公开(公告)号：US09612686B2

公开(公告)日：2017-04-04

申请号：US14946784

申请日：2015-11-20

Applicant: FREESCALE SEMICONDUCTOR, INC.

Inventor： Liang Qiu ,  Bin Feng ,  Xiaolei Wu

IPC: G06F3/045 ,  G06F3/041 ,  G06F3/044 ,  H03K17/96 ,  G05F3/26

CPC classification number: G06F3/0418 ,  G05F3/262 ,  G06F3/044 ,  H03K17/962 ,  H03K2217/960705 ,  H03K2217/960725

Abstract: In a touch interface, a sensor provides an output signal that is a function of a sensed capacitance. The sensor includes a charger for repetitively applying first and second voltages to charge the sensed capacitance to first and second charge values in first and second phases respectively. A sampler includes a first current mirror for providing first and second sample current signals that are a function of the first and second charge values respectively. An accumulator uses an accumulator signal to provide the output signal. The accumulator repetitively uses the first and second sample current signals differentially to modify a charge on an accumulator capacitor and provide the accumulator signal. The accumulator signal is a progressive function of the sensed capacitance but cancels noise in the first and second sample signals at frequencies less than a repetition rate of operation of the accumulator.

公开(公告)号：US20160364079A1

公开(公告)日：2016-12-15

申请号：US14946784

申请日：2015-11-20

Applicant: FREESCALE SEMICONDUCTOR, INC.

Inventor： Liang Qiu ,  Bin Feng ,  Xiaolei Wu

IPC: G06F3/041 ,  G06F3/044

CPC classification number: G06F3/0418 ,  G05F3/262 ,  G06F3/044 ,  H03K17/962 ,  H03K2217/960705 ,  H03K2217/960725

Abstract: In a touch interface, a sensor provides an output signal that is a function of a sensed capacitance. The sensor includes a charger for repetitively applying first and second voltages to charge the sensed capacitance to first and second charge values in first and second phases respectively. A sampler includes a first current mirror for providing first and second sample current signals that are a function of the first and second charge values respectively. An accumulator uses an accumulator signal to provide the output signal. The accumulator repetitively uses the first and second sample current signals differentially to modify a charge on an accumulator capacitor and provide the accumulator signal. The accumulator signal is a progressive function of the sensed capacitance but cancels noise in the first and second sample signals at frequencies less than a repetition rate of operation of the accumulator.

Abstract translation: 在触摸界面中，传感器提供作为感测电容的函数的输出信号。 该传感器包括用于重复地施加第一和第二电压的充电器，用于将所感测的电容分别充电到第一和第二相中的第一和第二充电值。 采样器包括用于分别提供作为第一和第二充电值的函数的第一和第二采样电流信号的第一电流镜。 累加器使用累加器信号来提供输出信号。 蓄电池重复地使用第一和第二采样电流信号差分地修改蓄电池电容器上的电荷并提供累加器信号。 累加器信号是感测电容的渐进功能，但是以小于累加器的重复操作频率的频率消除第一和第二采样信号中的噪声。

公开(公告)号：US09509295B1

公开(公告)日：2016-11-29

申请号：US14992007

申请日：2016-01-10

Applicant: FREESCALE SEMICONDUCTOR, INC.

Inventor： Meng Liu ,  Bin Feng ,  Liang Qiu

IPC: H03K5/135 ,  H03K3/84

CPC classification number: H03K5/135

Abstract: A spread-spectrum clock (SSC) generator for generating an SSC signal. The SSC generator has a first up/down counter that operates for a fixed, first duration (t1), a first PRBS generator that operate for a variable, second duration (t2), a second up/down counter that operates for a fixed, third duration (t3), and a second PRBS generator that operates for a variable, fourth duration (t4). A state machine sequentially triggers the first counter and the first PRBS generator to generate a positive portion of a cycle of the SSC signal and then sequentially triggers the second counter and the second PRBS generator to generate a negative portion of the cycle of the SSC signal. For a set of parameters stored in configurable registers, the first and third durations are fixed from cycle to cycle, while the second and fourth durations vary from cycle to cycle.

Abstract translation: 扩频时钟（SSC）发生器，用于产生SSC信号。 SSC发生器具有第一上/下计数器，其操作固定的第一持续时间（t1），第一PRBS发生器，其操作变量，第二持续时间（t2），第二上/下计数器，其操作固定的， 第三持续时间（t3）和第二持续时间（t4）操作的第二PRBS发生器。 状态机依次触发第一计数器和第一PRBS发生器以产生SSC信号的周期的正部分，然后顺序地触发第二计数器和第二PRBS发生器以产生SSC信号的周期的负部分。 对于存储在可配置寄存器中的一组参数，第一和第三持续时间是从周期到周期固定的，而第二和第四持续时间随周期而变化。

公开(公告)号：US09983725B2

公开(公告)日：2018-05-29

申请号：US15253906

申请日：2016-09-01

Applicant: FREESCALE SEMICONDUCTOR, INC.

Inventor： Xiaolei Wu ,  Liang Qiu

IPC: G06F3/041 ,  G06F3/044

CPC classification number: G06F3/0416 ,  G06F3/044

Abstract: An electronic device includes mutual capacitance sensing circuitry for a capacitive touch pad. The touch pad has pairs of transmit and receive electrodes. The sensing circuitry intermittently charges and discharges the transmit electrode, and then measures corresponding voltage level changes at the receive electrode. A non-linear voltage-to-current converter is used to detect the voltage level changes, which allows for great sensitivity to mutual capacitance changes.

公开(公告)号：US09715321B2

公开(公告)日：2017-07-25

申请号：US14946750

申请日：2015-11-19

Applicant: FREESCALE SEMICONDUCTOR, INC.

Inventor： Xiaolei Wu ,  Liang Qiu

IPC: G06F3/045 ,  G06F3/044 ,  G06F3/041 ,  H03K17/96

CPC classification number: G06F3/044 ,  G06F3/0418 ,  H03K17/962 ,  H03K2217/960705 ,  H03K2217/960725 ,  H03K2217/96074

Abstract: A sensor for providing an output signal that is a function of a sensed capacitance, in a touch interface for example. The sensor includes a charger for repetitively applying first and second voltages to charge the sensed capacitance to first and second charge values in first and second phases respectively. A sampler provides first and second sample signals that are a function of the first and second charge values respectively. An accumulator uses an accumulator signal to provide the output signal. The accumulator repetitively uses the first sample signal incrementally and the second sample signal decrementally in providing the accumulator signal. The accumulator signal is a progressive function of the sensed capacitance but tends to cancel a noise in the first and second sample signals at frequencies less than a repetition rate of operation of the accumulator.

公开(公告)号：US09407242B2

公开(公告)日：2016-08-02

申请号：US14743828

申请日：2015-06-18

Applicant: FREESCALE SEMICONDUCTOR, INC.

Inventor： Liang Qiu ,  Wenzhong Zhang

IPC: H03K3/00 ,  H03K3/356

CPC classification number: H03K3/356 ,  H03K3/356113 ,  H03K19/018521

Abstract: A voltage level shifter for high voltage applications has a low voltage domain current mirror having first and second branches. A high voltage switch and a resistor are connected in series with the second branch. An output stage provides an output signal that is a function of a voltage difference across the resistor, and the output stage and the resistor are in the high voltage domain. Assertion of an input signal in the low voltage domain develops a first current in the first branch, and causes the high voltage switch to pass in the resistor a second current from the second branch that is a function of the first current and develops the voltage difference across the resistor. Only the high voltage switch needs to have high breakdown voltage characteristics.

Abstract translation: 用于高电压应用的电压电平转换器具有具有第一和第二分支的低电压域电流镜。 高压开关和电阻与第二支路串联。 输出级提供作为电阻器两端的电压差的函数的输出信号，并且输出级和电阻器处于高电压域。 在低电压域中输入信号的断言在第一分支中形成第一电流，并且使得高压开关从第二分支传递电阻器到第二电流的第二电流，该第二分支是第一电流的函数，并且产生电压差 跨过电阻 只有高压开关需要具有较高的击穿电压特性。