参数资料
| 型号： | AD8436-EVALZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 10/24页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL FOR AD8436 |
| 产品培训模块： | Introduction to Analog RMS-to-DC Technology: Converters and Applications |
| 标准包装： | 1 |
| 主要目的： | 接口，RMS 到 DC 转换器 |
| 已用 IC / 零件： | AD8436 |
| 已供物品： | 板 |
AD8436
THEORY OF OPERATION
OVERVIEW
The AD8436 is an implicit function rms-to-dc converter that
renders a dc voltage dependent on the rms (heating value) of an
ac voltage. In addition to the basic converter, this highly integrated
functional circuit block includes two fully independent, optional
amplifiers, a standalone FET input buffer amplifier and a precision
dc output buffer amplifier (see Figure 1). The rms core includes
a precision current responding full-wave rectifier and a log-antilog
transistor array for current squaring and square rooting to imple-
ment the classic expression for rms (see Equation 1). For basic
applications, the converter requires only an external capacitor, for
averaging (see Figure 31). The optional on-board amplifiers
offer utility and flexibility in a variety of applications without
incurring additional circuit board footprint. For lowest power,
the amplifier supply pins are left unconnected.
Why RMS?
The rms value of an ac voltage waveform is equal to the dc voltage
providing the same heating power to a load. A common measure-
ment technique for ac waveforms is to rectify the signal in a
straightforward way using a diode array of some sort, resulting in
Data Sheet
For additional information, select Section I of the 2 nd edition of
RMS Core
The core consists of a voltage-to-current converter (precision
resistor), absolute value, and translinear sections. The translinear
section exploits the properties of the bipolar transistor junctions
for squaring and root extraction (see Figure 24). The external
shows that there is no effect of signal input on the transition times,
as seen in the dc output. Although the rms core responds to input
voltages, the conversion process is current sensitive. If the rms
input is ac-coupled, as recommended, there is no output offset
voltage, as reflected in Table 1. If the rms input is dc-coupled, the
input offset voltage is reflected in the output and can be calibrated
as with any fixed error.
V+
the average value. The average value of various waveforms (sine,
+
OUT
square, and triangular, for example) varies widely; true rms is
the only metric that achieves equivalency for all ac waveforms.
See Table 5 for non-rms-responding circuit errors.
AC IN
V-TO-I
ABSOLUTE
VALUE
CIRCUIT
5kΩ
CAVG
V+
16kΩ
The acronym “rms” means root-mean-square and reads as follows:
“the square root of the average of the sum of the squares ” of the
peak values of any waveform. RMS is shown in the following
equation:
V–
e rms =
1
T
T
∫ 0 V(t) 2 dt
(1)
Figure 24. RMS Core Block Diagram
Table 5. General AC Parameters
Reading of an Average Value Circuit
Waveform Type (1 V Peak)
Sine
Square
Triangle
Noise
Rectangular
Pulse
Crest Factor
1.414
1.00
1.73
3
2
10
RMS Value
0.707
1.00
0.577
0.333
0.5
0.1
Calibrated to an RMS Sine Wave
0.707
1.11
0.555
0.295
0.278
0.011
Error (%)
0
11.0
?3.8
?11.4
?44
SCR
?89
DC = 50%
DC = 25%
2
4.7
0.495
0.212
0.354
0.150
?28
?30
Rev. B | Page 10 of 24
相关PDF资料 |
PDF描述 |
|---|---|
| AD9352-5/PCBZ | EVALUATION BOARD |
| AD9550/PCBZ | BOARD EVALUATION FOR AD9550 |
| AD9985A/PCBZ | KIT EVALUATION FOR AD9985A |
| ADA4850-2YCP-EBZ | BOARD EVAL FOR ADA4850-2YCP |
| ADA4899-1YCP-EBZ | BOARD EVAL FOR ADA4899-1YCP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AD8436JCPZ-R7 | 功能描述:IC CONV TRUE RMS-DC LP 20LFCSP RoHS:是 类别:集成电路 (IC) >> PMIC - RMS 至 DC 转换器 系列:- 标准包装:46 系列:- 电流 - 电源:1.2mA 电源电压:±18 V，36 V 安装类型:表面贴装 封装/外壳:16-SOIC（0.295"，7.50mm 宽） 供应商设备封装:16-SOIC W 包装:管件 |
| AD8436JCPZ-R7_PROMO | 制造商:Analog Devices 功能描述:IC RMS TO DC LFCSP-20 |
| AD8436JCPZ-RL | 功能描述:IC CONV TRUE RMS-DC LP 20LFCSP RoHS:是 类别:集成电路 (IC) >> PMIC - RMS 至 DC 转换器 系列:- 标准包装:46 系列:- 电流 - 电源:1.2mA 电源电压:±18 V，36 V 安装类型:表面贴装 封装/外壳:16-SOIC（0.295"，7.50mm 宽） 供应商设备封装:16-SOIC W 包装:管件 |
| AD8436JCPZ-WP | 功能描述:IC CONV TRUE RMS-DC LP 20LFCSP RoHS:是 类别:集成电路 (IC) >> PMIC - RMS 至 DC 转换器 系列:- 标准包装:46 系列:- 电流 - 电源:1.2mA 电源电压:±18 V，36 V 安装类型:表面贴装 封装/外壳:16-SOIC（0.295"，7.50mm 宽） 供应商设备封装:16-SOIC W 包装:管件 |
| AD843A | 制造商:AD 制造商全称:Analog Devices 功能描述:34 MHz, CBFET Fast Settling Op Amp |
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