MT1550 MICROTUNE | Alldatasheet

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RF SILICON AND SYSTEMS SOLUTIONS FOR BROADBAND COMMUNICATIONS, AUTOMOTIVE ELECTRONICS AND WIRELESS CONNECTIVITY M I C R O T U N E M I C R O T U N E MT1550 UPSTREAM AMPLIFIER PRODUCT BRIEF The MT1550 is a 3.3V programmable gain upstream amplifier with integrated anti- aliasing filter. The MT1550 is a low-cost programmable-gain power amplifier IC for use in CATV upstream applications. The Microtune® MT1550 is a 3.3 volt part optimized for the DOCSIS® 1.0, 1.1, 2.0 and Euro-DOCSIS™ upstream standard. An on-chip input anti-aliasing filter is included to reduce external system costs. The device’s specified frequency range is from 5 MHz to 65 MHz, with an output P1dB > 67 dBmV through a 1:1 impedance-ratio transformer. A 3-wire digital serial bus controls the variable gain, with gain control available in 1 dB steps and a nominal 59 dB gain range. The MT1550 may be disabled via an external control pin. The transmit- disable mode not only minimizes output noise by shutting off the output stage, but also maintains its output impedance at nominal levels. Output transients are nominally less than 16 mVp-p at 61 dBmV output level during transmit enable/disable switching. Operating from a single 3.3 V supply, the amplifier typically draws 247 mA at maximum gain or minimum attenuation. Additional internal circuitry reduces the amplifier’s power consumption depending on gain setting. Transmit-disable mode reduces the typical current draw to 60 mA, while shutdown mode further reduces it to 85 µA. The MT1550 is available in a 20- pin Quad Flat No-Lead (QFN) package with an exposed pad for the extended industrial temperature range of -40°C to +85°C. MT1550 APPLICATIONS

  • Cable modems
  • Telephony over cable
  • Set-top box CATV

FEATURES

  • Integrated on-chip anti- aliasing filter
  • P1dB of 67 dBmV
  • Low power-up/down transients of 16 mVp-p typical at 61 dBmV output
  • Ultra low third harmonic distortion
  • Single 3.3 V supply
  • 59 dB gain range
  • Gain programmable in 1 dB steps
  • Low transmit output noise floor: -50 dBmV in 160 kHz
  • Low transmit-disable output noise: -68 dBmV
  • Two power-down modes
  • DOCSIS 1.0, 1.1, 2.0 and Euro-DOCSIS compatible MT1550 Upstream Amplifier

PB-00058 — Rev 1.2 October 2005 Microtune, Inc., 2201 Tenth Street, Plano, TX 75074, USA Tel: +1-972-673-1600, Fax: +1-972-673-1602, E-mail: sales@microtune.com, Web site: www.microtune.com For a detailed list of design centers, sales offices, and sales representatives, visit our Web site at www.microtune.com. The information in this document is believed to be accurate and reliable. Microtune assumes no responsibility for any consequen ces arising from the use of this information, nor from any infringement of patents or the rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent o r other rights of Microtune. The information in this publication replaces and supersedes all information previously supplied, and is subject to change without notice. The customer is responsible for assuring that proper design and operating safeguards are observed to minimize inherent and procedural hazards. Microtune assumes no responsibility for applications assistance or customer product design. The devices described in this document are not authorized for use in medical, life-support equipment, or any other application involving a potential risk of severe property or environmental damage, personal injury, or death without prior express written approval of Microtune. Any such use is understood to be entirely at the user’s risk. Microtune is a registered trademark of Microtune, Inc. MicroTuner, MicroStreamer, VideoCaster, DataCaster, and the Microtune logo are trademarks of Microtune, Inc. All other tradema rks belong to their respective companies. Microtune’s products are protected by one or more of the following U.S. patents: DE10011662; GB1026825; ES1026825; DE19628727; DE19904588.7-09; DE348698; FR348698; GB348698; IT348698; DE3821716; US5,933,946; DE50000802.7-08; DE552624 and additional patents pending or filed. Entire contents Copyright © 1996 - 2005 Microtune, Inc. 072105 DC ELECTRICAL CHARACTERISTICS High voltage 2.0 V Low voltage 0.7 V Current 0 µA AC ELECTRICAL CHARACTERISTICS TXEN TXEN enable/disable time 5 µs TXEN transient duration 1.5 µs TXEN transient step size, VOUT = 61dBmV 16 64 mVp-p TXEN transient step size, min gain 7 mVp-p INPUT/OUTPUT Input impedance 1.55 kΩ Output return loss, Z0 = 75Ω 16 dB STRESS RATINGS PARAMETER M IN M AX U NIT VCC (VCC1, VCC2) -0.7 5 V VOUT+, VOUT- -0.7 5.5 V Input voltage levels (all inputs), VCM −0.7 VCC + 0.7 V Junction temperature +125 °C Storage temperature range -40 +150 °C Lead temperature (soldering, 4 seconds) +245 °C GND1 1 Vin+ 2 Vin- 3 DGND 4 CS 5 SDA 6 SCLK 7 TXEN 8 SHDN 9 GND2 10

11 Vcm

13 Vout-

14 Vout+

16 GND2

17 Vcc2

18 Vcsns

19 Vcc1

20 Vrsns

PARAMETER M IN TYP M AX U NIT Supply voltage 3.15 3.45 V Supply current, shutdown mode 85 125 µA SUPPLY CURRENT, TRANSMIT MODE, FILTER ENABLED Gain code = 52 to 63 247 mA DIGITAL INPUT PARAMETER M IN TYP M AX U NIT Output 1dB compression point 70 dBmV Output step size 1 dB VOLTAGE GAIN Gain code = 4 -30 dB Gain code = 63 29 dB GAIN RESPONSE Fin = 42MHz 1.1 dB Fin = 65MHz 1.5 dB MT1550 Block Diagram Serial Interface PA Control VCC2 Variable Attenuator VCC1 Anti-Alias Filter Power Amp VOUT+ VOUT- VCM VIN+ VIN- DGND SDA SCLK TXEN VRSNS RSNS 4.70 kΩ Vcc RFout 1:1 Ohms 0.1 µF 0.1 µF CEXT Filter Tuning CS SHDN VCSNS 59 pF CSNS MT1550 Pin Diagram