AD5313 datasheet(16/20 Pages) AD

16 / 20 page

REV. 0

AD5334/AD5335/AD5336/AD5344

–16–

SUGGESTED DATABUS FORMATS

In many applications the GAIN input of the AD5334 and

AD5336 may be hard-wired. However, if more flexibility is

required, it can be included in a data bus. This enables the user

to software program GAIN, giving the option of doubling the

resolution in the lower half of the DAC range. In a bused system

GAIN may be treated as a data input since it is written to the

device during a write operation and takes effect when

LDAC is

taken low. This means that the output ampliﬁer gain of multiple

DAC devices can be controlled using a common GAIN line.

The AD5336 databus must be at least 10 bits wide and is best

suited to a 16-bit databus system.

Examples of data formats for putting GAIN on a 16-bit databus

are shown in Figure 32. Note that any unused bits above the

actual DAC data may be used for GAIN.

DB0

DB1

DB2

DB3

DB4

DB5

DB6

DB7

DB8

DB9

GAIN

AD5336

X = UNUSED BIT

Figure 32. AD5336 Data Format for Byte Load with GAIN

Data on 8-Bit Bus

APPLICATIONS INFORMATION

Typical Application Circuits

The AD5334/AD5335/AD5336/AD5344 can be used with a

wide range of reference voltages and offer full, one-quadrant

multiplying capability over a reference range of 0.25 V to VDD.

More typically, these devices may be used with a ﬁxed, preci-

sion reference voltage. Figure 33 shows a typical setup for the

devices when using an external reference connected to the refer-

ence inputs. Suitable references for 5 V operation are the AD780

and REF192. For 2.5 V operation, a suitable external reference

would be the AD589, a 1.23 V bandgap reference.

AD5334/AD5335/

AD5336/AD5344

VOUT*

0.1 F

VDD = 2.5V TO 5.5V

VDD

GND

AD780/REF192

WITH VDD = 5V

AD589 WITH VDD = 2.5V

VREF*

GND

VOUT

VIN

EXT

REF

*ONLY ONE CHANNEL OF VREF AND VOUT SHOWN

10 F

Figure 33. AD5334/AD5335/AD5336/AD5344 Using

External Reference

Driving VDD from the Reference Voltage

If an output range of zero to VDD is required, the simplest

solution is to connect the reference inputs to VDD. As this supply

may not be very accurate, and may be noisy, the devices

may be powered from the reference voltage, for example

using a 5 V reference such as the ADM663 or ADM666,

as shown in Figure 34.

AD5334/AD5335/

AD5336/AD5344

VOUT*

VDD

GND

VREF*

GND

VOUT(2)

VIN

ADM663/ADM666

VSET

SHDN

SENSE

6V TO 16V

*ONLY ONE CHANNEL OF VREF AND VOUT SHOWN

0.1 F

10 F

0.1 F

Figure 34. Using an ADM663/ADM666 as Power and

Reference to AD5334/AD5335/AD5336/AD5344

Bipolar Operation Using the AD5334/AD5335/AD5336/AD5344

The AD5334/AD5335/AD5336/AD5344 have been designed

for single supply operation, but bipolar operation is achievable

using the circuit shown in Figure 35. The circuit shown has been

conﬁgured to achieve an output voltage range of –5 V < VO <

+5 V. Rail-to-rail operation at the ampliﬁer output is achievable

using an AD820 or OP295 as the output ampliﬁer.

The output voltage for any input code can be calculated as

follows:

VO = [(1 + R4/R3)

× (R2/(R1 + R2) × (2 × VREF × D/2

N)] – R4 × V

REF/R3

where:

D is the decimal equivalent of the code loaded to the DAC, N is

DAC resolution and VREF is the reference voltage input.

With:

VREF = 2.5 V

R1 = R3 = 10 k

Ω

R2 = R4 = 20 k

Ω and VDD = 5 V.

VOUT = (10

× D/2N) – 5

AD5334/AD5335/

AD5336/AD5344

GND

VDD = 5V

EXT

REF

VOUT*

AD780/REF192

WITH VDD = 5V

AD589 WITH VDD = 2.5V

GND

VIN

VOUT

VREF*

VDD

10k

20k

+5V

–5V

*ONLY ONE CHANNEL OF VREF AND VOUT SHOWN

0.1 F

10 F

Figure 35. Bipolar Operation using the AD5334/AD5335/

AD5336/AD5344

AD5313 Datasheet(PDF) 16 Page - Analog Devices

AD5313 Datasheet(HTML) 16 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Datasheet Download

Link URL