MP7645B
CMOS
Buffered Multiplying 12-Bit
Digital-to-Analog Converter
FEATURES
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Greater than 2000 V ESD Protection
Differential Linearity +1/2 LSB Tmin to Tmax
Microprocessor Compatible
Low Glitch Energy
Gain Error Tempco (2 ppm/°C max)
Low Sensitivity to Amplifier Offset
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Four Quadrant Multiplication
Latch-Up Free
TTL/5 V CMOS Compatible
Guaranteed Monotonic
GENERAL DESCRIPTION
The MP7645B is an improved precision, monolithic 12-bit
CMOS 4-quadrant multiplying DAC with an on-board data latch.
The latch is loaded by a single 12-bit wide word. Data is loaded
into the input latch under the control of CS and WR inputs.
These control inputs are level triggered; tying these inputs low
makes the input latch transparent allowing direct unbuffered op-
eration of the DAC.
– Stability – The MP7645B incorporates a unique decoding
technique yielding excellent accuracy and stability over tem-
perature. Monotonicity is guaranteed over the entire tem-
perature range including the industrial and military ranges.
The gain error specification of 2 ppm/
°
C over a 100
°
C tem-
perature range equals 0.8 LSB of error.
– Digital Feedthrough – The MP7645B has 5 to 8 times less dig-
ital feedthrough than similar buffered DACs.
– Low Sensitivity to Output Amplifier Offset – The additional
linearity error incurred by amplifier offset is reduced by a fac-
tor of at least 3 in the MP7645B over conventional DACs.
High latch-up resistance and high ESD protection make this a
rugged, reliable attenuator!
SIMPLIFIED BLOCK DIAGRAM
V
DD
R
FB
V
REF
12-Bit
Multiplying DAC
12
I
OUT
AGND
CS
WR
Input Data
Latches
DGND
12
DB11-DB0
Rev. 2.00
1
EXAR [ EXAR CORPORATION ]
