MAX11359AETL Maxim Integrated, MAX11359AETL Datasheet - Page 59

• Manufacturer Part Number: MAX11359AETL
• Description: Analog to Digital Converters - ADC
• Manufacturer: Maxim Integrated

Specifications of MAX11359AETL

• Number Of Channels: 10
• Architecture: Sigma-Delta
• Conversion Rate: 10 SPs to 512 SPs
• Resolution: 16 bit
• Input Type: Differential
• Interface Type: 4-Wire Serial, Microwire, QSPI, SPI
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Power Dissipation: 2051.3 mW
• Number Of Converters: 1
• Voltage Reference: 1.251 V 1.996 V, 2.422 V

AVDD and DVDD provide power to the MAX11359A. The
AV
ers up the digital section. The power supply for both AVDD
and DVDD ranges from +1.8V to +3.6V. Both AVDD and
DVDD must be greater than +1.8V for device operation.
AVDD and DVDD can connect to the same power supply.
Bypass AVDD to AGND with a 10µF electrolytic capacitor
in parallel with a 0.1µF ceramic capacitor, and bypass
DVDD to DGND with a 10µF electrolytic capacitor in paral-
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
Maxim Integrated
UPIOs, RTC, Voltage Monitors, and Temp Sensor
DD
V
1 LSB (Bipolar Mode) = ±2V
16-Bit Data-Acquisition System with ADC, DAC,
REF
1 LSB (Unipolar Mode) = V
DAC CONTENTS
powers up the analog section, while the DVDD pow-
= 1.25V
MSB
1111 1111 11
1000 0000 01
1000 0000 00
0111 1111 11
0000 0000 01
0000 0000 00
REF
equals the reference voltage at REF and
DAC A
LSB
MAX11359A
ADC Transfer Functions
+V
REF
REF
REF
ANALOG OUTPUT
+V
+V
+V
+V
(512/1024) = +V
/(Gain x 65,536)
REF
FBA
Power Supplies
/(Gain x 65,536)
REF
REF
REF
(1023/1024)
(513/1024)
(511/1024)
(1/1024)
0
10kΩ
10kΩ
OUTA
REF
/2
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
DAC CONTENTS
2
.
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
MAX11359A
⎡
⎢
⎣
⎛
⎜
⎝
DAC Unipolar Output
FB_
1024
DAC Bipolar Output
2
OUT_
N
-V
REF
ANALOG OUTPUT
⎞
⎟ −
⎠
R
V
+V
-V
2
REF
+V
-V
= R
(512/512) = -V
REF
REF
1
= 1.25V
REF
1
REF
⎤
⎥
⎦
R
+3.3V
-3.3V
2
(511/512)
(511/512)
0
(1/512)
(1/512)
V
REF
OUT
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