Abstract:
A conventional analog-to-digital conversion circuit has a problem that conversion errors cannot be suppressed. According to one embodiment, the analog-to-digital conversion circuit includes a first digital-to-analog conversion circuit 30 of a capacitance distribution type, a second digital-to-analog conversion circuit 31 of a capacitance distribution type, and a comparison circuit 32 for comparing output voltages of the two digital-to-analog conversion circuits, and before performing a successive comparison operation for successively changing a reference voltage applied to the first digital-to-analog conversion circuit, generates an intermediate digital value having a digital value corresponding to a voltage value of an analog input signal, determines a reference voltage to be applied to the second digital-to-analog conversion circuit 31 in accordance with the intermediate digital value, and thereafter performs a successive comparison operation using the first digital-to-analog conversion circuit 30 in a state in which the state of the second digital-to-analog conversion circuit 31 is held.
Abstract:
The semiconductor integrated circuit device includes a T-type switch circuit TS[k] that is between an input port A[k] and an input terminal Ain of an analog/digital conversion circuit and that includes first, second, and third PMOS transistors MP1, MP2, and MPc, and first, second, and third NMOS transistors MN1, MN2, and MNc; and a fourth PMOS transistor MPu for pre-charging the input terminal Ain to a power supply voltage VCCA. In detecting the presence or absence of a disconnection from the input port A[k] to a signal input terminal Vint[k], first, the input terminal Ain is pre-charged to the power supply voltage VCCA via the fourth PMOS transistor MPu and also the second NMOS transistor MN2 and the second PMOS transistor MP2 are turned on, and the first NMOS transistor MN1, the first PMOS transistor MP1, the third PMOS transistor MPc, and third the NMOS transistor MNc are turned off.
Abstract:
A semiconductor device performs sequential comparison of an analog input signal and a reference voltage to digitally convert the analog input signal. The semiconductor device includes an upper DAC generating a high-voltage region of the reference voltage based on a predetermined code, a lower DAC generating a low-voltage region of the reference voltage based on the code, and an injection DAC having the same configuration as that of the lower DAC and adjusting the low-voltage region of the reference voltage.
Abstract:
In a conventional calibration method of an analog to digital converter, it has been difficult to easily derive a plurality of correction coefficients. A semiconductor apparatus according to an embodiment includes a plurality of unit elements that are provided to correspond to the total number of weights for each bit of the digital intermediate value b[1:0] output from a sub ADC, and the same capacitance, the same resistance value, or the same current value being set to the plurality of unit elements. Further included is a corresponding bit switching unit configured to switches the bits of the digital intermediate value based on which the plurality of unit elements generate analog values. At the time of calibration, combinations of the plurality of unit elements and the bits are rotated, and correction coefficients are derived by digital intermediate values obtained according to each combination.
Abstract:
The semiconductor integrated circuit device includes a T-type switch circuit TS[k] that is between an input port A[k] and an input terminal Ain of an analog/digital conversion circuit and that includes first, second, and third PMOS transistors MP1, MP2, and MPc, and first, second, and third NMOS transistors MN1, MN2, and MNc; and a fourth PMOS transistor MPu for pre-charging the input terminal Ain to a power supply voltage VCCA. In detecting the presence or absence of a disconnection from the input port A[k] to a signal input terminal Vint[k], first, the input terminal Ain is pre-charged to the power supply voltage VCCA via the fourth PMOS transistor MPu and also the second NMOS transistor MN2 and the second PMOS transistor MP2 are turned on, and the first NMOS transistor MN1, the first PMOS transistor MP1, the third PMOS transistor MPc, and third the NMOS transistor MNc are turned off.