EVAL-AD7841EB Analog Devices Inc, EVAL-AD7841EB Datasheet - Page 12

• Manufacturer Part Number: EVAL-AD7841EB
• Description: BOARD EVAL FOR AD7841
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7841EB

• Number Of Dac's: 8
• Number Of Bits: 14
• Outputs And Type: 8, Single Ended
• Sampling Rate (per Second): 32k
• Data Interface: Parallel
• Settling Time: 31µs
• Dac Type: Voltage
• Voltage Supply Source: Analog and Digital, Dual ±
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7841
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

AD7841
The AD8803 has an output voltage range of GND to V
to 5 V). To trim the V
on the AD8803 DAC can be set using the V
allowing 8 bits of resolution between the two points. This will
allow the V
To trim the V
voltage in the required negative voltage range is required. Neither
the AD7804 or the AD8803 can provide this range in normal
operation as their output range is 0 V to 5 V. There are two
methods of producing this negative voltage. One method is to
REF
REF
(+) pin to be adjusted to remove gain errors.
(–) voltage, some method of providing a trim
CONTROLLER
ADDR BUS
DATA BUS
REF
SDATA
(+) input, the appropriate trim range
SCLK
LOGIC LEVEL
SHIFT
DECODER
ADDR
0.037 (0.94)
0.025 (0.64)
0.040 (1.02)
0.032 (0.81)
SEATING
REFL
ADDITIONAL PINS OMITTED FOR CLARITY
PLANE
FSIN/CS
FSIN/CS
and V
0.096 (2.44)
0.083 (2.11)
0.077 (1.96)
SCLK
SCLK
D IN
D IN
Dimensions shown in inches and (mm).
MAX
OUTLINE DIMENSIONS
REFH
44-Lead MQFP (S-44)
DD
8/10-BIT
8/10-BIT
DAC
DAC
0.8°
0.040 (1.02)
0.032 (0.81)
8°
(0 V
pins
GND
GND
+5V
V
V
5V
DD
DD
34
44
provide a positive output voltage and then to level shift that ana-
log voltage to the required negative range. Alternatively these
DACs can be operated with supplies of 0 V and –5 V, with the
V
Now these can be used to provide the negative reference volt-
ages for the V
signals driving the DACs need to be level-shifted from the 0 V
to +5 V range to the –5 V to 0 V range. Figure 13 shows a
typical application circuit to provide programmable reference
capabilities for the AD7841.
33
1
DD
0.033 (0.84)
0.029 (0.74)
pin connected to 0 V and the GND pin connected to –5 V.
0.548 (13.925)
0.546 (13.875)
0.398 (10.11)
0.390 (9.91)
(PINS DOWN)
TOP VIEW
0V TO
0V TO +5V
0.016 (0.41)
0.012 (0.30)
REF
5V
(–) inputs on the AD7841. However, the digital
23
11
V
V
DATA BUS
REF
REF
22
12
( )AB
(+)AB
AD7841
A0, A1, A2
GND
V
V
OUT
OUT
A
B
V
V
OUT
OUT
A
B