STW5098 datasheet(23/85 Pages) STMICROELECTRONICS

23 / 85 page

STw5098

Functional description

23/85

Each stereo Microphone preamplifier is powered up with bits ENMICL and ENMICR in

CR1.

●

Line In amplifier: each line in amplifier is designed for high level input signal. The input

gain is in the range -20 dB up to 18 dB. The Line In amplifier input is selected with bits

LINSEL in CR18, and it is disconnected when LINMUTE=1. If a single ended input is

selected then the amplifier uses the selected pin as the positive input and connects the

negative input (for both left and right channels) to CAPLINEIN pin, which has to be

connected through a capacitor to a low noise ground (typically the same reference

ground of the input).

The stereo Line In amplifier is powered up with bits ENLINL and ENLINR in CR1.

4.10

Analog output drivers

Each entity of the STw5098 provides 3 different analog signal outputs and 1 common mode

reference output. The description here below is for one entity. VCCP and VCCL are common

for both entities.

●

Line out drivers: it is a stereo differential output, it can be used as single-ended output

just by using the positive or negative pin. It can drive 1 k

Ω resistive load. The load can

be connected between the positive and negative pins or between one pin and ground

through a decoupling capacitor. The output gain is regulated with LOG bits in CR7, in

the range 0 to -18 dB, simultaneously for left and right channels. When used as a single

ended output the effective gain is 6 dB lower. It is muted with bit MUTELO in CR19. The

input signal of this stereo output can come from the analog mixer or directly from MIC

preamplifiers. The output Common Mode Voltage level is controlled with bits VCML in

CR19. The supply voltage of line out drivers is VCCP.

The line out drivers are powered up with bits ENLOL and ENLOR in CR1. The output

pins are in high impedance state with a 180k

Ω pull-down resistor when the line out

drivers are powered down.

●

Headphones drivers: it is a stereo single ended output. It can drive 16 ohm resistive

load and deliver up to 40 mW. The output gain is regulated with HPLG and HPRG bits

in CR8 and CR9 respectively, with a range of -40 to 6 dB. It is muted with bit MUTEHP

in CR19. The input signal of this stereo output comes from the analog mixer.The output

common mode voltage is controlled with bits VCML in CR19. The supply voltage of

headphones drivers is VCCP.

The headphones drivers are powered up with bits ENHPL and ENHPR in CR2.The

output pins are in high impedance state when the headphones drivers are powered

down.

●

Common mode voltage driver: it is a single ended output with output voltage value

selectable with bits VCML in CR19, from 1.2 V to 1.65 V in steps of 150 mV. The output

voltage should be set to the value closest to VCCP/2 to optimize output drivers

performance. The common mode voltage driver is designed to be connected to the

common pin of stereo headphones, so that decoupling capacitors are not needed at

HPL and HPR outputs. The supply voltage of the common mode voltage driver is

VCCP.

The common mode voltage driver is powered up with bit ENHPVCM in CR2.The output

pin is in high impedance state when the common mode voltage driver is powered down.

STW5098 数据表(PDF) 23 Page - STMicroelectronics

STW5098 数据表(HTML) 23 Page - STMicroelectronics

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

数据表下载