CEC1712 datasheet(67/338 Pages) MICROCHIP

67 / 338 page

 2020-2021 Microchip Technology Inc.

DS00003416C-page 67

CEC1712

4.4.4

SYSTEM POWER SEQUENCING

The following table defines the behavior of the main power rails in each of the defined ACPI power states.

4.5

Clocks

The following section defines the clocks that are generated and derived.

4.5.1

RAW CLOCK SOURCES

The table defines raw clocks .

TABLE 4-3:

TYPICAL POWER SUPPLIES VS. ACPI POWER STATES

Supply

Name

ACPI Power State

Description

(FULL

ON)

(POS)

(STR)

(STD)

(Soft Off)

(MECH Off)

VTR1

OFF

“Always-on” Supply

VTR2

OFF

3.3V/1.8V Power Supply

for Bank 2

VBAT

Note

Battery Back-up Supply

Note:

This device requires that the VBAT power is on when the VTR(Note 3) power supply is on. External circuitry,

a diode isolation circuit, is implemented on the motherboard to extend the battery life. This external circuitry

ensures the VBAT pin will derive power from the VTR power well when it is on. Therefore, the VBAT supply

will never appear to be off when the VTR rail is on.

TABLE 4-4:

SOURCE CLOCK DEFINITIONS

Clock Name

Frequency

Description

Source

32KHZ_IN

32.768 kHz

(nominal)

Single-ended external clock input pin 32KHZ_IN pin

32.768 kHz Crystal

Oscillator

32.768 kHz

A 32.768 kHz parallel resonant crystal

connected between the XTAL1 and

XTAL2 pins. The accuracy of the

clock depends on the accuracy of the

crystal and the characteristics of the

analog components used as part of

the oscillator

The crystal oscillator source can

bypass the crystal with a single-

ended clock input. This option is con-

figured with the Clock Enable Regis-

ter.

Pin Interface (XTAL1 and XTAL2)

When used singled-ended, input pin

is XTAL2

32.768 kHz Silicon

Oscillator

32.768 kHz

32.768 kHz low power Internal Oscil-

lator. The frequency is 32.768KHz

±2%.

Internal Oscillator powered by VBAT.

32 MHz Ring

Oscillator

32MHz

The 32MHz Ring Oscillator is used to

supply a clock for the 48MHz main

clock domain while the 48MHz PLL is

not locked. Its frequency can range

from 32Mhz to 96MHz. This clock is

passed though a divide by 2 circuit to

generate clock in the range 16MHz to

48MHz

CEC1712 Datasheet(PDF) 67 Page - Microchip Technology

CEC1712 Datasheet(HTML) 67 Page - Microchip Technology

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