MAX1146 Datasheet, PDF (20/25 Pages) Maxim Integrated Products – Multichannel, True-Differential, Serial, 14-Bit ADCs

Multichannel, True-Differential,
Serial, 14-Bit ADCs
1...111
1...110
1...101
1...100
1 LSB =
V_REF
16384
VREF
1...111
1...110
1...101
1...100
0...001
0...000
0...111
1 LSB =
VREF
16384
VREF
0...011
0...010
0...001
0...000
0123
INPUT VOLTAGE (LSB)
Figure 14. Unipolar Transfer Function
16381 16383
edge and is clocked into the µP on SCLK’s rising edge.
The first 8-bit data stream contains the first 8-bits of
DOUT starting with the MSB. The second 8-bit data
stream contains the remaining 6 result bits.
QSPI Interface
Using the high-speed QSPI interface (Figure 17) with
CPOL = 0 and CPHA = 0, the MAX1146–MAX1149 sup-
port a maximum fSCLK of 2.1MHz. One 16-bit reading is
necessary to obtain the entire 14-bit result from the
ADC. DOUT data transitions on the serial clock’s falling
edge and is clocked into the µP on SCLK’s rising edge.
The first 14 bits are the data.
PIC16/PIC17 SSP Module Interface
The MAX1146–MAX1149 are compatible with a
PIC16/PIC17 microcontroller (µC), using the synchro-
nous serial-port (SSP) module. To establish SPI com-
0...011
0...010
0...001
0...000
0123
8191 8193
8192
INPUT VOLTAGE (LSB)
Figure 15. Bipolar Transfer Function
16381 16383
munication, connect the controller as shown in Figure
18 and configure the PIC16/PIC17 as system master.
Initialize the synchronous serial-port control register
(SSPCON) and synchronous serial-port status register
(SSPSTAT) to the bit patterns shown in Tables 8 and 9.
In SPI mode, the PIC16/PIC17 µCs allow 8 bits of data
to be synchronously transmitted and received simulta-
neously. Two consecutive 8-bit readings are necessary
to obtain the entire 14-bit result from the ADC. DOUT
data transitions on the serial clock’s falling edge and is
clocked into the µC on SCLK’s rising edge. The first 8-
bit data stream contains the first 8 data bits starting
with the MSB. The second data stream contains the
remaining bits, D5 through D0.
I/O
SCK
MISO
V_DD
SPI
SS
CS
SCLK
DOUT
MAX1146–
MAX1149
I/O
SK
SI
MICROWIRE
CS
SCLK
DOUT
MAX1146–
MAX1149
Figure 16a. SPI Connections
Figure 16b. MICROWIRE Connections
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