MCP3301T MICROCHIP [Microchip Technology], MCP3301T Datasheet - Page 23

• Manufacturer Part Number: MCP3301T
• Description: 13-Bit Differential Input, Low Power A/D Converter with SPI Serial Interface
• Manufacturer: MICROCHIP [Microchip Technology]

6.2
Communication with the device is completed using a
standard SPI compatible serial interface. Initiating com-
munication with the MCP3301 begins with the CS
going low. If the device was powered up with the CS pin
low, it must be brought high and back low to initiate
communication. The device will begin to sample the
analog input on the first rising edge of CLK after CS
goes low. The sample period will end in the falling edge
of the second clock, at which time the device will output
a low null bit. The next 13 clocks will output the result
of the conversion with the sign bit first, followed by the
FIGURE 6-2:
FIGURE 6-3:
 2011 Microchip Technology Inc.
CLK
D
CS
D
OUT
CS
CLK
OUT
t ACQ
Communicating with the MCP3301
* After completing the data transfer, if further clocks are applied with CS low, the ADC will output LSB first data,
followed by zeros indefinitely. See
** t
high impedance node, leaving the CLK running to clock out the LSB-first data or zeros.
HI-Z
HI-Z
DATA
* After completing the data transfer, if further clocks are applied with CS low, the ADC will output zeros indefi-
nitely.
** t
high impedance node, leaving the CLK running to clock out the LSB-first data or zeros.
DATA
t ACQ
t SUCS
: during this time, the bias current and the comparator power down and the reference input becomes a
t SUCS
NULL
BIT
: during this time, the bias current and the comparator power down and the reference input becomes a
Communication with MCP3301 (MSB first Format).
Communication with MCP3301 (LSB first Format).
NULL
SB
BIT
B11 B10
SB
B11 B10 B9
B9
B8
t CONV
B7
Figure 6-2
B6
B8
B5
t SAMPLE
B7
t CONV
B4
below.
B6
B3
B2
B5
B1
t SAMPLE
B4
12 remaining data bits, as shown in
always output from the device on the falling edge of the
clock. If all 13 data bits have been transmitted and the
device continues to receive clocks while the CS is held
low, the device will output the conversion result LSB
first, as shown in
provided to the device while CS is still low (after the
LSB first data has been transmitted), the device will
clock out zeros indefinitely.
B0
B3
B1
B2
B2
B3
B1 B0
t CSH
B4
B5
*
t DATA **
t DATA **
Power Down
B6
Figure
Power
Down
HI-Z
B7
B8
6-3. If more clocks are
MCP3301
B9 B10
NULL
BIT
SB B11 B10 B9
Figure
B11
DS21700D-page 23
t CSH
SB
*
6-2. Data is
HI-Z