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AD7401A の電気的特性と機能
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AD7401AのメーカーはAnalog Devicesです、この部品の機能は「Isolated Sigma-Delta Modulator」です。 |
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製品の詳細 ( Datasheet PDF )
| 部品番号 AD7401A |
| 部品説明 Isolated Sigma-Delta Modulator |
| メーカ Analog Devices |
ロゴ |
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Isolated Sigma-Delta Modulator
AD7401A
FEATURES
20 MHz maximum external clock rate
Second-order modulator
16 bits, no missing codes
±2 LSB INL typical at 16 bits
1 μV/°C typical offset drift
On-board digital isolator
On-board reference
±250 mV analog input range
Low power operation: 17 mA typical at 5.5 V
−40°C to +125°C operating range
16-lead SOIC package
Internal clock version: AD7400A
Safety and regulatory approvals
UL recognition
5000 V rms for 1 minute per UL 1577
CSA Component Acceptance Notice #5A
VDE Certificate of Conformity
DIN V VDE V 0884-10 (VDE V 0884-10):2006-12
VIORM = 891 V peak
APPLICATIONS
GENERAL DESCRIPTION
The AD7401A1 is a second-order, sigma-delta (Σ-Δ) modulator
that converts an analog input signal into a high speed, 1-bit data
stream with on-chip digital isolation based on Analog Devices,
Inc., iCoupler® technology. The AD7401A operates from a 5 V
power supply and accepts a differential input signal of ±250 mV
(±320 mV full scale). The analog input is continuously sampled
by the analog modulator, eliminating the need for external
sample-and-hold circuitry. The input information is contained
in the output stream as a density of ones with a data rate up to
20 MHz. The original information can be reconstructed with
an appropriate digital filter. The serial I/O can use a 5 V or a 3 V
supply (VDD2).
The serial interface is digitally isolated. High speed CMOS,
combined with Analog Devices, Inc., iCoupler® technology ,
means the on-chip isolation provides outstanding performance
characteristics, superior to alternatives such as optocoupler
devices. The part contains an on-chip reference. The AD7401A
is offered in a 16-lead SOIC and has an operating temperature
range of −40°C to +125°C.
AC motor controls
Shunt current monitoring
Data acquisition systems
Analog-to-digital and opto-isolator replacements
FUNCTIONAL BLOCK DIAGRAM
VDD1
VDD2
VIN+
VIN–
T/H
Σ-∆ ADC
BUF
REF
CONTROL LOGIC
UPDATE
ENCODE
WATCHDOG
AD7401A
WATCHDOG
DECODE
UPDATE
MDAT
DECODE
ENCODE
MCLKIN
GND1
Figure 1.
1 Protected by U.S. Patents 5,952,849; 6,873,065; and 7,075,329. Other patents pending.
GND2
Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113 ©2008–2011 Analog Devices, Inc. All rights reserved.
1 Page
AD7401A
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
General Description ......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Timing Specifications .................................................................. 5
Insulation and Safety-Related Specifications............................ 6
Regulatory Information............................................................... 6
DIN V VDE V 0884-10 (VDE V 0884-10):2006-12 Insulation
Characteristics .............................................................................. 7
Absolute Maximum Ratings............................................................ 8
ESD Caution.................................................................................. 8
Pin Configuration and Function Descriptions............................. 9
Typical Performance Characteristics ........................................... 10
REVISION HISTORY
7/11—Rev. B to Rev. C
Changes to Minimum External Air Gap (Clearance) Parameter,
Table 3 and Minimum External Tracking (Creepage) Parameter,
Table 3 ................................................................................................ 6
Changes to Figure 5; Pin 1 Description, Table 8; and Pin 7
Description, Table 8.......................................................................... 9
3/11—Rev. A to Rev. B
Change to General Description Section ........................................ 1
Changes to Table 1............................................................................ 3
Terminology .................................................................................... 13
Theory of Operation ...................................................................... 14
Circuit Information.................................................................... 14
Analog Input ............................................................................... 14
Differential Inputs ...................................................................... 15
Current Sensing Applications................................................... 15
Voltage Sensing Applications.................................................... 15
Digital Filter ................................................................................ 16
Applications Information .............................................................. 18
Grounding and Layout .............................................................. 18
Evaluating the AD7401A Performance ................................... 18
Insulation Lifetime ..................................................................... 18
Outline Dimensions ....................................................................... 19
Ordering Guide .......................................................................... 19
1/11—Rev. 0 to Rev. A
Change to Features, UL Recognition Value ...................................1
Change to Table 3, Input-to-Output Momentary Withstand
Voltage Value...............................................................................................6
Changes to Table 4, Isolation Voltage Value, and Endnote 1.......6
7/08—Revision 0: Initial Version
Rev. C | Page 2 of 20
3Pages
AD7401A
TIMING SPECIFICATIONS
VDD1 = 4.5 V to 5.5 V, VDD2 = 3 V to 5.5 V, TA = −40°C to +125°C, unless otherwise noted.
Table 2.
Parameter1
fMCLKIN2, 3
t1 4
t24
t3
t4
Limit at TMIN, TMAX
20
5
25
15
0.4 × tMCLKIN
0.4 × tMCLKIN
Unit
MHz max
MHz min
ns max
ns min
ns min
ns min
Description
Master clock input frequency
Master clock input frequency
Data access time after MCLKIN rising edge
Data hold time after MCLKIN rising edge
Master clock low time
Master clock high time
1 Sample tested during initial release to ensure compliance.
2 Mark space ratio for clock input is 40/60 to 60/40 for fMCLKIN ≤ 16 MHz and 48/52 to 52/48 for 16 MHz < fMCLKIN < 20 MHz.
3 VDD1 = VDD2 = 5 V ± 5% for fMCLKIN > 16 MHz to 20 MHz.
4 Measured with the load circuit of Figure 2 and defined as the time required for the output to cross 0.8 V or 2.0 V.
200µA
IOL
TO OUTPUT
PIN CL
25pF
1.6V
200µA
IOH
Figure 2. Load Circuit for Digital Output Timing Specifications
MCLKIN
MDAT
t1 t2
Figure 3. Data Timing
t3
t4
Rev. C | Page 5 of 20
6 Page
合計 : 21 ページ |
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| 部品番号 | 部品説明 | メーカ |
| AD7401 | Isolated Sigma-Delta Modulator | Analog Devices |
| AD7401A | Isolated Sigma-Delta Modulator | Analog Devices |