AD5380 Analog Devices, AD5380 Datasheet - Page 35

• Manufacturer Part Number: AD5380
• Description: 40-Channel 14-Bit 3 V/5 V Single-Supply Voltage-Output DAC
• Manufacturer: Analog Devices

Specifications of AD5380

• Resolution (bits): 14bit
• Dac Update Rate: 125kSPS
• Dac Settling Time: 8µs
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: Par,Ser,SPI

THERMAL MONITOR FUNCTION
The AD5380 contains a temperature shutdown function to
protect the chip in case multiple outputs are shorted. The short-
circuit current of each output amplifier is typically 40 mA.
Operating the AD5380 at 5 V produces a power dissipation of
200 mW per shorted amplifier. With five channels shorted, this
gives an extra watt of power dissipation. For the 100-lead LQFP,
the θ
The thermal monitor is enabled by the user via CR8 in the
control register. The output amplifiers on the AD5380 are
automatically powered down if the die temperature exceeds
approximately 130°C. After a thermal shutdown has occurred,
the user can re-enable the part by executing a soft power-up if
the temperature has dropped below 130°C or by turning off the
thermal monitor function via the control register.
JA
is typically 44°C/W.
0.01μF
REFOUT/REFIN
14-BIT DAC
14-BIT DAC
AD5380
AVDD
+5V
VOUT1
VOUT39
Figure 43. AD5380 in a MEMS Based Optical Switch
OUTPUT RANGE
0V TO 200V
G = 50
G = 50
Rev. A | Page 35 of 40
ACTUATORS
FOR MEMS
MIRROR
ARRAY
ADSP-21065L
AD5380 IN A MEMS BASED OPTICAL SWITCH
In their feed-forward control paths, MEMS based optical
switches require high resolution DACs that offer high channel
density with 14-bit monotonic behavior. The 40-channel, 14-bit
AD5380 DAC satisfies these requirements. In the circuit in
Figure 43, the 0 V to 5 V outputs of the AD5380 are amplified
to achieve an output range of 0 V to 200 V, which is used to
control actuators that determine the position of MEMS mirrors
in an optical switch. The exact position of each mirror is
measured using sensors. The sensor outputs are multiplexed
into a high resolution ADC in determining the mirror position.
The control loop is closed and driven by an ADSP-21065L, a
32-bit SHARC® DSP with an SPI-compatible SPORT interface.
The ADSP-21065L writes data to the DAC, controls the
multiplexer, and reads data from the ADC via the serial
interface.
MULTIPLEXER
SENSOR
AND
SINGLE CHANNEL
8-CHANNEL ADC
ADC (AD7671)
(AD7856)
OR
AD5380