MAX1228BEEP+ Maxim Integrated Products, MAX1228BEEP+ Datasheet - Page 13

• Manufacturer Part Number: MAX1228BEEP+
• Description: IC ADC 12BIT 300KSPS 20-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1228BEEP+

• Number Of Bits: 12
• Sampling Rate (per Second): 300k
• Data Interface: MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 727mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-QSOP
• Number Of Adc Inputs: 12
• Architecture: SAR
• Conversion Rate: 300 KSPs
• Resolution: 12 bit
• Interface Type: Serial
• Voltage Reference: Internal 4.096 V or External
• Supply Voltage (max): 5 V
• Mounting Style: SMD/SMT
• 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
Select scan mode 00 or 01 to return one result per sin-
gle-ended channel and one result per differential pair
within the requested range, plus one temperature result if
selected. Select scan mode 10 to scan a single input
channel numerous times, depending on NSCAN1 and
NSCAN0 in the averaging register (Table 6). Select scan
mode 11 to return only one result from a single channel.
Write a byte to the setup register to configure the clock,
reference, and power-down modes. Table 3 details the
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.
Unipolar/Bipolar Registers
Averaging Register
Setup Register
REF
REF
. The out-
/ 2. The
13