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CXD2073Q

Application Circuit for D/A Converter

DAVD

DAVS

: analog power supply 5V

: analog ground

AYO

VRF

IRF

ACO

VG

VB

0.1µ

0.1µ

3.3k

(R')

200

(R)

C OUT

Y OUT

200

(R)

0.1µ

2k

3k

0.1µ

10µ

6

8

7

9

12

4

10

11

• Method of selecting output resistance

The CXD2073Q has a built-in current output-type D/A converter. To obtain the output voltages, connect

resistors to AYO and ACO pins.

VFS = IFS

× R

Here, VFS is output full-scale voltage, IFS is output full-scale current, and R is the output resistance

connected to each IO.

In addition, connect a resistance of 16 times the output resistor to the reference current pin IRF. In the case

where the value comes to be impractical, use a value of resistance as close to the value calculated as

possible. At that time,

VFS = VRF

× 16 × R/R'.

R is the output resistance connected to each IO, R' is the resistance connected to IRF, and VRF is the VRF

pin voltage. Power consumption can be reduced by using higher resistance values, but then glitch energy

and data settling time increase contrastingly. Select optimum resistance values according to the system

applications.

In case of the circuit above, VFS = 2 [V]

× 16 × 0.2k/3.3k ≈ 1.93 [V], IFS = 1.93/0.2k ≈ 9.65 [mA].