DAC122S085_07 Datasheet, PDF (1/20 Pages) –

January 2007
DAC122S085
12-Bit Micro Power DUAL Digital-to-Analog Converter with
Rail-to-Rail Output
General Description
The DAC122S085 is a full-featured, general purpose DUAL
12-bit voltage-output digital-to-analog converter (DAC) that
can operate from a single +2.7V to 5.5V supply and consumes
0.6 mW at 3V and 1.6 mW at 5V. The DAC122S085 is pack-
aged in 10-lead LLP and MSOP packages. The 10-lead LLP
package makes the DAC122S085 the smallest DUAL DAC in
its class. The on-chip output amplifier allows rail-to-rail output
swing and the three wire serial interface operates at clock
rates up to 40 MHz over the entire supply voltage range.
Competitive devices are limited to 25 MHz clock rates at sup-
ply voltages in the 2.7V to 3.6V range. The serial interface is
compatible with standard SPI™, QSPI, MICROWIRE and
DSP interfaces.
The reference for the DAC122S085 serves all four channels
and can vary in voltage between 1V and V_A, providing the
widest possible output dynamic range. The DAC122S085 has
a 16-bit input shift register that controls the outputs to be up-
dated, the mode of operation, the powerdown condition, and
the binary input data. Both outputs can be updated simulta-
neously or individually depending on the setting of the two
mode of operation bits.
A power-on reset circuit ensures that the DAC output powers
up to zero volts and remains there until there is a valid write
to the device. A power-down feature reduces power con-
sumption to less than a microWatt with three different termi-
nation options.
The low power consumption and small packages of the
DAC122S085 make it an excellent choice for use in battery
operated equipment.
The DAC122S085 is one of a family of pin compatible DACs,
including the 8-bit DAC082S085 and the 10-bit DAC102S085.
The DAC122S085 operates over the extended industrial tem-
perature range of −40°C to +105°C.
Features
■ ^{Guaranteed Monotonicity}
■ ^{Low Power Operation}
■ ^{Rail-to-Rail Voltage Output}
■ ^{Power-on Reset to 0V}
■ ^{Simultaneous Output Updating}
■ ^{Wide power supply range (+2.7V to +5.5V)}
■ ^{Industry's Smallest Package}
■ ^{Power Down Modes}
Key Specifications
■ ^Resolution
■ ^INL
■ ^DNL
■ ^{Settling Time}
■ ^{Zero Code Error}
■ ^{Full-Scale Error}
■ ^{Supply Power}
■ — ^Normal
— Power Down
12 bits
±8 LSB (max)
+0.7 / −0.5 LSB (max)
8.5 µs (max)
+15 mV (max)
−0.75 %FS (max)
0.6 mW (3V) / 1.6 mW (5V) typ
0.3 µW (3V) / 0.8 µW (5V) typ
Applications
■ ^{Battery-Powered Instruments}
■ ^{Digital Gain and Offset Adjustment}
■ ^{Programmable Voltage & Current Sources}
■ ^{Programmable Attenuators}
Pin Configuration
20195201
SPI™ is a trademark of Motorola, Inc.
© 2007 National Semiconductor Corporation
201952
20195202
www.national.com