Semiconductor integrated circuit device
View Patent ↗The semiconductor integrated circuit (RF IC) for a mobile telephone capable of transmitting/receiving the signals of plural bands reduces the DC offsets of the amplifiers located in the following stages of the mixers that demodulate or down-convert the reception signals. The invention scrambles the signal lines to transmit the outputs of the plural mixers that demodulate or down-convert the reception signals of different bands, so as to avoid the adjacent signal lines from making the same combination from the starting ends to the finishing ends.
1. A semiconductor integrated circuit which receives signals of plural bands and is capable of demodulating, comprising:
plural mixers; and
plural signal lines to transmit outputs of the plural mixers, the plural signal lines being provided with plural scramble areas within which the signal lines intersect each other,
wherein, if the number of the signal lines to transmit the outputs of the mixers is given by N, then the total number of the scramble areas of the signal lines is determined to be N−1, where the N is equal to an integer of 4,
wherein each of said plural mixers is a circuit that inputs a reception signal of a predetermined frequency and an oscillation signal of a predetermined frequency, and attains a signal of a frequency equivalent to the frequency difference of the reception signal and the oscillation signal,
wherein the plural mixers include a first mixer that inputs a reception signal of a predetermined frequency and a first oscillation signal of a predetermined frequency, and a second mixer that inputs the reception signal and a second oscillation signal having 90° phase difference from the first oscillation signal, and
wherein the plural signal lines include a first signal wire to carry a first signal, a second signal wire to carry an inverted signal of the first signal, a third signal wire to carry a third signal, which has a 90° phase difference from the first signal, and a fourth signal wire to carry an inverted signal of the third signal; wirings of the signal lines are laid out in a manner that the first signal wire and the second signal wire thereof run adjacently in parallel, the third signal wire and the fourth signal wire run adjacently in parallel, in one of the scramble areas, along a signal transmission direction, the first and second signal wires switch position with the third and fourth signal wires respectively, and the third and fourth signal wires switch position with the second and first signal wires, respectively.
2. The semiconductor integrated circuit according to claim 1 , wherein arrays of the plural signal lines in areas divided by the scramble areas are each different in each of the areas.