ATA6616-P3QW Atmel, ATA6616-P3QW Datasheet - Page 278

• Manufacturer Part Number: ATA6616-P3QW
• Description: TXRX MULTICHIP MOD LIN SIP 38QFN
• Manufacturer: Atmel
• Series: AVR® ATA66 LIN-SBCr

Specifications of ATA6616-P3QW

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, LIN, SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 38-VQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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278
Decoupling Capacitors
Atmel ATA6616/ATA6617
The operating frequency (i.e. system clock) of the processor determines in 95% of cases the
value needed for microcontroller decoupling capacitors.
The hypotheses used as first evaluation for decoupling capacitors are:
Figure 4-114. Capacitor Description
According to the operating frequency of the product, the decoupling capacitances are chosen
considering the frequencies to filter,
The relation between frequencies to cut and decoupling characteristics are defined by:
where:
Then, in normalized value range, the decoupling capacitors become:
Table 4-93.
These decoupling capacitors must to be implemented as close as possible to each pair of
power supply pins:
Nevertheless, a bulk capacitor of 10-47µF is also needed on the power distribution network of
the PCB, near the power source.
For further information, please refer to Application Notes AVR040 “EMC Design Consider-
ations” and AVR042 “Hardware Design Considerations“on the Atmel web site.
fop
• The operating frequency (
• An SMC capacitor connected to 2 micro-vias on a PCB has the following characteristics:
peaks are located at
=
– 1.5 nH from the connection of the capacitor to the PCB,
– 1.5 nH from the capacitor intrinsic inductance.
– L: the inductance equivalent to the global inductance on the Vcc/GND lines.
– C
– 16-17 for logic sub-system,
– 5-6 for analogical sub-system.
---------------------
2
fop, Operating Frequency
1
1
LC
& C
1
2
Decoupling Capacitors versus Frequency
: decoupling capacitors (C
16MHz
12MHz
10MHz
8MHz
6MHz
4MHz
and
f
op
and 2
0.75 nH
f
op
2
) supplies itself the maximum peak levels of noise. The main
fop
f
f
op
op
=
.
and 2
---------------------
2
1
Capacitor
= 4
1
1.5 nH
LC
2
f
op
C
.
2
120nF
220nF
560nF
).
33nF
56nF
82nF
C
1
0.75 nH
PCB
120nF
10nF
15nF
22nF
33nF
56nF
9132D–AUTO–12/10
C
2