DOC7707 datasheet(47/307 Pages) ETC1

47 / 307 page

7707F–AVR–11/10

AT90USB82/162

Figure 9-1.

Reset Logic

Notes:

1. The POR will not work unless the supply voltage has been below VPOT (falling)

9.3

Power-on Reset

A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detection level

is defined in Table 9-1. The POR is activated whenever V

CC is below the detection level. The

POR circuit can be used to trigger the start-up Reset, as well as to detect a failure in supply

voltage.

A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. Reaching the

Power-on Reset threshold voltage invokes the delay counter, which determines how long the

Table 9-1.

Reset Characteristics

Symbol

Parameter

Condition

Min

Typ

Max

Units

VPOT

Power-on Reset Threshold Voltage (rising)

1.4

2.3

Power-on Reset Threshold Voltage (falling)(1)

1.3

2.3

VPOR

VCC Start Voltage to ensure internal Power-on

Reset signal

-0.1

0.1

VCCRR

VCC Rise Rate to ensure internal Power_on

Reset signal

0.8

V/ms

VRST

RESET Pin Threshold Voltage

0.2

Vcc

0.85

Vcc

tRST

Minimum pulse width on RESET Pin

5V, 25°C

400

MCU Status

Brown-out

Reset Circuit

BODLEVEL [2..0]

Delay Counters

CKSEL[3:0]

TIMEOUT

DATA BUS

Clock

Generator

SPIKE

FILTER

Pull-up Resistor

USB Device

Reset Detection

Watchdog

Oscillator

SUT[1:0]

Power-on Reset

Circuit

DOC7707 Datasheet(PDF) 47 Page - List of Unclassifed Manufacturers

DOC7707 Datasheet(HTML) 47 Page - List of Unclassifed Manufacturers

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL