ATmega32A Datasheet - Sunrom Technologies

ATmega32AFigure 27-3.SymbolNotes: 1. The Power-on Reset will not work unless the supply voltage has been below V POT (falling).2. V BOT may be below nominal minimum operating voltage for some devices. For devices wherethis is the case, the device is tested down to V CC = V BOT during the production test. This guartCLCH Rise Time 1.6 0.5 μst CHCL Fall Time 1.6 0.5 μsΔt CLCLExternal Clock DriveParameterChange in period fromone clock cycle to thenextV CC = 2.7V to 5.5V V CC = 4.5V to 5.5VMin Max Min MaxUnits2 2 %27.5 System and Reset CharacteristicsFigure 27-4. External RC Oscillator, Typical Frequencies (V CC = 5V)R [kΩ] (1) C [pF] f (2)33 22 650kHz10 22 2.0MHzNotes: 1. R should be in the range 3 kΩ - 100 kΩ, and C should be at least 20 pF. The C values given inthe table includes pin capacitance. This will vary with package type.2. The frequency will vary with package type and board layout.Table 27-1.Reset, Brown-out and Internal Voltage Reference CharacteristicsSymbol Parameter Condition Min Typ Max UnitsV POTV RSTt RSTPower-on Reset ThresholdVoltage (rising)1.4 2.3 VPower-on Reset ThresholdVoltage (falling) (1) 1.3 2.3 VRESET Pin ThresholdVoltageMinimum pulse width onRESET Pin0.2 V CC 0.9 V CC V1.5 µsV BOTBrown-out Reset Threshold BODLEVEL = 1 2.5 2.7 2.9Voltage (2) BODLEVEL = 0 3.6 4.0 4.2Vt BODMinimum low voltage period BODLEVEL = 1 2 µsfor Brown-out DetectionBODLEVEL = 0 2 µsV HYSTBrown-out Detectorhysteresis50 mVV BG Bandgap reference voltage 1.15 1.23 1.35 Vt BGBandgap reference start-uptime40 70 µsI BGBandgap reference currentconsumption10 µA8155C–AVR–02/11300