ATMEGA8HVD-4MX Atmel, ATMEGA8HVD-4MX Datasheet - Page 42

• Manufacturer Part Number: ATMEGA8HVD-4MX
• Description: MCU AVR 8K FLASH 2.1-8V 4MHZ QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8HVD-4MX

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 5
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 2.4 V
• Data Converters: A/D 1x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 18-MLF® Exposed Pad (Staggered Leads), DFN
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Connectivity: -

10.6
10.6.1
42
ATmega4HVD/8HVD Start-up Sequence
ATmega4HVD/8HVD
Start-up with one FET connected
Figure 10-7. Black-out Reset with high current consumption at V
The Voltage Regulator will not start until it is enabled by the Charger Detect module. Before
this happens the chip will be in Power-off mode and only the Charger Detect module is
enabled. In order for the Charger Detect module to enable the Voltage Regulator, the V
voltage must exceed the Power-On Threshold, V
the Voltage Regulator starts up and a Power-On Reset forces the chip into RESET state.
During start-up with only one FET (D-FET), cell charging through the body diode of the Dis-
charge FET will start immediately when a charger is connected, even if the chip has not
started yet. The voltage on the BATT pin equals the cell voltage (VFET) plus a diode drop dur-
ing the complete start-up sequence, and will hence increase as the cell is being charged.
A typical start-up sequence for the application is illustrated in
Figure 10-8. Powering up ATmega4HVD/8HVD (1-FET example)
When V
VCC to increase rapidly while CREG is being charged. At the same time the digital part of the
Internal Reset
Power-on
BATT
V
INTERNAL_RESET
REG
reaches the power-on threshold V
V
CHIP STATE
BLOT, START-UP
BLOD
V
V
2.2 V
POR
V
BATT
REG
POT
CHARGER CONNECTED
Power-off
V
BLOT
CHARGER DETECTED
POT
POT
, the voltage regulator starts up. This causes
. When the voltage at V
Reset
t
TOUT
Figure 10-8 on page
REG
Active
BATT
exceeds V
8052B–AVR–09/08
42.
BATT
POT
,