FS98O24 datasheet(32/77 Pages) FORTUNE

32 / 77 page

4.5. Low Battery Comparator

Figure 4-6 low battery comparator function block

Low Battery Comparator is used for VDD low voltage detection. FS98O24 embeds a voltage divider which can

generate 1/2 VDD and the 1/3 VDD. A multiplexer is used to connect the voltage divides to component input.

The multiplexer’s output is compares with 1.2V. The Control register flags are SILB[1:0] and the EN_LB. The

Output flag is LBOUT which is for read only. Please see Figure 4-6.

Table 4-7 low battery comparator register table

Address

Name

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Value on Power on Reset

32H

NETJ

EN_LB

SILB[1:0]

00000000

33H

NETK

LBOUT

000uu000

Operation:

Operate as Section 4.1 to get the VGG (two times VDD or external Power Supply).

Operate as Section 4.2 to get the VDDA (3.6V)

Operate as Section 4.3 to active the Analog Bias Circuit

Set SILB to choose the Comparator input. Please see Table 4-8

Table 4-8 low battery comparator voltage detection selection table

SILB [1:0]

Detection Voltage

if LBOUT = 1

1/2 VDD

VDD > 2.3 volt

1/3 VDD

VDD > 3.5 volt

ADP2

ADP2 > 1.2 volt

Set the EN_LB register flag, and the Low Battery Comparator is enabled.

The output, LBOUT, is the result of the comparator.

MUX

EN_LB

1.2V

1/2 VDD

1/3 VDD

SILB[1:0]

ADP2

LBOUT

90KΩ

SILB=10

FS98O24 Datasheet(PDF) 32 Page - Fortune Semiconductor Corp.

FS98O24 Datasheet(HTML) 32 Page - Fortune Semiconductor Corp.

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

Datasheet Download

Link URL