5 system and reset characteristics, 6 external interrupt characteristics, Will generate a reset – Rainbow Electronics ATtiny43U User Manual

Page 158: Attiny43u

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158

8048B–AVR–03/09

ATtiny43U

20.5

System and Reset Characteristics

Note:

1. The Power-on Reset will not work unless the supply voltage has been below V

POT

(falling)

Note:

1. V

BOT

may be below nominal minimum operating voltage for some devices. For devices where this is the case, the device is

tested down to V

CC

= V

BOT

during the production test. This guarantees that a Brown-out Reset will occur before V

CC

drops to

a voltage where correct operation of the microcontroller is no longer guaranteed.

20.6

External Interrupt Characteristics

Table 20-4.

Reset, Brown-Out and Internal Voltage Characteristics

Symbol

Parameter

Condition

Min

Typ

Max

Units

V

POT

Power-on Reset Threshold Voltage (rising)

T

A

= -40 - 85

°

C

1.1

1.4

1.6

V

Power-on Reset Threshold Voltage (falling)

(1)

T

A

= -40 - 85

°

C

0.6

1.3

1.6

V

V

PSR

Power-On Slope Rate

T

A

= -40 - 85

°

C

0.01

V/ms

V

RST

RESET Pin Threshold

0.2 V

CC

0.9 V

CC

V

t

RST

Minimum pulse width on RESET Pin

V

CC

= 1.8V

V

CC

= 3V

V

CC

= 5V

2000

700
400

ns

V

HYST

Brown-out Detector Hysteresis

50

mV

t

BOD

Min Pulse Width on Brown-out Reset

2

µs

V

BG

Internal bandgap reference voltage

V

CC

= 2.7V

T

A

= 25°C

1.0

1.1

1.2

V

t

BG

Internal bandgap reference start-up time

V

CC

= 2.7V

T

A

= 25°C

40

70

µs

I

BG

Internal bandgap reference current consumption

V

CC

= 2.7V,

T

A

= 25°C

15

µA

Table 20-5.

BODLEVEL Fuse Coding

(1)

BODLEVEL [2..0] Fuses

Min V

BOT

Typ V

BOT

Max V

BOT

Units

111

BOD Disabled

110

1.7

1.8

2.0

V

101

2.5

2.7

2.9

100

4.1

4.3

4.5

011

Reserved

010

001

000

Table 20-6.

Characteristics of Asynchronous External Interrupt

Symbol

Parameter

Condition

Min

Typ

Max

Unit

t

INT

Minimum pulse width for asynchronous external interrupt

50

ns

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