LTC6401-20 AC ELECTRICAL CHARACTERISTICSSpecifi cations are at TA = 25°C. V+ = 3V, V– = 0V, +IN and –INfl oating, VOCM = 1.25V, ⎯ E ⎯ N ⎯ A ⎯ B ⎯ L ⎯ E = 0V, No RL unless otherwise noted. SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS IMD3,140M Third-Order Intermodulation 2VP-P,OUT Composite, RL = 400Ω –71 dBc (f1 = 139.5MHz f2 = 140.5MHz) 2VP-P,OUT Composite, No RL –74 dBc 2VP-P,OUTFILT Composite, No RL –72 dBc OIP3,140M Third-Order Output Intercept Point 2VP-P,OUT Composite, No RL (Note 7) 41 dBm (f1 = 139.5MHz f2 = 140.5MHz) P1dB,140M 1dB Compression Point RL = 375Ω (Notes 5, 7) 18 dBm NF140M Noise Figure RL = 375Ω (Note 5) 6.4 dB eIN,140M Input Referred Voltage Noise Density Includes Resistors (Short Inputs) 2.1 nV/√⎯H⎯z eON,140M Output Referred Voltage Noise Density Includes Resistors (Short Inputs) 22 nV/√⎯H⎯z IMD3,130M/150M Third-Order Intermodulation 2VP-P,OUT Composite, RL = 375Ω (Note 5) –61 –69 dBc (f1 = 130MHz f2 = 150MHz) Measure at 170MHz Note 1: Stresses beyond those listed under Absolute Maximum Ratings temperatures. The LTC6401I is guaranteed to meet specifi ed performance may cause permanent damage to the device. Exposure to any Absolute from –40°C to 85°C. Maximum Rating condition for extended periods may affect device Note 5: Input and output baluns used. See Test Circuit A. reliability and lifetime. Note 6: Measured using Test Circuit B. Note 2: Input pins (+IN, –IN) are protected by steering diodes to either Note 7: Since the LTC6401-20 is a feedback amplifi er with low output supply. If the inputs go beyond either supply rail, the input current should impedance, a resistive load is not required when driving an AD converter. be limited to less than 10mA. Therefore, typical output power is very small. In order to compare the Note 3: The LTC6401C and LTC6401I are guaranteed functional over the LTC6401-20 with amplifi ers that require 50Ω output load, the LTC6401-20 operating temperature range of –40°C to 85°C. output voltage swing driving a given RL is converted to OIP3 and P1dB as Note 4: The LTC6401C is guaranteed to meet specifi ed performance from if it were driving a 50Ω load. Using this modifi ed convention, 2VP-P is by 0°C to 70°C. It is designed, characterized and expected to meet specifi ed defi nition equal to 10dBm, regardless of the actual RL. performance from –40°C to 85°C but is not tested or QA sampled at these TYPICAL PERFORMANCE CHARACTERISTICSS21 Phase and Group Delay vsFrequency ResponseGain 0.1dB FlatnessFrequency 25 1.0 100 1.5 TEST CIRCUIT B TEST CIRCUIT B TEST CIRCUIT B 0.8 20 0.6 0 1.2 GROUP DELAY (ns) 0.4 15 0.2 –100 0.9 0 GAIN (dB) 10 –0.2 –200 0.6 PHASE (DEGREE) –0.4 NORMALIZED GAIN (dB) 5 –0.6 –300 0.3 –0.8 PHASE GROUP DELAY 0 –1.0 –400 0 10 100 1000 3000 10 100 1000 0 200 400 600 800 1000 FREQUENCY (MHz) FREQUENCY (MHz) FREQUENCY (MHz) 640120 G01 640120 G02 640120 G03 640120f 5