AFE1103E/1KG4 [TI]

IC DATACOM, DIGITAL SLIC, PDSO48, GREEN, PLASTIC, SSOP-48, Digital Transmission Interface;
AFE1103E/1KG4
型号: AFE1103E/1KG4
厂家: TEXAS INSTRUMENTS    TEXAS INSTRUMENTS
描述:

IC DATACOM, DIGITAL SLIC, PDSO48, GREEN, PLASTIC, SSOP-48, Digital Transmission Interface

电信 光电二极管 电信集成电路
文件: 总12页 (文件大小:164K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
®
AFE1103  
AFE1103  
HDSL/MDSL ANALOG FRONT END  
FEATURES  
DESCRIPTION  
COMPLETE ANALOG INTERFACE  
T1, E1, AND MDSL OPERATION  
CLOCK SCALEABLE SPEED  
SINGLE CHIP SOLUTION  
Burr-Brown’s Analog Front End greatly reduces the  
size and cost of an HDSL or MDSL system by provid-  
ing all of the active analog circuitry needed to connect  
the Brooktree Bt8952 HDSL digital signal processor  
to an external compromise hybrid and a 1:2 HDSL line  
transformer. All internal filter responses as well as the  
pulse former output scale with clock frequency—  
allowing the AFE1103 to operate over a range of bit  
rates from 196kbps to 1.168Mbps.  
+5V ONLY (5V OR 3.3V DIGITAL)  
250mW POWER DISSIPATION  
48-PIN SSOP  
–40°C TO +85°C OPERATION  
Functionally, this unit is separated into a transmit and  
a receive section. The transmit section generates, fil-  
ters, and buffers outgoing 2B1Q data. The receive  
section filters and digitizes the symbol data received  
on the telephone line and passes it to the Bt8952. The  
HDSL Analog Interface is a monolithic device fabri-  
cated on 0.6µCMOS. It operates on a single +5V  
supply. It is housed in a 48-pin SSOP package. This  
unit is second sourced by Brooktree’s Bt8921.  
SECOND SOURCED BY BROOKTREE  
Bt8921  
txLINEP  
Pulse  
Line  
Former  
Driver  
txLINEN  
REFP  
PLLOUT  
PLLIN  
Voltage  
Reference  
VCM  
Transmit  
Control  
txDATP  
txDATN  
txCLK  
REFN  
rxSYNC  
rxLOOP  
rxGAIN  
Receive  
Control  
rxLINEP  
2
rxLINEN  
Delta-Sigma  
Modulator  
rxHYBP  
rxHYBN  
14  
Decimation  
Filter  
rxD13 - rxD0  
Patents Pending  
International Airport Industrial Park Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111  
Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132  
©1996 Burr-Brown Corporation  
PDS-1330A  
Printed in U.S.A. August, 1996  
SBWS001  
SPECIFICATIONS  
Typical at 25°C, AVDD = +5V, DVDD = +3.3V, ftx = 584kHz (E1 rate), unless otherwise specified.  
AFE1103E  
TYP  
PARAMETER  
COMMENTS  
MIN  
MAX  
UNITS  
RECEIVE CHANNEL  
Number of Inputs  
Input Voltage Range  
Common-Mode Voltage  
Input Impedance  
Differential  
Balanced Differential(1)  
1.5V CMV Recommended  
All Inputs  
2
±3.0  
+1.5  
V
V
See Typical Performance Curves  
Input Capacitance  
Input Gain Matching  
Resolution  
10  
±2  
pF  
%
Bits  
Line Input vs Hybrid Input  
14  
Programmable Gain  
Settling Time for Gain Change  
Four Gains: 0dB, 3.25dB, 6dB, and 9dB  
0
9
dB  
6
Symbol  
Periods  
%FSR(2)  
Gain + Offset Error  
Tested at Each Gain Range  
5
Output Data Coding  
Offset Binary  
Output Data Rate, rxSYNC(3)  
98  
98  
584  
584  
kHz  
TRANSMIT CHANNEL  
Transmit Symbol Rate, ftx  
T1 Transmit –3dB Point  
T1 Rate Power Spectral Density(4)  
E1 Transmit –3dB Point  
E1 Rate Power Spectral Density(4)  
Transmit Power(4, 5)  
kHz  
kHz  
Bellcore TA-NWT-3017 Compliant  
ETSI RTR/TM-03036 Compliant  
196  
See Typical Performance Curves  
292  
See Typical Performance Curves  
kHz  
13  
14  
dBm  
Pulse Output  
See Typical Performance Curves  
Common-Mode Voltage, VCM  
Output Resistance(6)  
AVDD/2  
1
V
DC to 1MHz  
TRANSCEIVER PERFORMANCE  
Uncancelled Echo(7)  
rxGAIN = 0dB, Loopback Enabled  
rxGAIN = 0dB, Loopback Disabled  
rxGAIN = 3.25dB, Loopback Disabled  
rxGAIN = 6dB, Loopback Disabled  
rxGAIN = 9dB, Loopback Disabled  
–67  
–67  
–69  
–71  
–73  
dB  
dB  
dB  
dB  
dB  
DIGITAL INTERFACE(6)  
Logic Levels  
VIH  
VIL  
VOH  
VOL  
|IIH| < 10µA  
|IIL| < 10µA  
IOH = –20µA  
IOL = 20µA  
DVDD –1  
–0.3  
DVDD –0.5  
DVDD +0.3  
+0.8  
V
V
V
V
+0.4  
Transmit/Receive Channel Interface  
ttx1  
ttx2  
txCLK Period  
txCLK Pulse Width  
1.7  
ttx1/16  
10.2  
15ttx1/16  
µs  
ns  
POWER  
Analog Power Supply Voltage  
Analog Power Supply Voltage  
Digital Power Supply Voltage  
Digital Power Supply Voltage  
Power Dissipation(4, 5, 8)  
Power Dissipation(4, 5, 8)  
PSRR  
Specification  
Operating Range  
Specification  
Operating Range  
DVDD = 3.3V  
5
V
V
V
4.75  
3.15  
5.25  
5.25  
3.3  
V
250  
300  
mW  
mW  
dB  
DVDD = 5V  
60  
TEMPERATURE RANGE  
Operating(6)  
–40  
+85  
°C  
NOTES: (1) With a balanced differential signal, the positive input is 180° out of phase with the negative input, therefore the actual voltage swing about the common  
mode voltage on each pin is ±1.5V to achieve a differential input range of ±3.0V or 6Vp-p. (2) FSR is Full-Scale Range. (3) The output data is available at twice the  
symbol rate with interpolated values. (4) With a pseudo-random equiprobable sequence of HDSL pulses; 13.5dBm applied to the transformer (27dBm output from  
txLINEP and txLINEN). (5) See the Discussion of Specifications section of this data sheet for more information. (6) Guaranteed by design and characterization. (7)  
Uncancelled Echo is a measure of the total analog errors in the transmitter and receiver sections including the effect of non-linearity and noise. See the Discussion  
of Specifications section of this data sheet for more information. (8) Power dissipation includes only the power dissipated within the component and does not include  
power dissipated in the external loads. See the Discussion of Specifications section for more information.  
®
AFE1103  
2
PIN DESCRIPTIONS  
PIN #  
TYPE  
NAME  
DESCRIPTION  
1
2
3
4
5
6
7
8
Ground  
Power  
Input  
Input  
Input  
PGND  
PVDD  
txCLK  
txDATN  
txDATP  
rxD0  
rxD1  
rxD2  
rxD3  
rxD4  
rxD5  
DGND  
DVDD  
rxD6  
rxD7  
Analog Ground for PLL  
Analog Supply (+5V) for PLL  
Symbol Clock (QCLK from Bt8952) (392kHz for T1, 584kHz for E1)  
XMITB Line from Bt8952  
XMIT Line from Bt8952  
ADC Output Bit-0 (RCV 2 from Bt8952)  
ADC Output Bit-1 (RCV 3 from Bt8952)  
ADC Output Bit-2 (RCV 4 from Bt8952)  
ADC Output Bit-3 (RCV 5 from Bt8952)  
ADC Output Bit-4 (RCV 6 from Bt8952)  
ADC Output Bit-5 (RCV 7 from Bt8952)  
Digital Ground  
Output  
Output  
Output  
Output  
Output  
Output  
Ground  
Power  
Output  
Output  
Output  
Output  
Output  
Output  
Output  
Output  
Ground  
Input  
Input  
Input  
Input  
Power  
Input  
Input  
Input  
Input  
Ground  
Ground  
Output  
Output  
Output  
Power  
Ground  
Output  
Power  
Output  
Ground  
NC  
NC  
NC  
NC  
Output  
Input  
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
Digital Supply (+3.3V to +5V)  
ADC Output Bit-6 (RCV 8 from Bt8952)  
ADC Output Bit-7 (RCV 9 from Bt8952)  
ADC Output Bit-8 (RCV 10 from Bt8952)  
ADC Output Bit-9 (RCV 11 from Bt8952)  
ADC Output Bit-10 (RCV 12 from Bt8952)  
ADC Output Bit-11 (RCV 13 from Bt8952)  
ADC Output Bit-12 (RCV 14 from Bt8952)  
ADC Output Bit-13 (RCV 15 from Bt8952)  
Digital Ground  
ADC Sync Signal (RCVCLK from Bt8952) (392kHz for T1, 584kHz for E1)  
Receive Gain Control Bit-0  
Receive Gain Control Bit-1  
Loopback Control Signal (loopback is enabled by positive signal)  
Analog Supply (+5V)  
Negative Input from Hybrid Network  
Positive Input from Hybrid Network  
Negative Line Input  
Positive Line Input  
Analog Ground  
Analog Ground  
Positive Reference Output, Nominally 3.5V  
Common-Mode Voltage (buffered), Nominally 2.5V  
Negative Reference Output, Nominally 1.5V  
Analog Supply (+5V)  
Analog Ground  
Transmit Line Output Negative  
Analog Supply (+5V)  
rxD8  
rxD9  
rxD10  
rxD11  
rxD12  
rxD13  
DGND  
rxSYNC  
rxGAIN0  
rxGAIN1  
rxLOOP  
AVDD  
rxHYBN  
rxHYBP  
rxLINEN  
rxLINEP  
AGND  
AGND  
REFP  
VCM  
REFN  
AVDD  
AGND  
txLINEN  
AVDD  
txLINEP  
AGND  
NC  
Transmit Line Output Positive  
Analog Ground  
Connection to Ground Recommended  
Connection to Ground Recommended  
Connection to Ground Recommended  
Connection to Ground Recommended  
PLL Filter Output  
NC  
NC  
NC  
PLLOUT  
PLLIN  
PLL Filter Input  
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN  
assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject  
to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not  
authorize or warrant any BURR-BROWN product for use in life support devices and/or systems.  
®
3
AFE1103  
PIN CONFIGURATION  
ABSOLUTE MAXIMUM RATINGS  
Analog Inputs: Current .............................................. ±100mA, Momentary  
±10mA, Continuous  
Top View  
SSOP  
Voltage .................................. AGND –0.3V to AVDD +0.3V  
Analog Outputs Short Circuit to Ground (+25°C) ..................... Continuous  
AVDD to AGND ........................................................................ –0.3V to 6V  
PVDD to PGND ........................................................................ –0.3V to 6V  
DVDD to DGND ........................................................................ –0.3V to 6V  
PLLIN or PLLOUT to PGND ......................................... –0.3V to PVDD +0.3V  
Digital Input Voltage to DGND ..................................0.3V to DVDD +0.3V  
Digital Output Voltage to DGND ...............................0.3V to DVDD +0.3V  
AGND, DGND, PGND Differential Voltage ......................................... 0.3V  
Junction Temperature (TJ) ............................................................ +150°C  
Storage Temperature Range .......................................... –40°C to +125°C  
Lead Temperature (soldering, 3s) ................................................. +260°C  
Power Dissipation ......................................................................... 700mW  
PGND  
PVDD  
txCLK  
txDATN  
txDATP  
rxD0  
1
2
3
4
5
6
7
8
9
48 PLLIN  
47 PLLOUT  
46 NC  
45 NC  
44 NC  
43 NC  
rxD1  
42 AGND  
41 txLINEP  
40 AVDD  
39 txLINEN  
38 AGND  
37 AVDD  
36 REFN  
35 VCM  
rxD2  
PACKAGE/ORDERING INFORMATION  
rxD3  
PACKAGE  
DRAWING TEMPERATURE  
rxD4 10  
rxD5 11  
PRODUCT  
PACKAGE  
NUMBER(1)  
RANGE  
AFE1103E  
48-Pin Plastic SSOP  
333  
–40°C to +85°C  
DGND 12  
DVDD 13  
rxD6 14  
NOTE: (1) For detailed drawing and dimension table, please see end of data  
sheet, or Appendix C of Burr-Brown IC Data Book.  
AFE1103E  
rxD7 15  
34 REFP  
33 AGND  
32 AGND  
31 rxLINEP  
30 rxLINEN  
29 rxHYBP  
28 rxHYBN  
27 AVDD  
26 rxLOOP  
25 rxGAIN1  
ELECTROSTATIC  
DISCHARGE SENSITIVITY  
This integrated circuit can be damaged by ESD. Burr-Brown  
recommends that all integrated circuits be handled with  
appropriate precautions. Failure to observe proper handling  
and installation procedures can cause damage.  
rxD8 16  
rxD9 17  
rxD10 18  
rxD11 19  
rxD12 20  
rxD13 21  
DGND 22  
rxSYNC 23  
rxGAIN0 24  
ESD damage can range from subtle performance degradation  
to complete device failure. Precision integrated circuits may  
be more susceptible to damage because very small parametric  
changes could cause the device not to meet its published  
specifications.  
®
AFE1103  
4
TYPICAL PERFORMANCE CURVES  
At Output of Pulse Transformer  
Typical at 25°C, AVDD = +5V, DVDD = +3.3V, unless otherwise specified.  
POWER SPECTRAL DENSITY LIMIT  
–20  
–40  
–38dBm/Hz for T1  
–80dB/decade  
T1  
–40dBm/Hz for E1  
E1  
–60  
–118dBm/Hz  
–80  
196kHz  
292kHz  
–120dBm/Hz  
for E1  
–100  
–120  
1K  
10K  
100K  
1M  
10M  
Frequency (Hz)  
CURVE 1. Upper Bound of Power Spectral Density Measured at the Transformer Output.  
0.4T 0.4T  
B = 1.07  
C = 1.00  
D = 0.93  
QUATERNARY SYMBOLS  
NORMALIZED  
LEVEL  
+3  
+1  
–1  
–3  
A
B
C
D
E
F
0.01  
1.07  
1.00  
0.93  
0.03  
–0.01  
–0.16  
–0.05  
0.0264  
2.8248  
2.6400  
2.4552  
0.0792  
–0.0264  
–0.4224  
–0.1320  
0.0088  
0.9416  
0.8800  
0.8184  
0.0264  
–0.0088  
–0.1408  
–0.0440  
–0.0088  
–0.9416  
–0.8800  
–0.8184  
–0.0264  
0.0088  
–0.0264  
–2.8248  
–2.6400  
–2.4552  
–0.0792  
0.0264  
G
H
0.1408  
0.0440  
0.4224  
0.1320  
1.25T  
A = 0.01  
E = 0.03  
A = 0.01  
F = –0.01  
–1.2T  
H = –0.05  
14T  
F = –0.01  
50T  
G = –0.16  
–0.6T 0.5T  
CURVE 2. Transmitted Pulse Template and Actual Performance as Measured at the Transformer Output.  
INPUT IMPEDANCE vs BIT RATE  
200  
T1 = 784kbps, 45kΩ  
E1 = 1168kbps, 30kΩ  
150  
100  
T1  
50  
E1  
0
100  
300  
500  
700  
900  
1100  
1300  
Bit Rate (kbps)  
CURVE 3. Input Impedance of rxLINE and rxHYB.  
®
5
AFE1103  
rxLOOP INPUT  
THEORY OF OPERATION  
rxLOOP is the loopback control signal. When enabled, the  
rxLINEP and rxLINEN inputs are disconnected from the  
AFE. The rxHYBP and rxHYBN inputs remain connected.  
Loopback is enabled by applying a positive signal (Logic 1)  
to rxLOOP.  
The transmit channel consists of a switched-capacitor pulse  
forming network followed by a differential line driver. The  
pulse forming network receives symbol data from the XMIT  
and XMITB outputs of the Bt8952 and generates a 2B1Q  
output waveform. The output meets the pulse mask and  
power spectral density requirements defined in European  
Telecommunications Standards Institute document RTR/  
TM-03036 for E1 mode and in sections 6.2.1 and 6.2.2.1 of  
Bellcore technical advisory TA-NWT-001210 for T1 mode.  
The differential line driver uses a composite output stage  
combining class B operation (for high efficiency driving  
large signals) with class AB operation (to minimize cross-  
over distortion).  
ECHO CANCELLATION IN THE AFE  
The rxHYB input is designed to be subtracted from the  
rxLINE input for first order echo cancellation. To accom-  
plish this, note that the rxLINE input is connected to the  
same polarity signal at the transformer (positive to positive  
and negative to negative) while the rxHYB input is con-  
nected to opposite polarity through the compromise hybrid  
(negative to positive and positive to negative) as shown in  
Figure 2.  
The receive channel is designed around a fourth-order delta  
sigma A/D converter. It includes a difference amplifier  
designed to be used with an external compromise hybrid for  
first order analog crosstalk reduction. A programmable gain  
amplifier with gains of 0dB to +9dB is also included. The  
delta sigma modulator operating at a 24X oversampling ratio  
produces 14 bits of resolution at output rates up to 584kHz.  
The basic functionality of the AFE1103 is illustrated in  
Figure 1 shown below.  
RECEIVE DATA CODING  
The data from the receive channel A/D converter is coded in  
offset binary.  
ANALOG INPUT  
OUTPUT CODE (rxD13 - rxD0)  
Positive Full Scale  
Negative Full Scale  
11111111111111  
00000000000000  
The receive channel operates by summing the two differen-  
tial inputs, one from the line (rxLINE) and the other from the  
compromise hybrid (rxHYB). The connection of these two  
inputs so that the hybrid signal is subtracted from the line  
signal is described in the paragraph titled “Echo Cancella-  
tion in the AFE”. The equivalent gain for each input in the  
difference amp is 1. The resulting signal then passes to a  
programmable gain amplifier which can be set for gains of  
0dB through 9dB. The ADC converts the signal to a  
14-bit digital word, rxD13-rxD0.  
RECEIVE CHANNEL PROGRAMMABLE  
GAIN AMPLIFIER  
The gain of the amplifier at the input of the Receive Channel  
is set by two gain control pins, rxGAIN1 and rxGAIN0. The  
resulting gain between 0dB and +9dB is shown below.  
rxGAIN1  
rxGAIN0  
GAIN  
0dB  
0
0
1
1
0
1
0
1
3.25dB  
6dB  
9dB  
txDATP  
txLINEP  
txLINEN  
Pulse Former  
txDATN  
Differential  
Line Driver  
rxHYBP  
rxHYBN  
14  
ADC  
rxD13 - rxD0  
rxLINEP  
rxLINEN  
Programmable  
Gain Amp  
Difference  
Amplifier  
FIGURE 1. Functional Block Diagram of AFE1103.  
®
AFE1103  
6
0.1µF  
0.1µF  
0.1µF  
PLLOUT  
PLLIN  
REFP  
VCM  
REFN  
1k  
1:2 Transformer  
Tip  
13Ω  
txLINEP  
txLINEN  
DVDD  
0.01µF  
200Ω  
13Ω  
Ring  
0.1µF  
8kΩ  
8kΩ  
Neg  
Pos  
Bt8952  
XMIT  
0.01µF  
Compromise  
Hybrid  
txDATP  
XMITB  
QCLK  
txDATN  
Neg  
Pos  
txCLK  
RCVCLK  
rxSYNC  
rxLOOP  
rxGAIN1  
rxGAIN0  
rxD13 - rxD0  
750Ω  
0.1µF  
2kΩ  
rxHYBP  
rxHYBN  
AGAIN1  
AGAIN0  
AFE1103  
100pF  
750Ω  
REFN  
2kΩ  
0.1µF  
RCV15 - RCV2  
14  
Input anti-alias  
filter fC 1MHz  
0.1µF  
PGND  
DGND  
AGND  
AGND  
AGND  
AGND  
rxLINEN  
rxLINEP  
2kΩ  
750Ω  
REFN  
2kΩ  
100pF  
0.1µF  
750Ω  
DVDD  
PVDD  
AVDD AVDD AVDD  
5V to 3.3V Digital  
0.1µF  
5V Analog  
1 - 10µF  
0.1µF 0.1µF 0.1µF  
10µF  
0.1µF  
+
5 - 10resistor for isolation  
FIGURE 2. Basic Connection Diagram.  
rxHYB AND rxLINE INPUT ANTI-ALIASING FILTERS  
rxHYB AND rxLINE INPUT BIAS VOLTAGE  
The –3dB frequency of the input anti-aliasing filter for the  
rxLINE and rxHYB differential inputs should be about  
1MHz. Suggested values for the filter are 750for each of  
the two input resistors and 100pF for the capacitor. Together  
the two 750resistors and the 100pF capacitor result in  
–3dB frequency of just over 1MHz. The 750input resis-  
tors will result in a minimal voltage divider loss with the  
input impedance of the AFE1103.  
The transmitter output on the txLINE pins is centered at  
midscale, 2.5V. But, the rxLINE input signal is centered at  
1.5V in the circuit shown in Figure 2 above.  
Inside the AFE1103, the rxHYB and rxLINE signals are  
subtracted as described in the paragraph on echo cancella-  
tion above. This means that the rxHYB inputs need to be  
centered at 1.5V just as the rxLINE signal is centered at  
1.5V. REFN (Pin 36) is a 1.5V voltage source. The external  
compromise hybrid must be designed so that the signal into  
the rxHYB inputs is centered at 1.5V.  
This circuit applies at both T1 and E1 rates. For slower rates,  
the antialiasing filters will give best performance with their  
–3dB frequency approximately equal to the bit rate. For  
example, a –3dB frequency of 500kHz should be used for a  
single pair bit rate of 500kbps.  
®
7
AFE1103  
TIMING DIAGRAM  
Transmit Timing  
ttx1  
ttx2  
txCLK  
txDATP (+3 Symbol)  
txDATP (+1 Symbol)  
txDATP (–1 Symbol)  
txDATP (–3 Symbol)  
ttx1/4  
ttx1/2  
3ttx1/4  
ttx1/16 min  
Receive Timing  
nttx1/16  
rxSYNC  
nttx1/16 + 3ttx1/96  
nttx1/16 + 51ttx1/96  
Data 1  
Data 1a  
Data 2  
rxD13 - rxD0  
10ns  
10ns  
10ns  
10ns  
NOTES: (1) Any transmit sequence not shown will result in a zero symbol. (2) All transitions are specified relative to the rising edge of  
txCLK. (3) Maximum allowable error for any txDAT edge is ±ttx1/12 (±17.8ns at E1 rate; ±26.6ns at T1 rate). (4) txDATN is the inverse of  
txDATP. (5) Both txDAT inputs are read by the AFE1103 at 1/8, 3/8, and 5/8 of a symbol period from the rising edge of txCLK. (6)  
rxSYNC can shift to one of 16 discrete delay times from the rising edge of txCLK. (7) It is recommended that rxD13 - rxD0 be read on  
the rising edge of rxSYNC.  
FIGURE 3. Timing Diagram.  
RECEIVE TIMING  
The bandwidth of the A/D converter decimation filter is  
equal to one half of the symbol rate. The A/D converter data  
output rate is 2X the symbol rate. The specifications of the  
AFE1103 assume that one A/D converter output is used per  
symbol period and the other interpolated output is ignored.  
The Receive Timing Diagram above suggests using the  
rxSYNC pulse to read the first data output in a symbol  
period. Either data output may be used. Both data outputs  
may be used for more flexible post-processing.  
The rxSYNC signal controls portions of the A/D converter’s  
decimation filter and the data output timing of the A/D  
converter. It is generated at the symbol rate by the user and  
must be synchronized with txCLK. The leading edge of  
rxSYNC can occur at the leading edge of txCLK or it can be  
shifted by the user in increments of 1/16 of a symbol period  
to one of 15 discrete delay times after the leading edge of  
txCLK.  
®
AFE1103  
8
tion in the digital circuitry does decrease with lower clock  
frequency. In addition, the power dissipation in the digital  
section is decreased when operating from a smaller supply  
voltage, such as 3.3V. (The analog supply, AVDD, must  
remain in the range 4.75V to 5.25V.)  
DISCUSSION OF  
SPECIFICATIONS  
UNCANCELLED ECHO  
The key measure of transceiver performance is uncancelled  
echo. This measurement is made as shown in the diagram of  
Figure 4. The AFE is connected to an output circuit includ-  
ing a typical 1:2 line transformer. The line is simulated by a  
135resistor. Symbol sequences are generated by the tester  
and applied both to the AFE and to the input of an adaptive  
filter. The output of the adaptive filter is subtracted from the  
AFE output to form the uncancelled echo signal. Once the  
filter taps have converged, the RMS value of the uncancelled  
echo is calculated. Since there is no far-end signal source or  
additive line noise, the uncancelled echo contains only noise  
and linearity errors generated in the transmitter and receiver.  
The power dissipation listed in the specifications section  
applies under these normal operating conditions: 5V Analog  
Power Supply; 3.3V Digital Power Supply; standard 13.5dBm  
delivered to the line; and a pseudo-random equiprobable  
sequence of HDSL output pulses. The power dissipation  
specifications includes all power dissipated in the AFE1103,  
it does not include power dissipated in the external load.  
The external power is 16.5dBm, 13.5dBm to the line and  
13.5dBm to the impedance matching resistors. The external  
load power of 16.5dBm is 45mW. The typical power dissi-  
pation in the AFE1103 under various conditions is shown in  
Table I.  
The data sheet value for uncancelled echo is the ratio of the  
RMS uncancelled echo (referred to the receiver input through  
the receiver gain) to the nominal transmitted signal (13.5dBm  
into 135, or 1.74Vrms). This echo value is measured under  
a variety of conditions: with loopback enabled (line input  
disconnected); with loopback disabled under all receiver  
gain ranges; and with the line shorted (S1 closed in Figure 4).  
TYPICAL POWER  
BIT RATE  
PER AFE1103  
(Symbols/sec)  
DISSIPATION  
IN THE AFE1103  
(mW)  
DVDD  
(V)  
584 (E1)  
584 (E1)  
392 (T1)  
392 (T1)  
146 (E1/4)  
146 (E1/4)  
3.3  
5
3.3  
5
3.3  
5
250  
300  
240  
270  
230  
245  
POWER DISSIPATION  
Approximately 75% of the power dissipation in the AFE1103  
is in the analog circuitry, and this component does not  
change with clock frequency. However, the power dissipa-  
TABLE I. Typical Power Dissipation.  
13  
13Ω  
1:2  
5.6Ω  
5.6Ω  
Transmit  
Data  
txDATP  
txLINEP  
txLINEN  
135Ω  
S1  
0.047µF  
576Ω  
rxHYBP  
1.54kΩ  
2kΩ  
100pF  
AFE1103  
0.01µF  
150Ω  
2kΩ  
rxHYBN  
576Ω  
0.047µF  
0.1µF  
750Ω  
rxLINEP  
2kΩ  
100pF  
2kΩ  
rxLINEN  
REFN  
750Ω  
0.1µF  
Uncanceled  
Echo  
rxD13 - rxD0  
FIGURE 4. Uncancelled Echo Test Diagram.  
®
9
AFE1103  
In most systems, it will be natural to derive PVDD from the  
AVDD supply. A 5to 10resistor should be used to  
connect PVDD to the analog supply. This resistor in combi-  
nation with the 10µF capacitor form a lowpass filter—  
keeping glitches on AVDD from affecting PVDD. Ideally,  
PVDD would originate from the analog supply (via the  
resistor) near the power connector for the printed circuit  
board. Likewise, PGND should connect to a large PCB trace  
or small ground plane which returns to the power supply  
connector underneath the PVDD supply path. The PGND  
“ground plane” should also extend underneath PLLIN and  
PLLOUT (pins 47 and 48).  
LAYOUT  
The analog front end of an HDSL system has a number of  
conflicting requirements. It must accept and deliver digital  
outputs at fairly high rates of speed, phase-lock to a high-  
speed digital clock, and convert the line input to a high-  
precision (14-bit) digital output. Thus, there are really three  
sections of the AFE1103: the digital section, the phase-  
locked loop, and the analog section.  
The power supply for the digital section of the AFE1103 can  
range from 3.3V to 5V. This supply should be decoupled to  
digital ground with a ceramic 0.1µF capacitor placed as  
close to DGND (pin 12) and DVDD (pin 13) as possible.  
Ideally, both a digital power supply plane and a digital  
ground plane should run up to and underneath the digital  
pins of the AFE11103 (pins 3 through 26). However, DVDD  
may be supplied by a wide printed circuit board (PCB) trace.  
A digital ground plane underneath all digital pins is strongly  
recommended.  
The remaining portion of the AFE1103 should be considered  
analog. All AGND pins should be connected directly to a  
common analog ground plane and all AVDD pins should be  
connected to an analog 5V power plane. Both of these planes  
should have a low impedance path to the power supply.  
Ideally, all ground planes and traces and all power planes  
and traces should return to the power supply connector  
before being connected together (if necessary). Each ground  
and power pair should be routed over each other, should not  
overlap any portion of another pair, and the pairs should be  
separated by a distance of at least 0.25 inch (6mm). One  
exception is that the digital and analog ground planes should  
be connected together underneath the AFE1103 by a small  
trace.  
The phase-locked loop is powered from PVDD (pin 2) and its  
ground is referenced to PGND (pin 1). Note that PVDD must  
be in the 4.75V to 5.25V range. This portion of the AFE1103  
should be decoupled with both a 10µF Tantalum capacitor  
and a 0.1µF ceramic capacitor. The ceramic capacitor should  
be placed as close to the AFE1103 as possible. The place-  
ment of the Tantalum capacitor is not as critical, but should  
be close. In each case, the capacitor should be connected  
between PVDD and PGND.  
®
AFE1103  
10  
PACKAGE OPTION ADDENDUM  
www.ti.com  
19-May-2005  
PACKAGING INFORMATION  
Orderable Device  
AFE1103E  
Status (1)  
ACTIVE  
ACTIVE  
ACTIVE  
Package Package  
Pins Package Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)  
Qty  
Type  
Drawing  
SSOP  
DL  
48  
48  
48  
30 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR  
no Sb/Br)  
AFE1103E/1K  
AFE1103E/1KG4  
SSOP  
SSOP  
DL  
DL  
1000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR  
no Sb/Br)  
1000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR  
no Sb/Br)  
(1) The marketing status values are defined as follows:  
ACTIVE: Product device recommended for new designs.  
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.  
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in  
a new design.  
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.  
OBSOLETE: TI has discontinued the production of the device.  
(2)  
Eco Plan  
-
The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS  
&
no Sb/Br)  
-
please check  
http://www.ti.com/productcontent for the latest availability information and additional product content details.  
TBD: The Pb-Free/Green conversion plan has not been defined.  
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements  
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered  
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.  
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame  
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)  
(3)  
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder  
temperature.  
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is  
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the  
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reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on  
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited  
information may not be available for release.  
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI  
to Customer on an annual basis.  
Addendum-Page 1  
IMPORTANT NOTICE  
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