Datasheet

V
OUT
Resistor
String
DAC
Power-Down
Circuitry
Resistor
Network
V
FB
Amplifier
DAC8560
www.ti.com SLAS464B –DECEMBER 2006– REVISED NOVEMBER 2011
POWER-DOWN MODES The advantage of this switching is that the output
impedance of the device is known while it is in
The DAC8560 supports four separate modes of
power-down mode. As shown in Table 5, there are
operation. These modes are programmable by setting
three different power-down options. V
OUT
can be
two bits (PD1 and PD0) in the control register.
connected internally to GND through a 1kΩ resistor, a
Table 5 shows how to control the operating mode
100kΩ resistor, or open circuited (High-Z). The output
with data bits PD1 (DB17) and PD0 (DB16).
stage is illustrated in Figure 66.
Table 5. Operating Modes
PD1 PD0 OPERATING MODE
(DB17) (DB16)
0 0 Normal operation
0 1 Power-down 1 kΩ to GND
1 0 Power-down 100 kΩ to GND
1 1 Power-down High-Z
When both bits are set to '0', the device works
normally with its typical current consumption of
530μA at 5.5V. However, for the three power-down
modes, the supply current falls to 1.2μA at 5.5V
Figure 66. Output Stage During Power Down
(0.7μA at 3.6V). Not only does the supply current fall,
but the output stage is also internally switched from
the output of the amplifier to a resistor network of
All analog circuitry is shut down when the
known values.
power-down mode is activated. However, the
contents of the DAC register are unaffected when in
power down. The time to exit power-down is typically
2.5μs for V
DD
= 5V, and 5μs for V
DD
= 3V. See the
Typical Characteristics for more information.
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