Zakładka z wyszukiwarką danych komponentów
  Polish  ▼
ALLDATASHEET.PL

X  

AD654JNZ Arkusz danych(PDF) 9 Page - Analog Devices

Numer części AD654JNZ
Szczegółowy opis  Low Cost Monolithic Voltage-to-Frequency Converter
Download  13 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Producent  AD [Analog Devices]
Strona internetowa  http://www.analog.com
Logo AD - Analog Devices

AD654JNZ Arkusz danych(HTML) 9 Page - Analog Devices

Back Button AD654JNZ Datasheet HTML 5Page - Analog Devices AD654JNZ Datasheet HTML 6Page - Analog Devices AD654JNZ Datasheet HTML 7Page - Analog Devices AD654JNZ Datasheet HTML 8Page - Analog Devices AD654JNZ Datasheet HTML 9Page - Analog Devices AD654JNZ Datasheet HTML 10Page - Analog Devices AD654JNZ Datasheet HTML 11Page - Analog Devices AD654JNZ Datasheet HTML 12Page - Analog Devices AD654JNZ Datasheet HTML 13Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 9 / 13 page
background image
AD654
–8–
REV.
At the receiver side, the output transistor is operated in the
photo-transistor mode; that is with the base lead (Pin 6) open.
This allows the highest possible output current. For reasonable
speed in this mode, it is imperative that the load impedance be
as low as possible. This is provided by the single transistor stage
current-to-voltage converter, which has a dynamic load imped-
ance of less than 10 ohms and interfaces with TTL at the output.
USING A STAND-ALONE FREQUENCY COUNTER/LED
DISPLAY DRIVER FOR VOLTMETER APPLICATIONS
Figure 10 shows the AD654 used with a stand-alone frequency
counter/LED display driver. With CT = 1000 pF and RT = 1 k
the AD654 produces an FS frequency of 100 kHz when VIN =
+1 V. This signal is fed into the ICM7226A, a universal counter
system that drives common anode LEDs. With the FUNCTION
pin tied to D1 through a 10 k
Ω resistor the ICM7226A counts the
frequency of the signal at AIN. This count period is selected by
the user and can be 10 ms, 100 ms, 1s, or 10 seconds, as shown on
Pin 21. The longer the period selected, the more resolution the
count will have. The ICM7226A then displays the frequency on
the LEDs, driving them directly as shown. Refreshing of the LEDs
is handled automatically by the ICM7226. The entire circuit op-
erates on a single +5 V supply and gives a meter with 3, 4, or 5
digit resolution.
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
8
7
6
5
1
2
3
4
VIN
(0V TO 1V)
5V
5V
1k
1000pF
500
825
1k
AD654
DI PIN 30
10k
30k
5V
5V
10MHz
CRYSTAL
22M
39pF
39pF
5V
5V
10k
5V
D1 (10ms)
D2 (100ms)
D3 (1s)
D4 (10s)
4
8
8
D.P.
g
e
d
c
b
a
f
LED
OVERFLOW
INDICATOR
D8
D7
D6
D5
D4
D3
D2
D1
AIN
HOLD
NC
OSL JN
OSL OUT
NC
D1
D2
D3
D4
D5
V+
D6
D7
D8
RANGE
ICM7226A
FUNCTION
dp
e
g
a
GND
d
b
c
f
+
NC = NO CONNECT
Figure 10. AD654 With Stand-Alone Frequency Counter/
LED Display Driver
Longer count periods not only result in the count having more
resolution, they also serve as an integration of noisy analog signals.
For example, a normal-mode 60 Hz sine wave riding on the input
of the AD654 will result in the output frequency increasing on
the positive half of the sine wave and decreasing on the negative
half of the sine wave. This effect is cancelled by selecting a count
period equal to an integral number of noise signal periods. A
100 ms count period is effective because it not only has an inte-
gral number of 60 Hz cycles (6), it also has an integral number
of 50 Hz cycles (5). This is also true of the 1 second and 10 sec-
ond count period.
AD654-BASED ANALOG-TO-DIGITAL CONVERSION
USING A SINGLE CHIP MICROCOMPUTER
The AD654 can serve as an analog-to-digital converter when
used with a single component microcomputer that has an inter-
val timer/event counter such as the 8048. Figure 11 shows the
AD654, with a full-scale input voltage of +1 V and a full-scale
output frequency of 100 kHz, connected to the timer/counter
input Pin T1 of the 8048. Such a system can also operate on a
single +5 V supply.
The 8748 counter is negative edge triggered; after the STRT
CNT instruction is executed subsequent high to low transitions
on T1 increment the counter. The maximum rate at which the
counter may be incremented is once per three instruction cycles;
using a 6 MHz crystal, this corresponds to once every 7.5
µs, or
a maximum frequency of 133 kHz. Because the counter overflows
every 256 counts (8 bits), the timer interrupt is enabled. Each
overflow then causes a jump to a subroutine where a register is
incremented. After the STOP TCNT instruction is executed, the
number of overflows that have occurred will be the number in
this register. The number in this register multiplied by 256 plus
the number in the counter will be the total number of negative
edges counted during the count period. The count period is
handled simply by decrementing a register the number of times
necessary to correspond to the desired count time. After the
register has been decremented the required number of times the
STOP TCNT instruction is executed.
The total number of negative edges counted during the count
period is proportional to the input voltage. For example, if a 1 V
full-scale input voltage produces a 100 kHz signal and the count
period is 100 ms, then the total count will be 10,000. Scaling
from this maximum is then used to determine the input voltage,
i.e., a count of 5000 corresponds to an input voltage of 0.5 V.
As with the ICM7226, longer count times result in counts hav-
ing more resolution; and they result in the integration of noisy
analog signals.
C


Podobny numer części - AD654JNZ

ProducentNumer częściArkusz danychSzczegółowy opis
logo
Analog Devices
AD654JNZ AD-AD654JNZ Datasheet
359Kb / 12P
   Low Cost Monolithic Voltage-to-Frequency Converter
REV. C
More results

Podobny opis - AD654JNZ

ProducentNumer częściArkusz danychSzczegółowy opis
logo
Analog Devices
AD654 AD-AD654 Datasheet
180Kb / 11P
   Low Cost Monolithic Voltage-to-Frequency Converter
REV. B
AD654 AD-AD654_15 Datasheet
359Kb / 12P
   Low Cost Monolithic Voltage-to-Frequency Converter
REV. C
AD654JRZ AD-AD654JRZ Datasheet
359Kb / 12P
   Low Cost Monolithic Voltage-to-Frequency Converter
REV. C
AD652JPZ-REEL AD-AD652JPZ-REEL Datasheet
786Kb / 28P
   Monolithic Synchronous Voltage-to-Frequency Converter
REV. C
AD652KPZ AD-AD652KPZ Datasheet
786Kb / 28P
   Monolithic Synchronous Voltage-to-Frequency Converter
REV. C
AD652 AD-AD652_15 Datasheet
786Kb / 28P
   Monolithic Synchronous Voltage-to-Frequency Converter
REV. C
AD652 AD-AD652_17 Datasheet
631Kb / 29P
   Monolithic Synchronous Voltage-to-Frequency Converter
AD652JPZ AD-AD652JPZ Datasheet
786Kb / 28P
   Monolithic Synchronous Voltage-to-Frequency Converter
REV. C
AD652KPZ-REEL AD-AD652KPZ-REEL Datasheet
786Kb / 28P
   Monolithic Synchronous Voltage-to-Frequency Converter
REV. C
AD651 AD-AD651 Datasheet
1Mb / 16P
   Monolithic Synchronous Voltage-to-Frequency Converter
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13


Arkusz danych Pobierz

Go To PDF Page


Link URL




Polityka prywatności
ALLDATASHEET.PL
Czy Alldatasheet okazała się pomocna?  [ DONATE ] 

O Alldatasheet   |   Reklama   |   Kontakt   |   Polityka prywatności   |   Linki   |   Lista producentów
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