DAC8803 Datasheet, PDF (27/30 Pages) Texas Instruments – Quad, Current Output, Serial Input 14-Bit Multiplying Digital-to-Analog Converter

DAC8803
www.ti.com
SBAS340A – JANUARY 2005 – REVISED APRIL 2005
APPLICATION INFORMATION
The DAC8803, a 2-quadrant multiplying DAC, can be used to generate a unipolar output. The polarity of the
full-scale output I_OUT is the inverse of the input reference voltage at V_REF.
Some applications require full 4-quadrant multiplying capabilities or bipolar output swing. An additional external
op amp A2 is added as a summing amp. In this circuit the first and second amps (A1 and A2) provide a gain of
2X that widens the output span to 20 V. A 4-quadrant multiplying circuit is implemented by using a 10-V offset of
the reference voltage to bias A2. According to the following circuit transfer equation ( Equation 2), input data (D)
from code 0 to full scale produces output voltages of V_OUT = -10 V to V_OUT = 10 V.
V_OUT + (Dń32, 768 * 1) V_REF
(2)
10 V
V_REF
10 kW
5 kW
10 kW
A2
V_OUT
−10 V < V_OUT< +10 V
V_DD V_REFX V_FBX
One Channel
DAC8803
I_OUTX
A1
V_SS A_GNDFA _AGNDX
Digital interface connections omitted for clarity.
Figure 59. Four-Quadrant Multiplying Application Circuit
Cross-Reference
The DAC8803 has an industry-standard pinout. Table 4 provides the cross-reference information.
PRODUCT
DAC8803IDB
INL (LSB)
±1
DNL (LSB)
±1
Table 4. Cross-Reference
SPECIFIED
TEMPERATURE
RANGE
-40°C to +85°C
PACKAGE
DESCRIPTION
28-Lead MicroSOIC
PACKAGE
OPTION
SSOP-28
CROSS-
REFERENCE PART
AD5554BRS
27