Data Sheet

AD5735

Rev. B | Page 35 of 48

DAC Control Register

The DAC control register is used to configure each DAC channel. The DAC control register options are shown in Table 23 and Table 24.

Table 23. Programming the DAC Control Register

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

0

1

0

X1

X1

X1

X1

INT_ENABLE CLR_EN OUTEN

RSET

DC_DC

OVRNG R2

R1

R0

1

X = don’t care.

Table 24. DAC Control Register Bit Descriptions

Bit Name

Description

INT_ENABLE

Powers up the dc-to-dc converter, DAC, and internal amplifiers for the selected channel. This bit applies to individual

channels only; it does not enable the output. After setting this bit, it is recommended that a >200 µs delay be observed

before enabling the output to reduce the output enable glitch. See Figure 29 and Figure 46 for plots of this glitch.

CLR_EN

Per-channel clear enable bit. This bit specifies whether the selected channel is cleared when the CLEAR pin is activated.

0 = channel is not cleared when the part is cleared (default).

1 = channel is cleared when the part is cleared.

OUTEN

Enables or disables the selected output channel.

0 = channel disabled (default).

1 = channel enabled.

RSET

Selects the internal current sense resistor or an external current sense resistor for the selected DAC channel.

0 = external resistor selected (default).

1 = internal resistor selected.

DC_DC

Powers up or powers down the dc-to-dc converter on the selected channel. All dc-to-dc converters can be powered up

simultaneously using the DCDC_ALL bit in the main control register. To power down the dc-to-dc converter, the OUTEN

and INT_ENABLE bits must also be set to 0.

0 = dc-to-dc converter is powered down (default).

1 = dc-to-dc converter is powered up.

OVRNG

Enables 20% overrange on the voltage output channel only. No current output overrange is available.

0 = overrange disabled (default).

1 = overrange enabled.

R2, R1, R0

Selects the output range to be enabled.

R2

R1

R0

Output Range Selected

0

0

0

0 V to 5 V voltage range (default)

0

0

1

0 V to 10 V voltage range

0

1

0

±5 V voltage range

0

1

1

±10 V voltage range

1

0

0

4 mA to 20 mA current range

1

0

1

0 mA to 20 mA current range

1

1

0

0 mA to 24 mA current range