Motor de Búsqueda de Datasheet de Componentes Electrónicos
  Spanish  ▼
ALLDATASHEET.ES

X  

AD650 Datasheet(PDF) 4 Page - Analog Devices

No. de pieza AD650
Descripción Electrónicos  Voltage-to-Frequency and Frequency-to-Voltage Converter
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricante Electrónico  AD [Analog Devices]
Página de inicio  http://www.analog.com
Logo AD - Analog Devices

AD650 Datasheet(HTML) 4 Page - Analog Devices

  AD650 Datasheet HTML 1Page - Analog Devices AD650 Datasheet HTML 2Page - Analog Devices AD650 Datasheet HTML 3Page - Analog Devices AD650 Datasheet HTML 4Page - Analog Devices AD650 Datasheet HTML 5Page - Analog Devices AD650 Datasheet HTML 6Page - Analog Devices AD650 Datasheet HTML 7Page - Analog Devices AD650 Datasheet HTML 8Page - Analog Devices AD650 Datasheet HTML 9Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 4 / 12 page
background image
AD650
REV. C
–4–
CIRCUIT OPERATION
UNIPOLAR CONFIGURATION
The AD650 is a charge balance voltage-to-frequency converter. In
the connection diagram shown in Figure 1, or the block diagram
of Figure 2a, the input signal is converted into an equivalent cur-
rent by the input resistance RIN. This current is exactly balanced
by an internal feedback current delivered in short, timed bursts
from the switched 1 mA internal current source. These bursts of
current may be thought of as precisely defined packets of charge.
The required number of charge packets, each producing one
pulse of the output transistor, depends upon the amplitude of
the input signal. Since the number of charge packets delivered
per unit time is dependent on the input signal amplitude, a linear
voltage-to-frequency transformation will be accomplished. The
frequency output is furnished via an open collector transistor.
A more rigorous analysis demonstrates how the charge balance
voltage-to-frequency conversion takes place.
A block diagram of the device arranged as a V-to-F converter is
shown in Figure 2a. The unit is comprised of an input integra-
tor, a current source and steering switch, a comparator and a
one-shot. When the output of the one-shot is low, the current
steering switch S1 diverts all the current to the output of the op
amp; this is called the Integration Period. When the one-shot
has been triggered and its output is high, the switch S1 diverts
all the current to the summing junction of the op amp; this is
called the Reset Period. The two different states are shown in
Figure 2 along with the various branch currents. It should be
noted that the output current from the op amp is the same for
either state, thus minimizing transients.
Figure 1. Connection Diagram for V/F Conversion,
Positive Input Voltage
Figure 2a. Block Diagram
Figure 2b. Reset Mode
Figure 2c. Integrate Mode
Figure 2d. Voltage Across CINT
The positive input voltage develops a current (IIN = VIN/RIN)
which charges the integrator capacitor CINT. As charge builds up
on CINT, the output voltage of the integrator ramps downward
towards ground. When the integrator output voltage (Pin 1)
crosses the comparator threshold (–0.6 volt) the comparator
triggers the one shot, whose time period, tOS is determined by
the one shot capacitor COS.
Specifically, the one shot time period is:
tOS
= COS × 6.8 ×103 sec /F + 3.0 ×10–7 sec
(1)
The Reset Period is initiated as soon as the integrator output
voltage crosses the comparator threshold, and the integrator
ramps upward by an amount:
∆V = t
OS
dV
dt
=
tOS
CINT
1mA – IN
()
(2)
After the Reset Period has ended, the device starts another Inte-
gration Period, as shown in Figure 2, and starts ramping downward
again. The amount of time required to reach the comparator
threshold is given as:
TI
= ∆V
dV
dt
=
tOS/CINT(1 mA – IIN )
IN /CINT
= tOS
1 mA
IIN
–1
(3)
The output frequency is now given as:
fOUT
=
1
tOS
+ TI
=
IIN
tOS
×1 mA
= 0.15 F • Hz
A
VIN /RIN
COS
+ 4.4 ×10–11F
(4)
Note that CINT, the integration capacitor has no effect on the
transfer relation, but merely determines the amplitude of the
sawtooth signal out of the integrator.
One Shot Timing
A key part of the preceding analysis is the one shot time period
that was given in equation (1). This time period can be broken
down into approximately 300 ns of propagation delay, and a sec-
ond time segment dependent linearly on timing capacitor COS.
When the one shot is triggered, a voltage switch that holds Pin 6


Número de pieza similar - AD650

Fabricante ElectrónicoNo. de piezaDatasheetDescripción Electrónicos
logo
Analog Devices
AD650 AD-AD650 Datasheet
449Kb / 21P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
AD650ACHIPS AD-AD650ACHIPS Datasheet
392Kb / 20P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
Rev. E
AD650ACHIPS AD-AD650ACHIPS Datasheet
449Kb / 21P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
AD650AD AD-AD650AD Datasheet
392Kb / 20P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
Rev. E
AD650AD AD-AD650AD Datasheet
449Kb / 21P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
More results

Descripción similar - AD650

Fabricante ElectrónicoNo. de piezaDatasheetDescripción Electrónicos
logo
Burr-Brown (TI)
VFC32 BURR-BROWN-VFC32 Datasheet
76Kb / 7P
   Voltage-to-Frequency and Frequency-to-Voltage CONVERTER
logo
Analog Devices
AD650 AD-AD650_17 Datasheet
449Kb / 21P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
ADVFC32 AD-ADVFC32_15 Datasheet
345Kb / 6P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
Rev. B
logo
Texas Instruments
VFC32 TI1-VFC32 Datasheet
411Kb / 11P
[Old version datasheet]   Voltage-to-Frequency and Frequency-to-Voltage CONVERTER
logo
Analog Devices
ADVFC32 AD-ADVFC32 Datasheet
141Kb / 6P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
REV. A
logo
Burr-Brown (TI)
VFC320 BURR-BROWN-VFC320 Datasheet
122Kb / 9P
   Voltage-to-Frequency and Frequency-to-Voltage CONVERTER
logo
Analog Devices
AD650 AD-AD650_15 Datasheet
392Kb / 20P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
REV. E
ADVFC32 AD-ADVFC32_17 Datasheet
375Kb / 7P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
ADVFC32KNZ AD-ADVFC32KNZ Datasheet
345Kb / 6P
   Voltage-to-Frequency and Frequency-to-Voltage Converter
REV. B
logo
Texas Instruments
VFC320 TI-VFC320 Datasheet
233Kb / 12P
[Old version datasheet]   Voltage-to-Frequency and Frequency-to-Voltage CONVERTER
More results


Html Pages

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


Datasheet Descarga

Go To PDF Page


Enlace URL




Política de Privacidad
ALLDATASHEET.ES
¿ALLDATASHEET es útil para Ud.?  [ DONATE ] 

Todo acerca de Alldatasheet   |   Publicidad   |   Contáctenos   |   Política de Privacidad   |   Intercambio de Enlaces   |   Lista de Fabricantes
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