MAX5580AETP-T Maxim Integrated, MAX5580AETP-T Datasheet - Page 31

• Manufacturer Part Number: MAX5580AETP-T
• Description: Digital to Analog Converters - DAC
• Manufacturer: Maxim Integrated

Specifications of MAX5580AETP-T

• Number Of Converters: 4
• Resolution: 12 bit
• Interface Type: QSPI, SPI, Serial (3-Wire, Microwire)
• Supply Voltage - Max: 5.25 V
• Supply Voltage - Min: 2.7 V

Figure 7 shows the unity-gain MAX5580 in a unipolar
output configuration. Table 23 lists the unipolar out-
put codes.
The MAX5580 outputs can be configured for bipolar
operation, as shown in Figure 8. The output voltage is
given by the following equation:
where CODE represents the numeric value of the
DAC’s binary input code (0 to 4095 decimal). Table 24
shows digital codes and the corresponding output volt-
age for the circuit in Figure 8.
The MAX5581/MAX5583/MAX5585 have force-sense
outputs, which provide a direct connection to the invert-
ing terminal of the output op amp, yielding the most
flexibility. The force-sense output has the advantage
that specific gains can be set externally for a given
application. The gain error for the MAX5581/MAX5583/
MAX5585 is specified in a unity-gain configuration (op-
amp output and inverting terminals connected), and
additional gain error results from external resistor
tolerances. The force-sense DACs allow many useful
circuits to be created with only a few simple external
components.
An example of a custom, fixed gain using the
MAX5581’s force-sense output is shown in Figure 9. In
this example, the external reference is set to 1.25V, and
the gain is set to +1.1V/V with external discrete resis-
tors to provide an approximate 0 to 1.375V DAC output
voltage range.
where CODE represents the numeric value of the
DAC’s binary input code (0 to 4095 decimal).
In this example, R2 = 12kΩ and R1 = 10kΩ to set the
gain = 1.1V/V:
V
OUT
V
= [(0.5 x V
OUT
V
OUT_
= [(0.5 x 1.25V x CODE) / 4096] x 2.2
Applications Information
= V
REF_
______________________________________________________________________________________
REF
x CODE) / 4096] x [1 + (R2 / R1)]
Configurable Output Gain
x (CODE - 2048) / 2048
12-/10-/8-Bit, Voltage-Output DACs
Unipolar Output
Bipolar Output
Buffered, Fast-Settling, Quad,
Figure 8. Bipolar Output Circuit
Figure 9. Configurable Output Gain
Table 24. Bipolar Code Table (Gain = +1)
MSB
1111
1000
1000
0111
0000
0000
MAX6126
MAX6126
DAC CONTENTS
1111
0000
0000
1111
0000
0000
REF
REF
MAX5580
MAX5582
MAX5584
DAC_
0000
1111
0001
1111
0001
0000
LSB
MAX5581
DAC_
-V
REF
+V
ANALOG OUTPUT
-V
10kΩ
+V
-V
(2048 / 2048) = -V
REF
REF
REF
REF
(2047 / 2048)
(2047 / 2048)
(1 / 2048)
(1 / 2048)
0
10kΩ
OUT_
FB_
V+
V-
R2 = 12kΩ
0.1%
25ppm
R1 = 10kΩ
0.1%
25ppm
REF
V
OUT_
31