Features：

• Single supply voltagering slic: +3.3V to +5.0V
• Integral high efficiency DC/DC converter.
• Highly integrated withringing 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 ground60dB(300Hz-3400Hz)
• Two-Wire Impedance600R
• Four-wire return loss>24Db
• weighted noise -75dB
• Ringing voltage130VP-P
• Constant current 23-31mA
• Supply Voltage3.2V-5.5VDC

Description：

• The R-TONE KS0835F 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 KS0835F has been designed to work with loop lengths of typically 1.0km
• The KS0835F 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 KS0835F 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 KS0835F 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：

DC Electrical Characteristics*

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*

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.

Pin Description:

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 KS0835F 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.  。 

KS0835FProduct Selector

PackageSize： (mm   ±3mm )

PCB Decal ： (mm   ±3mm )