AD5305 Analog Devices, AD5305 Datasheet - Page 19

• Manufacturer Part Number: AD5305
• Manufacturer: Analog Devices

Specifications of AD5305

• 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

When both bits are set to 0, the DAC works normally with its
normal power consumption of 600 μA at 5 V. However, for the
three power-down modes, the supply current falls to 200 nA at
5 V (80 nA at 3 V). Not only does the supply current drop, but
the output stage is also internally switched from the output of
the amplifier to a resistor network of known values. This has an
advantageous because the output impedance of the part is known
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. There are three different options. The output is
connected internally to GND through a 1 kΩ resistor, a 100 kΩ
resistor, or it is left open-circuited (three-state). Resistor
tolerance = ±20%. The output stage is illustrated in Figure 35.
Rev. G | Page 19 of 24
The bias generator, the output amplifiers, the resistor string, and
all other associated linear circuitry are shut down when the
power-down mode is activated. However, the contents of the
DAC registers are unchanged when in power-down. The time to
exit power-down is typically 2.5 μs for V
V
SCL pulse to when the output voltage deviates from its power-
down voltage. See Figure 21 for a plot.
DD
= 3 V. This is the time from the rising edge of the eighth
STRING DAC
RESISTOR
Figure 35. Output Stage During Power-Down
POWER-DOWN
CIRCUITRY
AMPLIFIER
AD5305/AD5315/AD5325
RESISTOR
NETWORK
DD
= 5 V and 5 μs when
V
OUT