DAC8562

REV. A

–6–

As with any analog system, it is recommended that the

DAC8562 power supply be bypassed on the same PC card that

contains the chip. Figure 10 shows the power supply rejection

versus frequency performance. This should be taken into ac-

count when using higher frequency switched-mode power sup-

plies with ripple frequencies of 100 kHz and higher.

One advantage of the rail-to-rail output amplifier used in the

DAC8562 is the wide range of usable supply voltage. The part is

fully specified and tested over temperature for operation from

+4.75 V to +5.25 V. If reduced linearity and source current ca-

pability near full scale can be tolerated, operation of the

DAC8562 is possible down to +4.3 volts. The minimum operat-

ing supply voltage versus load current plot, in Figure 11, pro-

TIMING AND CONTROL

The DAC8562 has a 12-bit DAC register that simplifies inter-

face to a 12-bit (or wider) data bus. The latch is controlled by

the Chip Enable (CE) input. If the application does not involve

a data bus, wiring CE low allows direct operation of the DAC.

The data latch is level triggered and acquires data from the data

bus during the time period when CE is low. When CE goes

high, the data is latched into the register and held until CE re-

turns low. The minimum time required for the data to be

present on the bus before CE returns high is called the data

the amount of time that the data has to remain on the bus after

CE

goes high. The high speed timing offered by the DAC8562

provides for direct interface with no wait states in all but the

fastest microprocessors.

Typical Performance Characteristics

5

2

0

10

100

100k

10k

1k

1

3

4

LOAD RESISTANCE –

Ω

RL TIED TO AGND

D = FFFH

DATA = FFFH

DATA = 000H

Figure 5. Output Swing vs. Load

TIME = 1ms/DIV

10

90

100

0%

50mV

1ms

NBW = 630kHz

Figure 8. Broadband Noise

1

10

1000

100

100

1

0.01

0.1

10

OUTPUT SINK CURRENT – µA

DATA = 000H

Figure 6. Pull-Down Voltage vs.

Output Sink Current Capability

5

0

5

1

0

3

2

4

3

24

1

LOGIC VOLTAGE VALUE – Volts

Figure 9. Supply Current vs. Logic

Input Voltage

80

–100

–60

–80

1

–20

–40

0

20

40

60

3

2

OUTPUT VOLTAGE – Volts

NEG

CURRENT

LIMIT

DATA = 800H

100

0

10

100

100k

10k

1k

60

80

20

40

FREQUENCY – Hz

DATA = FFFH

Figure 10. Power Supply Rejection

vs. Frequency