The LT®6552 is a specialized dual-differencing 75MHzoperational amplifier ideal for rejecting common modenoise as a video line receiver. The input pairs are designedto operate with equal but opposite large-signal differencesand provide exceptional high frequency commonmode rejection (CMRR of 65dB at 10MHz), therebyforming an extremely versatile gain block structure thatminimizes component count in most situations. The dualinput pairs are free to take on independent common modelevels, while the two voltage differentials are summedinternally to form a net input signal.
Portable, battery-powered operation of electronic apparatushas become increasingly desirable. Medical, remotedata acquisition, power monitoring and other applicationsare good candidates for battery operation. In some circumstances,due to space, power or reliability considerations,it is preferable to operate the circuitry from a single 1.5Vcell. Unfortunately, a 1.5V supply eliminates almost alllinear ICs as design candidates. In fact, the LM10 opamp-reference and the LT®1017/LT1018 comparators arethe only IC gain blocks fully specifi ed for 1.5V operation.Further complications are presented by the 600mV dropof silicon transistors and diodes. This limitation consumesa substantial portion of available supply range, makingcircuit design diffi cult. Additionally, any circuit designedfor 1.5V operation must function at end-of-life batteryvoltage, typically 1.3V. (See Box Section, “Componentsfor 1.5V Operation.”)
