DAC7750IPWPR.B datasheet(20/56 Pages) TI2

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8.3 Feature Description

8.3.1 DAC Architecture

The resistor-string section is simply a string of resistors, each with the same value, from REFIN to GND, as

Figure 8-1 shows. This type of architecture makes sure the DAC is monotonic. The 16-bit (DAC8750) or 12-bit

(DAC7750) binary digital code loaded to the DAC register determines at which node on the string the voltage

is tapped off before it is fed into the voltage-to-current conversion stage. The current-output stage converts the

voltage output from the string to current. When the output is disabled, it is in a high-impedance (Hi-Z) state. After

power-on, the output is disabled.

To Current Output

Figure 8-1. DAC Structure: Resistor String

8.3.2 Current Output Stage

The current output stage consists of a preconditioner and a current source, as shown in Figure 8-2. This stage

provides a current output according to the DAC code. The output range can be programmed as 0 mA to 20 mA,

0 mA to 24 mA, or 4 mA to 20 mA. Use an external transistor to reduce the power dissipation of the device. The

maximum compliance voltage on IOUT equals (AVDD – 2 V). In single power-supply mode, the maximum AVDD

is 36 V, and the maximum compliance voltage is 34 V. After power on, the IOUT pin is in a Hi-Z state.

12-/16-BitBa_

DACBa_

RSET

IOUT

BOOST

AVDD

R3-SENSE

Figure 8-2. Current Output

DAC7750, DAC8750

SBAS538D – DECEMBER 2013 – REVISED DECEMBER 2021

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DAC7750IPWPR.B 数据表(PDF) 20 Page - Texas Instruments