ATmega8HVA Atmel Corporation, ATmega8HVA Datasheet - Page 124

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ATmega8HVA

Manufacturer Part Number
ATmega8HVA
Description
Manufacturer
Atmel Corporation
Datasheets

Specifications of ATmega8HVA

Flash (kbytes)
8 Kbytes
Pin Count
28
Max. Operating Frequency
4 MHz
Cpu
8-bit AVR
# Of Touch Channels
3
Hardware Qtouch Acquisition
No
Max I/o Pins
6
Ext Interrupts
3
Usb Speed
No
Usb Interface
No
Spi
1
Graphic Lcd
No
Video Decoder
No
Camera Interface
No
Adc Channels
6
Adc Resolution (bits)
12
Adc Speed (ksps)
1.9
Resistive Touch Screen
No
Temp. Sensor
Yes
Crypto Engine
No
Sram (kbytes)
0.5
Eeprom (bytes)
256
Self Program Memory
YES
Dram Memory
No
Nand Interface
No
Picopower
No
Temp. Range (deg C)
-20 to 85
I/o Supply Class
1.8 to 9.0
Operating Voltage (vcc)
1.8 to 9.0
Fpu
No
Mpu / Mmu
no / no
Timers
2
Output Compare Channels
4
Input Capture Channels
2
32khz Rtc
No
Calibrated Rc Oscillator
Yes
23. Battery Protection
23.1
23.2
Table 23-1.
124
Battery Protection Type
Short-circuit Protection
Discharge Over-current
Protection
Charge Over-current
Protection
Discharge High-current
Protection
Charge High-current
Protection
Features
Overview
ATmega8HVA/16HVA
Effect of Battery Protection Types
The Current Battery Protection circuitry (CBP) monitors the charge and discharge current and
disables C-FET and D-FET if a Short-circuit, Over-current or High-current condition is detected.
There are five different programmable detection levels: Short-circuit Detection Level, Discharge
Over-current Detection Level, Charge Over-current Detection Level, Discharge High-current
Detection Level, Charge High-current Detection Level. There are three different programmable
delays for activating Current Battery Protection: Short-circuit Reaction Time, Over-current Reac-
tion Time and High-current Reaction Time. After Current Battery Protection has been activated,
the application software must re-enable the FETs. The Battery Protection hardware provides a
hold-off time of 1 second before software can re-enable the discharge FET. This provides safety
in case the application software should unintentionally re-enable the discharge FET too early.
The activation of a protection also issues an interrupt to the CPU. The battery protection inter-
rupts can be individually enabled and disabled by the CPU.
The effect of the various battery protection types is given in
In order to reduce power consumption, Short-circuit, Discharge High-current and Discharge
Over-current Protection are automatically deactivated when the D-FET is disabled. The Charge
Over-current and Charge High-current Protection are disabled when the C-FET is disabled. Note
however that Charge Over-current Protection and Charge High-current Protection are never
automatically disabled when the chip is operated in DUVR mode.
Short-circuit Protection
Discharge Over-current Protection
Charge Over-current Protection
Discharge High-current Protection
Charge High-current Protection
Programmable and Lockable Detection Levels and Reaction Times
Autonomous Operation Independent of CPU
Interrupt Requests
Entry
Entry
Entry
Entry
Entry
Disabled
Disabled
Disabled
Disabled
Disabled
C-FET
Disabled
Disabled
Disabled
Disabled
Disabled
D-FET
Table
23-1.
Operational
Operational
Operational
Operational
Operational
MCU
8024A–AVR–04/08

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