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RF SILICON AND SYSTEMS SOLUTIONS FOR BROADBAND COMMUNICATIONS, AUTOMOTIVE ELECTRONICS AND WIRELESS CONNECTIVITY
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
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
MT 1 55 0 UP ST RE A M A MP LI FI ER
PRODUCT BRIEF
Vcsns
Vrsns
Vcc1
PARAMETER
Supply voltage Supply current, shutdown mode Gain code = 52 to 63
MIN
3.15
TYP
70 259
MAX
3.45 110
UNIT
V µA mA
Vcc2 17
SUPPLY CURRENT, TRANSMIT MODE, FILTER ENABLED DIGITAL INPUT
High voltage Low voltage Current 2.0 0.7 0 V V µA
16
20
19
18
GND2
DC ELECTRICAL CHARACTERISTICS
GND1 Vin+ VinDGND CS
1 2 3 4 5
15 14 13 12 11
NC Vout+ VoutNC Vcm
AC ELECTRICAL CHARACTERISTICS
PARAMETER
Output 1dB compression point Output step size Gain accuracy
MIN
TYP
69 1 59 -29.5 29.5 0.2 0.4
MAX
UNIT
dBmV dB dB dB dB dB dB
VOLTAGE GAIN
SDA SCLK TXEN SHDN
VCC2
GAIN RESPONSE
Fin = 42MHz Fin = 65MHz
TXEN
TXEN enable/disable time TXEN transient duration TXEN transient step size, VOUT = 61dBmV TXEN transient step size, min gain 5 1.5 16 64 7 1.55 16 µs µs
VCC1
MT1550 Pin Diagram
mVp-p mVp-p kΩ dB
VIN+
GND2
Gain code = 4 Gain code = 63
10
6
7
8
9
Vcc VOUT+ 1:1 Ohms
INPUT/OUTPUT
Input impedance Output return loss, Z0 = 75Ω
Anti-Alias Filter
Variable Attenuator
Power Amp
RFout
VCM VINVOUTFilter Tuning Serial Interface PA Control VRSNS RSNS 4.70 kΩ 1% 0.1 µF CEXT
STRESS RATINGS
PARAMETER
VCC (VCC1, VCC2) VOUT+, VOUTInput voltage levels (all inputs), VCM Junction temperature Storage temperature range Lead temperature (soldering, 4 seconds) -40
MIN
-0.7 -0.7 −0.7
MAX
5 5.5 VCC + 0.7 +125 +150 +245
UNIT
V V
0.1 µF
DGND
VCSNS
SHDN
SCLK
°C °C
CSNS
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 .