L3234

L3234 L3235 HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX AND KEY SYSTEM APPLICATIONS HIGHLY INTEGRATED SUBSCRIBER LINE INTERFACE KIT FOR PABX AND KEY SYSTEM APPLICATIONS IMPLEMENTS ALL KEY ELEMENTS OF THE BORSCHT FUNCTION INTEGRATED ZERO CROSSING BALANCED RINGING INJECTION ELIMINATES EXTERNAL RELAY AND CENTRALISED RINGING GENERATOR ZERO NOISE INJECTED ON ADJACENT LINES DURING RINGING SEQUENCE LOW POWER IN STANDBY AND ACTIVE MODES BATTERY FEED WITH PROGRAMMABLE LIMITING CURRENT PARALLEL LATCHED DIGITAL INTERFACE SIGNALLING FUNCTIONS (OFF HOOK, GND-KEY) LOW NUMBER OF EXTERNAL COMPONENTS INTEGRATED THERMAL PROTECTION INTEGRATED OVER CURRENT PROTECTION 0°C TO 70°C: L3234/L3235 -40°C TO 85°C: L3234T/L3235T HEPTAWATT ORDERING NUMBER: L3234 PLCC28 ORDERING NUMBER: L3235 DESCRIPTION The L3234/L3235 is a highly integrated SLIC KIT targeted to PABX and key system applications The kit integrates the majority of functions required to interface a telephone line. The L3234/L3235 implements the main features of the broths function: - Battery Feed (Balanced Mode) - Ringing Injection - Signalling Detection - Hybrid Function The Kit comprises 2 devices, the L3234 ringing injector fabricated in Bipolar in 140V Technology. Its function is to amplify and inject in balanced mode with zero crossing the ringing signal. The device requires an external positive supply of 100V and a low level sinusoid of approx. 950mVrms. The L3235 Line Feeder is integrated in 60V Bipolar Technology. The L3235 provides battery feed to the line with programmable current limitation. The two to four wire voice frequency signal conversion is implemented by the L3235 and line terminating and balance impedances are externally programmable. The L3234/L3235 kit is designed for low power dissipation. In a short loop condition the extra power is dissipated on an external transistor. The Kit is controlled by five wire parallel bus and interfaces easily to all first and programmable second generation COMBOS. (see figg. 1 and 2) Janauary 1995 1/26 This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice. L3234 - L3235 Figure 1: Typical Application Circuit with Second Generation COMBO for Complete Subscriber Circuit (Protection-SLIC-COMBO) 2/26 L3234 - L3235 Figure 2: Typical Application Circuit with First Generation COMBO for Complete Subscriber Circuit (Protection-SLIC-COMBO) 3/26 L3234 - L3235 L3234 Solid State Ringing Injector DESCRIPTION The L3234 is a monolithic integrated circuit which is part of a kit of solid state devices for the subscriber line interface. The L3234 sends a ringing signal into a two wires analog telephone line in balanced mode. The AC ringing signal amplitude is up to 60Vrms, and for that purpose a positive supply voltage of +100V shall be available on the subscriber card. The L3234 receives a low amplitude ringing signal (950mVrms) and provide the voltage/current amplification (60Vrms/70mA) when the enable input is active (CS > 2V). In disable mode (CS < 0.8V) the power consumption of the chip is very low ( 140V / VCBO > 250V). BLOCK DIAGRAM HEPTAWATT The package is a moulded plastic power package (Heptawatt) suitable also for surface mounting. 4/26 L3234 - L3235 PIN CONNECTION (Top view) 7 6 5 4 3 2 1 OUT2 V100 OUT1 GND VCC CS VA D94TL131 ABSOLUTE MAXIMUM RATINGS Symbol V100 VCC VA CS Tj Tstg 5V Power Supply Voltage Low Voltage Ringing Signal (with V100 = 120Vdc) Logical Ring Drive Input Max. Junction Temperature Storage Temperature Parameter Positive Power Supply Voltage Value +120 5.5 1.4 VCC 150 -55 to +150 o o Unit V V Vrms C C OPERATING RANGE Symbol V100 VCC VA Top Tjop High Power Supply Voltage Low Power Supply Voltage Low Voltage Ringing Signal Operating Temperature for L3234 L3234T Max. Junction Operating Temperature (due to thermal protection) Parameter Value 95 to 105 5 ±5% 600 to 950 within 10Hz - 100Hz 0 to 70 -40 to 85 130 Unit V V Vrms °C °C °C Note: Operating ranges define those limits between which the functionality of the device is guaranteed. THERMAL DATA Symbol Rth j-case R th j-amb Description Thermal Resistance Junction-case Thermal Resistance Junction-ambient Max. Max. Value 4 50 Unit o o C/W C/W PIN DESCRIPTION Pin 1 2 3 4 5 6 Name VA CS VCC GND OUT1 V100 Logical Ring Drive Input +5V Low Power Supply Common Analog-Digital Ground Ringing Signal Output +100V High Power Supply 5/26 Description Low Voltage Ringing Signal Input L3234 - L3235 of the L3234 Solid State Ringing injector when used with the L3235 Line Feeder. OPERATION DESCRIPTION The Fig. 3 show the simplified circuit configuration Figure 3: L3234/L3235Circuit Configuration +100V GND +5V C100 CVCC TIP A CO1 V100 RO1 OUT1 RO2 OUT2 CS 5 6 GND 4 VCC 3 LINE TERMINALS RING B CO2 RINGING INJECTOR 7 L3234 1 CA VA VA D94TL132 CS 2 LINE FEEDER GND -VBAT L3235 EXTERNAL COMPONENTS LIST In the following table are shown the recommended external components values for L3234. Ref. R01, R02 C01, C02 CA C100 CVCC Value 82Ω 10µF - 160V 4.7µF - 10V 100nF - 100V 100nF Involved Parameter or Function Ringing Feeding Series Resistors Ringing Feeding De coupling Capacitors Low Level Ringing Signal De coupling Capacitor Positive Battery Filter +5V Supply Filter When the ringing function is selected by the subscriber card, a low level signal is continuously applied to pin 1 through a de coupling capacitor. Then the logical ring drive signal CS provided by L3235 is applied to pin 2 with a cadenced mode. The ringing cycles are synchronised by the L3234 in such a way that the ringing starts and stops always when the analog input signal crosses zero. When the ringing injection is enabled (CS = ”1”), an AC ringing signal is injected in a balanced mode into the telephone line. When the ringing injection is disabled (CS = ”0”), the output voltage on OUT2 raises to the high power supply, whereas on OUT1, it falls down to ground. The L3234 has a low output impedance when sending the signal, and high output impedance when the ringing signal is disabled In fig. 4 the dynamic features of L3234 are shown. 6/26 L3234 - L3235 Figure 4: Dynamic Features of L3234 DATA TRANSMISSION INTERFERENCE TEST The L3234 meet the requirements of the technical specification ST/PAA/TPA/STP/1063 from the CNET. The test circuit used is indicated below. The measured error rate for data transmission is lower than 10-6 during the ringing phase. This test measures if during the ringing phase the circuit induce any noise to the closer lines. Figure 5: Test Circuit Data Transmission Interference Test 7/26 L3234 - L3235 ELECTRICAL CHARACTERISTICS (Test conditions: V100 = +100V, VCC = +5V, Tamb = 25°C, unless otherwise specified) Note: Testing of all parameter is performed at 25°C. Characterisation, as well as the design rule used allow correlation of tested performance with actual performances at other temperatures. All parameters listed here are met in the range 0°C to +70°C. For applications requiring operations in the standard temperature range (0°C to 70°C) use L3234. If operations are required in the extended temperature range (-40°C to 85°C), use the L3234T. Symbol Parameter Test Condition Min. Typ. Max. Unit Fig STAND BY MODE: CS = ”0” IS (V100) IS (VCC) VSOUT1 VSOUT2 ZSOUT1 ZSOUT2 THD Consumption DC Output Voltage Output Impedance ZOUT Matching Harmonic Distortion During Emission VLINE < 6dBm; f = 1kHz -46 VA = 950mVrms; 50Hz VA = 950mVrms; 50Hz 92 70 70 15 -40 45 560 100 800 6 µA µA V V kΩ kΩ % dB 7 6 RINGING PHASE: CS = ”1” DC OPERATION IR (V100) IR (VCC) VROUT1 VROUT2 VIH IIH (CS = 0) VIL IIL (CS = 0) Ilim DC Line Current Limitation VA = 0V 70 Consumption DC Output Voltage Threshold Voltage on the Logical Input CS ZLINE = ∞ VA = 950mVrms; 50Hz VA = 0V VA = 950mVrms; 50Hz 44 44 2.0 1 0.8 1 150 2.5 2.2 5 3 56 56 mA mA V V V µA V µA mA 8 12 AC OPERATION VOUT1/VA VOUT2/VA VOUT1 -VOUT1 THD VLINE ZIN (VA) ZOUT Ringing Gain Ringing Signal Harmonic Distortion Input Impedance Differential Output Impedance ZLINE = 2.2µF + 1kΩ VA = 0dBm ZLINE = 2.2µF + 1kΩ VA = 950mVrms; 50Hz VA = 950mVrms; 50Hz VA = 950mVrms; 50Hz ILINE < 50mArms 40 20 29.5 29.5 57 30 30 60 5 dB dB Vrms 9 % kΩ Ω 10 11 9 TEST CIRCUITS Figure 6. 8/26 L3234 - L3235 TEST CIRCUITS (continued) Figure 7. VCC V100 CS 4.7µ F 2 3 6 7 VOUT2 82Ω VOUT1 82Ω 10µF/160V B V ZLINE=600Ω L3234 1 4 5 10µF/160V A -VBAT GND 1MΩ LINE FEEDER VE 1KHz D94TL133 Figure 8. Figure 9. 9/26 L3234 - L3235 TEST CIRCUITS (continued) Figure 10. Figure 11. Figure 12. 10/26 L3234 - L3235 L3235 Subscriber Line Interface Circuit DESCRIPTION Circuit description The L3235 Subscriber Line Interface Circuit (SLIC) is a bipolar integrated circuit in 60V technology optimized for PABX application. The L3235 supplies a line feed voltage with a current limitation which can be modified by an external resistor (RLIM). The SLIC incorporates loop currents, ground key detection functions with an externally programmable constant time. The two to four wires and four to two wires voice frequency signal conversion is performed by the L3235 and the line terminating and the balancing impedances are externally programmable. The device integrates an automatic power limitation circuit. In short loop condition the extra power is dissipated on one external transistor (Text). This aproach allows to assembly the L3235 in a low cost standard plastic PLCC28 package. The chip is protected by thermal protection at Tj = 150°C. The SLIC is able to give a power up command for Combo in off hook condition and an enable logic for solid state ringing injector L3234. The L3235 package is 28 pin plastic PLCC. The L3235 has been designed to operate togheter with L3234 performing complete BORSHT function without any electromechanical ringing relay (see the application circuit fig. 16). ABSOLUTE MAXIMUM RATINGS Symbol VBAT VCC VSS Tj Tstg Battery Voltage Positive Supply Voltage Negative Supply Voltage Max. Junction Temperature Storage Temperature Parameter Value -54 5.5 -5.5 150 -55 to +150 Unit V V V °C °C PLCC28 PIN CONNECTION OPERATING RANGE Symbol VBAT VCC VSS Top Tj Battery Voltage Positive Supply Voltage Negative Supply Voltage Operating Temperature for L3235 L3235T Max Junction Operating Temperature Parameter Min. -52 4.75 -5.25 0 -40 Max. -24 5.25 -4.75 70 85 130 Unit V V V °C °C °C Note: Operating ranges define those limits between which the functionality of the device is guaranteed. 11/26 L3234 - L3235 THERMAL DATA Symbol R th j-amb Description Thermal Resistance Junction-ambient Max Value 80 Unit °C/W PIN DESCRIPTION Pin 1 2 3 4 5 6 7 8 9 10 Name Vbat RING ZAC VREG AGND BGND CAC RPC TX ZB Negative Battery Supply Input. RING wire of 2 Wire Line Interface. Non Inverting Input of the AC Impedance Synthesis Circuit. Emitter Connection for the External Transistor. Analog/Digital Ground. Battery Ground. This is the Reference for the Battery Voltage (note 1). AC Current Feedback Input. External Protection Resistors AC Transmission Compensation. Four Wire Transmitting Amplifier Output. Non Inverting Operational Input Inserted in the Hybrid Circuit for 2W to 4W Conversion. The Network Connected from this Pin to Ground shall be a copy of the Line Impedance. VRX Output Buffer 2W to 4W Conversion. High Impedance Four Wire Receiving Input. Positive 5V Supply Voltage. Voltage Reference Output; a Resistor Connected to this pin sets the Internal Bias Current. Negative 5V Supply Voltage. Transversal Line Current Feedback Divided by 50. Non Inverting Operational Input to Implement DC Character. Driver for External Transistor Base. Voltage Reference Output; a Resistor Connected to this Pin Sets the Value of Line Current Limitation. Ringing Logic Input from Line Card Controller. Stand by Logic Input (SBY = 1 Set Line Current Limitation at 3mA). Power u.p Logic Output for the Codec Filter. (PU = 0 means Codec Filter Activated) Ring Injector Enable for L3234 Output. (CS = 1 means L3234 Ringing Injection Enable). Hook Status Logic Output (OH = 0 means off hook). Ground Key Status Logic Output (GDK = 0 means Ground Key on). Time Constant Hook Detector Filter Input. Time Constant GK Detector Filter Input. Tip Wire of 2 Wire Line Interface. Description 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 ZA RX VCC REF VSS IL VPOL BASE LIM RNG SBY PU CS OH GDK RTF GKF TIP Note 1: AGND and BGND pins must be tied together at a low impedance point (e.g. at card connector level). 12/26 L3234 - L3235 L3235 FUNCTIONAL DIAGRAM FUNCTIONAL DESCRIPTION DIGITAL INTERFACE The different operating modes of the L3235 are programmed through a digital interface based on two input pins: 1)SBY input programs the stand-by or Active/Ringing modes. 2)RNG input programs the ringing ON/OFF activation condition for the L3234. The L3235 digital interface has four output pins : 1)OH provides the on hook/off hook or ring trip informations (active low). 2)GDK provides the ground key on/off information (active low). 3)PU must be connected to the enable input pin of CODEC/FILTER devices like ETC 5054/57 and automatically activates this device when in active mode off-hook is detected or when ringing mode is selected. 4)CS output must be connected to the CS enable input of the solid state ringing injector L3234. In this way the L3234 will be enabled when ringing mode is programmed and will be automatically disabled when the ring trip condition will be detected reducing the ringing signal disconnection time after ring trip. The table 1 here below resumes the different operation modes and the relative logic output signals. The two current detection (hook and GND key) have internal fixed threshold. Externally it is possible to program their time costant through two R-C components connected respectively to pin 26 (RTF) and pin 27 (GKF). 13/26 L3234 - L3235 Table 1. OPERATING MODE INPUT PIN SBY 0 0 0 0 0 0 0 0 1 1 RNG 0 0 0 0 1 1 1 1 0 1 LINE STATUS 0: ON HOOK 1: OFF HOOK 0 0 1 1 0 0 1 1 X X 0: NO GND KEY 1: GND KEY ON 0 1 0 1 0 1 0 1 X X OH 1 0 0 0 1 0 0 0 1 1 OUTPUT PIN GDK 1 0 1 0 1 0 1 0 1 1 PU 1 0 0 0 0 0 0 0 1 0 CS 0 0 0 0 1 0(*) 0(*) 0(*) 0 1 ACTIVE RINGING STAND-BY (*)This status is latched and doesn’t change until RNG turn to 0 OPERATING MODES Stand-By (SBY = 1 and RNG = 0) In Stand-By mode the L3235 limits the DC Loop current to 3 mA. In this mode all the AC circuits are active and all the AC characteristics are the same as in Active Mode. Also the two Line Current detectors (hook and GND key) are active but due to the loop current limited to 3 mA they will not be activated. This mode is useful in emergency condition when it is very important to limits the system power dissipation. Ringing Mode (SBY = 0 and RNG = 1) When ringing mode is selected ”CS” pin is set to 1 in order to activate the L3234 ringing injector. See L3234 for detailed description. Ring trip is detected by means of the same internal circuitry used for off-hook detection. An off-hook delay time lower than 1⁄2 FRING should be selected. (see ext. components list). When ring trip is detected ”CS” is automatically set to ”0” allowing in this way a quick ringing disconnection. After Ring trip detection the Card Controller must set the L3235 in active mode to remove the internal latching of the ”CS” information. Active mode (SBY = 0 and CS1 = 0) In Active mode the L3235 has the DC characteristic show in Fig.13 The DC characteristics of L3235 has two different feeding conditions: 1)Current Limiting Region : (short loop) the DC impedance of the SLIC is very high (>20 Kohm) therefore the system works as a current generator. By the ext. resistor RLIM connected at pin 19 it is possible to program limiting current values from 20 mA to 70 mA. 2) Voltage source region (long loop). The DC impedance of the L3235 is almost equal to zero therefore the system works like a voltage generator with in series the two external protection resistors Rp. When a limiting current value higher than 40 mA is programmed the device will automatically reduce to 40 mA the loop current for very short loop. This is done in order to limit the maximum power dissipation in very short loop to values lower than 2W for the external transistor and lower than 0.5W for the L3235 itself. This improve the system reliability reducing the L3235 power dissipation and therefore the internal junction temperature. 14/26 L3234 - L3235 Figure 13: DC characteristic in Active Mode with two different values of limiting current (30mA and 70 mA). Figure 14: Line current versus loop resistance with two different values of limiting current (30mA and 70mA) AC characteristic A simplified AC model of the transmission circuits is shown in figure 15. Where : Vrx Vtx Vl Eg Zl is the received signal is the transmitted signal is the AC transversal voltage at line terminations. is the line open circuit AC voltage is the line impedance are the protection resistors is the line impedance balancing network is the SLIC impedance balancing network program the AC line termination impedance used for external protection resistors insertion loss compensation Il/50 is the AC transversal current divided by 50 CAC AC feedback current decoupling Rp ZB ZA ZAC R PC 15/26 L3234 - L3235 Figure 15: Simplified AC Circuits Two wire impedance To calculate the impedance presented to the two wire line by the SLIC including the protection resistors R p and defined as ZS let: Vrx = 0 Il/50’ = Il/50 (in first approximation) Rp = 50Ω ZS = Z AC/25 + 2RP ZAC to make ZS = 600Ω ZAC = 25 • (ZS - 2R P) ZAC = 25 ⋅ (600 - 100) ZAC = 12.5KΩ Two wire to four wire gain (Tx gain) Let Vrx = 0 Vtx Gtx = Vl Vtx ZAC + RPC =2 ⋅ Vl ZAC + 50RP Example: Calculate Gtx making RPC = 50 ⋅ RP ZAC + 50 ⋅ RP Gtx = 2 ⋅ =2 ZAC + 50 ⋅ RP As you can see the RPC resistor is providing the compensation of the insertion loss introduced by the two external protection resistors RP. Four wire to two wire gain (Rx gain) Let Eg = 0 Vl 50 ⋅ Zl Grx = = Vrx 25⋅ (Zl + 2RP ) + ZAC Example: Calculate Grx making ZAC = 25 ⋅ (ZML - 2 ⋅ RP) 50 ⋅ Zl Grx = 25 ⋅ (Zl + 2RP − 2RP + ZML) 16/26 Grx = 2 ⋅ Zl Zl + ZML In particular for ZS = Z l: Grx = 1 Hybrid function To calculated the transhybrid loss (Thl) let: Eg = 0 Thl = ZB 50 ⋅ ( 2 ⋅ RP + Zl ) − 2RPC VTx =4( + ZA − ) = VRx ZB 50 ⋅ ( 2 ⋅ RP + Zl ) − 2RAC Example: Calculating Thl making RS = 50 ⋅ RP, ZS = 25 ⋅ (ZSlic - 2 ⋅ RP) ZB Zl Thl = 4 ⋅ ( − ) ZB + ZA Zl + ZML In particular if ZS ZA = ZB Zl Thl = 0 From the above relation it is evident that if ZS is equal to the Zl used in Thl test, the two ZA, ZB impedances can be two resistor of the same value. AC transmission circuit stability To ensure stability of the feedback loop shown in block diagram form in figure 15 two capacitors are required. Figure 16 includes these capacitors Cc and Ch. AC - DC separation The high pass filter capacitor CAC provides the separation between DC circuits and AC circuits. A CAC value of 100mF will position the low end frequency response 3dB break point at 7Hz, fsp = 1 2π ⋅ 220Ω ⋅ CAC L3234 - L3235 External components list for L3235 To set the SLIC into operation the following parameters have to be defined: - The AC SLIC impedance at line terminals ”Zs” to which the return loss measurements is referred. It can be real (typ. 600Ω) or complex. - The equivalent AC impedance of the line ”Zl” used for evaluation of the trans-hybrid loss performance (2/4 wire conversion). It is usually a complex impedance. - The value of the two protection resistors Rp in series with the line termination. Once, the above parameters are defined, it is possible to calculate all the external components using the following table. The typical values has been obtained supposing: Zs = 600Ω; Zl = 600Ω; Rp = 50Ω Name RF CF R GF C GF RR RLIM CR RP RT CAC RPC ZAC CC ZAS R AS ZB CH CTX D1, D2 Text Suggested Value 39KΩ 390nF 39KΩ 390nF 51KΩ 8.4KΩ to 33KΩ 4.7µF 6.3 V 30% 50 1M Ω 20% 100µF 6.3V 20% 2500Ω 1% 12500Ω 1% 220pF 20% 12500Ω 1% 2500Ω 1% 15KΩ 1% 220pF 20% 4.7µF 30% 1N4007 (3) Function Delay Time On-hook Off-hook Delay Time GK Detector Bias Set Ext. Current Limit. Progr. Negative Battery Filter Protection Resistors Termination Resistor DC/AC current feedback splitting RP insertion loss compensation 2W AC Impedance programmation AC Feedback compensation Slic Impedance Balancing Net. Line impedance Balancing Net. CC Transybrid loss Compensation DC Decoupling Tx Output Line Rectifier External Transistor ±5V supply filter VBAT supply filter Formula τ = 0.69 ⋅ CF ⋅ 39KΩ τ = 0.69 ⋅ C GF ⋅ 39KΩ 564 ILIM − 3mA (1) RLIM = CAC = 1 2π ⋅ 16KΩ ⋅ fp 47 < RP < 100Ω (2) 1 2π ⋅ 220Ω ⋅ fsp CAC = R PC = 25 ⋅ (2RP) ZAC = 25 ⋅ (ZS - 2RP) f1 = 300KHz CC = 1 2π f1 ⋅ 50RP ZAS = 25 ⋅ (ZS - 2RP) RAS = 25 ⋅ (2RP) ZB = 25 ⋅ Zl C H = CC ⋅ CTX = ZAC ZAS 1 6.28 ⋅ fp ⋅ Zload PDiss > 2W, VCEO > 60V H FE > 40, IC > 100mA VBE < 0.8V @ 100mA CVSS; CVDD C VB 100nF 100nF/100V Notes: 1) For proper operation Cf should be selected in order to verify the following conditions: A) cf > 150nF B) τ < 1/2 • fRING fRING: Ringing signal frequency 2) For protection purposes the RP resistor is usually splitted in two part RP1 and RP2, with RP1 > 30Ω. 3) ex: BD140; MJE172; MJE350.... (SOT32 or SOT82 package available also for surface mount). For low power application (reduced battery voltage) BCP53 (SOT223 surface mount package) can be used. Depending on application enviroment an heatsink could be necessary. 17/26 L3234 - L3235 Figure 16: Typical Appication Circuit Including L3234 and Protection 18/26 L3234 - L3235 ELECTRICAL CHARACTERISTICS (Test condition: refer to the test circuit of the fig. 17; VCC = 5V, VSS = -5V, Vbat = -48V, Tamb = 25°C, unless otherwise specified) Note: Testing of all parameters is performed at 25°C. Characterization, as well as the design rules used allow correlation of tested performance with actual performance at other temperatures. All parameters listed here are met in the range 0°C to +70°C. For applications requiring operations in the standard temperature range (0°C to 70°C) use L3234. If operations are required in the extended temperature range (-40°C to 85°C), use the L3234T. Symbol Parameter Test Condition Min. Typ. Max. Unit Fig. STAND-BY Vls ILCC Output Voltage at TIP/RING pins Short Circuit Current ILINE = 0 Stand-by, SBY = 1 35.7 2 3 39 4 V mA DC OPERATION VlP Ilim Ilim IO If Ilgk Gklim Gkov Imax IVCC IVSS IVbat Output Voltage at TIP/RING pins Current Progr. Current Progr. On-hook Threshold Off-hook Threshold GK Detector Threshold Ground Key Current Limitation Ground Key Threshold Overloap Max. Output Current at TIP/RING Supply Current from VCC Supply Current from VSS Supply Current from Vbat ILINE = 0 ILINE = 50mA Ilim Prog. = 70mA 8.4KΩ < RLIM < 33KΩ 35.7 35.2 63 20 10 10 13 1 90 6.2 1.6 2.8 140 8 2.1 3.6 39 39 77 70 5 17 22 V V mA mA 70 RING to BGND Gklim-Ilgk Ilim = 70mA Iline = 0 Iline = 0 Iline = 0 mA mA mA mA mA mA AC OPERATION Ztx Zrx Rl Thl Gs Gsf Gsl Gr Grf Grl Np4W Np2W Svrr Svrr Sending Output Impedance Receiving Input Impedance 2W Return Loss Trans Hybrid Loos Sending Gain Flatness Linearity Receiving Gain Flatness Linearity Psoph. Noise at Tx Psoph. Noise at Line Relative to Vbat versus Line Terminal versus Tx Terminal Relative to Vcc and Vss versus Line Terminal versus Tx Terminal L/T Conversion measured at line Terminals T/L Conversion Measured at Line Terminals pin 9 (Tx) pin 12 (Rx) f = 300 to 3400Hz f = 300 to 3400Hz f = 1020Hz Il = 20mA f = 300 to 3400Hz -20dB to 10dBm f = 1020Hz Il = 20mA f = 300 to 3400Hz -20dBm to +4dBm 10 1 20 20 5.82 -0.2 -0.2 0.2 -0.2 -0.2 36 36 6.02 Ω MΩ dB dB dB dB dB dB dB dB dBmp dBmp dB dB dB dB dB dB dB 0 -69 -75 f = 1020Hz VS = 100mVpp f = 1020Hz VS = 100mVpp f = 300 to 3400 Iline = 20mA f = 300 to 3400 Iline = 20mA 49 53(*) 46(*) 6.22 0.2 0.2 0.2 0.2 0.2 -62 -68 -30 -24 -20 -14 A1 A2 A3 A4 A5 L tc Tlc A6 A7 (*) Selected parts L3235C 19/26 L3234 - L3235 ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Condition Min. Typ. Max. Unit Fig. DIGITAL STATIC INTERFACE Vil Vih Iil Iih Vol Voh Input Voltage at Logical ”0” Input Voltage at Logical ”1” Input Current at Logical ”0” Input Current at Logical ”1” Output Voltage at Logical ”0” Output Voltage at Logical ”1” Input SBY, CS1 Input SBY, CS1 Input SBY, CS1 Input SBY, CS1 Iout = 1mA Iout = 10µA Iout = 10µA Iout = 1mA 4 2.7 0 2 0.8 5 10 10 0.5 0.4 V V µA µA V V V V Figure 17: Test Circuit 20/26 L3234 - L3235 APPENDIX A L3235 TEST CIRCUITS Referring to the test circuit reported in fig 17 you can find the proper configuration for the main measurements. Figure A1: 2W Return Loss In particular: A-B: Line terminals C: Tx sending output on 4W side D: Rx receiving input on 4W Side 100µF 100µF RL = 20 log | ZML + Z | | ZML − Z | = 20 log | 2VS | |E| Figure A2: Trans-hybrid Loss 100µF THL = 20log VS VR 100µF Figure A3: Sending Gain 100µF 100µF 21/26 L3234 - L3235 TEST CIRCUITS (continued) Figure A4: Receiving Gain 100µF 100µF Figure A5: SVRR Relative to Battery Voltage VB 100µF 100µF Figure A6: Longitudinalto Transversal Conversion 22/26 L3234 - L3235 Figure A7: Transversal to LongitudinalConversion APPENDIX B LAYOUT SUGGESTIONS Standard layout rules should be followed in order to get the best system performances: 1) Use always 100nF filtering capacitor close to the supply pins of each IC. 2) The L3235 bias resistor (RR) should be connected close to the corresponding pins of L3235 (REF and AGND). 23/26 L3234 - L3235 HEPTAWATT (Surface Mount) PACKAGE MECHANICAL DATA DIM. MIN. A C D D1 E F F1 G G1 G2 H2 H3 L L1 L2 L3 L5 L6 L7 M V2 Dia 3.65 3.85 2.41 4.91 7.49 9.2 10.05 4.6 3.9 6.55 5.9 2.6 15.1 6 0.17 4.1 6.75 6.1 2.8 2.54 5.08 7.62 2.4 1.2 0.35 0.6 mm TYP. MAX. 4.8 1.37 2.8 1.35 0.55 0.8 0.9 2.67 5.21 7.8 10.4 10.4 5.05 4.3 6.95 6.3 3 15.8 6.6 0.32 8°(max) 0.144 0.152 0.095 0.193 0.295 0.362 0.396 0.181 0.153 0.253 0.232 0.102 0.594 0.236 0.007 0.161 0.265 0.240 0.110 0.100 0.200 0.300 0.094 0.047 0.014 0.024 MIN. inch TYP. MAX. 0.189 0.054 0.110 0.053 0.022 0.031 0.035 0.105 0.205 0.307 0.409 0.409 0.198 0.170 0.273 0.248 0.118 0.622 0.260 0.012 24/26 L3234 - L3235 PLCC28 PACKAGE MECHANICAL DATA DIM. MIN. A B D D1 D2 E e e3 F F1 G M M1 1.24 1.143 12.32 11.43 4.2 2.29 0.51 9.91 1.27 7.62 0.46 0.71 0.101 0.049 0.045 10.92 mm TYP. MAX. 12.57 11.58 4.57 3.04 MIN. 0.485 0.450 0.165 0.090 0.020 0.390 0.050 0.300 0.018 0.028 0.004 0.430 inch TYP. MAX. 0.495 0.456 0.180 0.120 25/26 L3234 - L3235 Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. © 1995 SGS-THOMSON Microelectronics - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A. 26/26