RT0845

  • Single supply voltage ring slic: +3.3V to +5.0V
  • Integral high efficiency DC/DC converter.
  • Highly integrated with ringing generator.
  • Tip/Ring polarity reversal.
  • 2 / 4 wire conversion
  • Constant current feed
  • High performance with low price
  • Excellent sound quality
  • On-Hook Transmission for caller line ID.
  • Designed for GSM network
  • Easy to use, with a minimum number of external components.

 

相关产品

 
 

RT0845

 RING Subscriber Line Interface Circuit (RING SLIC)  MODULE  Product Description

Version

Date

Author

Approved By

Remarks

V1.0

20210531

LI xiao yan

Rock

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

© 2021 Shenzhen Ring&tone  Electronic Technology Co., Ltd. All rights reserved.

This document contains proprietary information of ring&tone and is not to be disclosed or used without the prior written permission of ring&tone.

Due to update and improvement of ring&tone products and technologies, information in this document is subjected to change without notice.

Features

  • Single supply voltage ring slic: +3.3V to +5.0V
  • Integral high efficiency DC/DC converter.
  • Highly integrated with ringing generator.
  • Tip/Ring polarity reversal.
  • 2 / 4 wire conversion
  • Constant current feed
  • High performance with low price
  • Excellent sound quality
  • On-Hook Transmission for caller line ID.
  • Designed for GSM network
  • Easy to use, with a minimum number of external components.

 

Applications

  • Fixed Cellular Terminals (FCT) applications.
  • POS MODEM applications
  • Internet Telephony (VoIP) applications.
  • Fixed Wireless Terminals (FWT) applications.
  • DVB Terminals applications.
  • Wireless local loop (WLL) applications.
  • GSM gateway

Index

  • unbalanced to ground 60dB(300Hz-3400Hz)
  • Two- Wire Impedance 600R
  • Four-wire return loss >24Db
  • weighted noise -75dB
  • Ringing voltage 130VP-P
  • Constant current  23-31mA
  • Supply Voltage 3.2V-5.5VDC    

     

     

    Description

    The R-TONE RT0845 is a single Subscriber Line Interface Circuit (SLIC).

    The combination of features and packaging offers extremely efficient use of board area, saving  significant system size and cost, minimising time to market for Telephony Systems developers.

    The RT0845 has been designed to work with loop lengths of typically 1.0km

    The RT0845 has integral dc/dc converter and ringing generation thus providing all the line powering requirements from a single supply.24V(off-hook)and 48V(on-hook)and 75V(ringing).

    The RT0845 requires a minimum of external components, making it ideal for low line count, short loop length applications, such as WLL Terminal (WLL), Fixed Cellular Terminals (FCT), Fixed Wireless Terminals (FWT) and Internet Telephony (VoIP).

    The RT0845 has an integral DC/DC converter, which generates the battery voltage in the device.  This means that only a single supply of between +3.3V to +5.0V is needed, unlike conventional SLICs which will also need a battery voltage of anything between 20V and60V ( 75V for ringing).  This confers a significant cost, space and time to market benefit on the equipment designer.

    • Absolute Maximum Ratings

     

    Parameter

    Symbol

    Min

    Max

    Units

    1

    DC Supply Voltage

    VCC

    -0.3

    5.5

    V

    2

    Maximum Power Dissipation, Off Hook @ 25oC

    PSLIC

     

    1.2

    W

    3

    Operating Temperature

    TOP

    -40

    +85

    oC

    4

    Storage Temperature

    TS

    -55

    +100

    oC

     

    • DC Electrical Characteristics*

    Characteristic

    Sym

    Min

    Typ

    Max

    Units

    Test Comments

     

     

     

    Supply Current

     

     

    ICC

     

    40

    50

     

    mA

     

    5V  (on-hook)

    3.3V(on-hook)

     

    270

    320

     

    mA

    5V  (off-hook)

    3.3V(off-hook)

    during ring

     

    180

    220

     

    mA

    5V  (during ring)

    3.3V(during ring)

     

     

     

     

     

    Constant current

    Ibat

    21

    23

    35

    mA

     

    Power Dissipation

    Pd

     

    30/850

     

     

    mW

     

    On/off hook (during 23mA Constant current)

    Ringing voltage

    Ving

     

    130

     

    VP-P

     

    off-hook voltage

    Vab

     

    48

     

    V

     

     

    Supply current in power down

     

    IPD

     

    7

    5

     

    mA

    mA

    @ 5.0V

    @ 3.3V

    All DC Electrical Characteristics are over the Recommended Operating Conditions with VCC at +5.0V +1%,or +3.3V +1%, unless

    otherwise stated.

    2) Operating currents are dependent on the users application.

    *Typical figures are at 25°C and are for design aid only. Not Guaranteed

    • AC Electrical Characteristics*

    Characteristic

    Sym

    Min

    Typ

    Max

    Units

    Test Comments

    Two- Wire Impedance

    Z0

     

    600

     

    Ω

     

    Absolute Voltage Gain

    T,R-VX

    VR-T,R

    -6

    -6

    0

    0

    6

    6

    dB

     

    Relative Gain. Referenced to 1kHz

    Gf

    -0.5

     

    +0.5

    dB

    Over frequency range 300 to

    3400 Hz

    Two-wire return loss

    RL

    30

     

     

    dB

    300-3400HZ,600R load

    Four-wire return loss

    THL

    30

     

     

    dB

    300-3400HZ, 600R load

    unbalanced to ground

     

    60

     

     

    dB

    300-3400HZ,off-hook

    common-mode rejection ratio

    CMRR

    45

    55

     

    dB

     

    weighted noise

     

    -75

     

     

    dB

     

    total harmonic distortion

    THD

    70

     

     

    dB

    300-3400HZ,off-hook

    This applies to 3 phones with tone ringers or 2 phones with mechanical bells.

    *Typical figures are at 25°C and are for design aid only.

    • RT0845 Pin Description:

    Pin #

    Name

    Description

    1

    RING

    Ring. Connects to the subscriber line Ring.

    2

    TIP

    Tip. Connects to the subscriber line Tip.

    3

    F/R,25Hz

    Forward/Reverse.  A logic (H) will reverse the Tip and Ring voltage polarities.  F/R is toggled to produce the ringing output.

    Logic (L) for other modes.

     

    4

     

    RM

    Ringing Mode. Sets bias conditions during ringing. Must be set to logic (H) during ringing. Logic (L) for other modes.

    5

    SHK

    Switch Hook. Indicates an off-hook condition when at logic (H).

    6

    VR

    Audio In Negative. Analog input signal from the Codec (which is output on Tip and Ring).

    7

    VX

    Audio Out. This is the analog output signal (from Tip and Ring)

    to the Codec.  

    8

    NC

    No Connection.  Do not connect to this pin.

    9

    GND

    DC/DC Ground.  Ground input for the DC/DC converter.

    10

    +VDC

    DC/DC Supply.  +5.0V or +3.3V input for the DC/DC converter.

     

    11

     

    PD

    Power Down DC/DC Converter. A logic (L) on this pin powers down the module.  DO NOT put logic (H) on this pin.

     

    • RT0845D Pin Description:

    Pin #

    Name

    Description

    1

    TIP

    Tip. Connects to the subscriber line Tip.

    2

    RING

    Ring. Connects to the subscriber line Ring.

    3

    IC

    Internal Connection. Do not connect externally to this pin.

     

    4

     

    PD

    Power Down of DC/DC Converter. A logic 0 powers off the DC/DC converter. Leave open circuit for free run operation. DO NOT input logic 1 to this pin.

    5

    NC

    No Connection. This pin is not connected internally.

    6

    NC

    No Connection. This pin is not connected internally.

    7

    RM

    Ringing Mode. Sets bias conditions during ringing. Must be set to logic 1 during ringing. Logic 0 for other modes.

    8

    GNDA

    Analog Ground. Normally connected to system ground.

    9

    +VA

    Analog Supply. Connect to the +3.3V supply via an RC filter, to supply power to the analog circuits.

    10

    ZT2

    No Connection. This pin is connected internally.

    11

    ZT1

    No Connection. This pin is connected internally.

    12

    ZB

    No Connection. This pin is connected internally.

    13

    VIN

    Audio In. Analog input signal from the Codec (which is output on Tip and Ring). Connect via a 100nF capacitor.

    14

    NC

    No Connection. This pin is not connected internally.

    15

    VOUT

    Audio Out. Analog output signal (from Tip and Ring) to the Codec. Connect via a 100nF capacitor.

    16

    F/R

    Forward/Reverse. A logic 0 will reverse the Tip and Ring voltage polarities. F/R is toggled to produce the ringing output.

    17

    SHK

    Switch Hook. Indicates an off-hook condition when at logic 1.

    18

    GNDPWR

    DC/DC Ground. Ground input for the DC/DC converter.

    19

    +VPWR

    DC/DC Supply. +3.3V input for the DC/DC converter.

    20

    GNDPWR

    DC/DC Ground. Ground input for the DC/DC converter.

    21

    +VPWR

    DC/DC Supply. +3.3V input for the DC/DC converter.

     

  • 1 Ringing

    The ringing signal is generated by switching the SLIC into ringing mode, by setting the RM pin high, and  then toggling the F/R pin at the required frequency and cadence. The toggling  of  the  F/R  pin  produces  a  balanced  signal  at  Tip  and  Ring.

    During ringing the integral DC/DC converter is switched produce a battery voltage of  75V.The  slope of the edges on the ringing waveform is set internally to give the correct waveform with 20Hz to 25Hz ringing frequency.

    2 Tip & Ring Polarity Reversal

    If F/R is held at logic (H) (Forward) the d.c. voltage at Ring is negative with respect to Tip. If F/R is taken to logic (L) (Reverse) the voltage at Ring is positive with respect to Tip.

     

    3 Switch Hook Detection

    When an “off-hook” condition occurs during ringing, the ring-trip circuit on the RT0845 senses the loop current flowing and signals the off-hook condition on the SHK output. The SHK signal must be “de-bounced” (by the controlling processor) for 10ms to remove any spurious  pulses.  。

     

     

     

     

     

     

    • RT0845 Product Selector

     

    Marking

    Supply Voltage (V)

    Constant current feed to line (mA)

    Gain  2 Wire to VOUT

    Gain VIN to 2Wire

    Ringing voltage (Vp-p)

    Supply Current, on-hook (mA)

    Supply current, off-hook
    (mA)

    Ringing Load (REN)

    Package

    RT0845

    3.2~5.5

    23~31

    0dB

    0dB

    120~135

    50-35

    310-270

    3

    SIL

    RT0845D

    3.2~5.5

    23~31

    0dB

    0dB

    120~135

    50-35

    310-270

    3

    DIP

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    • RT0845 Package  Size (mm   ±3mm )

    • RT0845 PCB Decal (mm ±3mm )

     

     

    • RT0845D Package  Size (mm   ±3mm )