AD7225KR Analog Devices Inc, AD7225KR Datasheet - Page 15

• Manufacturer Part Number: AD7225KR
• Description: IC DAC 8BIT QUAD W/AMP 24-SOIC
• Manufacturer: Analog Devices Inc

Specifications of AD7225KR

• 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: 24-SOIC (7.5mm Width)
• Data Interface: -

AGND BIAS
The AD7225 AGND pin can be biased above system ground
(AD7225 DGND) to provide an offset zero analog output
voltage level. Figure 18 shows a circuit configuration to achieve
this for DAC Channel A of the AD7225. The output voltage,
V
where D
DAC Latch A (0 ≤ D
OUT
A, can be expressed as:
V
OUT
A
A = V
is a fractional representation of the digital word in
BIAS
+ D
A
≤ 255/256).
A
(V
IN
)
Rev. C | Page 15 of 24
For a given V
the effective V
specified operation. Note that, because the AGND pin is
common to all four DACs, this method biases up the output
voltages of all the DACs in the AD7225. Note that V
of the AD7225 should be referenced to DGND.
V
IN
AGND
V
BIAS
IN
DD
, increasing AGND above system ground reduces
AD7225*
− V
Figure 18. AGND Bias Circuit
REF
*DIGITAL INPUTS OMITTED FOR CLARITY.
, which must be at least 4 V to ensure
V
SS
DAC A
V
REF
A
V
DGND
DD
V
OUT
A
AD7225
DD
and V
SS