AD5732 Analog Devices, AD5732 Datasheet - Page 27

• Manufacturer Part Number: AD5732
• Description: Complete, Dual, 14-Bit, Serial Input, Unipolar/Bipolar, Voltage Output DAC
• Manufacturer: Analog Devices

Specifications of AD5732

• Resolution (bits): 14bit
• Dac Update Rate: 1MSPS
• Dac Settling Time: 10µs
• Max Pos Supply (v): +16.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: Ser,SPI

DESIGN FEATURES
ANALOG OUTPUT CONTROL
In many industrial process control applications, it is vital that
the output voltage be controlled during power-up. When the
supply voltages change during power-up, the V
clamped to 0 V via a low impedance path (approximately 4 kΩ).
To prevent the output amplifiers from being shorted to 0 V
during this time, Transmission Gate G1 is also opened (see
Figure 42). These conditions are maintained until the power
supplies have stabilized and a valid word is written to a DAC
register. At this time, G2 opens and G1 closes.
POWER-DOWN MODE
Each DAC channel of the AD5722/AD5732/AD5752 can be
individually powered down. By default, all channels are in
power-down mode. The power status is controlled by the power
control register (see Table 26 and Table 27 for details). When a
channel is in power-down mode, its output pin is clamped to
ground through a resistance of approximately 4 kΩ, and the
output of the amplifier is disconnected from the output pin.
CONTROL
VOLTAGE
MONITOR
Figure 42. Analog Output Control Circuitry
AND
G1
G2
V
OUT
OUT
A
x pins are
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OVERCURRENT PROTECTION
Each DAC channel of the AD5722/AD5732/AD5752 incorporates
individual overcurrent protection. The user has two options for
the configuration of the overcurrent protection: constant current
clamp or automatic channel power-down. The configuration of
the overcurrent protection is selected via the clamp enable bit in
the control register.
Constant Current Clamp (Clamp Enable = 1)
If a short circuit occurs in this configuration, the current is
clamped at 20 mA. This event is signaled to the user by the
setting of the appropriate overcurrent (OC
control register. Upon removal of the short-circuit fault, the
OC
Automatic Channel Power-Down (Clamp Enable = 0)
If a short circuit occurs in this configuration, the shorted channel
powers down and its output is clamped to ground via a resistance
of approximately 4 kΩ. At this time, the output of the amplifier
is disconnected from the output pin. The short-circuit event is
signaled to the user via the overcurrent (OC
power-up (PU
After the fault is rectified, the channels can be powered up again
by setting the PU
THERMAL SHUTDOWN
The AD5722/AD5732/AD5752 incorporate a thermal shutdown
feature that automatically shuts down the device if the core
temperature exceeds approximately 150°C. The thermal shutdown
feature is disabled by default and can be enabled via the TSD
enable bit of the control register. In the event of a thermal
shutdown, the TSD bit of the power control register is set.
X
bit is cleared.
X
) bits indicate which DACs have powered down.
X
bits.
AD5722/AD5732/AD5752
X
) bit in the power
X
) bits, and the