M I C R O T U N E RF SILICON AND SYSTEMS SOLUTIONS FOR BROADBAND COMMUNICATIONS, AUTOMOTIVE ELECTRONICS AND WIRELESS CONNECTIVITY MT1550 APPLICATIONS • • • Cable modems Telephony over cable Set-top box CATV FEATURES • • • • • • • • • • • • Integrated on-chip antialiasing filter Maximum output level of 67dBmV Low power-up/down transients of 16mVp-p typical at 61dBmV output Ultra low third harmonic distortion Single +3.3V supply 59dB gain range Gain programmable in 1dB steps Low transmit output noise floor: -50dBmV in 160kHz Low transmit-disable output noise: 1nV / √Hz Two power-down modes Primarily for set-top boxes DOCSIS 1.1 compatible M I C R O T U N E The MT1550 is a low-cost programmable-gain power amplifier IC for use in CATV upstream PRODUCT BRIEF applications. The Microtune® MT1550 is a 3.3 volt part optimized for the DOCSIS 1.1 upstream The MT1550 is a 3.3V programmable standard. The MT1550 also includes gain upstream amplifier with integrated an on-chip input anti-aliasing filter, anti-aliasing filter. thereby reducing external system costs. The device’s specified frequency range is from 5MHz to 65MHz, and can output 67dBmV through a 1:1 impedance-ratio transformer. A 3wire digital serial bus controls the variable gain, with gain control available in 1dB steps and a nominal 59dB gain range. The MT1550 may be disabled via an external control pin. The transmitdisable mode not only minimizes MT1550 Upstream Amplifier output noise by shutting off the output stage, but also maintains its output impedance at nominal levels. Output transients are nominally less than 16mVp-p at 61dBmV output level during transmit enable/disable switching. Operating from a single +3.3V supply, the amplifier’s typical current draw at maximum gain, or minimum attenuation, is 259mA. Additional internal circuitry reduces the amplifier’s power consumption depending on gain setting. Transmit-disable mode power supply current is reduced to a nominal of 62mA. A shutdown mode further reduces current to a nominal of 70µA. The MT1550 is available in a 20pin MicroLeadFrame™ package with an exposed pad for the extended industrial temperature range of -40°C to +85°C. MT1550 UPSTREAM AMPLIFIER MT 1 55 0 UP ST RE A M A MP LI FI ER GND2 16 V µA Vcc2 70 17 UNIT Vcsns MAX 3.45 110 18 TYP Vcc1 MIN 3.15 19 PARAMETER Supply voltage Supply current, shutdown mode Vrsns DC ELECTRICAL CHARACTERISTICS 20 PRODUCT BRIEF SUPPLY CURRENT, TRANSMIT MODE, FILTER ENABLED Gain code = 52 to 63 259 mA 0 V V µA DIGITAL INPUT High voltage Low voltage Current 2.0 0.7 AC ELECTRICAL CHARACTERISTICS PARAMETER MIN TYP Output 1dB compression point Output step size Gain accuracy MAX UNIT 69 1 59 dBmV dB dB -29.5 29.5 dB dB 0.2 0.4 dB dB GND1 1 15 NC Vin+ 2 14 Vout+ Vin- 3 13 Vout- DGND 4 12 NC CS 5 11 Vcm 16 64 mVp-p 7 mVp-p Anti-Alias Filter INPUT/OUTPUT 1.55 16 kΩ dB -0.7 5 V VOUT+, VOUT- -0.7 5.5 V Input voltage levels (all inputs), VCM −0.7 VCC + 0.7 V +125 °C Junction temperature -40 +150 °C +245 °C 9 10 SHDN GND2 8 TXEN Filter Tuning Serial Interface CSNS PA Control VRSNS 0.1 µF RSNS 4.70 kΩ 1% TXEN VCC (VCC1, VCC2) VOUT- SCLK UNIT 1:1 Ohms 0.1 µF CEXT CS MAX Lead temperature (soldering, 4 seconds) Vcc VOUT+ VCM DGND MIN Storage temperature range Power Amp VIN- STRESS RATINGS PARAMETER Variable Attenuator VIN+ VCSNS Input impedance Output return loss, Z0 = 75Ω 7 µs µs VCC2 5 1.5 VCC1 TXEN enable/disable time TXEN transient duration TXEN transient step size, VOUT = 61dBmV TXEN transient step size, min gain SCLK MT1550 Pin Diagram TXEN SDA Fin = 42MHz Fin = 65MHz 6 GAIN RESPONSE SHDN Gain code = 4 Gain code = 63 SDA VOLTAGE GAIN 59 pF 5% MT1550 Block Diagram Microtune, Inc., 2201 Tenth Street, Plano, TX 75074, USA Tel: +1-972-673-1600, Fax: +1-972-673-1602, E-mail: [email protected], 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 consequences 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 or 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, and the Microtune logo are trademarks of Microtune, Inc. Bluetooth is a trademark owned by Bluetooth SIG, Inc. and is used by Microtune under license. All other trademarks belong to their respective companies. Microtune’s products are protected by one or more of the following U.S. patents: 5,625,325; 5,648,744; 5,717,730; 5,737,035; 5,739,730; 5,805,988; 5,847,612; 6,100,761; 6,104,242; 6,144,402; 6,163,684; 6,169,569; 6,172,378; 6,177,964; 6,211,745; 6,218,899; 6,268,778; 6,310,387; 6,323,736; 6,355,537; 6,429,502; 6,462,327; and additional patents pending or filed. Entire contents Copyright © 1996 - 2002 Microtune, Inc. PB-00058 — Rev 1.0 DEC 2002 RFout