Motore di ricerca datesheet componenti elettronici
  Italian  ▼
ALLDATASHEETIT.COM

X  

AD7416 Scheda tecnica(PDF) 11 Page - Analog Devices

Il numero della parte AD7416
Spiegazioni elettronici  10-Bit Digital Temperature Sensor (AD7416) and Four Single-Channel ADCs
Download  24 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Produttore elettronici  AD [Analog Devices]
Homepage  http://www.analog.com
Logo AD - Analog Devices

AD7416 Scheda tecnica(HTML) 11 Page - Analog Devices

Back Button AD7416_10 Datasheet HTML 7Page - Analog Devices AD7416_10 Datasheet HTML 8Page - Analog Devices AD7416_10 Datasheet HTML 9Page - Analog Devices AD7416_10 Datasheet HTML 10Page - Analog Devices AD7416_10 Datasheet HTML 11Page - Analog Devices AD7416_10 Datasheet HTML 12Page - Analog Devices AD7416_10 Datasheet HTML 13Page - Analog Devices AD7416_10 Datasheet HTML 14Page - Analog Devices AD7416_10 Datasheet HTML 15Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 11 / 24 page
background image
AD7416/AD7417/AD7418
Rev. I | Page 11 of 24
THEORY OF OPERATION
CIRCUIT INFORMATION
The AD7417 and AD7418 are single-channel and four-channel,
15 μs conversion time, 10-bit ADCs with on-chip temperature
sensor, reference, and serial interface logic functions on a single
chip. The AD7416 has no analog input channel and is intended
for temperature measurement only. The ADC section consists
of a conventional successive approximation converter based
around a capacitor DAC. The AD7416, AD7417, and AD7418
are capable of running on a 2.7 V to 5.5 V power supply, and the
AD7417 and AD7418 accept an analog input range of 0 V to
+VREF. The on-chip temperature sensor allows an accurate
measurement of the ambient device temperature to be made.
The working measurement range of the temperature sensor is
−40°C to +125°C. The parts require a 2.5 V reference that can
be provided from the part’s own internal reference or from an
external reference source.
CONVERTER DETAILS
Conversion is initiated on the AD7417/AD7418 by pulsing the
CONVST input. The conversion clock for the part is internally
generated so that no external clock is required except when
reading from and writing to the serial port. The on-chip track-
and-hold goes from track mode to hold mode, and the conversion
sequence is started on the falling edge of the CONVST signal.
A conversion is also initiated in the automatic conversion mode
every time a read or write operation to the AD7416/AD7417/
AD7418 takes place. In this case, the internal clock oscillator
(which runs the automatic conversion sequence) is restarted
at the end of the read or write operation. The track-and-hold
goes into hold mode approximately 3 μs after the read or write
operation is complete, and a conversion is then initiated. The
result of the conversion is available either 15 μs or 30 μs later,
depending on whether an analog input channel or the tempera-
ture sensor is selected. The track-and-hold acquisition time of
the AD7417/AD7418 is 400 ns.
A temperature measurement is made by selecting the Channel 0
of the on-chip mux and carrying out a conversion on this
channel. A conversion on Channel 0 takes 30 μs to complete.
Temperature measurement is explained in the Temperature
Measurement section.
The on-chip reference is not available to the user, but REFIN can
be overdriven by an external reference source (2.5 V only).
All unused analog inputs should be tied to a voltage within the
nominal analog input range to avoid noise pickup. For
minimum power consumption, the unused analog inputs
should be tied to GND.
TYPICAL CONNECTION DIAGRAM
Figure 9 shows a typical connection diagram for the AD7417.
Using the A0, A1, and A2 pins allows the user to select from up
to eight AD7417 devices on the same serial bus, if desired. An
external 2.5 V reference can be connected at the REFIN pin. If an
external reference is used, a 10 μF capacitor should be connected
between REFIN and GND. SDA and SCL form the 2-wire I2C
compatible interface. For applications where power consump-
tion is of concern, the automatic power-down at the end of a
conversion should be used to improve power performance (see
the Operating Modes section.)
+
+
SUPPLY
2.7V TO 5.5V
2-WIRE
SERIAL
INTERFACE
0.1µF
10µF
10µF FOR
EXTERNAL
REFERENCE
OPTIONAL
EXTERNAL
REFERENCE
AD780/
REF192
0V TO 2.5V
INPUT
SDA
SCL
GND
OTI
CONVST
VDD
REFIN
AD7417 A0
A1
A2
AIN1
AIN2
AIN3
AIN4
MICROCONTROLLER/
MICROPROCESSOR
Figure 9. Typical AD7417 Connection Diagram
ANALOG INPUTS
Figure 10 shows an equivalent circuit of the analog input
structure of the AD7417 and AD7418. The two diodes, D1
and D2, provide ESD protection for the analog inputs. Care
must be taken to ensure that the analog input signal never
exceeds the supply rails by more than 200 mV to prevent these
diodes from becoming forward-biased and start conducting
current into the substrate. The maximum current these diodes
can conduct without causing irreversible damage to the part is
20 mA. Capacitor C2 in Figure 10 is typically about 4 pF and
can primarily be attributed to pin capacitance. Resistor R1 is a
lumped component made up of the on resistance of a multiplexer
and a switch. This resistor is typically about 1 kΩ. Capacitor C1
is the ADC sampling capacitor and has a capacitance of 3 pF.
VDD
VBALANCE
AIN
R1
1kΩ
CONVERT PHASE: SWITCH OPEN
TRACK PHASE: SWITCH CLOSED
D1
D2
C2
4pF
C1
3pF
Figure 10. Equivalent Analog Input Circuit
ON-CHIP REFERENCE
The AD7417/AD7418 have an on-chip 1.2 V band gap reference
that is amplified by a switched capacitor amplifier to give an
output of 2.5 V. The amplifier is only powered up at the start of
the conversion phase and is powered down at the end of the
conversion. The on-chip reference is selected by connecting the
REFIN pin to analog ground, which causes SW1 (see Figure 11) to
open and the reference amplifier to power up during a conver-
sion. Therefore, the on-chip reference is not available externally.


Codice articolo simile - AD7416_10

Produttore elettroniciIl numero della parteScheda tecnicaSpiegazioni elettronici
logo
Analog Devices
AD7416 AD-AD7416_15 Datasheet
396Kb / 24P
   10-Bit Digital Temperature Sensor
Rev. I
More results

Descrizione simile - AD7416_10

Produttore elettroniciIl numero della parteScheda tecnicaSpiegazioni elettronici
logo
Analog Devices
AD7416 AD-AD7416 Datasheet
325Kb / 20P
   10-Bit Digital Temperature Sensor (AD7416) and Single/Four-Channel ADC (AD7417/AD7418)
REV. G
AD7816 AD-AD7816 Datasheet
279Kb / 20P
   Single- and 4-Channel, 9 us, 10-Bit ADCs with On-Chip Temperature Sensor
REV. C
AD7417 AD-AD7417_15 Datasheet
396Kb / 24P
   10-Bit Digital Temperature Sensor
Rev. I
AD7814 AD-AD7814_17 Datasheet
151Kb / 9P
   10-Bit Digital Temperature Sensor
AD7416 AD-AD7416_15 Datasheet
396Kb / 24P
   10-Bit Digital Temperature Sensor
Rev. I
AD7418 AD-AD7418_15 Datasheet
396Kb / 24P
   10-Bit Digital Temperature Sensor
Rev. I
AD7314 AD-AD7314_17 Datasheet
194Kb / 9P
   10-Bit Digital Temperature Sensor
logo
Sipex Corporation
SP8542 SIPEX-SP8542 Datasheet
219Kb / 16P
   Two and Four Channel 12-Bit Multiplexed Sampling ADCs
logo
Analog Devices
ADT7411 AD-ADT7411 Datasheet
456Kb / 36P
   SPI/I2C Compatible, 10-Bit Digital Temperature Sensor and 8-Channel ADC
REV. A
ADT7411 AD-ADT7411_06 Datasheet
1Mb / 36P
   SPI짰-/I2C짰-Compatible, 10-Bit Digital Temperature Sensor and 8-Channel ADC
REV. B
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24


Scheda tecnica Scarica

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEETIT.COM
Lei ha avuto il aiuto da alldatasheet?  [ DONATE ] 

Di alldatasheet   |   Richest di pubblicita   |   contatti   |   Privacy Policy   |   scambio Link   |   Ricerca produttore
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