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1. 发明公开

EP0641080A3 Method and apparatus for reducing jitter and improving testability of an oscillator 失效
标题翻译：为减少抖动的方法及装置，提高振荡器的可测试性。
公开(公告)号：EP0641080A3
公开(公告)日：1996-06-12
申请号：EP94110939.9
申请日：1994-07-14
申请人： MOTOROLA, INC.
发明人： Westwick, Alan L.
IPC分类号： H03L1/02 , H03M1/10 , G01R31/28 , H03B5/36 , H03K3/354
CPC分类号： H03K3/0231 , G01R31/2824 , H03J2200/10 , H03K3/0307
摘要： An oscillator such as a pulled-crystal oscillator (50) provides low clock jitter by converting a sinusoidal voltage on a crystal's (51) terminals into a digital square wave with a comparator (56). The oscillating frequency of the crystal (51) is pulled by selectively switching in extra capacitance through capacitor digital-to-analog converters (CDACs) (57, 58). The oscillator (50) has built-in testability which allows individual capacitors in the CDACs (57, 58) to be quickly tested for opens. A scan path is connected to the inputs of the CDACs (57, 58) for selecting individual capacitors. A first input terminal of the comparator (56) is precharged before a capacitor under test (171) is connected. A comparison voltage is provided to the second input terminal. The capacitor under test (171) is determined to be functional if, after being connected to the first input terminal of the comparator (56), it discharges the first input terminal to a voltage below the comparison voltage, causing the comparator (56) to switch.

2. 发明公开

EP0860950A2 Digital-to-analog data converter with internal reference and method of operation thereof 失效
标题翻译： Digital-Analog-Wandler mit interner Referenzquelle und Betriebsverfahrenhierfür
公开(公告)号：EP0860950A2
公开(公告)日：1998-08-26
申请号：EP98102769.1
申请日：1998-02-18
申请人： MOTOROLA, INC.
发明人： Cave, Michael D. , Westwick, Alan L. , Zavaleta, Mauricio , Barker, Todd
IPC分类号： H03M1/06
CPC分类号： H03M1/089 , H03M1/66
摘要： A data converter (10) includes an operational amplifier (14), a first reference input element (18), a second reference input element (22), voltage references 40, and a control element (34). The control element (34) generates control signals (36, 38) based on a digital input. The first reference input element (18) provides a sampled first reference signal (16) to a first input node (13), the sampling of the first temperature variant signal being based on the control signals. The second reference input element (22) provides a sampled difference of the second and third reference signals (20 & 21) to the first input node, the sampling of the second and third temperature variant signals being based on the control signals. The operational amplifier (14) integrates the inputs to perform a digital-to-analog conversion that is substantially temperature invariant.
摘要翻译：数据转换器（10）包括运算放大器（14），第一参考输入元件（18），第二参考输入元件（22），电压基准40和控制元件（34）。控制元件（34）基于数字输入产生控制信号（36,38）。第一参考输入元件（18）向第一输入节点（13）提供采样的第一参考信号（16），第一温度变化信号的采样基于控制信号。第二参考输入元件（22）将第二和第三参考信号（20和21）的采样差提供给第一输入节点，第二和第三温度变化信号的采样基于控制信号。运算放大器（14）对输入进行积分以执行实质上温度不变的数模转换。

3. 发明公开

EP0641080A2 Method and apparatus for reducing jitter and improving testability of an oscillator 失效
标题翻译：为减少抖动的方法及装置，提高振荡器的可测试性。
公开(公告)号：EP0641080A2
公开(公告)日：1995-03-01
申请号：EP94110939.9
申请日：1994-07-14
申请人： MOTOROLA, INC.
发明人： Westwick, Alan L.
IPC分类号： H03L1/02 , H03M1/10 , G01R31/28 , H03B5/36 , H03K3/354
CPC分类号： H03K3/0231 , G01R31/2824 , H03J2200/10 , H03K3/0307
摘要： An oscillator such as a pulled-crystal oscillator (50) provides low clock jitter by converting a sinusoidal voltage on a crystal's (51) terminals into a digital square wave with a comparator (56). The oscillating frequency of the crystal (51) is pulled by selectively switching in extra capacitance through capacitor digital-to-analog converters (CDACs) (57, 58). The oscillator (50) has built-in testability which allows individual capacitors in the CDACs (57, 58) to be quickly tested for opens. A scan path is connected to the inputs of the CDACs (57, 58) for selecting individual capacitors. A first input terminal of the comparator (56) is precharged before a capacitor under test (171) is connected. A comparison voltage is provided to the second input terminal. The capacitor under test (171) is determined to be functional if, after being connected to the first input terminal of the comparator (56), it discharges the first input terminal to a voltage below the comparison voltage, causing the comparator (56) to switch.
摘要翻译：的振荡器：诸如拉晶体振荡器（50），通过在晶体的（51）终端的正弦电压转换成数字方波的比较器（56）提供低的时钟抖动。晶体（51）的振荡频率，通过选择性地在附加电容通过电容器数字 - 模拟转换器（CDACs）开关（57,58）拉动。振荡器（50）还内置了可测试性其中在CDACs（57，58）允许个别电容器快速打开进行测试。的扫描路径连接到CDACs（57，58），用于选择各个电容器的输入端。下测试（171）的电容器被连接到比较器（56）的第一输入端被预充电。的比较电压被提供给第二输入端。被测电容器（171）是确定性的开采是功能性，如果，被连接到所述比较器（56）的第一输入端子之后，将其排放所述第一输入端连接到比较电压以下的电压，使比较器（56），以开关。

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