NT91214 Ver la hoja de datos (PDF) - Unspecified

Número de pieza

componentes Descripción

Fabricante

NT91214

Tone/Pulse Dialer

Unspecified 

6. One-key redialing

Off Hook D1 . . . Dn RD or On Hook HFI ↓

D1 . . . Dn RD

If the dialing of D1 to Dn is finished, pressing

RD will cause the pulse dialing pin to go low for 1.67

seconds of break time and an 824 ms pause will

automatically be added. If the pulses of the number

dialed with D1 to Dn have not finished, the

pressing of the redial key will be ignored.

7. Flash dialing

Off Hook F D1 . . . Dn or On Hook

HFI ↓ F D1 . . . Dn

The flash keys emulate quick On-Off Hook operations.

Pressing the flash keys, F1 or F2 , will cause a

NT91214/15 Series

break of 96 ms or 640 ms (or, 297 ms or 640 ms,

depending on the model) on the DP output pin. Then, it

pauses for 824 ms and continues dialing the digits,

D1 to Dn . These digits are then stored in the redial

memory.

Each time the flash key is pressed, the redial memory

will

be cleared to store a new entry. In addition, the MODE

IN

status will be checked again for the setting of the

TONE/PULSE DIALING mode.

Similarly, to make sure that the IC is working properly,

new flash key inputs will be ignored as long as the digits

that were dialed have not finished.

Timing Waveforms

1. Timing Waveform in PULSE Mode:

HK or HFO

Key Input

KT

XMIT MUTE

DP

2

1

T KD: debouncing time 21 ms

TKTD (23 ms), f = 437Hz

Td

TM

T IDP

TM

TM

TB

3

21ms

Td:

TIDP:

TKTO:

TKD:

Delay time of Key valid to dialing signal out, typically 0ms

Inter-digit pause time

Key-in tone duration

Debouncing time

Note: " HK " or "HFO" indicates chip works when hook switch " HK " goes low or Hands-Free control output HFO goes

high.

14

V1.0

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