AD5331 Analog Devices, AD5331 Datasheet - Page 19

• Manufacturer Part Number: AD5331
• Manufacturer: Analog Devices

Specifications of AD5331

• Resolution (bits): 10bit
• Dac Update Rate: 143kSPS
• Dac Settling Time: 7µs
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: Par

POWER-DOWN MODE
The AD5330/AD5331/AD5340/AD5341 have low power
consumption, dissipating only 0.35 mW with a 3 V supply and
0.7 mW with a 5 V supply. Power consumption can be further
reduced when the DAC is not in use by putting it into power-
down mode, which is selected by taking Pin PD low.
When the PD pin is high, the DAC works normally with a
typical power consumption of 140 μA at 5 V (115 μA at 3 V).
In power-down mode, however, the supply current falls to
200 nA at 5 V (80 nA at 3 V) when the DAC is powered down.
Not only does the supply current drop, but the output stage
is also internally switched from the output of the amplifier,
making it open-circuit. This has the advantage that the output
is three-state while the part is in power-down mode and provides
a defined input condition for whatever is connected to the
output of the DAC amplifier. The output stage is illustrated in
Figure 39
Table 9. AD5330/AD5331/AD5340 Truth Table
CLR
1
1
0
1
1
1
1
Table 10. AD5341 Truth Table
CLR
1
1
0
1
1
1
1
1
1
X = don’t care.
X = don’t care.
.
LDAC
1
1
X
1
1
0
0
0
LDAC
1
1
X
1
0
0
CS
1
X
X
0
0
0
0
X
CS
1
X
X
0
0
X
1
WR
X
1
X
0→1
0→1
0→1
0→1
X
WR
X
1
X
0→1
0→1
X
HBEN
X
X
X
0
1
0
1
X
1
Function
No data transfer
No data transfer
Clear all registers
Load input register
Load input register and DAC register
Update DAC register
No data transfer
No data transfer
Clear all registers
Load low byte input register
Load low byte input register and DAC register
Update DAC register
Rev. A | Page 19 of 28
Function
Load high byte input register
Load high byte input register and DAC register
The bias generator, the output amplifier, the resistor string, and
all other associated linear circuitry are shut down when the
power-down mode is activated. However, the contents of the
registers are unaffected when in power-down. The time to exit
power-down is typically 2.5 μs for V
V
when the output voltage deviates from its power-down voltage
(see
DD
= 3 V. This is the time from a rising edge on the PD pin to
Figure 31
STRING DAC
RESISTOR
AD5330/AD5331/AD5340/AD5341
Figure 39. Output Stage During Power-Down
).
AMPLIFIER
DD
POWER-DOWN
= 5 V and 5 μs when
CIRCUITRY
V
OUT