DAC8832 Datasheet, PDF (17/26 Pages) Texas Instruments – 16-Bit, Ultra-Low Power, Voltage-Output Digital-to-Analog Converter

www.ti.com
DAC8832
SBAS380A – FEBRUARY 2006 – REVISED APRIL 2006
APPLICATION INFORMATION
UNIPOLAR OUTPUT OPERATION
The DAC8832 is capable of driving unbuffered loads of 60kΩ. Unbuffered operation results in low supply current
(typically 5µA) and a low offset error. The DAC8832 can be configured to output both unipolar and bipolar
voltages. Figure 44 shows a typical unipolar output voltage circuit. The code table for this mode of operation is
shown in Table 1.
+5 V
+2.5 V
0.1 µF
+
0.1 µF
10 µF
LDAC
CS
SCLK
SDI
V_DD
V_REF−S V_REF−F
OPA277
OPA704
R_INV
R_FB
RFB
OPA727
+V
DAC
INV
V_OUT
−V
AGNDF
Input
Register
DAC Latch
AGNDS
DAC8832
DGND
V_O = 0 to +V_REF
Figure 44. Unipolar Output Mode
Table 1. Unipolar Code
DAC LATCH CONTENTS
MSB
LSB
ANALOG OUTPUT
1111 1111 1111 1111
1000 0000 0000 0000
0000 0000 0000 0001
0000 0000 0000 0000
V_REF × (65,535/65,536)
V_REF × (32,768/65,536) = 1/2 V_REF
V_REF × (1/65,536)
0V
Assuming a perfect reference, the worst-case output voltage may be calculated in the following equation:
Unipolar Mode Worst-Case Output:
V_{OUT_UNI}
+
D
2¹⁶
ǒ_{VREF ) VGE}Ǔ _{) VZSE ) INL}
Where:
V_{OUT_UNI} = Unipolar mode worst-case output
D = Code loaded to DAC
V_REF = Reference voltage applied to part
V_GE = Gain error in volts
V_ZSE = Zero scale error in volts
INL = Integral nonlinearity in volts
Submit Documentation Feedback
17