DAC8554IPW datasheet(24/34 Pages) TI2

24 / 34 page

www.ti.com

USING THE REF02 AS A POWER SUPPLY

BIPOLAR OPERATION USING THE DAC8554

OUTX

+ VREF

65536

) R2

* VREF

OUTX

65536

* 5V

REF02

Three-Wire

Serial

Interface

+5V

REF

=0Vto5V

OUT

SYNC

SCLK

+15V

DAC8554

REF

OUT

REF

(Otherpinsomittedforclarity.)

+5V

+6V

OPA703

DAC8554

10 F

0.1 F

10kW

DAC8554

SLAS431B – JUNE 2005 – REVISED OCTOBER 2006

FOR THE DAC8554

The DAC8554 has been designed for single-supply

Due to the extremely low supply current required by

operation, but a bipolar output range is also possible

the DAC8554, a possible configuration is to use a

using the circuit in Figure 55. The circuit shown will

REF02 (+5V precision voltage reference) to supply

give an output voltage range of

±V

REF. Rail-to-rail

the required voltage to the DAC8554 supply input as

operation at the amplifier output is achievable using

well

the

reference

input,

illustrated

an amplifier such as the OPA703, as shown in

Figure 54. This is especially useful if the power

Figure 55.

supply is quite noisy or if the system supply voltages

The output voltage for any input code can be

are at some value other than 5V. The REF02 will

calculated as follows:

output a steady supply voltage for the DAC8554. If

the REF02 is used, the current it needs to supply to

the DAC8554 is 0.85mA typical for AVDD = 5V. When

a DAC output is loaded, the REF02 also needs to

supply the current to the load. The total typical

where D represents the input code in decimal

current required (with a 5k

Ω load on a given DAC

(0–65535).

output) is:

With VREF = 5V, R1 = R2 = 10kΩ.

0.85mA + (5V/5k

Ω) = 1.085mA

Using this example, an output voltage range of

±5V

with 0000h corresponding to a –5V output and

FFFFh corresponding to a 5V output can be

achieved. Similarly, using VREF = 2.5V, a ±2.5V

output voltage range can be achieved.

Figure 54. REF02 as a Power Supply to the

DAC8554

Figure 55. Bipolar Operation With the DAC8554

Submit Documentation Feedback

DAC8554IPW Datasheet(PDF) 24 Page - Texas Instruments

DAC8554IPW Datasheet(HTML) 24 Page - Texas Instruments

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 25 26 27 28 29 30 31 32 33 34

Datasheet Download

Link URL