LTC6401-20 PIN FUNCTIONSV+ (Pins 1, 3, 10): Positive Power Supply (Normally tied –OUTF, +OUTF (Pins 6, 7): Filtered Outputs. These pins have to 3V or 3.3V). All three pins must be tied to the same 50Ω series resistors and a 1.7pF shunt capacitance. voltage. Bypass each pin with 1000pF and 0.1μF capaci- ⎯ E ⎯ N ⎯ A ⎯ B ⎯ L ⎯ E (Pin 11): This pin is a logic input referenced to tors as close to the pins as possible. V–. If low, the part is enabled. If high, the part is disabled VOCM (Pin 2): This pin sets the output common mode and draws approximately 1mA supply current. voltage. A 0.1μF external bypass capacitor is recom- +IN (Pins 13, 14): Positive Input. Pins 13 and 14 are mended. internally shorted together. V– (Pins 4, 9, 12, 17): Negative Power Supply. All four –IN (Pins 15, 16): Negative Input. Pins 15 and 16 are pins must be connected to the same voltage/ground. internally shorted together. –OUT, +OUT (Pins 5, 8): Unfi ltered Outputs. These pins Exposed Pad (Pin 17): V–. The Exposed Pad must be con- have 12.5Ω series resistors. nected to the same voltage/ground as pins 4, 9, 12. BLOCK DIAGRAM V– ENABLE V+ V– 12 11 10 9 BIAS CONTROL RG RF ROUT +IN +OUT 100Ω 1000Ω 12.5Ω 13 8 RFILT +OUTF 50Ω +IN IN+ OUT– 7 14 C R FILT FILT –IN 1.7pF –OUTF 50Ω 15 6 IN– OUT+ RG RF ROUT –IN –OUT 100Ω 1000Ω 12.5Ω 16 5 2k COMMON MODE CONTROL 5.3pF 640120 BD 1 2 3 4 V+ VOCM V+ V– 640120f 9