Datasheet

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POWER-DOWN MODE

DAC7554

SLAS399A – OCTOBER 2004 – REVISED NOVEMBER 2004

In power-down mode, the DAC outputs are programmed to one of three output impedances, 1 k Ω , 100 k Ω , or

floating.

Table 2. Power-Down Mode Control

EXTENDED CONTROL DATA BITS

FUNCTION

LD1 LD0 Sel1 Sel0 DB11 DB10 DB9 DB8 DB7 DB6-DB0

1 1 1 1 0 0 0 0 0 X PWD Hi-Z (selected channel = A)

1 1 1 1 0 0 0 0 1 X PWD 1 k Ω (selected channel = A)

1 1 1 1 0 0 0 1 0 X PWD 100 k Ω (selected channel = A)

1 1 1 1 0 0 0 1 1 X PWD Hi-Z (selected channel = A)

1 1 1 1 0 0 1 0 0 X PWD Hi-Z (selected channel = B)

1 1 1 1 0 0 1 0 1 X PWD 1 k Ω (selected channel = B)

1 1 1 1 0 0 1 1 0 X PWD 100 k Ω (selected channel = B)

1 1 1 1 0 0 1 1 1 X PWD Hi-Z (selected channel = B)

1 1 1 1 0 1 0 0 0 X PWD Hi-Z (selected channel = C)

1 1 1 1 0 1 0 0 1 X PWD 1 k Ω (selected channel = C)

1 1 1 1 0 1 0 1 0 X PWD 100 k Ω (selected channel = C)

1 1 1 1 0 1 0 1 1 X PWD Hi-Z (selected channel = C)

1 1 1 1 0 1 1 0 0 X PWD Hi-Z (selected channel = D)

1 1 1 1 0 1 1 0 1 X PWD 1 k Ω (selected channel = D)

1 1 1 1 0 1 1 1 0 X PWD 100 k Ω (selected channel = D)

1 1 1 1 0 1 1 1 1 X PWD Hi-Z (selected channel = D)

1 1 1 1 1 X X 0 0 X PWD Hi-Z (all channels)

1 1 1 1 1 X X 0 1 X PWD 1 k Ω (all channels)

1 1 1 1 1 X X 1 0 X PWD 100 k Ω (all channels)

1 1 1 1 1 X X 1 1 X PWD Hi-Z (all channels)

DB11 ALL CHANNELS FLAG

0 See DB7–DB10

1 DB10 and DB9 are Don't Care

DB10 DB9 Channel Select

0 0 Channel A

0 1 Channel B

1 0 Channel C

1 1 Channel D

DB8 DB7 Power-Down Mode

0 0 Power-down Hi-Z

0 1 Power-down 1 k Ω

1 0 Power-down 100 k Ω

1 1 Power-down Hi-Z