ATMEGA3250PV-10AUR Atmel, ATMEGA3250PV-10AUR Datasheet - Page 32

• Manufacturer Part Number: ATMEGA3250PV-10AUR
• Description: MCU AVR 32K FLASH 10MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250PV-10AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 10MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.5
32
Low-frequency Crystal Oscillator
ATmega325P/3250P
Table 8-4.
Notes:
The Low-frequency Crystal Oscillator is optimized for use with a 32.768 kHz watch crystal.
When selecting crystals, load capasitance and crystal’s Equivalent Series Resistance, ESR
must be taken into consideration. Both values are specified by the crystal vendor.
ATmega325P/3250P oscillator is optimized for very low power consumption, and thus when
selecting crystals, see
9.0 pF and 12.5 pF crystals
Table 8-5.
Note:
The Low-frequency Crystal Oscillator provides an internal load capacitance of typical 6 pF at
each TOSC pin. The external capacitance (C) needed at each TOSC pin can be calculated by
using:
where CL is the load capacitance for a 32.768 kHz crystal specified by the crystal vendor and C
is the total stray capacitance for one TOSC pin.
Crystals specifying load capacitance (CL) higher than 6 pF, require external capacitors applied
as described in
To find suitable load capacitance for a 32.768 kHz crystal, please consult the crystal datasheet.
CKSEL0
0
1
1
1
1
1. These options should only be used when not operating close to the maximum frequency of the
2. These options are intended for use with ceramic resonators and will ensure frequency stability
1. Maximum ESR is typical value based on characterization
device, and only if frequency stability at start-up is not important for the application. These
options are not suitable for crystals.
at start-up. They can also be used with crystals when not operating close to the maximum fre-
quency of the device, and if frequency stability at start-up is not important for the application.
SUT1..0
Start-up Times for the Crystal Oscillator Clock Selection (Continued)
Maximum ESR Recommendation for 32.768 kHz Watch Crystal
Figure 8-2 on page
11
00
01
10
11
Crystal CL (pF)
12.5
6.5
9.0
Table 8-5 on page 32
Start-up Time from
Power-down and
Power-save
1K CK
1K CK
16K CK
16K CK
16K CK
31.
(2)
(2)
C
=
2 CL
for maximum ESR recommendations on 6.5 pF,
⋅
Additional Delay from
–
C
14CK + 4.1 ms
14CK + 4.1 ms
14CK + 65 ms
14CK + 65 ms
(V
s
CC
Reset
14CK
= 5.0V)
Max ESR [kΩ]
75
65
30
Ceramic resonator, fast
rising power
Ceramic resonator,
slowly rising power
Crystal Oscillator, BOD
enabled
Crystal Oscillator, fast
rising power
Crystal Oscillator, slowly
rising power
Recommended Usage
(1)
8023F–AVR–07/09
S