Intersil Corporation HC55171 Datasheet

HC55171

Data Sheet July 1998 File Number

5 REN Ringing SLIC for
ISDN Modem/TA and WLL

The HC55171 is backward compatible to the HC5517 with
the added capability of driving 5 REN loads. The HC55171 is
ideal for any modem or remote networking access
application that requires plain old telephone service POTS,
capability. The linear amplifier design allows a choice of
Sinusoidal, Square wave or Trapezoidal ringing. The voltage
feed architecture eliminates the need for a high current gain
node achieving improved system noise immunity, an
advantage in highly integrated systems.

The device is manufactured in a high voltage Dielectric
Isolation (DI) process with an operating voltage range from

-16V,foroff-hookoperation and -80V for ring signal injection.
The DI process provides substrate latch up immunity,
resulting in a robust system design.

Ordering Information

TEMP. RANGE

PART NUMBER

HC55171IM -40 to 85 28 Ld PLCC N28.45
HC55171CM 0 to 75 28 Ld PLCC N28.45
HC55171IB -40 to 85 28 Ld SOIC M28.3
HC55171CB 0 to 75 28 Ld SOIC M28.3

(oC) PACKAGE

PKG.

NO.

4323.4

Features

• 5 REN Thru SLIC Ringing Capability to 75V

• Trapezoid, Square and Sinusoid Ringing Capability

• Bellcore Compliant Ringing Voltage Levels

• Lowest Component Count Trapezoidal Solution

• Single Additional +5V Supply

• Pin For Pin Compatible With HC5517

• DI Provides Latch-Up Immunity

PEAK

Applications

• ISDN Internal/External Modems

• ISDN Terminal Adapters/Routers

• Wireless Local Loop Subscriber Terminals

• Cable Telephony Set-Top Boxes

• Digital Added Main Line

• Integrated LAN/PBX

• Related Literature

- AN9606, Operation of the HC5517/171 Evaluation
Board

- AN9607, Impedance Matching Design Equations

- AN9628, AC Voltage Gain

- AN9608, Implementing Pulse Metering

- AN9636, Implementing an Analog Port for ISDN Using
the HC5517

- AN549, The HC-5502X/4X Telephone Subscriber Line
Interface Circuits (SLIC)

Block Diagram

TIP FEED

TIP SENSE

RING FEED
RING SENSE 1
RING SENSE 2

V

REF

RTI

V

BAT

V

CC

AGND
BGND

62

2-WIRE

INTERFACE

BIAS

V

4-WIRE

INTERFACE

LOOP CURRENT

DETECTOR

FAULT

DETECTOR

CURRENT

LIMIT

RING TRIP

DETECTOR

IIL LOGIC INTERFACE

F1 F0 RS

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

TST RDI

http://www.intersil.com or 407-727-9207 | Copyright © Intersil Corporation 1999

-

+

RELAY

DRIVER

RX

V

TX

V

RING

- IN 1

OUT 1

SHD
ALM

I

LMT

RTD
RDO

HC55171

Absolute Maximum Ratings T

Maximum Supply Voltages

VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.5V to +7V

VCC- V

Relay Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.5V to +15V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90V

BAT

Operating Conditions

Temperature Range

HC55171IM, HC55171IB . . . . . . . . . . . . . . . . . . . . -40oC to 85oC

HC55171CM, HC55171CB . . . . . . . . . . . . . . . . . . . .0oC to 75oC

Relay Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+5V to +12V

Positive Power Supply, VCC. . . . . . . . . . . . . . . . . . . . . . . . +5V ±5%

Negative Power Supply, V

CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operationofthe
device at these or any other conditions above those indicated in the operational sections of this specification is not implied

NOTE:

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

. . . . . . . . . . . . . . . . . . . .-16V to -80V

BAT

Electrical Specifications Unless Otherwise Specified, Typical Parameters are at T

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

RINGING TRANSMISSION PARAMETERS

=25oC Thermal Information

A

Thermal Resistance (Typical, Note 1) θJA(oC/W)

PLCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Maximum Junction Temperature Plastic . . . . . . . . . . . . . . . . .150oC

Maximum Storage Temperature Range. . . . . . . . . . -65oC to 150oC

Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300oC

(SOIC, PLCC - Lead Tips Only)

Die Characteristics

Transistor Count. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .224

Diode Count. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Die Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 x 144

Substrate Potential. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .V

Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bipolar-DI

Operating TemperatureRange, V
at 600Ω 2-Wire terminating impedance.

= -24V,VCC= +5V,AGND = BGND = 0V.All AC Parametersare specified

BAT

= 25oC, Min-Max Parameters are over

A

BAT

V

Input Impedance (Note 2) - 5.4 - kΩ

RING

4-Wire to 2-Wire Gain V

AC TRANSMISSION PARAMETERS

RX Input Impedance 300Hz to 3.4kHz (Note 2) - 108 - kΩ
OUT1 Positive Output Voltage Swing RL = 10kΩ (Note 2) +2.5 - - V
OUT1 Negative Output Voltage Swing RL = 10kΩ (Note 2) -4.5 - - V
4-Wire Input Overload Level 300Hz to 3.4kHz RL = 1200Ω, 600Ω Reference

2-Wire Return Loss Matched for 600Ω, f = 300Hz (Note 2) 37 - - dB

2-Wire Longitudinal to Metallic Balance
Off Hook

4-Wire Longitudinal Balance Off Hook 300Hz to 3400Hz (Note 2) - 55 - dB
Longitudinal Current Capability I
Insertion Loss, 2W-4W 0dBmO, 1kHz, Includes Tranhybrid Amp Gain = 3 - ±0.05 ±0.2 dB
Insertion Loss, 4W-2W 0dBmO,1kHz - ±0.05 ±0.2 dB
Insertion Loss, 4W-4W 0dBmO, 1kHz, Includes Tranhybrid Amp Gain = 3 - - ±0.25 dB

to V

RING

(Note 2)

Matched for 600Ω, f = 1000Hz (Note 2) 40 - - dB
Matched for 600Ω, f = 3400Hz (Note 2) 30 - - dB
Per ANSI/IEEE STD 455-1976 300Hz to 3400Hz

(Note 2)

= 40mA, TA = 25oC (Note 2) - 40 - mA

LINE

(Note 2) - 40 - V/V

T-R

- +3.1 - V

58 63 - dB

PEAK

RMS

Frequency Response 300Hz to 3400Hz Referenced to Absolute Level

at 1kHz, 0dBm Referenced 600Ω

63

- ±0.02 ±0.06 dB

HC55171

Electrical Specifications Unless Otherwise Specified, Typical Parameters are at T

Operating TemperatureRange, V
at 600Ω 2-Wire terminating impedance. (Continued)

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

Level Linearity +3 to 0dBm, Referenced to -10dBm (Note 2) - - ±0.10 dB

0 to -40dBm, Referenced to -10dBm (Note 2) - - ±0.12 dB

-40 to -55dBm, Referenced to -10dBm (Note 2) - - ±0.30 dB
Absolute Delay, 2W-4W 300Hz to 3400Hz (Note 2) - - 1.0 µs
Absolute Delay, 4W-2W 300Hz to 3400Hz (Note 2) - - 1.0 µs
Absolute Delay, 4W-4W 300Hz to 3400Hz (Note 2) - 0.95 - µs
Transhybrid Loss VIN = 1V
Total Harmonic Distortion

2-Wire/4-Wire, 4-Wire/2-Wire, 4-Wire/4-Wire
Idle Channel Noise

2-Wire and 4-Wire

PSRR, VCC to 2W 30Hz to 200Hz, RL = 600Ω (Note 2) 30 35 - dB
PSRR, VCC to 4W 45 47 - dB
PSRR, VBAT to 2W 23 28 - dB

Reference Level 0dBm at 600Ω
300Hz to 3400Hz (Note 2)

C-Message (Note 2) - 3 - dBrnC
Psophometric (Note 2) - -87 - dBmp

at 1kH (Note 2) 36 40 - dB

P-P

= -24V,VCC= +5V,AGND = BGND = 0V.All AC Parametersare specified

BAT

= 25oC, Min-Max Parameters are over

A

- - -50 dB

PSRR, VBAT to 4W 33 38 - dB
PSRR, VCC to 2W 200Hz to 3.4kHz, RL = 600Ω (Note 2) 33 35 - dB
PSRR, VCC to 4W 44 46 - dB
PSRR, VBAT to 2W 40 50 - dB
PSRR, VBAT to 4W 50 60 - dB
PSRR, VCC to 2W 3.4kHz to 16kHz, RL = 600Ω (Note 2) 30 34 - dB
PSRR, VCC to 4W 35 40 - dB
PSRR, VBAT to 2W 30 40 - dB
PSRR, VBAT to 4W 40 50 - dB

DC PARAMETERS

Loop Current Programming Range (Note 3) 20 - 60 mA
Loop Current Programming Accuracy -10 - +10 %
Loop Current During Power Denial RL = 200Ω, V
Fault Current, Tip to Ground (Note 2) - 90 - mA
Fault Current, Ring to Ground - 100 - mA
Fault Current, Tip and Ring to Ground (Note 2) - 130 - mA
Switch Hook Detection Threshold 9 12 15 mA

= -48V - ±4-mA

BAT

Ring Trip Comparator Voltage Threshold -0.28 -0.24 -0.22 V
Thermal ALARM Output Safe Operating Die Temperature Exceeded

(Note 2)

Dial Pulse Distortion (Note 2) - 0.1 0.5 ms

- 160 -

o

64

C

HC55171

Electrical Specifications Unless Otherwise Specified, Typical Parameters are at T

Operating TemperatureRange, V

= -24V,VCC= +5V,AGND = BGND = 0V.All AC Parametersare specified

BAT

= 25oC, Min-Max Parameters are over

A

at 600Ω 2-Wire terminating impedance. (Continued)

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

UNCOMMITTED RELAY DRIVER

On Voltage, V

OL

IOL (RDO) = 30mA - 0.2 0.5 V

Off Leakage Current - ±10 ±100 µA

TTL/CMOS LOGIC INPUTS (F0, F1, RS, TST, RDI)

Logic Low Input Voltage 0 - 0.8 V
Logic High Input Voltage 2.0 - 5.5 V
Input Current IIH, 0V ≤ VIN≤ 5V - - -1 µA
Input Current IIL, 0V ≤ VIN≤ 5V - - -100 µA

LOGIC OUTPUTS (SHD, RTD, ALM)

Logic Low Output Voltage I
Logic High Output Voltage I

= 800µA - 0.1 0.5 V

LOAD

= 40µA 2.7 - 5.5 V

LOAD

POWER DISSIPATION --­Power Dissipation On Hook VCC = +5V, V

VCC = +5V, V

Power Dissipation Off Hook VCC = +5V, V

= -80V, R

BAT

= -48V, R

BAT

= -24V, R

BAT

= ∞ - 300 - mW

LOOP

= ∞ - 150 - mW

LOOP

LOOP

= 600Ω,

- 280 - mW

IL = 25mA

I

CC

I

BAT

VCC = +5V, V
VCC = +5V, V
VCC = +5V, V

= -80V, R

BAT

= -48V, R

BAT

= -24V, R

BAT

VCC = +5V, VB- = -80V, R
VCC = +5V, VB- = -48V, R
VCC = +5V, VB- = -24V, R

= ∞ -36mA

LOOP

= ∞ -25mA

LOOP

= ∞ - 1.9 5 mA

LOOP

= ∞ - 3.6 7 mA

LOOP

= ∞ - 2.6 6 mA

LOOP

= ∞ - 2.3 4.5 mA

LOOP

NOTES:

2. These parameters arecontrolledby design or processparameters and are notdirectlytested. These parameters arecharacterized upon

initial design release, upon design changes which would affect these characteristics, and at intervals to assure product quality and
specification compliance.

3. This parameter directly affects device junction temperature. Refer to Power Dissipation discussion of data sheet for design information.

65

Functional Diagram

HC55171

TF

TIP

SENSE

RING

SENSE 1

RING

SENSE 2

RF

R

2R

-

+
2R

25K

-

+

25K

R
R

R/2

R/20

TA

RA

90K

TF

25

14

15

16

26

-

+

4.5K

100K
100K
100K

100K

4.5K

R
R
R
R

90K
90K

RF

-

+

V

RX

17 12

+2V

OUT 1

VB/2

REF

SHD

RTD

-

+

-IN 1

OP AMP

V

RING

13 24 19 2

FAULT

DET

GM

V

-

+

TX

THERM

LTD

RF2

V

CC

BIAS

NETWORK

SH

TSD

GK

RFC

AGND

IIL LOGIC INTERFACE

1

22

BGND

27

V

BAT

4

F1

5

F0

6

RS

9

TST

7

SHD

8

RTD

10

ALM

21

RDO

R = 108kΩ

3

V

REF

18

HC55171 DEVICE TRUTH TABLE

F1 F0 STATE

0 0 Loop power Denial Active
0 1 Power Down Latch RESET, Power on

RESET

10

RD Active

1 1 Normal Loop feed

The truth table for the internal logic of the HC55171 is pro­vided in the above table. This family of ringing SLICS can be
configured to support traditional unbalanced ringing and thru
SLIC balanced ringing. Refer to the HC5509A1R3060 for
unbalanced ringing application information. The device oper­ating states used by thru SLIC ringing applications are loop
power denial and normal feed. During loop power denial, the
tip and ring amplifiers are disabled (high impedance) and the
DC voltage of each amplifier approaches ground. The SLIC
will not provide current to the subscriber loop during this mode
and will not detect loop closure. Voice transmission occurs
during the normal loop feed mode. During normal loop feed
the SLIC is completely operational and performs all transmis­sion and supervisory functions.

28

RTINU I

11

LMT

20

RDI

Power Dissipation

Careful thermal design is required to guarantee that the
maximum junction temperature of 150

o

C of the device is not
exceeded. The junction temperature of the SLIC can be cal­culated using:

TJTAθJAICCVCCI

BATVBATILOOP

()2R

•()–+()+=

LOOP

Where TAis maximum ambient temperature and θJAis junc­tion to air thermal resistance (and is package dependent).
The entire term in parentheses yields the SLIC power dissi­pation. The power dissipation of the subscriber loop does
not contribute to device junction temperature and is sub­tracted from the power dissipation term. Operating at 85
the maximum PLCC SLIC power dissipation is 1.18W. Like­wise, the maximum SOIC SLIC power dissipation is 0.92W.

(EQ. 1)

o

C,

66

HC55171

Circuit Operation and Design Information

Introduction

The HC55171 is a high voltage Subscriber Line Interface Cir­cuit (SLIC) specifically designed for through SLIC ringing
applications. Through SLIC ringing applications are broadly
defined as any application that requires ringing capability but
does not have the standard wired central office interface. The
most common implementation of the ringing SLIC is in the
analog pots port. The analog pots port provides the ringing
function as well as interface compatibility with answering and
fax machines.

Subscriber Line Interface Basics

The basic SLIC provides DC loop current to power the handset,
supports full duplex analog transmission between the handset
and CODEC, matches the impedance of the SLIC to the
impedance of the handset and performs loop supervision func­tions to detect when the handset is off hook.

adds through the SLIC ringing capability to this suite of fea­tures.

The analog interfaces of the SLIC are categorized as the
2-wire interface(high voltageDC,differential AC) and the 4-wire
interface (low voltage DC, single ended AC).

DC Loop Current

The Tip and Ring terminals of the subscriber line circuit are
biased at negative potentials with respect to ground. The Tip
terminal DC potential is slightly negative with respect to
ground, and the ring terminal DC potential is slightly positive
with respect to the battery voltage (resulting in a large nega­tive voltage). The HC55171 typical Tip DC voltage is -4V and
the typical ring DC voltage is defined as V
ple, when the battery voltage is -24V the ring voltage is -20V.

To clearly comprehend the Tip and Ring interface it is helpful
to understand that the handset and the SLIC constitute a DC
and AC current loop as shown in Figure 1. The loop is often
referred to as the subscriber loop.

LOOP

CURRENT

FIGURE 1. SUBSCRIBER LOOP

When the handset is on hook (idle) the phone is an open cir­cuit load and the DC loop current is zero. The SLIC can still
provide AC transmission in this condition, which supports
caller id services. The DC resistance of the off hook handset
is typically 400Ω. Since the Tip DC voltage is more positive
than the ring DC voltage, DC loop current flows from Tip to
Ring when the handset is off hook. The SLIC is designed
with feedback to limit the maximum loop current when the
handset is off hook.

The ringing SLIC

+ 4V. For exam-

BAT

TIP

RING

SLIC

Full Duplex Analog Transmission

Familiarity with the signal paths of the SLIC is critical in
understanding the full duplex transmission capability of the
device. The analog interfaces of the SLIC are categorized as
2-wire interfaces and 4-wire interfaces.

The 2-wire interface of the SLIC consists of the bidirectional
Tip and Ring terminals of the device. A differential transmit­ter drives AC signals out of the Tip and Ring terminals to the
handset. A differential receiver across Tip and Ring receives
AC signals from the handset. The differential receiver is con­nected across sense resistors that are in the Tip and Ring
signal paths. The differential transmitter and receiver con­cept is depicted in Figure 2.

DIFFERENTIAL
TRANSMITTER

-1

-

+

-

+

FIGURE 2. DIFFERENTIAL TRANSMIT/RECEIVE CONCEPT

-

+
DIFFERENTIAL

RECEIVER

Since the receiver is connected across the transmit signal
path, one may deduce that in addition to receiving signals
from the handset, the receiver will detect part of the transmit
signal. Indeed this does occur and is the reason that all SLIC
circuits require a hybrid balance or echo cancellation func­tion.

The 4-wire interface of the SLIC consists of the receive
(VRX) and transmit (OUT1) terminals. The 4-wire interfaces
are single ended signal paths. The receiver is a dedicated
input port and the transmitter is a dedicated output port. The
4-wire receive input of the SLIC drives the 2-wire differential
transmitter and the 2-wire differential receiver drives the 4­wire transmit output.

The complete signal path for voice signals includes two digi­tal data busses, a CODEC and a SLIC. There is a receive
data bus and transmit data bus, each with an independent 3­wire serial interface. The CODEC contains a coder and
decoder. The coder converts the SLIC analog transmit out­put to digital data for the transmit data bus. The receive digi­tal data bus is converted to analog data and drives the SLIC
receive input.

The CODECs use logarithmic compression schemes to
extend the resolution of the 8-bit data to 14 bits. The
accepted compression schemesareA-law(Intersil CODEC ­CD22357A) and µ-law (Intersil CODEC - CD22354A). The
complete signal path from the handset to the CODEC is
shown in Figure 3.

67