AD5381BST-3 Analog Devices Inc, AD5381BST-3 Datasheet - Page 23

• Manufacturer Part Number: AD5381BST-3
• Description: IC DAC 12BIT 40CH 3V 100-LQFP
• Manufacturer: Analog Devices Inc

Specifications of AD5381BST-3

• Design Resources: 40 Channels of Programmable Voltage with Excellent Temperature Drift Performance Using AD5381 (CN0010) AD5381 Channel Monitor Function (CN0013)
• Settling Time: 6µs
• Number Of Bits: 12
• Data Interface: Serial, Parallel
• Number Of Converters: 40
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 80mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 100-LQFP
• For Use With: EVAL-AD5381EB - BOARD EVAL FOR AD5381
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Table 16. Control Register Contents
MSB
CR11
Control Register Write/Read
REG1 = REG0 = 0, A5 to A0 = 001100, R/ W status determines
if the operation is a write (R/ W = 0) or a read (R/ W = 1). DB11
to DB0 contains the control register data.
Control Register Contents
CR11: Power-Down Status. This bit is used to configure the
output amplifier state in power-down.
CR10: REF Select. This bit selects the operating internal
reference for the AD5381. CR10 is programmed as follows:
CR9: Current Boost Control. This bit is used to boost the
current in the output amplifier, thereby altering its slew rate.
This bit is configured as follows:
CR8: Internal/External Reference. This bit determines if the
DAC uses its internal reference or an externally applied
reference.
CR7: Channel Monitor Enable (see Channel Monitor Function
section).
CR11 = 1. Amplifier output is high impedance (default on
power-up).
CR11 = 0. Amplifier output is 100 kΩ to ground.
CR10 = 1: Internal reference is 2.5 V (AD5381-5 default), the
recommended operating reference for AD5381-5.
CR10 = 0: Internal reference is 1.25 V (AD5381-3 default),
the recommended operating reference for AD5381-3.
CR9 = 1: Boost Mode On. This maximizes the bias current
in the output amplifier, optimizing its slew rate but increasing
the power dissipation.
CR9 = 0: Boost Mode Off (default on power-up). This
reduces the bias current in the output amplifier and reduces
the overall power consumption.
CR8 = 1: Internal Reference Enabled. The reference output
depends on data loaded to CR10.
CR8 = 0: External Reference Selected (default on power-up).
CR7= 1: Monitor Enabled. This enables the channel monitor
function. After a write to the monitor channel in the SFR
register, the selected channel output is routed to the
MON_OUT pin. VOUT39 operates at the MON_OUT pin.
CR10
CR9
CR8
CR7
CR6
Rev. B | Page 23 of 40
CR5
CR6: Thermal Monitor Function. When enabled, this function
is used to monitor the internal die temperature of the AD5381.
The thermal monitor powers down the output amplifiers when
the temperature exceeds 130°C. This function can be used to
protect the device in cases where power dissipation may be
exceeded if a number of output channels are simultaneously
short-circuited. A soft power-up will re-enable the output
amplifiers if the die temperature has dropped below 130°C.
CR5: Don’t Care.
CR4 to CR0: Toggle Function Enable. This function allows the
user to toggle the output between two codes loaded to the A
and B registers for each DAC. Control Register Bits CR4 to CR0
are used to enable individual groups of eight channels for
operation in toggle mode. A Logic 1 written to any bit enables
a group of channels; a Logic 0 disables a group. LDAC is used
to toggle between the two registers.
Table 17.
CR Bit
CR4
CR3
CR2
CR1
CR0
Channel Monitor Function
REG1 = REG0 = 0, A5 to A0 = 001010
DB11–DB6 = Contain data to address the monitored channel.
A channel monitor function is provided on the AD5381. This
feature, which consists of a multiplexer addressed via the inter-
face, allows any channel output to be routed to the MON_OUT
pin for monitoring using an external ADC. In channel monitor
mode, VOUT39 becomes the MON_OUT pin, to which all
monitored pins are routed. The channel monitor function must
be enabled in the control register before any channels are routed
to MON_OUT. On the AD5381, DB11 to DB6 contain the
channel address for the monitored channel. Selecting Channel
Address 63 three-states MON_OUT.
CR7 = 0: Monitor Disabled (default on power-up). When the
monitor is disabled, the MON_OUT pin assumes its normal
DAC output function.
CR6 = 1: Thermal Monitor Enabled.
CR6 = 0: Thermal Monitor Disabled (default on power-up).
CR4
CR3
Group
4
3
2
1
0
CR2
CR1
Channels
32–39
24–31
16–23
8–15
0–7
AD5381
LSB
CR0