Datenblatt-Suchmaschine für elektronische Bauteile
  German  ▼
ALLDATASHEETDE.COM

X  

AD7741BN Datenblatt(PDF) 10 Page - Analog Devices

Teilenummer AD7741BN
Bauteilbeschribung  Single and Multichannel, Synchronous Voltage-to-Frequency Converters
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Hersteller  AD [Analog Devices]
Direct Link  http://www.analog.com
Logo AD - Analog Devices

AD7741BN Datenblatt(HTML) 10 Page - Analog Devices

Back Button AD7741BN Datasheet HTML 4Page - Analog Devices AD7741BN Datasheet HTML 5Page - Analog Devices AD7741BN Datasheet HTML 6Page - Analog Devices AD7741BN Datasheet HTML 7Page - Analog Devices AD7741BN Datasheet HTML 8Page - Analog Devices AD7741BN Datasheet HTML 9Page - Analog Devices AD7741BN Datasheet HTML 10Page - Analog Devices AD7741BN Datasheet HTML 11Page - Analog Devices AD7741BN Datasheet HTML 12Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 10 / 12 page
background image
REV. 0
AD7741/AD7742
–10–
APPLICATIONS
The basic connection diagram for the part is shown in Figure 9.
In the connection diagram shown, the AD7742 analog inputs
are configured as fully differential, bipolar inputs with a gain of
1. A quartz crystal provides the master clock source for the part.
It may be necessary to connect capacitors (C1 and C2 in the
diagram) on the crystal to ensure that it does not oscillate at over-
tones of its fundamental operating frequency. The values of ca-
pacitors will vary depending on the manufacturer’s specifications.
CLKOUT
CLKIN
REFIN
fOUT
GND
UNI/
BIP
GAIN
C1
C2
DIFF
INPUT 1
DIFF
INPUT 2
CHANNEL
SELECT
VIN1
VIN2
VIN3
VIN4
A0
A1
VDD
PD
AD7742
+5V
REFOUT
Figure 9. Basic Connection Diagram
A/D Conversion Techniques Using the AD7741/AD7742
When used as an ADC, VFCs provide certain advantages in-
cluding accuracy, linearity and being inherently monotonic. The
AD7741/AD7742 has a true integrating input which smooths
out noise peaks.
The most popular method of using a VFC in an A/D system is
to count the output pulses of fOUT for a fixed gate interval (see
Figure 10). This fixed gate interval should be generated by
dividing down the clock input frequency. This ensures that any
errors due to clock jitter or clock frequency drift are eliminated.
The ratio of the fOUT to the clock frequency is what is important
here, not the absolute value of fOUT. The frequency division can
be done by a binary counter where fCLKIN is the CLK input.
Figure 11 shows the waveforms of fCLKIN, fOUT and the Gate
signal. A counter counts the rising edges of fOUT while the Gate
signal is high. Since the gate interval is not synchronized with
fOUT, there is a possibility of a counting inaccuracy. Depending
on fOUT, an error of one count may occur.
COUNTER
AD7741
fOUT
VIN
CLOCK
GENERATOR
GATE
SIGNAL
TO
P
CLKIN
FREQUENCY
DIVIDER
Figure 10. A/D Conversion Using the AD7741 VFC
fCLKIN
fOUT
GATE
TGATE
4096x TCLOCK
Figure 11. Waveforms in an A/D Converter Using a VFC
The clock frequency and the gate time determine the resolution
of such an ADC. If 12-bit resolution is required and fCLKIN is
5 MHz (therefore, fOUT max is 2.25 MHz), the minimum gate
time required is calculated as follows:
N counts at Full Scale (2.25 MHz) will take
(N/2.25
× 106) seconds = minimum gate time.
N is the total number of codes for a given resolution; 4096 for
12 bits
minimum gate time = (4096/2.25
× 106) sec = 1.820 ms.
Since TGATE × fOUT max = number of counts at full scale, a
faster conversion with the same resolution can be performed
with a higher fOUT max. This high fOUT max (3 MHz) is a main
feature of the AD7741/AD7742.
If the output frequency is measured by counting pulses gated to
a signal which is derived from the clock, the clock stability is
unimportant and the device simply performs as a voltage-
controlled frequency divider, producing a high resolution ADC.
The inherent monotonicity of the transfer function and wide
range of input clock frequencies allows the conversion time and
resolution to be optimized for specific applications.
There is another parameter is taken into account when choosing
the length of the gate interval. Because the integration period of
the system is equal to the gate interval, any interfering signal can
be rejected by counting for an integer number of periods of the
interfering signal. For example, a gate interval of 100 ms will
give normal-mode rejection of 50 Hz and 60 Hz signals.


Ähnliche Teilenummer - AD7741BN

HerstellerTeilenummerDatenblattBauteilbeschribung
logo
Analog Devices
AD7741BN AD-AD7741BN Datasheet
131Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
AD7741BN AD-AD7741BN Datasheet
135Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
AD7741BN AD-AD7741BN Datasheet
120Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
AD7741BNZ AD-AD7741BNZ Datasheet
120Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
More results

Ähnliche Beschreibung - AD7741BN

HerstellerTeilenummerDatenblattBauteilbeschribung
logo
Analog Devices
AD7741 AD-AD7741 Datasheet
131Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
AD7742 AD-AD7742_15 Datasheet
135Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
AD7741 AD-AD7741_15 Datasheet
135Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
EVAL-AD7741-42EBZ AD-EVAL-AD7741-42EBZ Datasheet
135Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
AD7741BNZ AD-AD7741BNZ Datasheet
120Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
AD7741BRZ AD-AD7741BRZ Datasheet
135Kb / 12P
   Single and Multichannel, Synchronous Voltage-to-Frequency Converters
REV. 0
logo
Microchip Technology
TC9400 MICROCHIP-TC9400 Datasheet
504Kb / 20P
   Voltage-to-Frequency/Frequency-to-Voltage Converters
2002
logo
TelCom Semiconductor, I...
TC9400 TELCOM-TC9400 Datasheet
154Kb / 13P
   VOLTAGE-TO-FREQUENCY/FREQUENCY-TO-VOLTAGE CONVERTERS
logo
Microchip Technology
TC9400 MICROCHIP-TC9400_06 Datasheet
691Kb / 24P
   Voltage-to-Frequency/Frequency-to-Voltage Converters
2006
logo
Texas Instruments
LM2917P TI1-LM2917P Datasheet
96Kb / 7P
[Old version datasheet]   FREQUENCY-TO-VOLTAGE CONVERTERS
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12


Datenblatt Download

Go To PDF Page


Link URL




Privatsphäre und Datenschutz
ALLDATASHEETDE.COM
War ALLDATASHEET hilfreich?  [ DONATE ] 

Über Alldatasheet   |   Werbung   |   Kontakt   |   Privatsphäre und Datenschutz   |   Linktausch   |   Hersteller
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com