AD5313 datasheet(18/24 Pages) AD

18 / 24 page

AD5304/AD5314/AD5324

Data Sheet

Rev. H | Page 18 of 24

APPLICATIONS INFORMATION

TYPICAL APPLICATION CIRCUIT

The AD5304/AD5314/AD5324 can be used with a wide range

of reference voltages where the devices offer full, one-quadrant

multiplying capability over a reference range of 0 V to VDD.

More typically, these devices are used with a fixed, precision

reference voltage. Suitable references for 5 V operation are the

AD780 and REF192 (2.5 V references). For 2.5 V operation, a

suitable external reference would be the AD589, a 1.23 V band

gap reference. Figure 40 shows a typical setup for the AD5304/

AD5314/AD5324 when using an external reference.

AD5304/AD5314/

AD5324

VDD = 2.5V TO 5.5V

SCLK

REFIN

DIN

SYNC

VOUTA

VOUTB

VOUTC

VOUTD

GND

SERIAL

INTERFACE

VOUT

VIN

EXTERNAL

REFERENCE

AD790/REF192

WITH VDD = 5V

OR AD589 WITH

VDD = 2.5V

1µF

0.1µF

10µF

Figure 40. AD5304/AD5314/AD5324 Using External Reference

If an output range of 0 V to VDD is required, the simplest solution is

to connect the reference input to VDD. As this supply is not very

accurate and can be noisy, the AD5304/AD5314/AD5324 can

be powered from the reference voltage; for example, using a 5 V

reference such as the REF195. The REF195 can output a steady

supply voltage for the AD5304/AD5314/AD5324. The current

required from the REF195 is 600 μA supply current and approxi-

mately 112 μA into the reference input. This is with no load on

the DAC outputs. When the DAC outputs are loaded, the REF195

also needs to supply the current to the loads. The total current

required (with a 10 kΩ load on each output) is

712 μA + 4 (5 V/10 kΩ) = 2.70 mA

The load regulation of the REF195 is typically 2 ppm/mA, resulting

in an error of 5.4 ppm (27 μV) for the 2.7 mA current drawn from

it. This corresponds to a 0.0014 LSB error at eight bits and

0.022 LSB error at 12 bits.

Bipolar Operation Using the AD5304/AD5314/AD5324

The AD5304/AD5314/AD5324 have been designed for single

supply operation, but a bipolar output range is also possible

using the circuit in Figure 41. This circuit gives an output voltage

range of ±5 V. Rail-to-rail operation at the amplifier output is

achievable using an AD820 or an OP295 as the output amplifier.

AD5304

REFIN

GND

VOUTA

VOUTB

VOUTC

VOUTD

SERIAL

INTERFACE

DIN SCLK SYNC

VOUT

VIN

GND

REF195

1µF

0.1µF

10µF

+6V TO +16V

VDD

+5V

–5V

±5V

+5V

AD820/

OP295

R1 = 10kΩ

R2 = 10kΩ

Figure 41. Bipolar Operation with the AD5304

The output voltage for any input code can be calculated as follows:

)

(

)

(

)

(

REFIN

OUT























where:

D is the decimal equivalent of the code loaded to the DAC.

N is the DAC resolution.

REFIN is the reference voltage input:

REFIN = 5 V, R1 = R2 = 10 kΩ

VOUT = (10 × D/2N) − 5 V

AD5313 датащи(PDF) 18 Page - Analog Devices

AD5313 датащи(HTML) 18 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 21 22 23 24

датащи скачать

ссылки URL