Abstract:
An example apparatus, system, and method for sampling in an interleaved sampling circuit having multiple channels. In an embodiment, an input clock is used to synchronize the transitions of sampling clocks from a first to second voltage level, relative to one another. The sampling clocks are input to a sampling circuit. The input clock switches a common switch that pulls each sampling clock to the second voltage level through a common path on input clock transitions from a first to a second clock state. The transition from the first to a second voltage level of each sampling clock triggers a sample taken on one of the channels. The first voltage level may be boosted to drive switches on in the sampling circuit. Synchronizing transitions of the outputs through the common switch and common path reduces timing mismatch between the sampling clocks controlling the channels.
Abstract:
A time-interleaved analog-to-digital converter (ADC) uses M sub-analog-to-digital converters (sub-ADCs) to, according to a sequence, sample an analog input signal to produce digital outputs. When the M sub-ADCs are interleaved, the digital outputs exhibit mismatch errors between the M sub-ADCs due to mismatches between the sub-ADCs. A more second order subtle effect is that the mismatch error for a particular digital output from a particular ADC, due to internal coupling or other such interaction and effects between the M sub-ADCs, can vary depending on which sub-ADC(s) were used before and/or after the particular sub-ADC. If M sub-ADCs are time-interleaved randomly, the mismatches between the M sub-ADCs become a function of the sub-ADC selection pattern in the sequence. The present disclosure describes mechanisms for measuring and reducing these order-dependent mismatches to achieve high dynamic range performance in the time-interleaved ADC.
Abstract:
An apparatus and method for implementing a bootstrapped switching circuit (100) having improved (i.e. faster) turn-on time is provided. In an embodiment, an inner switching loop (mn1x, C BOOTX , mp0x) is implemented in a bootstrapped switching circuit where the inner switching loop is configured to turn on an input switch (mn1, mn1x) in the bootstrapped drive circuit independent of the drive circuit output (qbtstrp). The embodiment decouples the inner switching loop circuitry from the output drive circuit of the bootstrapped switching circuit (mn1, C BOOT , MP0), which typically has a larger load capacitance than the inner switching loop. This allows the inner switching loop to turn on the input switch in the bootstrapped switching circuit faster and decreases the turn-on time of the bootstrapped switching circuit.
Abstract:
In one example embodiment, a programmable capacitor array (300) is provided for low distortion and minimizing linearity degradation of an input (Vin) by utilizing control circuitry (110) to switch on and off an array of MOSFET switches. The control circuitry (110) turns on a MOSFET (104) to load a capacitance (C1) on Vin and turns off the MOSFET (104) to remove the capacitance (C1) from Vin in response to a Din control signal. When the intention is to load the capacitance (C1) with Vin, the MOSFET is left on continuously. When the intention is to remove or unload the capacitance (C1) from Vin, the MOSFET (104) is primarily turned off, however, the MOSFET (104) is still periodically turned on with appropriate voltage levels in response to a clock signal (CLK) for periods of time when the loading of the capacitance (C1) on Vin is tolerable to the system, thereby ensuring minimal linearity degradation of Vin due to the programmable capacitor array system.
Abstract:
An example apparatus, system, and method for sampling in an interleaved sampling circuit having multiple channels. In an embodiment, an input clock is used to synchronize the transitions of sampling clocks from a first to second voltage level, relative to one another. The sampling clocks are input to a sampling circuit. The input clock switches a common switch that pulls each sampling clock to the second voltage level through a common path on input clock transitions from a first to a second clock state. The transition from the first to a second voltage level of each sampling clock triggers a sample taken on one of the channels. The first voltage level may be boosted to drive switches on in the sampling circuit. Synchronizing transitions of the outputs through the common switch and common path reduces timing mismatch between the sampling clocks controlling the channels.
Abstract:
In one example embodiment, a programmable capacitor array (300) is provided for low distortion and minimizing linearity degradation of an input (Vin) by utilizing control circuitry (110) to switch on and off an array of MOSFET switches. The control circuitry (110) turns on a MOSFET (104) to load a capacitance (C1) on Vin and turns off the MOSFET (104) to remove the capacitance (C1) from Vin in response to a Din control signal. When the intention is to load the capacitance (C1) with Vin, the MOSFET is left on continuously. When the intention is to remove or unload the capacitance (C1) from Vin, the MOSFET (104) is primarily turned off, however, the MOSFET (104) is still periodically turned on with appropriate voltage levels in response to a clock signal (CLK) for periods of time when the loading of the capacitance (C1) on Vin is tolerable to the system, thereby ensuring minimal linearity degradation of Vin due to the programmable capacitor array system.