AD7225KP-REEL Analog Devices Inc, AD7225KP-REEL Datasheet - Page 18

• Manufacturer Part Number: AD7225KP-REEL
• Description: IC DAC 8BIT QUAD W/AMP 28-PLCC
• Manufacturer: Analog Devices Inc

Specifications of AD7225KP-REEL

• Rohs Status: RoHS non-compliant
• Settling Time: 4µs
• Number Of Bits: 8
• Number Of Converters: 4
• Voltage Supply Source: Dual ±
• Power Dissipation (max): 500mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-LCC (J-Lead)
• Data Interface: -

AD7225
less, there exists a good correlation with the actual performance
of the transversal filter (see Figure 23).
DIGITAL WORD MULTIPLICATION
Because each DAC of the AD7225 has a separate reference input,
the output of one DAC can be used as the reference input for
another. This means that multiplication of digital words can be
performed (with the result given in analog form). For example,
if the output from DAC A is applied to V
from DAC B, V
where D
words in DAC Latch A and DAC Latch B, respectively.
If D
In this manner, the four DACs can be used on their own or in
conjunction with an external summing amplifier to generate
complex waveforms. Figure 24 shows one such application.
In this case, the output waveform, Y, is represented by
where x is the digital code that is applied to all four DAC
latches.
A
V
Y = −(x
= D
OUT
A
B = D
B
and D
= D, the result is D
4
+ 2x
A
OUT
B
× D
are the fractional representations of the digital
3
B, can be expressed as:
+ 3x
B
× V
2
+ 2x + 4) × V
REF
A
2
× V
REF
A.
IN
REF
B, then the output
Rev. C | Page 18 of 24
V
*DIGITAL INPUTS OMITTED FOR CLARITY.
IN
Figure 24. Complex Waveform Generation
V
V
V
V
AGND DGND
REF
REF
REF
REF
A
B
C
D
AD7225*
15V
V
DD
V
V
V
V
OUT
OUT
OUT
OUT
V
SS
A
B
C
D
100kΩ
25kΩ
50kΩ
33kΩ
50kΩ
100kΩ
Y