MAX1243BCSA Maxim Integrated Products, MAX1243BCSA Datasheet - Page 33

• Manufacturer Part Number: MAX1243BCSA
• Description: ADC (A/D Converters) Integrated Circuits (ICs)
• Manufacturer: Maxim Integrated Products

Specifications of MAX1243BCSA

• Number Of Adc Inputs: 1
• Architecture: SAR
• Conversion Rate: 73 KSPs
• Resolution: 10 bit
• Input Type: Voltage
• Interface Type: 3-Wire (SPI, QSPI, Microwire)
• Voltage Reference: External
• Supply Voltage (max): 5.25 V
• Supply Voltage (min): 2.7 V
• Maximum Power Dissipation: 471 mW
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Package / Case: SO-8
• Minimum Operating Temperature: 0 C
• Lead Free Status / Rohs Status: No

and forces them to a high-impedance state. DAC out-
puts 0 and 1 remain in their previous state.
Figures 6–9 illustrate the conversion timing for the
MAX1221/MAX1223/MAX1343. All 12-bit conversion
results are output in 2-byte format, MSB first, with four
leading zeros. Data appears on DOUT on the falling
edges of SCLK. Data is binary for unipolar mode and
two’s complement for bipolar mode and temperature
results. See Figures 3, 4, and 5 for input/output and
temperature-transfer functions.
Figure 3 shows the unipolar transfer function for single-
ended or differential inputs. Figure 4 shows the bipolar
transfer function for differential inputs. Code transitions
occur halfway between successive-integer LSB values.
Output coding is binary, with 1 LSB = V
unipolar and bipolar operation, and 1 LSB = +0.125°C
for temperature measurements. Bipolar true-differential
results and temperature-sensor results are available in
two’s complement format, while all others are in binary.
See Tables 6, 7, and 8 for details on which setting
(unipolar or bipolar) takes precedence.
In unipolar mode, AIN+ can exceed AIN- by up to
V
other by up to V
If the first byte of an entry in the FIFO is partially read
(CS is pulled high after fewer than eight SCLK cycles),
the remaining bits are lost for that byte. The next byte of
data that is read out contains the next 8 bits. If the first
byte of an entry in the FIFO is read out fully, but the
Figure 3. Unipolar Transfer Function—Full Scale (FS) = V
REF1
. In bipolar mode, either input can exceed the
111....111
111....110
111....101
000....011
000....010
000....001
000....000
12-Bit, Multichannel ADCs/DACs with FIFO,
Partial Reads and Partial Writes
REF1
0
______________________________________________________________________________________
FS = V
1 LSB = V
1
2
/ 2.
REF
3
REF
Temperature Sensing, and GPIO Ports
ADC Transfer Functions
INPUT VOLTAGE (LSB)
/ 4096
FULL-SCALE
TRANSITION
Output-Data Format
FS - 3/2 LSB
REF1
FS
/ 4096 for
REF
second byte is read out partially, the rest of that byte is
lost. The remaining data in the FIFO is unaffected and
can be read out normally after taking CS low again, as
long as the 4 leading bits (normally zeros) are ignored.
If CS is pulled low before EOC goes low, a conversion
may not be completed and the FIFO data may not be
correct. Incorrect writes (pulling CS high before com-
pleting eight SCLK cycles) are ignored and the register
remains unchanged.
Figure 4. Bipolar Transfer Function—Full Scale ( ± FS) = ± V REF / 2
Figure 5. Temperature Transfer Function
011....111
011....110
000....010
000....001
000....000
111....111
111....110
111....101
100....001
100....000
011....111
011....110
011....101
000....001
000....000
111....111
100....011
100....010
100....001
100....000
OUTPUT CODE
-256
-FS
FS = V
ZS = COM
-FS = -V
1 LSB = V
REF
REF
V
REF
/ 2 + V
REF
INPUT VOLTAGE (LSB)
/ 2
/ 4096
TEMPERATURE (°C)
COM
-1
(COM)
0
0
V
REF
+1
= V
REF+
V
REF
- V
+FS - 1 LSB
REF-
+255.5
V
V
REF
REF
(COM)
33