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APPLICATION INFORMATION

BASIC CONNNECTIONS

4

5

1

2

3

6

8

7

10

9

DAC5574

GND

A1

A0

SDA

SCL

SDA

SCL

1 k

Ω to 10 kΩ (typical)

Microcontroller or

Microprocessor With

USING GPIO PORTS FOR I

DAC5574

SLAS407 – DECEMBER 2003

The following sections give example circuits and tips for using the DAC5574 in various applications. For more

information, contact your local TI representative, or visit the Texas Instruments website at http://www.ti.com.

For many applications, connecting the DAC5574 is extremely simple. A basic connection diagram for the

DAC5574 is shown in Figure 38. The 0.1 µF bypass capacitors help provide the momentary bursts of extra

current needed from the supplies.

Figure 38. Typical DAC5574 Connections

The DAC5574 interfaces directly to standard mode, fast mode and high-speed mode I

microcontroller's I

DAC5574. The DAC5574 does not perform clock-stretching (i.e., it never pulls the clock line low), so it is not

necessary to provide for this unless other devices are on the same I

Pullup resistors are necessary on both the SDA and SCL lines because I

of the these resistors depend on the bus operating speed and capacitance on the bus lines. Higher-value

resistors consume less power, but increase the transition times on the bus, limiting the bus speed. Lower-value

resistors allow higher speed at the expense of higher power consumption. Long bus lines have higher

capacitance and require smaller pullup resistors to compensate. If the pullup resistors are too small the bus

drivers may not be able to pull the bus line low.

Most microcontrollers have programmable input/output pins that can be set in software to act as inputs or

outputs. If an I

protocol simulated, or bit-banged, in software. An example of this for a single DAC5574 is shown in Figure 39.

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