CS47L35 datasheet(162/300 Pages) CIRRUS

162 / 300 page

162

DS1085F3

CS47L35

4.12 External Accessory Detection

The external connections for the headphone detect circuit are shown in Fig. 4-61.

Figure 4-61. Headphone Detect Interface

Note that, where external resistors are connected in series with the headphone load, as shown, it is recommended that

the HPDETn connection is to the headphone side of the resistors. If the HPDETn connection is made to the CS47L35 end

of these resistors, this leads to a corresponding offset in the measured impedance.

Under default conditions, the measurement time varies between 17–244 ms, depending on the impedance of the external

load. A high impedance is measured faster than a low impedance.

R668 (0x029C)

Headphone_

Detect_2

HP_DONE

Headphone Detect Status

0 = HP Detect not complete

1 = HP Detect done

14:0 HP_LVL[14:0]

0x0000

Headphone Detect Level

LSB = 0.5



8 = 4

or less

9 = 4.5



10 = 5



11 = 5.5



…

20,000 = 10 k

 or more

For HPDETL or HPDETR measurement (ACCDET_MODE = 001 or 010), HPD_LVL

is valid from 4

 to10 k, within the range selected by HP_IMPEDANCE_RANGE.

For MICDETn measurement (ACCDET_MODE = 100), HPD_LVL is valid from 400



to 6 k

. only.

If HP_LVL reports a value outside the selected range, the range should be adjusted

and the measurement repeated. A 0-

 result may be reported if the measurement is

less than the minimum value for the selected range.

R669 (0x029D)

Headphone_

Detect_3

9:0 HP_

DACVAL[9:0]

0x000

Headphone Detect Level (Coded as integer, LSB = 1.

See separate description for full decode information.)

R671 (0x029F)

Headphone_

Detect_5

9:0 HP_DACVAL_

DOWN[9:0]

0x000

Headphone Detect Level (Coded as integer, LSB = 1.

See separate description for full decode information.)

1. Default value is factory-set per device.

Table 4-80. Headphone Detect Control (Cont.)

Bit

Label

Default

Description

HPOUTFB

Headphone Detect /

Impedance

measurement

Headphone Detect selected

by ACCDET_MODE

HPDETL

HPDETR

HPOUTL

HPOUTR

(Note: HPOUTFB ground

connection close to headset jack )

MICDET

(optional series resistors)

CS47L35 датащи(PDF) 162 Page - Cirrus Logic

CS47L35 датащи(HTML) 162 Page - Cirrus Logic

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

датащи скачать

ссылки URL