ST5088 datasheet(20/33 Pages) STMICROELECTRONICS

20 / 33 page

Current limitation is approximatively 150 mApk.

CONTROL REGISTER CR7:

First byte of a READ or a WRITE instruction to

Control Register CR7 is as shown in TABLE 1.

Second byte is as shown in TABLE 9.

Tone/Ring amplifier gain selection

Output level of Ring/Tone generator, before at-

tenuation by programmable attenuator is 2.4 Vpk-

pk when f1 generator is selected alone or

summed with the f2 generator and 1.9 Vpk-pk

when f2 generator is selected alone.

Selected output level can be attenuated down to

-27 dB by programmable attenutator by setting

bits 4 to 7.

Frequency mode selection

Bits ’F1’ (3) and ’F2’ (2) permit selection of f1

and/or f2 frequency generator according to TA-

BLE 9.

When f1 (or f2) is selected, output of the

Ring/Tone is a squarewave (or a sinewave) signal

at the frequency selected in the CR8 (or CR9)

When f1 and f2 are selected in summed mode,

output of the Ring/Tone generator is a signal

where f1 and f2 frequency are summed.

In order to meet DTMF specifications, f2 output

level is attenuated by 2dB relative to the f1 output

level.

Frequency temporization must be controlled by the

microcontroller.

Any switching between two frequencies of the

same channel (f1 or f2) is done maintaining prac-

tically the phase continuity.

The actual change in the frequency of the tone

generator takes place within 1/16th of the period

of the highest of the two frequencies that are

switched between, plus 2

µs for internal data ac-

quisition.

Waveform selection

Bit ’SN’ (1) selects waveform of the output of the

Ring/Tone generator. Sinewave or squarewave

signal can be selected.

DTMF selection

Bit DE (0) permits connection of Ring/Tone/DTMF

generator on the Transmit Data path instead of

the Transmit Amplifier output. Earpiece feed-back

may be provided by sidetone circuitry by setting

bit SI or directly by setting bit RTE in Register

CR4. Loudspeaker feed-back may be provided di-

rectly by setting bit RTL in Register CR4.

CONTROL REGISTERS CR8 AND CR9

First byte of a READ or a WRITE instruction to

Control Register CR8 or CR9 is as shown in TA-

BLE 1. Second byte is respectively as shown in

TABLE 10 and 11.

Tone or Ring signal frequency value is defined by

the formula:

f1 = CR8 / 0.128 Hz and f2 = CR9 / 0.128 Hz

(with DFT = HFT = 0 in CR10)

where CR8 and CR9 are decimal equivalents of

the binary values of the CR8 and CR9 registers

respectively. Thus, any frequency between 7.8 Hz

and 1992 Hz may be selected in 7.8 Hz step.

TABLE 13 gives examples for the main frequen-

cies usual for Tone or Ring generation.

CONTROL REGISTER CR10

First byte of a READ or a WRITE instruction to

control register CR10 is as shown in TABLE 1.

Second byte is as shown in Table 12.

Extra +18dB in LS Gain

GLS = 1 sets extra 18dB Gain (total Gain = 27dB)

GLS = 0 sets standard Gain = 9dB like on ST5080

Anticlipping enable, thresholds and time con-

stants

ACE = 1 enables the operation of the Digital anti-

clipping section (D.A.S.), needed to avoid distor-

tion on sine wave when GLS = 1 (extra 18dB on LS)

anticlipping thresholdsof -15, -13, -9 and -7dBmo are

definedby bits 4 and 5 (VT1/VT0).

Gain recovery the constants (anticlipping release)

are selectable among four values, 256ms, 128ms,

32ms and 16ms by bits 2 and 3 (FD1/FD0).

Doubled Tone/Ringer Frequency Range

Double frequency range on tone & ringer gener-

ator is obtainedby putting DFT = 1 (and HFT = 0).

Formula for frequency generator is:

f1 = CR8/0.064Hz and f2 = CR9/0.064Hz.

Maximum frequency is 3984.4Hz and frequency

accuracy is 15.6Hz.

Halved Tone/Ringer Frequency Range

Halved frequency and double accuracy on tone &

ringer generator is obtained bu putting HFT = 1 (and

DFT = 0).

Formula for frequency generator is:

f1 = CR8/0.256Hz and f1 = CR9/0.256Hz

Frequency range is from 3.9Hz to 996.1Hz and

step is 3.9Hz with improved accuracy for low fre-

quencies combination.

HFT = DFT= 1 is a forbidden combination.

ST5088

20/33

ST5088 数据表(PDF) 20 Page - STMicroelectronics

ST5088 数据表(HTML) 20 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

数据表下载

链接网址

ST5088 数据表(PDF) 20 Page - STMicroelectronics

ST5088 数据表(HTML) 20 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

数据表 下载

链接网址

数据表下载