AD5380 Analog Devices, AD5380 Datasheet - Page 15

• 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

Mnemonic
VOUT39/MON_OUT
SER/PAR
CS/(SYNC/AD0)
WR/(DCEN/AD1)
DB13–DB0
A5–A0
REG1, REG0
SDO/(A/B)
BUSY
LDAC
CLR
RESET
PD
Function
This pin has a dual function. It acts a a buffered output for Channel 39 in default mode. However, when the monitor
function is enabled, this pin acts as the output of a 39-to-1 channel multiplexer that can be programmed to multiplex
one of Channels 0 to 38 to the MON_OUT pin. The MON_OUT pin’s output impedance is typically 500 Ω and is
intended to drive a high input impedance like that exhibited by SAR ADC inputs.
Interface Select Input. This pin allows the user to select whether the serial or parallel interface will be used. If it is tied
high, the serial interface mode is selected and Pin 97 (SPI/I
Parallel interface mode is selected when SER/PAR is low.
In parallel interface mode, this pin acts as chip select input (level sensitive, active low). When low, the AD5380 is
selected.
Serial Interface Mode. This is the frame synchronization input signal for the serial clocks before the addressed register
is updated.
I
for the device on the I
Multifunction Pin. In parallel interface mode, this pin acts as write enable. In serial interface mode, this pin acts as a
daisy-chain enable in SPI mode and as a hardware address pin in I
Parallel Interface Write Input (Edge Sensitive). The rising edge of WR is used in conjunction with CS low and the
address bus inputs to write to the selected device registers.
Serial Interface. Daisy-chain select input (level sensitive, active high). When high, this signal is used in conjunction
with SER/PAR high to enable the SPI serial interface Daisy-Chain mode.
I
for this device on the I
Parallel Data Bus. DB13 is the MSB and DB0 is the LSB of the input data-word on the AD5380.
Parallel Address Inputs. A5 to A0 are decoded to address one of the AD5380’s 40 input channels. Used in conjunction
with the REG1 and REG0 pins to determine the destination register for the input data.
In parallel interface mode, REG1 and REG0 are used in decoding the destination registers for the input data. REG1
and REG0 are decoded to address the input data register, offset register, or gain register for the selected channel and
to decide the special function registers.
Serial Data Output in Serial Interface Mode. Three-stateable CMOS output. SDO can be used for daisy-chaining a
number of devices together. Data is clocked out on SDO on the rising edge of SCLK, and is valid on the falling edge
of SCLK.
When operating in parallel interface mode, this pin acts as the A or B data register select when writing data to the
AD5380’s data registers with toggle mode selected (see the Toggle Mode Function section). In toggle mode, the
LDAC is used to switch the output between the data contained in the A and B data registers. All DAC channels
contain two data registers. In normal mode, Data Register A is the default for data transfers.
Digital CMOS Output. BUSY goes low during internal calculations of the data (x2) loaded to the DAC data register.
During this time, the user can continue writing new data to the x1, c, and m registers, but no further updates to the
DAC registers and DAC outputs can take place. If LDAC is taken low while BUSY is low, this event is stored. BUSY also
goes low during power-on reset, and when the BUSY pin is low. During this time, the interface is disabled and any
events on LDAC are ignored. A CLR operation also brings BUSY low.
Load DAC Logic Input (Active Low). If LDAC is taken low while BUSY is inactive (high), the contents of the input
registers are transferred to the DAC registers and the DAC outputs are updated. If LDAC is taken low while BUSY is
active and internal calculations are taking place, the LDAC event is stored and the DAC registers are updated when
BUSY goes inactive. However, any events on LDAC during power-on reset or on RESET are ignored.
Asynchronous Clear Input. The CLR input is falling edge sensitive. When CLR is activated, all channels are updated
with the data contained in the CLR code register. BUSY is low for a duration of 35 μs while all channels are being
updated with the CLR code.
Asynchronous Digital Reset Input (Falling Edge Sensitive). The function of this pin is equivalent to that of the power-
on reset generator. When this pin is taken low, the state machine initiates a reset sequence to digitally reset the x1, m,
c, and x2 registers to their default power-on values. This sequence typically takes 270 μs. The falling edge of RESET
initiates the RESET process and BUSY goes low for the duration, returning high when RESET is complete. While BUSY
is low, all interfaces are disabled and all LDAC pulses are ignored. When BUSY returns high, the part resumes normal
operation, and the status of the RESET pin is ignored until the next falling edge is detected.
Power Down (Level Sensitive, Active High). PD is used to place the device in low power mode, where AI
2 μA and DI
analog output will be configured as a high impedance output or will provide a 100 kΩ load to ground, depending on
how the power-down mode is configured. The serial interface remains active during power-down.
2
2
C Mode. This pin acts as a hardware address pin used in conjunction with AD1 to determine the software address
C Mode. This pin acts as a hardware address pin used in conjunction with AD0 to determine the software address
DD
to 20 μA. In power-down mode, all internal analog circuitry is placed in low power mode, and the
2
2
C bus.
C bus.
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2
C) is used to determine if the interface mode is SPI or I
2
C mode.
DD
reduces to
AD5380
2
C.