Application Note AN-347 5HIHUH 'HVL DPPDE HUHQ 'HVLJ XVLQ JUDP PD
|
|
|
Top Searches for this datasheet
HC55185 IDT821068 Programmable Octal CODEC
Application Note AN-347
5HIHUH 'HVL DPPDE HUHQ 'HVLJ XVLQ JUDP PDEOH &2'(&
purpose this application note provide reference design HC55185 IDT821068 Programmable Octal CODEC. network requirements many countries require analog subscriber line circuit (SLIC) terminate subscriber line with impedance voiceband frequencies which complex, rather than resistive (e.g. HC55185 accomplishes this impedance matching with single network connected between pin. IDT821068 Octal CODEC uses integrated programmable realize Impedance Matching, Transhybrid Balance, Frequency Response Correction Gain Setting functions. Discussed this application note following: 2-wire impedance matching Receive gain (4-wire 2-wire) transmit gain (2-wire 4-wire) calculations Reference design both 600W 200W +680W||0.1mF (China Complex Impedance)
DWFK
Impedance matching HC55185 subscriber load important optimization 2-wire return loss, which turn cuts down echoes voice communication path. Impedance matching HC55185 accomplished making SLIC's impedance (ZO, Figure equal desired terminating impedance minus value protection resistors (RP). With HC55185 programmed match 600, IDT821068 uses integrated programmable realize impedance. formula program HC55185 match 2-wire impedance 600W shown Equation
133.3 133.3
(EQ.
value with protection resistors 66.9k. closest standard value 66.5k.
Figure shows simplified transmission model HC55185 connection IDT821068 SLIC. Circuit analysis HC55185 yields following design equations: Sense Amplifier configured input differential amplifier with gain 3/4. voltage output sense amplifier (VSA) calculated using superposition. VSA1 voltage resulting from VSA2 voltage resulting from (reference Figure
(EQ. (EQ. (EQ.
(EQ. (EQ.
Where equal IMRSENSE (RSENSE 20W)
(EQ.
2000 Integrated Device Technology, Inc.
January 2002
6122
Application Note AN-347
voltage equal
(EQ.
defined Figure note polarity assigned VTR:
(EQ.
0.47µF RING INTERSIL HC55185 0.47µF 66.5k RESISTIVE 133.3(600 2*49) 66.9k VALUE 66.5k
4.7µF
FIGURE IMPEDANCE MATCHING
Setting equal zero, substituting Equation into Equation defining -VTR/DIM will enable user determine require feedback match line impedance
133.33
(EQ.
source impedance device defined 2Rp. line impedance. defined
133.33 Node Equation HC55185 input
(EQ. (EQ.
Substitute Equation into Equation
Loop Equation HC55185 feed amplifiers load Loop Equation Tip/Ring interface
(EQ. (EQ.
(EQ.
Substitute Equation -V2w/ZL into Equation
(EQ.
(EQ.
Substitute Equation into Equation combine terms
(EQ.
January 2002
Application Note AN-347
where: input voltage pin. internal node voltage that function loop current output Sense Amplifier. Internal current SLIC that difference between input receive current feedback current. metallic current. protection resistor (typical 49.9). external resistor/network matching line impedance. ring voltage output pins SLIC. ring voltage including voltage across protection resistors. line impedance. source impedance device.
RSENSE
INTERSIL HC55185 RECEIVE BLOCK VOUT1 VIN1
IDT821068 CHANNEL FILTER FILTER CHANNEL CHANNEL
RING
FEED AMPLIFIER
DR1/DD FEED AMPLIFIER FEEDBACK AMPLIFIER IM30 SENSE AMPLIFIER CHANNEL CHANNEL CHANNEL CHANNEL CHANNEL CORE PCM/GCI INTERFACE DX1/DU
RSENSE
FIGURE HC55185 SIMPLIFIED TRANSMISSION CIRCUIT IDT821068
4-wire 2-wire gain across HC55185 equal divided input voltage VRX, reference Figure receive gain calculated using Equation Equation expresses receive gain (VRX V2W) terms network impedances. From Equation value match line impedance (ZL) HC55185 plus protection resistors RP). This results 4-wire 2-wire gain shown Equation
(EQ.
January 2002
Application Note AN-347
HLYH HFHL 6\VWH
receive gain across system defined gain from highway phone (V2W). With receive gain through HC55185 receive gain across system entirely controlled programming IDT821068. IDT821068 program receive gain across system ways (reference Figure first programming signal gain analog form. analog receive gain, also known Digital Analog (D/A) gain, programmed IDT821068 either -6dB. second programming signal gain (via. coefficients) when digital form. digital form receive path programmed from -12dB with minimum 0.1dB steps. This results possible receive gain (D/A) programming range from +6dB -18dB. Note: Analog gain brings less noise than digital gain. When allocating CODEC gain, majority required gain should preformed analog stage. Reference section titled "Information Required Calculate IDT821068 CODEC Coefficients" information obtaining coefficients your design.
VPLW $FUR FURV
2-wire 4-wire gain equal VTX/ with reference Figure
Loop Equation
(EQ.
From Equation with
(EQ.
Substituting Equation into Equation simplifying.
(EQ.
Substituting Equation into Equation defining -V2W/ZL results Equation
(EQ.
Combining Equations results Equation
(EQ.
more useful form equation rewritten terms /V2W. voltage divider equation written convert from shown Equation
(EQ.
Substituting rearranging Equation terms results Equation
(EQ.
Substituting Equation into Equation results equation 2-wire 4-wire gain that's function synthesized input impedance SLIC protection resistors
0.416
(EQ.
600W, programmed with 498.76W (66.5kW/133.33), equal 49.9W. This results 2-wire 4-wire gain 0.416 -7.6dB.
January 2002
Application Note AN-347
VPLW $FUR 6\VWH FURV 6\VWHP
transmit gain across system defined gain from phone 2-wire side (V2W) highway. Setting gain IDT821068 will have account attenuated signal through HC55185. system gain entirely controlled programming IDT821068. IDT821068 program transmit gain across system ways (reference Figure first programming signal gain analog form. analog transmit gain, also known Analog Digital (A/D) gain, programmed IDT821068 either +6dB. second programming signal gain (via. coefficients) when digital form. digital form transmit path programmed from -6dB +12dB with minimum 0.1dB steps. This results possible transmit gain (A/D) programming range from -6dB +18dB. Note: Analog gain brings less noise than digital gain. When allocating CODEC gain, majority required gain should preformed analog stage. Reference section titled "Information Required Calculate IDT821068 CODEC Coefficients" information obtaining coefficients your design.
INTERSIL HC55185
CHANNEL VOUT1 0.47µF ANALOG GAIN -6dB
IDT821068 DIGITAL GAIN +6dB -12dB FILTER
RECEIVE PATH
RING
0.47µF 4.7µF
VIN1
ANALOG GAIN +6dB CHANNEL
DIGITAL GAIN -6dB +12dB
FILTER
TRANSMIT PATH DR1/DD CORE PCM/GCI INTERFACE DX1/DU
CHANNEL
FIGURE RECEIVE GAIN G(4-2), TRANSMIT GAIN (2-4)
EULG %DOD VK\E %DODQ
Transhybrid balance measure well input signal canceled (that being received SLIC) from transmit signal (that being transmitted from SLIC CODEC). Without this function, voice communication would difficult because echo. Transhybrid balancing filter inside IDT821068 used adjust transhybrid balance ensure echo cancellation meets ITU-T specifications. coefficient Echo Cancellation ECF.
UHFW
filter receive path filter transmit path programmed correct frequency distortion caused impedance matching filters. coefficients Frequency Response Correction receive path transmit path.
DWLR WLRQ &2'(&
calculate IDT821068 coefficient, customers should provide following information about their subscriber line card: Accurate SLIC PSPICE model. provided .lib file PSPICE schematic file. System Impedance Gain (Transmit path Receive path) Using coefficients provided IDT, overall performance system will pass ITU-T requirements.
January 2002
Application Note AN-347
When button selected from Operation General Interface screen, Operation screen will appear (Figure From this screen, user configure coefficients current channel.
FIGURE COEFFICIENT OPERATION SCREEN
'HVLJ 'HVLJQ
design criteria follows: 4-wire 2-wire gain (DR1/DD V2W) equal 2-wire 4-wire gain (V2W DX1/DU) equal 49.9W Figure gives reference design using Intersil HC55185 IDT821068 Programmable Octal CODEC. Also shown Figure voltage levels specific points circuit.
SHGD DWFK ,PSH
2-wire impedance matched line impedance using Equation repeated here Equation
133.3
(EQ.
line impedance 600W, equals
133.3 66.9k
(EQ.
closest standard value would 66.5kW.
January 2002
Application Note AN-347
G4-2
0dBm0(600) 0.7745VRMS 0dBm0(600) 0.7745VRMS 0dBm0(600) 0.7745VRMS 4.7µF
G2-4
SYSTEM REQUIREMENTS: IMPEDANCE: TRANSMIT GAIN (A/D): RECEIVE GAIN (D/A):
0dBm0(600) 0.7745VRMS
INTERSIL HC55185 RING 0.47µF VIN1 VOUT1
CHANNEL ANALOG GAIN ANALOG GAIN CHANNEL
IDT821068 DIGITAL GAIN DIGITAL GAIN +1.6dB
RECEIVE PATH DR1/DD CORE PCM/GCI INTERFACE DX1/DU
TRANSMIT PATH
0.47µF 90.9k
CHANNEL -7.5769dBm0(600) 0.3239VRMS
0dBm0(600) 0.7745VRMS
NOTE: Reference Table coefficients. FIGURE REFERENCE DESIGN HC55185 IDT821068 WITH LOAD IMPEDANCE
However, would very convenient cost effective system manufacturers only type line card meet different impedance requirements different gain requirements. programmability IDT821068 help system manufactures reach this goal. using different coefficients tweaking value this reference design meet both 600W 200W 680W||0.1mF impedance requirements. obtain best results, should optimized value. experimental experience, recommended 90.9kW With optimized value selected 90.9kW coefficients different Transmit Gains (A/D) Receive Gains (with line impedance 600W) given Tables Although impedance matching resistor (RS) HC55185 been changed, contribution from IDT821068 allows system still match load. With load matched, 2-wire 4-wire gain (Equation still equal -7.6dB.
HFLI WDWLR 6SHF WLRQ
design criteria China specific solution follows: Desired line circuit impedance 680//0.1mF Receive gain (V2W/(DR1/DD)) -3.5dB Transmit gain ((DX1/DU)/V2W) 0dBm0 defined into complex impedance 1020Hz 49.9W
Figure gives reference design using Intersil HC55185 IDT821068 Programmable Octal CODEC. Also shown Figure voltage levels specific points circuit. Note: transmit gain system (-2.19dB(811W) -3.5dB(600W)) explained following section.
$GMXVW $GMXVWP
voltage equivalent 0dBm0 into (0dBm0(811)) calculated using Equation (811 impedance complex China load 1020Hz).
January 2002
Application Note AN-347
0dBm 0.90055V 0.001
(EQ.
gain referenced back 0dBm0(600W) equal
0.90055V GAIN 1.309dB 0.7745VRMS
(EQ.
adjustment -3.5dBm0 load referenced 600W
Adjustment 3.5dBm0 1.309dBm0 2.19 (EQ.
voltage load (referenced 600W) given Equation
2.19 0.60196VRMS (EQ. 0.001
G4-2
-2.19dBm0(600) 0.60196VRMS RING INTERSIL HC55185 0.47µF 90.9k -2.19dBm0(600) 0.60196VRMS 4.7µF
-2.19dBm0(600) 0.60196VRMS 0.47µF VIN1 VPWRO+ VOUT1
SYSTEM REQUIREMENTS: IMPEDANCE: 200+600||0.1µF TRANSMIT GAIN (A/D): RECEIVE GAIN (D/A): -3.5dB IDT821068 DIGITAL GAIN -2.19dB DIGITAL GAIN +1.6dB
0dBm0(600) 0.7745VRMS
CHANNEL ANALOG GAIN ANALOG GAIN +6dB CHANNEL
RECEIVE PATH
TRANSMIT PATH DR1/DD CORE PCM/GCI INTERFACE DX1/DU
CHANNEL
-9.3294dBm0(600) 0.26461RMS
G2-4
VPCMOUT -3.5dBm0(600) 0.51769VRMS
NOTE: Reference Table coefficients. FIGURE REFERENCE DESIGN HC55185 IDT821068 WITH CHINA COMPLEX LOAD IMPEDANCE
DWFK
With optimized value selected 90.9k coefficients different Transmit Gains (A/D) Receive Gains (with line impedance (200 680||0.1µF) given Tables
January 2002
Application Note AN-347
TABLE COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (0dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB) COEFFICIENT IMF: ECF: ACT: ACR: CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT
CHANNEL
January 2002
Application Note AN-347
TABLE COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (0dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB) (Continued) IMF: ECF: ACT: ACR:
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
January 2002
Application Note AN-347
TABLE COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (-3.5dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB) COEFFICIENT IMF: ECF: ACT: ACR: CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF:
CHANNEL
January 2002
Application Note AN-347
TABLE COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (-3.5dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB) (Continued) ACT: ACR:
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
January 2002
Application Note AN-347
TABLE COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (-7.0dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB) COEFFICIENT IMF: ECF: ACT: ACR: CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT:
CHANNEL
January 2002
Application Note AN-347
TABLE COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (-7.0dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB) (Continued) ACR:
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
January 2002
Application Note AN-347
TABLE 0.1µF COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (0dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB)) COEFFICIENT IMF: ECF: ACT: ACR: CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT
CHANNEL
January 2002
Application Note AN-347
TABLE 0.1µF COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (0dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB)) (Continued) IMF: ECF: ACT: ACR:
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
January 2002
Application Note AN-347
TABLE 0.1µF COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (-3.5dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB)) COEFFICIENT IMF: ECF: ACT: ACR: CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT
CHANNEL
January 2002
Application Note AN-347
TABLE 0.1µF COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (-3.5dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB)) (Continued) IMF: ECF: ACT: ACR:
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
January 2002
Application Note AN-347
TABLE 0.1µF COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (-7.0dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB) COEFFICIENT IMF: ECF: ACT: ACR: CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
COEFFICIENT
CHANNEL
January 2002
Application Note AN-347
TABLE 0.1µF COEFFICIENTS, SYSTEM GAINS: (TRANSMIT GAIN (0dB), RECEIVE GAIN (-7.0dB)), CODEC ANALOG GAINS: (TRANSMIT PATH +6dB, RECEIVE PATH 0dB) (Continued) IMF: ECF: ACT: ACR:
COEFFICIENT IMF: ECF: ACT: ACR:
CHANNEL
January 2002
Other recent searches
UCC2540 - UCC2540 UCC2540 Datasheet
TDZ12 - TDZ12 TDZ12 Datasheet
STM915-14 - STM915-14 STM915-14 Datasheet
NJW1142A - NJW1142A NJW1142A Datasheet
MMBD7000LT1 - MMBD7000LT1 MMBD7000LT1 Datasheet
M3D121 - M3D121 M3D121 Datasheet
LSP3113 - LSP3113 LSP3113 Datasheet
IR2137 - IR2137 IR2137 Datasheet
IR2171 - IR2171 IR2171 Datasheet
IR2137Q - IR2137Q IR2137Q Datasheet
IR2171S - IR2171S IR2171S Datasheet
Privacy Policy | Disclaimer
© 2012 Datasheet Archive
