 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| Ordering number : EN5268A Monolithic Linear IC LA7780M QPSK Downconverter for CATV Systems Overview The LA7780M is a downconverter for QPSK data demodulation for digital CATV transmission. This IC integrates a preamplifier, an AGC amplifier, a mixer, an oscillator, a post-amplifier, and other circuits in a single chip, and provides all the functions required from cable signal input through output to the A/D converter. Functions * * * * * * * Preamplifier AGC amplifier Mixer Oscillator Post amplifier IF AGC (internal/external) AGC detector Features * Since a preamplifier is built in, the LA7780M has adequate sensitivity to handle the input signal from the cable directly. (Input signal level:-30 to +30 dBm) * Both internal and external AGC are supported as the AGC amplifier drive technique. * The output amplitude of the post amplifier used to drive the A/D converter is 2 Vp-p (typical). * Applications can be designed to use either a crystal or an inductor oscillator. Package Dimensions unit: mm 3108-MFP24D [LA7780M] 24 13 0.25 0.4 Specifications Maximum Ratings at Ta = 25C Parameter Maximum supply voltage Circuit voltage Symbol VCC max V max I4 Circuit current I13 I16 Allowable power dissipation Operating temperature Storage temperature Pd max Topr Tstg Pins 5, 6, and 17 Pins 4, 12, and 24 The pin 4 output current The pin 13 sink current The pin 16 sink current Ta 70C Conditions 1.27 0.1 2.25 0.67 SANYO: MFP24D Ratings 7.0 VCC 30 2 2 540 -20 to +70 -55 to +150 0.625 1 1 2 15.3 2.55max 9.2 10.5 7.9 Unit V V mA mA mA mW C C Any and all SANYO products described or contained herein do not have specifications that can handle applications that require extremely high levels of reliability, such as life-support systems, aircraft's control systems, or other applications whose failure can be reasonably expected to result in serious physical and/or material damage. Consult with your SANYO representative nearest you before using any SANYO products described or contained herein in such applications. SANYO assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all SANYO products described or contained herein. SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN D1698RM (OT) No. 5268-1/9 LA7780M Operating Conditions at Ta = 25C Parameter Recommended supply voltage Operating supply voltage range Symbol VCC VCC op Pins 5, 6, and 17 Pins 5, 6, and 17 Conditions Ratings 5.0 4.5 to 5.5 Unit V V AC Characteristics at Ta = 25C, VCC = 5.0 V, internal AGC mode, Pin 24 is left open. Parameter Circuit current RF input frequency range IF output level IF output IM3 IF output frequency bandwidth Local oscillator frequency range AGC amplifier input sensitivity AGC range AGC flatness Preamplifier gain Maximum preamplifier output level Oscillator output level Symbol Itotal f(in) VO(IF) VO(IM3) BW f(LO) Vin(RF2) GR VO(IF) G(RF1) VOmax VO(OSC) Conditions Pins 4, 5, 6, and 17: no signal Pins 1, 8, and 9 Pin 13: *1 Pin 13: *2 Pin 13: *3 Pins 18, 19, 20, and 21 Pins 8 and 9: *4 Pin 13: IF output level < 1 dB Pin 13: Compare with the state when Vin (RF2) = 30 dBmV Pin 4: *5 Pin 4: *6 Pin 23: The pin 23 frequency is 1/2 that of the local oscillator Ratings min 64 30 1.6 40 15 30 -25 60 -1 17 50 500 800 1000 -21 80 0 19 +1 21 200 -17 2.0 typ 80 max 95 150 2.5 Unit mA MHz Vp-p dB MHz MHz dBmV dB dB dB dBmV mVp-p Operating Modes Mode Internal AGC External AGC (Narrow control range: 3 to 5 V) External AGC (Wide control range: 0 to 5 V) Pin 10 GND GND (AGC divider inactive) Open (AGC divider active) Pin 11 With a capacitor between pin 11 and ground With a capacitor between pin 11 and ground With a capacitor between pin 11 and ground Pin 12 Connected to pin 11 External AGC voltage supply Pin 12 = high impedance External AGC voltage supply Pin 12 = low impedance (14 k) Internal AGC External AGC Note: In internal AGC mode, the IF output level can be adjusted by varying the pin 24 DC voltage. Caution: Note 1. Input: SG = 69.55 MHz, 20 dBm V Other conditions: Internal AGC mode Pin 24 left open. Output: The post amplifier output (pin 13) at 5 MHz Transfer ratio = 1 : 1 No. 5268-2/9 LA7780M Note 2. Input: SG1 = 69.55 MHz, SG2 = 70.55 MHz Other conditions: Internal AGC mode Pin 24 left open. Output: The post amplifier output (pin 13) Point = 20 dBmV (69.55 MHz) + 20 dBmV (70.55 MHz) Note 3. Post amplifier output level = -3 dB Remove the low-pass filter between pins 14 and 16. (Short the coil of 27 H and remove the capacitors of 27 pF and 15 pF.) Note 4. Input: SG1 = 69.55 MHz Other conditions: Internal AGC mode Pin 24 left open. Output: The signal level such that the post amplifier output (pin 13) falls by -3 dB. Note 5. SG = 75 MHz, 20 dBm V Note 6. SG1 = 75 MHz, SG2 = 76 MHz, Adjust the pin 1 level until the IM3 in the pin 4 output is 40 dB. Output:RF1-OUT (pin 4) VO(IM3) = 40 dB No. 5268-3/9 LA7780M Pin Assignment Top view Usage Notes * The oscillator may stop if the power supply rise time is extremely short. To prevent this problem, insert a 500 k resistor between pin 18 and ground or between pin 21 and ground. (This applies when a crystal oscillator is used.) * This IC should be used with the pin 13 output level between 1 Vp-p and 2 Vp-p. * Use a low-pass filter with a 6-dB attenuation between pins 14 and 16. * Since the high-frequency process is adopted, care must be taken to prevent the influence of static electricity. Block Diagram No. 5268-4/9 LA7780M Pin Descriptions Pin No. Function Pin voltage (V) Note Equivalent circuit 1 RF1 input 2.8 2 RF gain 1.3 Impedance connected to pin 2 must be > 45 3 GND 0 4 RF1 output Open collector 5 6 7 VCC VCC GND 5.0 5.0 0 8 9 RF2 input (1) RF2 input (2) 2.5 2.5 V = 2.5 V R = 1 k 10 Internal/external AGC switch 0 (GND) 1.0 (open) Pin 10 GND : Internal or external AGC (narrow control range) Pin 10 open : External AGC (wide control range) 11 12 AGC filter 2 AGC filter 1 Open collector Open base (Pin 10 GND) 4.0 (Pin 10 open) I1 = 20 A I2 = 100 A I3, I4 & Q1 are switched on and off by pin 10. Continued on next page. No. 5268-5/9 LA7780M Continued from preceding page. Pin No. Function Pin voltage (V) Note Equivalent circuit 13 Post-amp output 2, 3 R = 30 I = 7 mA 14 Post-amp input 2.0 V = 2.1 V R = 300 15 GND 0 16 IF output 1.7 R = 100 I = 3.5 mA 17 VCC 5.0 18 19 20 21 Oscillator input 4 Oscillator input 3 Oscillator input 2 Oscillator input 1 3.0 V = 3.0 V R = 5 k 3.0 I = 1 mA 22 GND 0 23 Divider output 3.3 R = 100 I = 1 mA 24 Output level adjustment 2.5 R = 25 k No. 5268-6/9 LA7780M Test Circuit No. 5268-7/9 Sample Application Circuit *: The choke coil between pins 19 and 20 is not required if the fundamental frequency of the crystal (not an overtone) is used. LA7780M No. 5268-8/9 LA7780M Specifications of any and all SANYO products described or contained herein stipulate the performance, characteristics, and functions of the described products in the independent state, and are not guarantees of the performance, characteristics, and functions of the described products as mounted in the customer's products or equipment. To verify symptoms and states that cannot be evaluated in an independent device, the customer should always evaluate and test devices mounted in the customer's products or equipment. SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all semiconductor products fail with some probability. It is possible that these probabilistic failures could give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire, or that could cause damage to other property. When designing equipment, adopt safety measures so that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective circuits and error prevention circuits for safe design, redundant design, and structural design. In the event that any or all SANYO products (including technical data, services) described or contained herein are controlled under any of applicable local export control laws and regulations, such products must not be exported without obtaining the export license from the authorities concerned in accordance with the above law. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or any information storage or retrieval system, or otherwise, without the prior written permission of SANYO Electric Co., Ltd. Any and all information described or contained herein are subject to change without notice due to product/technology improvement, etc. When designing equipment, refer to the "Delivery Specification" for the SANYO product that you intend to use. Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties. This catalog provides information as of October, 1998. Specifications and information herein are subject to change without notice. PS No. 5268-9/9 |
Price & Availability of LA7780M
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |