• 当前位置:
  • 首页
  • >
  • PDF资料
  • >
  • LMC6062AIM-NOPB PDF文件及第10页内容在线浏览

LMC6062AIM-NOPB

LMC6062AIM-NOPB首页预览图
型号: LMC6062AIM-NOPB
PDF文件:
  • LMC6062AIM-NOPB PDF文件
  • LMC6062AIM-NOPB PDF在线浏览
功能描述: LMC6062 Precision CMOS Dual Micropower Operational Amplifier
PDF文件大小: 1175.13 Kbytes
PDF页数: 共21页
制造商: TI1[Texas Instruments]
制造商LOGO: TI1[Texas Instruments] LOGO
制造商网址: http://www.ti.com
捡单宝LMC6062AIM-NOPB
PDF页面索引
120%
LMC6062
SNOS631D NOVEMBER 1994REVISED MARCH 2013
www.ti.com
Figure 25. LMC6062 Noninverting Gain of 10 Amplifier, Compensated to Handle Capacitive Loads
In the circuit of Figure 25, R1 and C1 serve to counteract the loss of phase margin by feeding the high frequency
component of the output signal back to the amplifier's inverting input, thereby preserving phase margin in the
overall feedback loop.
Capacitive load driving capability is enhanced by using a pull up resistor to V
+
(Figure 26). Typically a pull up
resistor conducting 10 μA or more will significantly improve capacitive load responses. The value of the pull up
resistor must be determined based on the current sinking capability of the amplifier with respect to the desired
output swing. Open loop gain of the amplifier can also be affected by the pull up resistor (see Electrical
Characteristics).
Figure 26. Compensating for Large Capacitive Loads
with a Pull Up Resistor
PRINTED-CIRCUIT-BOARD LAYOUT FOR HIGH-IMPEDANCE WORK
It is generally recognized that any circuit which must operate with less than 1000 pA of leakage current requires
special layout of the PC board. When one wishes to take advantage of the ultra-low bias current of the
LMC6062, typically less than 10 fA, it is essential to have an excellent layout. Fortunately, the techniques of
obtaining low leakages are quite simple. First, the user must not ignore the surface leakage of the PC board,
even though it may sometimes appear acceptably low, because under conditions of high humidity or dust or
contamination, the surface leakage will be appreciable.
To minimize the effect of any surface leakage, lay out a ring of foil completely surrounding the LMC6062's inputs
and the terminals of capacitors, diodes, conductors, resistors, relay terminals etc. connected to the op-amp's
inputs, as in Figure 27. To have a significant effect, guard rings should be placed on both the top and bottom of
the PC board. This PC foil must then be connected to a voltage which is at the same voltage as the amplifier
inputs, since no leakage current can flow between two points at the same potential. For example, a PC board
trace-to-pad resistance of 10
12
Ω, which is normally considered a very large resistance, could leak 5 pA if the
trace were a 5V bus adjacent to the pad of the input. This would cause a 100 times degradation from the
LMC6062's actual performance. However, if a guard ring is held within 5 mV of the inputs, then even a
resistance of 10
11
Ω would cause only 0.05 pA of leakage current. See Figure 28 for typical connections of guard
rings for standard op-amp configurations.
10 Submit Documentation Feedback Copyright © 1994–2013, Texas Instruments Incorporated
Product Folder Links: LMC6062
购买、咨询产品请填写询价信息:(3分钟左右您将得到回复)
询价型号*数量*批号封装品牌其它要求
删除
删除
删除
删除
删除
增加行数
  •  公司名:
  • *联系人:
  • *邮箱:
  • *电话:
  •  QQ:
  •  微信:

  • 关注官方微信

  • 联系我们
  • 电话:13714778017
  • 周一至周六:9:00-:18:00
  • 在线客服:

天天IC网由深圳市四方好讯科技有限公司独家运营

天天IC网 ( www.ttic.cc ) 版权所有©2014-2023 粤ICP备15059004号

因腾讯功能限制,可能无法唤起QQ临时会话,(点此复制QQ,添加好友),建议您使用TT在线询价。

继续唤起QQ 打开TT询价