MAX11359AETL+T Maxim Integrated Products, MAX11359AETL+T Datasheet - Page 59

• Manufacturer Part Number: MAX11359AETL+T
• Description: IC DAS SYSTEM 16BIT 40-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Data Acquisition System (DAS)r

Specifications of MAX11359AETL+T

• Resolution (bits): 16 b
• Sampling Rate (per Second): 477
• Data Interface: MICROWIRE™, QSPI™, Serial, SPI™
• Voltage Supply Source: Analog and Digital
• Voltage - Supply: 1.8 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 40-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AV
AV
ers up the digital section. The power supply for both AV
and DV
DV
AV
Bypass AV
in parallel with a 0.1µF ceramic capacitor, and bypass
DV
lel with a 0.1µF ceramic capacitor. For improved perfor-
mance, place the bypass capacitors as close to the device
as possible.
Figures 20 and 21 provide the ADC transfer functions
for unipolar and bipolar mode. The digital output code
format is binary for unipolar mode and two’s comple-
ment for bipolar mode. Calculate 1 LSB using the fol-
lowing equations:
where V
Gain equals the PGA gain.
Figure 23. DAC Unipolar Rail-to-Rail Output Circuit
Table 22. Unipolar Code
UPIOs, RTC, Voltage Monitors, and Temp Sensor
DD
DD
DD
DD
DD
V
REF
1 LSB (Bipolar Mode) = ±2V
16-Bit Data-Acquisition System with ADC, DAC,
1 LSB (Unipolar Mode) = V
DAC CONTENTS
powers up the analog section, while the DV
and DV
= 1.25V
and DV
to DGND with a 10µF electrolytic capacitor in paral-
must be greater than +1.8V for device operation.
MSB
1111 1111 11
1000 0000 01
1000 0000 00
0111 1111 11
0000 0000 01
0000 0000 00
DD
REF
DD
ranges from +1.8V to +3.6V. Both AV
equals the reference voltage at REF and
DD
DAC A
DD
to AGND with a 10µF electrolytic capacitor
LSB
MAX11359A
can connect to the same power supply.
provide power to the MAX11359A. The
______________________________________________________________________________________
ADC Transfer Functions
+V
REF
REF
REF
ANALOG OUTPUT
+V
+V
+V
+V
(512/1024) = +V
FBA
REF
/(Gain x 65,536)
REF
REF
Power Supplies
/(Gain x 65,536)
REF
(1023/1024)
(513/1024)
(511/1024)
(1/1024)
0
10kΩ
10kΩ
OUTA
DD
DD
REF
pow-
/2
and
DD
In unipolar mode, the output code ranges from 0 to
65,535 for inputs from zero to full-scale. In bipolar
mode, the output code ranges from -32,768 to +32,767
for inputs from negative full-scale to positive full-scale.
For a unipolar output, the output voltages and the refer-
ence have the same polarity. Figure 22 shows the
unipolar output circuit of the MAX11359A, which is also
the typical operating circuit for the DAC. Table 22 lists
some unipolar input codes and their corresponding
output voltages.
For larger output swing, see Figure 23. This circuit
shows the output amplifiers configured with a closed-
loop gain of +2V/V to provide 0 to 2.5V full-scale range
with the 1.25V reference.
The MAX11359A DAC output can be configured for
bipolar operation using the application circuit in
Figure 24:
where N is the decimal value of the DAC’s binary input
code.
Table 23 shows digital codes (offset binary) and corre-
sponding output voltages for Figure 24 assuming
R
Figure 24. DAC Bipolar Output Circuit
Table 23. Bipolar Code
1
= R
2
DAC CONTENTS
.
1111 1111 11
1000 0000 01
1000 0000 00
0111 1111 11
0000 0000 01
0000 0000 00
MSB
V
DAC_
REF
MAX11359A
V
OUT
LSB
R
=
1
V
REF
⎡
⎢
⎣
DAC Unipolar Output
⎛
⎜
⎝
FB_
DAC Bipolar Output
1024
OUT_
2
-V
N
REF
ANALOG OUTPUT
R
V
2
REF
+V
⎞
⎟ −
⎠
-V
= R
+V
-V
= 1.25V
(512/512) = -V
REF
REF
1
1
REF
REF
R
+3.3V
-3.3V
⎤
⎥
⎦
2
(511/512)
(511/512)
0
(1/512)
(1/512)
V
OUT
REF
59