SGS-THOMSON L3000S, L3030 Technical data

L3000

L3000S

L3030

SUBSCRIBER LINE INTERFACE KIT

.PROGRAMMABLE DC FEEDING RESIS-TAN- CE AND LIMITINGCURRENT (fourvalues avai-

.lable)

THREE OPERATING MODES :

.STAND-BY, CONVERSATION, RINGING NORMAL/BOOSTBATTERY, DIRECT/REVER-

.SE POLARITY

.SIGNALLING FUNCTION (off-hook/GND-key) FILTERED OFF-HOOK DETECTION IN

.STAND-BY (10ms)

QUICK OFF-HOOK DETECTION IN CONVERSATION (< 1ms) FOR LOW DIAL PULSE DE-

.TECTION DISTORTION

.HYBRID FUNCTION

RINGING GENERATION WITH QUASI ZERO OUTPUT IMPEDANCE, ZERO CROSSING INJECTION (no ext. relay needed) AND RING

.TRIP DETECTION

AUTOMATIC RINGING STOP WHEN OFF-

.HOOK IS DETECTED

PARALLEL AND SERIAL DIGITAL INTERFA-

.CES

.TELETAXE SIGNALINJECTION(2VRMS/5VRMS) LOW NUMBER OF EXTERNAL COMPO-

.NENTS

GOOD REJECTION OF THE NOISE ON BATTERY VOLTAGE (20dB at 10Hz and 35dB at

.1kHz)

POSSIBILITY TO WORK ALSO WITH HIGH

.COMMON MODE CURRENTS

INTEGRATED THERMAL PROTECTION WITH

.THERMAL OVERLOAD INDICATION SURFACE MOUNT PACKAGE (PLCC44 + PowerSO-20)

DESCRIPTION

The ST SLIC KIT (L3000S/L3030) is a set of solid state devices designed to integratemain of the functions needed to interface a telephone line. It consists of 2 integrated devices : the L3000S line interface circuit and the L3030 control unit.

This kit performs the main featuresof the BORSHT functions:

-Battery feed

-Ringing

-Signalling

-Hybrid

PRELI MINARY DAT A

PLCC44

FLEXIWATT15

	PowerSO20
slug-up	slug-down

ORDERING NUMBERS :

L3030 (PLCC44)

L3000SX-VM (FLEXIWATT15)

L3000SX (PowerSO20 slug-up)

L3000SX-77 (PowerSO20 slug-down)

Additional functions, such as battery reversal, extra batteryuse, line overvoltagesensing and meteringpulse injection are also featured ; most external characteristics,as ACand DC impedances,are programmable with external components.The SLIC injects ringing in balanced mode and for that, as well as for the operation in battery boosted, a positive battery voltage shall be available on the subscriber card. As the right ringing signal amplification both in voltage and in current is provided by SLIC, the ring signal generatorshall onlyprovide a low level signal (0.285Vrms).

This kit is fabricatedusing a 140V Bipolar technology for L3000Sand a 12V Bipolar I2L technologyfor L3030.

L3030 is available PLCC44 and L3000S in both FLEXIWATT15 and PowerSO-20 for surfacemount application.

This kit is suitable for all the following applications: C.O. (CentralOffice),DLC (Digital LoopCarrier) and high range PABX (Private Automatic Branch Exchange).

June 1997

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L3000S - L3030

PIN CONNECTIONS (top view)

FLEXIWATT15

PLCC44

VB-	1	20	VB-	VB-	10	11	VB-
N.C.	2	19	RING	VBIM	9	12	AGND
TIP	3	18	N.C.	VIN	8	13	REF
MNT	4	17	IL	VDD	7	14	C1
VB+	5	16	IT	BGND	6	15	C2
BGND	6	15	C2	VB+	5	16	IT
VDD	7	14	C1	MNT	4	17	IL
VIN	8	13	REF	TIP	3	18	N.C.
VBIM	9	12	AGND	N.C.	2	19	RING
VB-	10	11	VB-	VB-	1	20	VB-
		D97TL290				D94TL125

PowerSO-20 (slug-down) PowerSO-20 (slug-up)

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				L3000S - L3030
	PIN DESCRIPTION (L3000S)
	FLEX.	PSO	Name	Description
	N°	N°
	1	3	TIP	A line termination output with current capability up to 100mA (Ia is the current sourced
				from this pin).
	2	4	MNT	Positive Supply Voltage Monitor
	3	5	VB+	Positive Battery Supply Voltage
	4	6	BGND	Battery ground relative to the VB+ and the VB± supply voltages.
				It is also the reference ground for TIP and RING signals.
	5	7	VDD	Positive Power Supply + 5V
	6	8	VIN	2 wire unbalanced voltage input.
	7	9	VBIM	Output voltage without current capability, with the following functions :
				- give an image of the total battery voltage scaled by 40 to the low voltage part.
				- filter by an external capacitor the noise on VB±.
	8	1, 10	VB±	Negative Battery Supply Voltage
		11, 20
	9	12	AGND	Analog Ground. All input signals and the VDD supply voltage must be referred to this pin.
	10	13	REF	Voltage reference output with very low temperature coefficient. The connected resistor
				sets internal circuit bias current.
	11	14	C1	Digital signal input (3 levels) that defines device status with pin 12.
	12	15	C2	Digital signal input (3 levels) that defines device status with pin 11.
	13	16	IT	High precision scaled transversal line current signal.
				Ia + Ib
				IT = 100
	14	17	IL	Scaled longitudinal line current signal.
				Ib − Ia
				IL = 100
	15	19	RING	B line termination output with current capability up to 100mA (Ib is the current sunk into
				this pin).

±2, 18 N.C. Not connected

Notes: 1) Unless otherwise specified all the diagrams in this datasheet refers to the FLEXIWATT15 pin connection.

2)All informations relative to the PowerSO-20 package option should be considered as advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

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L3000S - L3030

PIN DESCRIPTION (L3030)

	Pin	Symbol	Function
	1	TST	This pin is connected internally for test purpose. It should not be used as a tie point for
			external components.
	2	REF	Bias Set
	3	AGND	Analog Ground
	4	VSS	± 5V
	5	VDD	+ 5V
	6	N.C.	Not connected.
	7	CZS	AC Feedback Input
	8	ACF	AC Line Impedance Synthesis
	9	ZAC	AC Impedance Adjustement
	10		These pins are connected internally for test purpose. It should not be used as a tie point
	11	TST
			for external components.
	12
	13	VOUT	Two wire unbalanced output.
	14	CM	Capacitor Multiplier Input
	15	RC	DC Feedback Input
	16	IT	Transversal Line Current
	17	RDC	DC Feeding System
	18	EIA	Read/write Command
	19	NCS	Chip Select Command
	20	DIO	Data Input/output
	21	DCKL	Clock Signal
	22	DGND	Digital Ground
	23	N.C.	Not connected.
	24	N.C.	Not connected.
	25	N.C.	Not connected.
	26	CI	Input/output Changing Command

27C1 State Control Signal 1

28C2 State Control Signal 2

	29	N.C.	Not connected.
	30	N.C.	Not connected.
	31	IL	Longitudinal Line Current
	32	CRTS	Ringtrip Det. & TTX Shaping
	33	TTXIN	Teletaxe Signal Input
	34	RGTTX	TTX Filter Level Compensation
	35	TTXF	TTX Filter Input
	36	ZB	Balancing Network
	37		These pins are connected internally for test purpose. It should not be used as a tie point
	38	TST
			for external components.
	39
	40	TX	4W Sending Output
	41	RX/RG	4W Receiving and Ring Input
	42	VBIM	Battery Image Input
	43	TST	These pins are connected internally for test purpose. It should not be used as a tie point
	44		for external components.

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L3000S - L3030

L3000S BLOCK DIAGRAM

L3030 BLOCK DIAGRAM

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L3000S - L3030

ABSOLUTE MAXIMUM RATINGS

Symbol	Parameter	Value	Unit
Vb±	Negative Battery Voltage	± 80	V
Vb+	Positive Battery Voltage	80	V
|Vb±| + |Vb+|	Total Battery Voltage	140	V
Vdd	Positive Supply Voltage	+ 6	V
Vss	Negative Supply Voltage	± 6	V
Vagnd ± Vbgnd	Max. Voltage between Analog Ground and Battery Ground	5	V
Tj	Max. Junction Temperature	+ 150	°C
Tstg	Storage Temperature	± 55 to + 150	°C

THERMAL DATA

Symbol	Parameter	Value		Unit
L3000S HIGH VOLTAGE		Flexiwatt	PWSO20
Rth j-case	Thermal Resistance Junction to Case	Max. 4	Typ. 2	°C/W
Rth j-amb	Thermal Resistance Junction to Ambient	Max. 50	Max. 60	°C/W
L3030 LOW VOLTAGE
Rth j-amb	Max. Resistance Junction to Ambient		80	°C/W

OPERATING RANGE

Symbol	Parameter
Toper	Operating Temperature Range
Vb±	Negative Battery Voltage
Vb+	Positive Battery Voltage
Vb± + Vb+	Total Battery Voltage
Vdd	Positive Supply Voltage
Vss	Negative Supply Voltage
Imax	Total Line Current (IL + IT)

FUNCTIONAL DESCRIPTION

L3000S - High Voltage Circuit

The L3000Slineinterfaceprovidesa batteryfeeding for telephonelines and ringing injection.The IC contains a state decoderthat underexternal controlcan force the following operational modes : stand-by, conversation and ringing.

In addition Power down mode can be forced connecting the bias current resistor to VDD or leaving it open.

Twopins, IL andIT, carryout the information concerning line statuswhich is detectedby sensingthe line current into the output stage.

The L3000S amplifies both the AC and DC signals entering at pin 6 (VIN) by a factor equal to 40.

Separate grounds are provided :

-Analog ground as a reference for analog signals

-Battery ground as a reference for the output stages

Min.	Typ.	Max.	Unit
0		70	°C
± 70	± 48	± 24	V
0	+ 72	+ 75	V
	120	130	V
+ 4.5		+ 5.5	V
± 5.5		± 4.5	V
		85	mA

The two groundshould be shortedtogetherat a low impedance point.

L3030 - Control Unit

The L3030 low voltage control unit controls L3000S line interface module, giving the proper information to set line feed characteristic, to inject ringing and TTX signal and synthetizes the line and balance impedances. An on chip digital interface allows a microprocessor to control all the operations. L3030 defines working states of line interface and also informs the card controller about line status.

L3000S - Working States

In order to carry out the different possible operations, the L3000S has several different working states.Each stateis definedby thevoltagerespectively applied by pins 27 and 28 of L3030 to the pins 11 and 12 of L3000S.

Three different voltage levels (± 3, 0, + 3) are available at each connection, so defining nine possible

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					L3000S - L3030
	Table 1.
				Pin 28 of L3030 / Pin 12 of L3000S	(C2)
			+ 3	0	± 3
		+ 3	Stand-by	Conversation in Normal	Conversation in Normal
				Battery Direct Polarity	Battery Reverse Polar
	Pin 27 of L3030	0	Not allowed.	Conversation in Boost	Conversation in Boost
	Pin 11 of L3000S
				Battery Direct Polarity	Battery Reverse Polar
		± 3	Not allowed.	Ringing with Direct	Not allowed.
				Polarity

states as listed in Table. 1.

Appropriate combinations of two pins define the three modes of the ST SLIC, that are :

a)Stand-by (SBY)

b)Conversation (CVS), Normal and Reverse polarity

c)Ringing (RING)

d)Boost Battery (BB), Normal and Reverse polarity

A fifth status, Power down (PD), can be set disconnectingthe bias resistor (RH) from pin 10 ofL3000S by means of an external transistor.

The main difference between Stand-by and Power down is that in SBY the power consumption on the voltage battery VB± (± 48V) is reduced but the L3000S DC feeding and monitoring circuits are still active. In PD the power consumption on VBis reduced to zero, and the L3000S is completely switched off.

The SBYstatus shouldbe used whenthe telephone

is in On hook and PD status onlyin emergencycondition when it is mandatory to cut any possible dissipation but no operation are requested.

OPERATING MODES

Stand-by (SBY) Mode

In this mode, the bias currents of both L3000S and L3030are reducedas onlysomeparts of the two circuits are completely active, control interface and current sensors among them. The current supplied to the line is limited at 7mA, and the slope of the DC characteristic corresponds to :

R = 23 x (RFS + 2RP)

The Line voltage in on Hook conditionisjust the batteryvoltage minus the voltage drop(approx. 15V)of the output stage amplifiers (see Fig. 1).

Figure 1 : DC Characteristics in Stand-byMode.

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L3000S - L3030

The AC characteristic is just the resistance of the two serial resistors RP.

In Stand-bymode the batterypolarity is just in direct condition,that is the TIP wire more positive than the RING one ; boost battery is not achievable. There are two possible line conditions where the SLIC is expected to be in stand-by mode :

1)ON-HOOK (Iline < 5mA). Normal on-hook condition.

2)OFF-HOOK (Iline > 7mA). Handset is unhooked, the SLIC is waiting for command to activate conversation.

When the SLIC is in stand-by mode, the power dissipation of L3000S does not exceed 120mW (from -48V) eventually increased of a certain amount if some current is flowing into the line.

The power dissipation of L3030 in the same condition, is typically 120mW.

The Stand-byMode is set when the byte sent to the L3030 Serial Digital Interface has the first two bits (BIT0R and BIT1R) equal to º0º.

Settingto 0 all the 8 bits of the command sent to the digital interface of L3030, the bias currents of both L3000S and L3030 are reduced and only some parts of the two circuits are active similarly to the stand-by mode ; in this situation, named powerdown denial, the line sensors are disabled (ON/OFF-HOOK line conditions cannot be recognized) and the current supplied to the line is limited at 0.25mA.

Conversation (CVS) or Active Mode

In conversationmodeitis possibleto selectbetween two different DC Characteristics by the BIT5R of the

Serial Interface.

1)Normal Battery (NB)

2)Boost Battery (BB)

It is also possibleto select(BIT4R)the polarity of the DC line voltage and (BIT6R-BIT7R) one of the four values of limiting current (25mA or 30mA or 45mA or 70mA).

Battery reverse can take place either before or during conversation.

As far as the DC characteristic in Normal Battery is concerned, three different feeding conditions are present :

a)current limiting region ; the DC impedance of the SLIC is very high (> 20 Kohm) and therefore the systemworkslike a currentgenerator,thecurrent value being set through the digital interface (25/30/45/70mA).

b)standard feeding system region ; the characteristic is equal to a ± 48V (± 60V) battery (note 1), in series with two resistors,whose value is set by external components (see external component list of L3030).

c)low impedance region ; the battery value is reducedto 33V (45V) and the serial resistance is reduced to the value specified in stand by mode, that is : 23 x (RFS + 2RP)

Switching betweenthe three region is automaticwithout discontinuity, and depends on the loop resistance.Fig. 2 showsthe DC characteristicin normal battery condition.

Whentheboostbatteryconditionisactivatedthe low impedance region can never be reached by the sy-

Figure 2 : DC Characteristic (n.b.) ILIM = 25/30/45/70mA.

Note : 1. This value of voltage battery, named apparent battery, is fixed internally by the control unit and is independent of the actual battery value. So, the voltage drop in the low impedance region is 15V. It is also possible to increase up to 25V this value setting BIT3R to 1.

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stem ; in this case the internal dropout voltage is equal to 30V.

Fig. 3 shows the DC characteristic in boost battery condition.

In conversationmode, on request of controlprocessor, whatever condition is set (normal or boost battery, direct or reverse polarity), you can inject the 12kHz(or16kHz)signal (permanentlyapplied at the pin 33 with 950mVrms typ. amplitude), as metering pulses. A patentedautomatic control system adjust the level of the metering signal, across the line, to 2Vrms setting BIT3 = 0, or to 5Vrms setting BIT3 = 1 ; this, regardless of the line impedance. Moreover the metering signal is ramped at the beginningand at the end of each pulse to preventundesirableclicking noise ; the slope is determined by the value of CINT (see the external component list of L3030). The SLIC also provides, in the transmit direction (fromline to 4-wire side),an amplifier to insert anexternal notch filter (series resonator)for suppressing the 12/16kHz residual signal.

Fig. 4 showsa suggestednotch Filter configuration.

The metering pulses can be injected with a DC line current equal to zero (ON-HOOK Operation).

If teletax is not used the notch filter can be replaced by a 1KΩ resistor.

Inconversationmode theACimpedanceatthe lineterminals,ZML,issynthetizedbytheexternalcomponents ZAC and RP, according to the following formula :

ZML = ZAC + (RP1 + RP2)

Dependingon the characteristic of the ZAC network, ZML canbe eithera pure resistance or a compleximpedance,soallowing ST SLICtomeetdifferentstandards as far as the return loss is concerned. The capacitorCCOMP guaranteesstability to the system.

The two-to-four wire conversion is achieved by means of a Wheatstone bridge configuration,the sides

Figure 4 : ExternalTeletaxe Filter.

f =	1
	2π ````√ LxC

L = R2 x R4 xR5 xC2

R3

L3000S - L3030

of which being :

1)the line impedance (Zline),

2)the SLIC impedance at line terminals (ZML),

3)thenetworkZA connectedbetweenpin 36and 41 of L3030 (see externalcomponentlist of L3030),

4)the network ZB between pin 36 and ground that shall copy the line impedance.

For a perfectbalancing,the following equationshall be verified :

ZAZB = ZlineZML

It is important to underline that ZA and ZB are not obliged to be equal to ZML and to Zline, but they both may be multiplied by a factor (up to ten) so allowing use of smaller capacitors.

Inconversation,the L3000Sdissipatesabout250mW foritsownoperation; thedissipationdependingonthe current supplied to the line shall be added.

The fig 5 and fig 6 show theDC characteristicfor two different Feeding resistance.

2 x 200 Ohm and 2 x 400 respectively.

Figure 3 : DC Characteristic (b.b.)

ILIM = 25/30/45/70mA.

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