AVR 4K FLASH 20MHZ 20SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY461-20SU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-SOIC (7.5mm Width)
• Processor Series: ATTINY4x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: 2-Wire, SPI, USI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 2
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 16 Channel
• Package: 20SOIC
• Device Core: AVR
• Family Name: ATtiny
• Maximum Speed: 20 MHz
• For Use With: ATSTK600-DIP40 - STK600 SOCKET/ADAPTER 40-PDIPATAVRBC100 - REF DESIGN KIT BATTERY CHARGER770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPI
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12.6
96
Dead Time Generator
ATtiny261/461/861
The Dead Time Generator is provided for the Timer/Counter1 PWM output pairs to allow driving
external power control switches safely. The Dead Time Generator is a separate block that can
be used to insert dead times (non-overlapping times) for the Timer/Counter1 complementary
output pairs OC1x and OC1x when the PWM mode is enabled and the COM1x1:0 bits are set to
“01”. See
Figure 12-7. Block Diagram of Waveform Generator and Dead Time Generator.
The tasks are shared as follows: the Waveform Generator generates the output (OCW1x) and
the Dead Time Generator generates the non-overlapping PWM output pair from the output.
Three Dead Time Generators are provided, one for each PWM output. The non-overlap time is
adjustable and the PWM output and it’s complementary output are adjusted separately, and
independently for both PWM outputs.
The Dead Time Generation is based on 4-bit down counters that count the dead time, as shown
in
Figure 12-8. Dead Time Generator
There is a dedicated prescaler in front of the Dead Time Generator that can divide the
Timer/Counter1 clock (PCK or CK) by 1, 2, 4 or 8. This provides for large range of dead times
that can be generated. The prescaler is controlled by two control bits DTPS11:10. The block has
also a rising and falling edge detector that is used to start the dead time counting period.
Depending on the edge, one of the transitions on the rising edges, OC1x or OC1x is delayed
until the counter has counted to zero. The comparator is used to compare the counter with zero
and stop the dead time insertion when zero has been reached. The counter is loaded with a 4-bit
DT1H or DT1L value from DT1 I/O register, depending on the edge of the Waveform Output
(OCW1x) when the dead time insertion is started. The Output Compare Output are delayed by
one timer clock cycle at minimum from the Waveform Output when the Dead Time is adjusted to
CK OR PCK
bottom
OCWnx
FOCn
Figure
CLOCK
top
TCCRnB REGISTER
12-8.
Figure 12-7
PRE-SCALER
DEAD TIME
PWMnx
Waveform Generator
below.
WGM10
CLOCK CONTROL
COMnx
CK OR PCK
OCWnx
CLOCK
DTn I/O REGISTER
4-BIT COUNTER
COMPARATOR
DTPSn
Dead Time Generator
DATA BUS (8-bit)
DTnH
DTnL
OCnx
OCnx
PWM1X
PWM1X
2588E–AVR–08/10
OCnx
OCnx
OCnx
OCnx
pin
pin