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FUNCTIONAL DIAGRAM
Complete Monolithic 12-Bit D/A Converter
SP DAC87
Data Converter Line
FEATURES
Single Chip Construction
On-Board Output Amplifier
Low Power Dissipation: 300 mW
Monotonicity Guaranteed Over Temperature
Guaranteed for Operation With ±12V Supplies
Buried Zener Reference
±1/2 LSB Max Nonlinearity
DESCRIPTION
The SP DAC87 is a 12-bit digital-to-analog converter
with both a high stability voltage reference and
output amplifier combined on a single monolithic
chip.
Innovative circuit design reduces the total power
consumption to 300 mW, which not only improves
reliability but also improves long-term stability.
The SP DAC87 incorporates a fully differential, non-
saturating precision current switching cell structure,
which provides greatly increased immunity to supply
voltage variation. This same structure also reduces
nonlinearities due to thermal transients as the various
bits are switched; nearly all critical components
operate at constant power dissipation.
High stability, SiCr thin film resistors are trimmed
with a fine-resolution laser, resulting in lower
differential nonlinearity errors. A low noise, high
stability, subsurface Zenerdiode is used to produce a
reference voltage with excellent long-term stability,
high external current capability and temperature
drift characteristics that challenge the best discrete
Zener references.
The SP DAC87 is available in a hermetically sealed
ceramic package and is specified for –55oC to +125oC
temperature operation. MIL-STD-883 processing is
available.
(MSB) BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
BIT 8
BIT 9
BIT 10
BIT 11
(LSB) BIT 12
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
12-BIT
RESISTER
LADDER
NETWORK
AND
CURRENT
SWITCHES
REF
CONTROL
CIRCUIT
5k
5k
6.3k
–
+
VREFOUT
GAIN ADJUST
+VS
COMMON
SUMMING JUNCTION
20V RANGE
10V RANGE
BIPOLAR OFFSET
REF INPUT
VOUT
– VS
NC
165CedarHillStreet,Marlborough,MA01752 Tel:508.485.6350 Fax: 508.485.5168
www.SpectrumMicrowave.com