DAC8718 Datasheet, PDF (37/60 Pages) Texas Instruments – Octal, 16-Bit, Low-Power, High-Voltage Output, Serial Input DIGITAL-TO-ANALOG CONVERTER

DAC8718
www.ti.com
SBAS467A – MAY 2009 – REVISED DECEMBER 2009
ANALOG OUTPUTS (V_OUT-0 to V_OUT-7, with reference to the ground of REF-x)
When the correction engine is off (SCE = '0'):
V_OUT = V_REF ´ Gain ´
INPUT_CODE
65536
- V_REF ´ (Gain - 1) ´
OFFSETDAC_CODE
65536
(1)
SPACE
When the correction engine is on (SCE = '1'):
V_OUT = V_REF ´ Gain ´
DAC_DATA_CODE
65536
- V_REF ´ (Gain - 1)
´
OFFSETDAC_CODE
65536
(2)
SPACE
Where:
DAC_DATA_CODE = ^{INPUT_CODE ´ (USER_GAIN + 215)} + USER_ZERO
2¹⁶
Gain = the DAC gain defined by the GAIN bit in the Configuration Register.
INPUT_CODE = data written into the Input Data Register (SCE = '1') or the DAC Data Register (SCE = '0').
OFFSETDAC_CODE = the data written into the Offset DAC Register.
USER_GAIN = the code of the Gain Register.
USER_ZERO = the code of the Zero Register.
For single-supply operation, the OFFSET-A pin must be connected to the AGND-A pin and the OFFSET-B pin
must be connected to the AGND-B pin through low-impedance connections (see the Layout section for details).
Offset DAC-A and Offset DAC-B are in a power-down state.
For dual-supply operation, the OFFSET-A and OFFSET-B default codes for a gain of 6 are 39322 with a ±10
LSB variation, depending on the linearity of the Offset DACs. The default code for a gain of 4 is 43691 with a ±10
LSB variation. The default codes of OFFSET-A and OFFSET-B are independently factory trimmed for both gains
of 6 and 4.
The power-on default value of the Gain Register is 32768, and the default value of the Zero Register is '0'. The
DAC input registers are set to a default value of 0000h.
Note that the maximum output voltage must not be greater than (AV_DD – 0.5V) and the minimum output voltage
must not be less than (AV_SS + 0.5V); otherwise, the output may be saturated.
Copyright © 2009, Texas Instruments Incorporated
Product Folder Link(s): DAC8718
Submit Documentation Feedback
37