Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

AD7228ABN Datasheet(PDF) 5 Page - Analog Devices

Part No. AD7228ABN
Description  LC2MOS Octal 8-Bit DAC
Download  8 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  AD [Analog Devices]
Homepage  http://www.analog.com
Logo 

AD7228ABN Datasheet(HTML) 5 Page - Analog Devices

   
Zoom Inzoom in Zoom Outzoom out
 5 / 8 page
background image
AD7228A
REV. A
–5–
OP AMP SECTION
Each voltage-mode D/A converter output is buffered by a unity
gain noninverting CMOS amplifier. This buffer amplifier is
tested with a 2 k
Ω and 100 pF load but will typically drive a
2 k
Ω and 500 pF load.
The AD7228A can be operated single or dual supply. Operating
the part from single or dual supplies has no effect on the positive-
going settling time. However, the negative-going settling time to
voltages near 0 V in single supply will be slightly longer than the
settling time for dual supply operation. Additionally, to ensure
that the output voltage can go to 0 V in single supply, a transis-
tor on the output acts as a passive pull-down as the output volt-
age nears 0 V. As a result, the sink capability of the amplifier is
reduced as the output voltage nears 0 V in single supply. In dual
supply operation, the full sink capability of 400
µA at 25°C is
maintained over the entire output voltage range. The single sup-
ply output sink capability is shown in Figure 4. The negative
VSS also gives improved output amplifier performance allowing
an extended input reference voltage range and giving improved
slew rate at the output.
Figure 4. Single Supply Sink Current
The output broadband noise from the amplifier is 300
µV
peak-to-peak. Figure 5 shows a plot of noise spectral density
versus frequency.
Figure 5. Noise Spectral Density vs. Frequency
DIGITAL INPUTS
The AD7228A digital inputs are compatible with either TTL or
5 V CMOS levels. All logic inputs are static-protected MOS
gates with typical input currents of less than 1 nA. Internal in-
put protection is achieved by on-chip distributed diodes.
SUPPLY CURRENT
The AD7228A has a maximum IDD specification of 22 mA and
a maximum ISS of 20 mA over the –55
°C to +125°C tempera-
ture range. This maximum current specification is actually de-
termined by the current at –55
°C. Figure 6 shows a typical plot
of power supply current versus temperature.
Figure 6. Power Supply Current vs. Temperature
APPLYING THIS AD7228A
UNIPOLAR OUTPUT OPERATION
This is the basic mode of operation for each channel of the
AD7228A, with the output voltage having the same positive po-
larity as VREF. Connections for unipolar output operation are
shown in Figure 7. The AD7228A can be operated from single
or dual supplies as outlined earlier. The voltage at the reference
input must never be negative with respect to GND. Failure to
observe this precaution may cause parasitic transistor action and
possible device destruction. The code table for unipolar output
operation is shown in Table II.
Figure 7. Unipolar Output Circuit


Html Pages

1  2  3  4  5  6  7  8 


Datasheet Download




Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
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