AD5306 Analog Devices, AD5306 Datasheet - Page 21

• Manufacturer Part Number: AD5306
• Manufacturer: Analog Devices

Specifications of AD5306

• Resolution (bits): 8bit
• Dac Update Rate: 167kSPS
• Dac Settling Time: 6µs
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: I2C/Ser 2-wire,Ser

AD5306/AD5316/AD5326 AS A DIGITALLY
PROGRAMMABLE WINDOW DETECTOR
A digitally programmable upper/lower limit detector using two
of the DACs in the AD5306/AD5316/AD5326 is shown in
Figure 39. The upper and lower limits for the test are loaded to
DACs A and B, which, in turn, set the limits on the CMP04. If
the signal at the V
window, an LED indicates the fail condition. Similarly, DAC C
and DAC D can be used for window detection on a second
V
V
REF
SCL
DIN
5V
IN
signal.
1
ADDITIONAL PINS OMITTED FOR CLARITY
0.1μF
V
V
SDA
SCL
REF
REF
A
B
AD5306/
AD5316/
AD5326
GND
10μF
1/2
IN
Figure 39. Window Detection
input is not within the programmed
V
1
DD
V
V
OUT
OUT
A
B
V
IN
CMP04
1/2
FAIL
PASS/FAIL
1kΩ
1/6 74HC05
PASS
1kΩ
Rev. F | Page 21 of 24
COARSE AND FINE ADJUSTMENT USING THE
AD5306/AD5316/AD5326
Two of the DACs in the AD5306/AD5316/AD5326 can be
paired together to form a coarse and fine adjustment function,
as shown in Figure 40. DAC A is used to provide the coarse
adjustment while DAC B provides the fine adjustment. Varying
the ratio of R1 and R2 changes the relative effect of the coarse
and fine adjustments. With the resistor values and external
reference shown, the output amplifier has unity gain for the
DAC A output; therefore, the output range is 0 V to 2.5 V − 1
LSB. For DAC B, the amplifier has a gain of 7.6 × 10
DAC B a range of 19 mV. Similarly, DAC C and DAC D can be
paired together for coarse and fine adjustment.
The circuit in Figure 40 is shown with a 2.5 V reference, but
reference voltages up to V
indicated allow a rail-to-rail output swing.
AD780/REF192
WITH V
EXT
REF
GND
V
IN
VOUT
DD
= 5V
0.1μF
1μF
Figure 40. Coarse/Fine Adjustment
10μF
V
V
REF
REF
DD
A
B
AD5306/
AD5316/
V
AD5326
AD5306/AD5316/AD5326
DD
may be used. The op amps
1/2
V
GND
= 5V
DD
V
V
OUT
OUT
51.2kΩ
A
B
R3
51.2kΩ
390Ω
R1
R2
390Ω
R4
5V
AD820/
OP295
−3
, giving
V
OUT