12

LTC1588/LTC1589/LTC1592

1588992fa

While not directly addressed by the simple equations in

Tables 2 and 3, temperature effects can be handled just as

easily for unipolar and bipolar applications. First, consult

ture induced effects.

For applications where fast settling time is important, Appli-

cation Note 74, entitled “

Component and Measurement

Advances Ensure 16-Bit DAC Settling Time,” offers a thor-

ough discussion of 16-bit DAC settling time and op amp

selection.

Precision Voltage Reference Considerations

Much in the same way selecting an operational amplifier

for use with the LTC1592 is critical to the performance of

the system, selecting a precision voltage reference also

requires due diligence. The output voltage of the LTC1592

is directly affected by the voltage reference; thus, any

voltage reference error will appear as a DAC output voltage

error.

There are three primary error sources to consider when

selecting a precision voltage reference for 16-bit applica-

tions: output voltage initial tolerance, output voltage tem-

perature coefficient and output voltage noise.

Initial reference output voltage tolerance, if uncorrected,

generates a full-scale error term. Choosing a reference

APPLICATIO S I FOR ATIO

Table 4. Partial List of LTC Precision Amplifiers Recommended for Use with the LTC1588/LTC1589/LTC1592,

with Relevant Specifications

AMPLIFIER SPECIFICATIONS

VOLTAGE

CURRENT

SLEW

GAIN BANDWIDTH

POWER

NOISE

NOISE

RATE

PRODUCT

with LTC1592

DISSIPATION

AMPLIFIER

µV

nA

V/mV

nV/

√Hz

pA/

√Hz

V/

µs

MHz

µsmW

LT1001

25

2

800

10

0.12

0.25

0.8

120

46

LT1097

50

0.35

1000

14

0.008

0.2

0.7

120

11

LT1112 (Dual)

60

0.25

1500

14

0.008

0.16

0.75

115

10.5/Op Amp

LT1124 (Dual)

70

20

4000

2.7

0.3

4.5

12.5

19

69/Op Amp

LT1468

75

10

5000

5

0.6

22

90

2.5

117

LT1469 (Dual)

125

10

2000

5

0.6

22

90

2.5

123/Op Amp

()

5V

()

5V

()

16.5k

OP AMP

A1 •

0

0

0

INL (LSB)

()

5V

()

5V

()

1.5k

()

66k

()

131k

()

131k

()

131k

()

131k

A2 •

0

0

0

DNL (LSB)

()

5V

()

5V

0

0

0

0

UNIPOLAR

OFFSET (LSB)

()

5V

()

5V

()

5V

A5 •

BIPOLAR GAIN

ERROR (LSB)

()

5V

()

5V

()

()

()

5V

()

5V

0

A4 •

BIPOLAR ZERO

ERROR (LSB)

UNIPOLAR GAIN

ERROR (LSB)

()

5V

()

5V

()

5V

()

5V

()

5V

A5 •

Table 3. Easy-to-Use Equations Determine Op Amp Effects on DAC Accuracy in All Output Ranges

Table 2. Variables for Each Output Range That Adjust the

Equations in Table 3

OUTPUT RANGE

A1

A2

A3

A4

A5

5V

1.1

2

1

10V

2.2

3

1.5

±5V

2

2

1.2

1

1.5

±10V

4

4

1.2

1

2.5

±2.5V

1

1

1.6

1

1

–2.5V to 7.5V

1.9

3

1

0.5

1.5