DAC8811 Datasheet, PDF (11/15 Pages) Texas Instruments – 16-Bit, Serial Input Multiplying Digital-to-Analog Converter

DAC8811
www.ti.com
SLAS411A – NOVEMBER 2004 – REVISED DECEMBER 2004
The value of R3 in the previous equation can be reduced to increase the output current drive of U3. U3 can drive
±20 mA in both directions with voltage compliance limited up to 15 V by the U3 voltage supply. Elimination of the
circuit compensation capacitor C1 in the circuit is not suggested as a result of the change in the output
impedance Z_O, according to Equation 4:
R1ȀR3(R1)R2)
Z_O + _{R1(R2Ȁ)R3Ȁ) * R1Ȁ(R2)R3)}
(4)
As shown in Equation 4, with matched resistors, Z_O is infinite and the circuit is optimum for use as a current
source. However, if unmatched resistors are used, Z_O is positive or negative with negative output impedance
being a potential cause of oscillation. Therefore, by incorporating C1 into the circuit, possible oscillation problems
are eliminated. The value of C1 can be determined for critical applications; for most applications, however, a
value of several pF is suggested.
R24
15 kW
C1 10 pF
V_REF
V_DD
V_DD R_FB
V_REF
U1
DAC8811
GND
U2
OPA277
I_OUT
−
+
R14
150 kW
U2
OPA277
−
+
R2
15 kW
R34
50 kW
V_OUT
R3
50 W
R1
150 kW
I_L
LOAD
Figure 23. Programmable Bidirectional Current Source Circuit
Cross-Reference
The DAC8811 has an industry-standard pinout. Table 4 provides the cross-reference information.
PRODUCT
DAC8811ICDGK
DAC8811IBDGK
DAC8811ICDRB
DAC8811IBDRD
N/A
INL (LSB)
±1
±2
±1
±2
±2
DNL (LSB)
±1
±1
±1
±1
±1
Table 4. Cross-Reference
SPECIFIED
TEMPERATURE
RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PACKAGE
DESCRIPTION
8-Lead MicroSOIC
8-Lead MicroSOIC
8-Lead Small Outline
8-Lead Small Outline
8-Lead SOIC
PACKAGE
OPTION
MSOP-8
MSOP-8
SON-8
SON-8
SOIC-8
CROSS-
REFERENCE PART
N/A
AD5543BRM
N/A
N/A
AD5543BR
11