Datasheet LT6600-2.5 (Analog Devices)

LT6600-2.5 Very Low Noise, Differential Amplifi er and 2.5MHz Lowpass Filter
FEATURES DESCRIPTION
n ±0.6dB (Max) Ripple 4th Order Lowpass Filter with The LT®6600-2.5 combines a fully differential amplifi er 2.5MHz Cutoff with a 4th order 2.5MHz lowpass fi lter approximating a n Programmable Differential Gain via Two External Chebyshev frequency response. Most differential ampli- Resistors fi ers require many precision external components to tail n Adjustable Output Common Mode Voltage or gain and bandwidth. In contrast, with the LT6600-2.5, n Operates and Specifi ed with 3V, 5V, ±5V Supplies two external resistors program differential gain, and the n 86dB S/N with 3V Supply and 1VRMS Output fi lter’s 2.5MHz cutoff frequency and passband ripple are n Low Distortion, 1VRMS, 800Ω Load internally set. The LT6600-2.5 also provides the necessary 1MHz: 95dBc 2nd, 88dBc 3rd level shifting to set its output common mode voltage to ac- n Fully Differential Inputs and Outputs commodate the reference voltage requirements of A/Ds. n Compatible with Popular Differential Amplifi er Using a proprietary internal architecture, the LT6600-2.5 Pinouts integrates an antialiasing fi lter and a differential ampli- n SO-8 and DFN-12 Packages fi er/driver without compromising distortion or low noise performance. At unity gain the measured in band signal-
APPLICATIONS
to-noise ratio is an impressive 86dB. At higher gains the input referred noise decreases so the part can process n High Speed ADC Antialiasing and DAC Smoothing in smaller input differential signals without signifi cantly Networking or Cellular Basestation Applications degrading the output signal-to-noise ratio. n High Speed Test and Measurement Equipment n The LT6600-2.5 also features low voltage operation. The Medical Imaging n differential design provides outstanding performance for a Drop-in Replacement for Differential Amplifi ers 4VP-P signal level while the part operates with a single 3V L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. supply. The LT6600-2.5 is available in SO-8 and DFN-12 packages. For similar devices with higher cutoff frequency, refer to the LT6600-5, LT6600-10, LT6600-15 and LT6600-20 data sheets.
TYPICAL APPLICATION (S8 Pin Numbers Shown) DAC Output Filter DAC Output Spectrum LT6600-2.5 Output Spectrum
0 0 5V 0.1μF –10 –10 5V –20 BASEBAND SIGNAL –20 52.3Ω 1580Ω 1 3 LADCOM – –30 –30 4 I 16-BIT 4kHz to 2.5MHz OUT A 7 + V + OUT –40 –40 LT6600-2.5 DISCRETE MULTI-TONE LTC1668 52.3Ω 2 (dBm) SIGNAL AT 50MSPS (dBm) –50 DAC OUTPUT IMAGE –50 IOUT B 8 – V – + OUT 5 CLK –60 –60 1580Ω 6 0.1μF –70 –70 –5V 50MHz –80 –80 –5V 660025 TA01a –90 –90 0 12 24 36 48 60 72 84 96 108 120 0 12 24 36 48 60 72 84 96 108 120 FREQUENCY (MHz) FREQUENCY (MHz) 660025 TA01b 660025 TA01c 660025fe 1