MAX1231EVKIT Maxim Integrated Products, MAX1231EVKIT Datasheet - Page 13

• Manufacturer Part Number: MAX1231EVKIT
• Description: EVAL KIT FOR MAX1231
• Manufacturer: Maxim Integrated Products

Specifications of MAX1231EVKIT

• Number Of Adc's: 1
• Number Of Bits: 12
• Sampling Rate (per Second): 300k
• Data Interface: Serial
• Inputs Per Adc: 16 Single Ended or 8 Differential
• Input Range: ±VREF/2
• Power (typ) @ Conditions: 1.86mW @ 300kSPS
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Utilized Ic / Part: MAX1231
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 2. Conversion Register
* See below for bit details.
CHSEL3
CHSEL2
CHSEL1
CHSEL0
SCAN1 SCAN0
SCAN1
SCAN0
CHSEL3
NAME
TEMP
BIT
—
0
0
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
7 (MSB) Set to 1 to select conversion register.
0 (LSB)
BIT
CHSEL2
0
1
0
1
6
5
4
3
2
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Scans channels 0 through N.
Scans channels N through the highest
numbered channel.
S cans channel N r ep eated l y. The aver ag i ng
r eg i ster sets the num b er of r esul ts.
No scan. Converts channel N once only.
Analog input channel select.
Analog input channel select.
Analog input channel select.
Analog input channel select.
Scan mode select.
Scan mode select.
Set to 1 to take a single temperature
measurement. The first conversion result
of a scan contains temperature information.
______________________________________________________________________________________
SELECTED BY BITS CHSEL3–CHSEL0)
CHSEL1
SCAN MODE (CHANNEL N IS
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
CHSEL0
FUNCTION
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Temp Sensor, Internal Reference
12-Bit 300ksps ADCs with FIFO,
CHANNEL (N)
SELECTED
AIN10
AIN11
AIN12
AIN13
AIN14
AIN15
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
AIN9
bits in the setup register. Bits 5 and 4 (CKSEL1 and
CKSEL0) control the clock mode, acquisition and sam-
pling, and the conversion start. Bits 3 and 2 (REFSEL1
and REFSEL0) control internal or external reference use.
Bits 1 and 0 (DIFFSEL1 and DIFFSEL0) address the
unipolar mode and bipolar mode registers and configure
the analog input channels for differential operation.
The final 2 bits (LSBs) of the setup register control the
unipolar/bipolar mode address registers. Set bits 1 and
0 (DIFFSEL1 and DIFFSEL0) to 10 to write to the unipo-
lar mode register. Set bits 1 and 0 to 11 to write to the
bipolar mode register. In both cases, the setup byte
must be followed immediately by 1 byte of data written
to the unipolar register or bipolar register. Hold CS low
and run 16 SCLK cycles before pulling CS high. If the
last 2 bits of the setup register are 00 or 01, neither the
unipolar mode register nor the bipolar mode register is
written. Any subsequent byte is recognized as a new
input data byte. See Tables 4 and 5 to program the
unipolar and bipolar mode registers.
If a channel is configured as both unipolar and bipolar,
the unipolar setting takes precedence. In unipolar
mode, AIN+ can exceed AIN- by up to V
put format in unipolar mode is binary. In bipolar mode,
either input can exceed the other by up to V
output format in bipolar mode is two's complement.
Write to the averaging register to configure the ADC to
average up to 32 samples for each requested result,
and to independently control the number of results
requested for single-channel scans.
Table 2 details the four scan modes available in the con-
version register. All four scan modes allow averaging as
long as the AVGON bit, bit 4 in the averaging register, is
set to 1. Select scan mode 10 to scan the same channel
multiple times. Clock mode 11 disables averaging.
Write to the reset register (as shown in Table 7) to clear
the FIFO or to reset all registers to their default states.
Set the RESET bit to 1 to reset the FIFO. Set the reset
bit to zero to return the MAX1227/MAX1229/MAX1231
to the default power-up state.
The MAX1227/MAX1229/MAX1231 power up with all
blocks in shutdown, including the reference. All registers
power up in state 00000000, except for the setup regis-
ter, which powers up in clock mode 10 (CKSEL1 = 1).
Power-Up Default State
Unipolar/Bipolar Registers
Averaging Register
Reset Register
REF
REF
. The out-
/2. The
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