2.7 V to 5.5 V, 140 μA, Rail-to-Rail Output
12-Bit DAC in an SOT-23
AD5320
Rev. C
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FEATURES
Single 12-bit DAC
6-lead SOT-23 and 8-lead MSOP packages
Micropower operation: 140 μA @ 5 V
Power-down to 200 nA @ 5 V, 50 nA @ 3 V
2.7 V to 5.5 V power supply
Guaranteed monotonic by design
Reference derived from power supply
Power-on reset to zero volts
Three power-down functions
Low power serial interface with Schmitt-triggered inputs
On-chip output buffer amplifier, rail-to-rail operation
SYNC
interrupt facility
APPLICATIONS
Portable battery-powered instruments
Digital gain and offset adjustment
Programmable voltage and current sources
Programmable attenuators
FUNCTIONAL BLOCK DIAGRAM
V
DD
V
OU
GND
AD5320
12-BIT
DAC
SCLK DIN
REF (+) REF (–)
REGISTER
NETWORK
POWER-DOWN
CONTROL LOGIC
DAC
REGISTER
OUTPUT
BUFFER
POWER-ON
RESET
SYNC
INPUT
CONTROL
LOGIC
00934-001
Figure 1.
GENERAL DESCRIPTION
The AD5320
1
is a single, 12-bit buffered voltage out digital-to-
analog converter (DAC) that operates from a single 2.7 V to
5.5 V supply consuming 115 μA at 3 V. Its on-chip precision
output amplifier allows rail-to-rail output swing to be achieved.
The AD5320 utilizes a versatile 3-wire serial interface that
operates at clock rates up to 30 MHz and is compatible with
standard SPI®, QSPI™, MICROWIRE™ and digital signal
processing (DSP) interface standards.
The reference for AD5320 is derived from the power supply
inputs and thus gives the widest dynamic output range. The
part incorporates a power-on reset circuit that ensures that the
DAC output powers up to zero volts and remains there until a
valid write takes place to the device. The part contains a power-
down feature that reduces the current consumption of the
device to 200 nA at 5 V and provides software selectable output
loads while in power-down mode. The part is put into power-
down mode over the serial interface.
The low power consumption of this part in normal operation
makes it ideally suited to portable, battery-operated equipment.
The power consumption is 0.7 mW at 5 V reducing to 1 μW in
power-down mode.
1
Patent pending; protected by U.S. Patent No. 5684481.
The AD5320 is one of a family of pin-compatible DACs. The
AD5300 is the 8-bit version and the AD5310 is the 10-bit
version. The AD5300/AD5310/AD5320 are available in 6-lead
SOT-23 packages and 8-lead MSOP packages.
PRODUCT HIGHLIGHTS
1. Available in 6-lead SOT-23 and 8-lead MSOP packages.
2. Low power, single-supply operation. This part operates
from a single 2.7 V to 5.5 V supply and typically consumes
0.35 mW at 3 V and 0.7 mW at 5 V, making it ideal for
battery-powered applications.
3. The on-chip output buffer amplifier allows the output of
the DAC to swing rail-to-rail with a slew rate of 1 V/μs.
4. Reference derived from the power supply.
5. High speed serial interface with clock speeds up to
30 MHz. Designed for very low power consumption. The
interface only powers up during a write cycle.
6. Power-down capability. When powered down, the DAC
typically consumes 50 nA at 3 V and 200 nA at 5 V.
