## 带“跟踪与保持”信号解调器的稳定斩波放大器

I. 简介

II.跟踪与保持信号解调器

T/H 输入是非反相和反相放大斩波信号，T/H 输出则应用于加法器。T/H 开关由在 CLK 期间产生的脉冲和带占空比 d 的 CLK_栏定时信号关闭。我们假设斩波信号通过放大器而不失真，这意味着放大器带宽是 ƒclk 的五倍或以上。

• 不需要任何 LP 滤波即可消除偏移。只有 T/H 不匹配和加法器不准确时才会产生残余偏移。
• 由于交错采样，与输出波形相关的典型的梯形波痕有 2ƒclk 基频，简化了移除流程。
• 如果需要，对跟踪脉冲进行适当的相对分析，没有衰减惩罚，从而消除输入开关瞬态产生的残余偏移。

(a)

(b)

(c)

(a)

(b)

III.输入参考偏移

(1)

IV.噪音问题

(2)

d 占空比 (TtkTclk)；
ƒclk 1 ⁄ Tclk = 时钟频率；
h 是 BWn ⁄ ƒclk比最接近的整数；
sinc(x) [sin(π × x) ] ⁄ π × x

(3)

(4)

V. 总结

[1] K. Hsieh et al., "A low-noise chopper stabilized differential switched-capacitor filtering technique," IEEE J. Solid-State Circuits, vol. SC-16, no. 6, pp.708-715, Dec. 1981.
[2] C. C. Enz et al., "A CMOS chopper amplifier," IEEE J. Solid-State Circuits, vol. SC-22, pp.335-341, June 1987.
[3] C. C. Enz and G. C. Temes, "Circuit techniques for reducing the effects of op-amp imperfections:Autozeroing, correlated double sampling, and chopper stabilization," Proc.IEEE, vol. 84, pp.1584-1613, Nov. 1996.
[4] C. Menolfi and Q. Huang, "A low-noise CMOS instrumentation amplifier for thermoelectric infrared detectors," IEEE J. Solid-State Circuits, vol. 32, pp.968-976, July 1997.
[5] A. Bilotti et al., "Monolithic magnetic hall sensor using dynamic quadrature offset cancellation," IEEE J. Solid-State Circuits, vol. 32, pp.829-836, June 1997.
[6] J. S. Fischer, "Noise sources and calculation techniques for switched capacitor filters," IEEE J. Solid-State Circuits, vol. SC-17, pp.742-752, Aug. 1982.
[7] C. Gobet, "Spectral distribution of a sampled first order lowpass filtered white noise," Electron.Lett., vol. 17, no. 19, pp.720-721, Sept. 1981.
[8] C. Gobet and A. Knob, "Noise analysis of switched capacitor networks," IEEE Trans.Circuits Syst., vol. CAS-30, pp.37-43, Jan. 1983.

1997 年 11 月 10 日收到原稿；1998 年 5 月 2 日修订。此作品由 Allegro™ MicroSystems 公司提供支持。此论文获副主编 M. Biey 推荐。

A. Bilotti 携手 Electrónica Bilotti, Olivos 1636，阿根廷。

G. Monreal 携手 Sensor Development Group, Allegro MicroSystems, LLC, Concord, NH 03306 美国。

## 带“跟踪与保持”信号解调器的稳定斩波放大器

I. 简介

II.跟踪与保持信号解调器

T/H 输入是非反相和反相放大斩波信号，T/H 输出则应用于加法器。T/H 开关由在 CLK 期间产生的脉冲和带占空比 d 的 CLK_栏定时信号关闭。我们假设斩波信号通过放大器而不失真，这意味着放大器带宽是 ƒclk 的五倍或以上。

• 不需要任何 LP 滤波即可消除偏移。只有 T/H 不匹配和加法器不准确时才会产生残余偏移。
• 由于交错采样，与输出波形相关的典型的梯形波痕有 2ƒclk 基频，简化了移除流程。
• 如果需要，对跟踪脉冲进行适当的相对分析，没有衰减惩罚，从而消除输入开关瞬态产生的残余偏移。

(a)

(b)

(c)

(a)

(b)

III.输入参考偏移

(1)

IV.噪音问题

(2)

d 占空比 (TtkTclk)；
ƒclk 1 ⁄ Tclk = 时钟频率；
h 是 BWn ⁄ ƒclk比最接近的整数；
sinc(x) [sin(π × x) ] ⁄ π × x

(3)

(4)

V. 总结

[1] K. Hsieh et al., "A low-noise chopper stabilized differential switched-capacitor filtering technique," IEEE J. Solid-State Circuits, vol. SC-16, no. 6, pp.708-715, Dec. 1981.
[2] C. C. Enz et al., "A CMOS chopper amplifier," IEEE J. Solid-State Circuits, vol. SC-22, pp.335-341, June 1987.
[3] C. C. Enz and G. C. Temes, "Circuit techniques for reducing the effects of op-amp imperfections:Autozeroing, correlated double sampling, and chopper stabilization," Proc.IEEE, vol. 84, pp.1584-1613, Nov. 1996.
[4] C. Menolfi and Q. Huang, "A low-noise CMOS instrumentation amplifier for thermoelectric infrared detectors," IEEE J. Solid-State Circuits, vol. 32, pp.968-976, July 1997.
[5] A. Bilotti et al., "Monolithic magnetic hall sensor using dynamic quadrature offset cancellation," IEEE J. Solid-State Circuits, vol. 32, pp.829-836, June 1997.
[6] J. S. Fischer, "Noise sources and calculation techniques for switched capacitor filters," IEEE J. Solid-State Circuits, vol. SC-17, pp.742-752, Aug. 1982.
[7] C. Gobet, "Spectral distribution of a sampled first order lowpass filtered white noise," Electron.Lett., vol. 17, no. 19, pp.720-721, Sept. 1981.
[8] C. Gobet and A. Knob, "Noise analysis of switched capacitor networks," IEEE Trans.Circuits Syst., vol. CAS-30, pp.37-43, Jan. 1983.

1997 年 11 月 10 日收到原稿；1998 年 5 月 2 日修订。此作品由 Allegro™ MicroSystems 公司提供支持。此论文获副主编 M. Biey 推荐。

A. Bilotti 携手 Electrónica Bilotti, Olivos 1636，阿根廷。

G. Monreal 携手 Sensor Development Group, Allegro MicroSystems, LLC, Concord, NH 03306 美国。