Datasheet LT1795 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | Dual 500mA/50MHz Current Feedback Line Driver Amplifier |
| Pages / Page | 12 / 10 — APPLICATIONS INFORMATION. DEMO BOARD. Figure 9. PACKAGE DESCRIPTIO. SW … |
| File Format / Size | PDF / 158 Kb |
| Document Language | English |
APPLICATIONS INFORMATION. DEMO BOARD. Figure 9. PACKAGE DESCRIPTIO. SW Package. 20-Lead Plastic Small Outline (Wide .300 Inch)
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Text Version of Document
LT1795
U U W U APPLICATIONS INFORMATION
Figure 9 shows the effect of the network on a 200pF load. and greatly reduces the peaking. A lower value feedback Without the optional compensation, there is a 6dB peak at resistor can now be used, resulting in a response which is 85MHz caused by the effect of the capacitance on the flat to ±1dB to 45MHz. The network has the greatest effect output stage. Adding a 0.01µF bypass capacitor between for CL in the range of 0pF to 1000pF. the output and the COMP pins connects the compensation Although the optional compensation works well with 14 capacitive loads, it simply reduces the bandwidth when it VS = ±15V 12 CL = 200pF is connected with resistive loads. For instance, with a 25Ω 10 RF = 3.4k NO load, the bandwidth drops from 48MHz to 32MHz when 8 RF = 1k COMPENSATION the compensation is connected. Hence, the compensation COMPENSATION 6 was made optional. To disconnect the optional compensa- 4 tion, leave the COMP pin open. 2 VOLTAGE GAIN (dB) 0 –2
DEMO BOARD
RF = 3.4k –4 COMPENSATION A demo board (DC261A) is available for evaluating the –6 1 10 100 performence of the LT1795. The board is configured as a FREQUENCY (MHz) differential line driver/receiver suitable for xDSL applica- 1795 F09
Figure 9
tions. For details, consult your local sales representative.
U PACKAGE DESCRIPTIO SW Package 20-Lead Plastic Small Outline (Wide .300 Inch)
(Reference LTC DWG # 05-08-1620) .030 ±.005 .050 BSC .045 ±.005 TYP .496 – .512 (12.598 – 13.005) NOTE 4 N 20 19 18 17 16 15 14 13 12 11 N .420 .325 ±.005 MIN NOTE 3 .394 – .419 (10.007 – 10.643) 1 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT .291 – .299 1 2 3 4 5 6 7 8 9 10 (7.391 – 7.595) NOTE 4 .037 – .045 .093 – .104 .010 – .029 (0.940 – 1.143) × 45° (2.362 – 2.642) (0.254 – 0.737) .005 (0.127) RAD MIN 0° – 8° TYP .050 (1.270) .004 – .012 .009 – .013 NOTE 3 BSC (0.102 – 0.305) (0.229 – 0.330) .014 – .019 .016 – .050 S20 (WIDE) 0502 (0.356 – 0.482) (0.406 – 1.270) NOTE: TYP INCHES 1. DIMENSIONS IN (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) 1795fa 10
U U W U APPLICATIONS INFORMATION
Figure 9 shows the effect of the network on a 200pF load. and greatly reduces the peaking. A lower value feedback Without the optional compensation, there is a 6dB peak at resistor can now be used, resulting in a response which is 85MHz caused by the effect of the capacitance on the flat to ±1dB to 45MHz. The network has the greatest effect output stage. Adding a 0.01µF bypass capacitor between for CL in the range of 0pF to 1000pF. the output and the COMP pins connects the compensation Although the optional compensation works well with 14 capacitive loads, it simply reduces the bandwidth when it VS = ±15V 12 CL = 200pF is connected with resistive loads. For instance, with a 25Ω 10 RF = 3.4k NO load, the bandwidth drops from 48MHz to 32MHz when 8 RF = 1k COMPENSATION the compensation is connected. Hence, the compensation COMPENSATION 6 was made optional. To disconnect the optional compensa- 4 tion, leave the COMP pin open. 2 VOLTAGE GAIN (dB) 0 –2
DEMO BOARD
RF = 3.4k –4 COMPENSATION A demo board (DC261A) is available for evaluating the –6 1 10 100 performence of the LT1795. The board is configured as a FREQUENCY (MHz) differential line driver/receiver suitable for xDSL applica- 1795 F09
Figure 9
tions. For details, consult your local sales representative.
U PACKAGE DESCRIPTIO SW Package 20-Lead Plastic Small Outline (Wide .300 Inch)
(Reference LTC DWG # 05-08-1620) .030 ±.005 .050 BSC .045 ±.005 TYP .496 – .512 (12.598 – 13.005) NOTE 4 N 20 19 18 17 16 15 14 13 12 11 N .420 .325 ±.005 MIN NOTE 3 .394 – .419 (10.007 – 10.643) 1 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT .291 – .299 1 2 3 4 5 6 7 8 9 10 (7.391 – 7.595) NOTE 4 .037 – .045 .093 – .104 .010 – .029 (0.940 – 1.143) × 45° (2.362 – 2.642) (0.254 – 0.737) .005 (0.127) RAD MIN 0° – 8° TYP .050 (1.270) .004 – .012 .009 – .013 NOTE 3 BSC (0.102 – 0.305) (0.229 – 0.330) .014 – .019 .016 – .050 S20 (WIDE) 0502 (0.356 – 0.482) (0.406 – 1.270) NOTE: TYP INCHES 1. DIMENSIONS IN (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) 1795fa 10
