RSLIC18 8482 ; Ringing Subscriber Line Interface Series Circuit (RSLIC) supports analog plain old telephone short, medium loop wireless service (POTS) and wireline applications. Ideal for remote subscriber units, this family of products is designed for high ring voltage low power consumption system requirements. The RSLIC18 series operates to 100V , which translates to a ringing voltage supplied directly to the terminal user. High operating voltage, user loop length can be extended to 500 Ω (ie 5000 feet) and beyond. Other key features of the entire product family include: low power consumption, use of sinusoidal or trapezoidal ringing waveforms, robust auto-detection mechanism that subscribers can hook up or down, minimal external discrete application components. Integrated test access is also available on select products to support loopback testing as well as line measurement testing. There are five products in the RSLIC18 series: HC55180 , HC55181, HC55183 and HC55184. The architecture of this family is based on a voltage source with low fixed loop gain to achieve high gain amplifier design with low system sensitivity to analog performance induced noise.

feature

Low standby power consumption with battery operation to 100V50mW Peak ringing amplitude 95V, 5 REN sinusoidal or trapezoidal ringing capability Integrated codec Ringer interface Integrated MTU DC feature Thermal Shutdown for 28 Lead Surface Mount Package Media Isolation (DI) High Voltage Design HC55180 Silent Polarity Reversal - 53dB Longitudinal Balance Loopback Test Capability Test Accessibility HC55183 - Integrated Battery Switch - 45dB Longitudinal Balance HC55184 - Integrated Battery Switch - Silent Polarity Reversal - 45dB Longitudinal Balance Available Lead Free Plus Annealed (RoHS Compliant)

application

Wireless Local Loop (WLL) Digital Additional Trunk (DAML)/Pairgain Integrated Services Digital Network (ISDN) Small Office Home Office (SOHO) PBX Wired/Computer Telephony

Absolute Maximum Ratings TA=25°C Thermal Information Maximum Supply Voltage

Vcc. -0.5V to +7V

V CC-V BAT (180, 181). 110 volts

V CC-V BAT (183184). 85 volts

Uncommitted switching voltage. -110 volts

Maximum tip/ring negative voltage pulse (Note 18). -115 volts

Maximum tip/ring positive voltage pulse (Note 18). 8 volts

ESD (Human Body Model). 500 volts

Operating Conditions Temperature Range

Industrial (I suffix). -40°C to 85°C

Commercial (C suffix). 0°C to 75°C

Positive Supply (V CC). +5V±5%

Negative supply (V BH, V BL) (180, 181). -16V to -100V

Negative supply (V BH, V BL) (183, 184). -24V to -75V

Uncommitted switch (loop or relay driver). +5V to -100V

Thermal Resistance (Typical, Note 1) θJA (Celsius/Watt) PLCC Package.

Maximum junction temperature plasticity. 150 degrees Celsius

Maximum storage temperature range. -65°C to 150°C

Maximum lead temperature (10s for soldering). 300 degrees Celsius (PLCC - lead only)

CAUTION: Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a pressure rating and operation

Installation under the above or any other conditions stated in the operating section of this specification is not implied.

Note:

1. θJA is measured in free air with components mounted on an evaluation PC board.

Electrical Specifications, unless otherwise specified, apply only to HC55183, 184, all others -40°C to 85°C, V BL= -24V , TA=0°C to 70°C, V BH=-100V, - 85V or -75V, V CC=+5V, AGND=BGND=0V, loop current limit=25mA. All AC parameters are specified with 600 Ω 2-wire termination impedance over the frequency band 300Hz to 3.4kHz. Protection resistance = 0Ω. These parameters generally apply to each product

Electrical Specifications, unless otherwise specified, apply only to HC55183, 184, all others -40°C to 85°C, V BL=-24V, TA=0°C to 70°C,

V BH=-100V, -85V or -75V, V CC=+5V, AGND=BGND=0V, loop current limit=25mA. All AC parameters are specified with 600Ω 2-wire termination impedance over the frequency band 300Hz to 3.4kHz. Protection resistance = 0Ω. These parameters generally apply to each product. (continued)

notes:

2. These parameters are specified during high battery operation. For HC55180, the external power supply is set to high battery voltage, and for HC55181, HC55183 and HC55184, BSEL=1.

3. These parameters are controlled by design or process parameters, not directly tested. These parameters are characterized by design releases and design changes that affect these characteristics.

4. Measure the differential ringing gain with VRS = 0.795 V RMS (for -100V devices), VRS = 0.663 V RMS (for -85V devices) and VRS = 0.575 V RMS (for -85V devices) for -75V devices.

5. These parameters are specified when the battery is low. For HC55180, the external power supply is set to low battery voltage, and for HC55181, HC55183 and HC55184, BSEL=0.

6. Only HC55180, HC55181 and HC55184 devices can guarantee forward and reverse active performance. The HC55183 is specified for forward active operation only.

Electrical Specifications, unless otherwise specified, apply only to HC55183, 184, all others -40°C to 85°C, V BL=-24V, VCC=+5V, AGND=BGND=0V, TA=0°C to 70°C, Loop Current Limit = 25mA. All AC parameters are specified as 600Ω 2-wire termination impedance in the 300Hz to 3.4kHz frequency band. Protection resistance = 0Ω. (continued)

notes:

7. HC55180 does not provide battery switch operation. Therefore, all battery voltage references should be VB. VB is the voltage applied to the common connection of the device V BL and V BH pins. See HC55180 basic application circuit.

8. When measuring the ringing voltage, VRS=0.839V RMS for -100V equipment, VRS=0.707V RMS for -85V equipment, VRS=0.619V RMS for -75V equipment. All measurements are at T=25°C.

9. The HC55183 and HC55184 devices specify a high battery voltage rating.

10. The device represents low output impedance during ringing. Therefore, the voltage across the ringing load is determined by the voltage divider formed by the protection resistor loop and the ringing load impedance.

11. HC55180, HC55183 and HC55184 use a single longitudinal balance slope.

12. Test longitudinal balance according to IEEE455-1985, each tip and ring terminal 368Ω.

13. These parameters are 100% tested at room temperature. These parameters are guaranteed not to pass statistical characterization tests across temperature.

14. HC55180, HC55183 and HC55184 do not support uncommitted switch operations.

15. HC55183 and HC55184 do not support forward loopback mode of operation.

16. HC55183 and HC55184 do not support Tip Open operation mode.

17. Power consumption figures are actual device measurements and will be less than worst-case calculations based on datasheet power supply current limits.

18. Features 2 x 10μs and 10 x 1000μs class 1 lightning surge waveforms (GR-1089-CORE).

Design equation

Cycle Monitoring Threshold Switch Hook Detection Switch Hook Detection Threshold is set by a single external resistor, Rsh. Equation 1 is used to calculate the value of Rsh. I SH is the desired DC link current threshold. This loop current threshold can be programmed from 5mA to 15mA. Ground Key Detection The ground key detector detects a DC current imbalance when the ring terminal is grounded. The ground key detection threshold is not externally programmable and is internally fixed to 12mA regardless of the switch hook threshold.

4-wire-to-2-wire gain The 4-wire-to-2-wire gain is defined as the receive gain. It is a function of termination impedance, combined impedance and protection resistance. Equation 6 calculates the receive gain, G 42.

When the device source impedance and guard resistance equal the termination impedance, the receive gain equals unity.

2-wire to 4-wire gain The 2-wire to 4-wire gain (G 24) is from the tip and ring to the VTX output. The transmit gain is calculated in Equation 7.

When the protection resistor is set to zero, the transmission gain is -6dB.

Complex Impedance Synthesis provides complex impedance synthesis with complex programming networks.

The reference designator in the programming network matches the evaluation board. Component RS has a different impedance synthesis than the resistor design formula. The design formula components for each are shown below.

Low Power Standby Overview

The low power standby mode (LPS, 000) should be used under idling line conditions. The device is designed to operate in this mode from high power. Most of the internal circuits are powered down, resulting in low power consumption. If no 2-wire (tip/ring) DC voltage is required under idling line conditions, the device may be operating from low power. Running the battery low reduces standby power consumption.

2-Wire Interface During LPS, the 2-wire interface is connected to the internal switch and voltage reference. Fingertips and rings turn off the amplifier to save power. The device will provide MTU compliance, loop current and loop monitoring. Figure 2 shows the interface that provides a 2-wire internal circuit for low-power standby

Overview of Inverse Activation

The reverse active mode (RA, 011) provides the same functionality as the forward active mode. On-hook transmission, DC loop feed and voice transmission support. Loop monitoring is provided by either switch hook detector (E0=1) or ground key detector (E0=0). The unit can be powered by high or low battery. During reverse activation, the tip and ring DC voltage features swap roles. That said, the ring is usually 4V underground and the tip is usually bigger than the battery. Otherwise, all feed and speech transmission characteristics are the same as for forward activation. Silent polarity reversal from forward activation to reverse activation and vice versa is called polarity reversal. Many applications require slew rate control for polarity reversal events. Requirements range from minimizing crosstalk to protocol signaling. The device uses an external low voltage capacitor (C POL) to set the inversion time. Once programmed, the inversion time remains nearly constant under various load conditions. In addition, the reverse timing capacitor isolates the loop from the AC, so loop stability is not affected. The internal circuit for setting the polarity inversion time is as follows.

During forward activation, current from source I1 charges the external timing capacitor C pole and the switch opens. Internal resistors provide clamping function to the voltage on the POL node. During reverse activation, the switch is closed and I2 (which is about twice as large as I1) is removed from I1 and the timing capacitor. The current at the POL node provides drive to a differential pair that controls the tip and ring DC voltages. where time is the required reversal time. Polarized capacitors can be used for the C pole. Low voltage pole pins and minimum voltage offset ±0.75V, good for polarized capacitors.

Power consumption

The power consumption equation for forward active operation also applies to reverse active mode.

Ringtones overview

Ringing pattern (RNG, 100) supports multiple ringing waveforms. A programmable loop trip feature provides loop monitoring and automatic disconnect when making a call. The device is designed to run high on battery from this mode. The device linearly amplifies the applied signal to the ringing input, VRS. The differential ringing gain device is 80V/V. The circuit model of the ringing path is shown in the following figure.

Uncommitted Switch Overview

A non-commitment switch is a three-terminal device for flexibility. Independent logic control input, SWC, allows switch operation regardless of device operating mode. The switch is activated by logic low. The negative terminals of the positive devices are labeled SW+ and SW, respectively. Relay Drivers Uncommitted switches can be used as relay drivers by connecting SW+ to the relay coil and SW- to ground. This switch has a maximum turn-on voltage of 0.6V and a load current of 45mA.

As the device provides ringing waveforms, relays may support functions such as Subscriber Disconnect, Test Access, or Line Interface Bypass. External use of the non-commitment type does not require a snubber diode switch as a relay driver. Test Load This switch can be used to connect a test load to the top and ring. Test loads can provide termination for external test equipment. Properly Connected Below shows uncommitted switches to alert and bell. Diodes in series with the test load block from when the polarity is reversed from the tip and ring terminals. In addition to the reverse activation state, the polarity of the tip and ring is reversed within half the ringing period. With independent logic control and blocking diodes, uncommitted switches can be connected continuously to tip and ring terminals.

Design parameters: loop jump threshold = 90mA peak, switch hook threshold = 12mA, loop current limit = 24.6mA, combined device impedance = 210kΩ/400 = 525Ω with 39Ω protection resistor, impedance between tip and ring terminals = 603Ω. If applicable, these part values apply to the basic application circuit of the HC55180, HC55181, HC55183, and HC55184. Pins not shown in the basic application circuit have no connect (NC) pins.