MCP3002-I/SN Microchip Technology, MCP3002-I/SN Datasheet - Page 19

• Manufacturer Part Number: MCP3002-I/SN
• Description: IC ADC 10BIT 2.7V 2CH SPI 8-SOIC
• Manufacturer: Microchip Technology

Specifications of MCP3002-I/SN

• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Number Of Bits: 10
• Sampling Rate (per Second): 200k
• Data Interface: Serial, SPI™
• Number Of Converters: 1
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Architecture: SAR
• Conversion Rate: 200 KSPs
• Input Type: Voltage
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

6.0
6.1
With most microcontroller SPI ports, it is required to send
groups of eight bits. It is also required that the
microcontroller SPI port be configured to clock out data
on the falling edge of clock and latch data in on the rising
edge. Depending on how communication routines are
used, it is very possible that the number of clocks
required for communication will not be a multiple of
eight. Therefore, it may be necessary for the MCU to
send more clocks than are actually required. This is
usually done by sending ‘leading zeros’ before the start
bit, which are ignored by the device. As an example,
Figure 6-1
be interfaced to a MCU with a hardware SPI port.
Figure 6-1
which requires that the SCLK from the MCU idles in the
‘low’ state, while
SPI Mode 1,1 where the clock idles in the ‘high’ state.
FIGURE 6-1:
low).
© 2008 Microchip Technology Inc.
X = Don’t Care Bits
MCU Received Data
MCU Transmitted Data
(Aligned with rising
(Aligned with falling
edge of clock)
edge of clock)
APPLICATIONS INFORMATION
Using the MCP3002 with
Microcontroller (MCU) SPI Ports
depicts the operation shown in SPI Mode 0,0,
and
SCLK
D
Figure 6-2
OUT
D
CS
IN
Figure 6-2
SPI Communication with the MCP3002 using 8-bit segments (Mode 0,0: SCLK idles
1
show how the MCP3002 can
X
Data stored into MCU receive register
X
shows the similar case of
2
after transmission of first 8 bits
X
Start
Bit
1
3
X
SGL/
DIFF
4
X
ODD/
SIGN
5
X
NULL
MS
BF
BIT
(Null)
6
0
B9
X
7
B9
B8
X
8
B8
X
B7
9
B7
Data stored into MCU receive register
X
B6
after transmission of second 8 bits
10
As shown in
A/D Converter contains one leading zero before the
start bit. Arranging the leading zero this way produces
the output 10 bits to fall in positions easily manipulated
by the MCU. When the first 8 bits are transmitted to the
device, the MSB data bit is clocked out of the A/D
Converter on the falling edge of clock number 6. After
the second eight clocks have been sent to the device,
the receive register will contain the lowest-order eight
bits of the conversion results. Easier manipulation of the
converted data can be obtained by using this method.
B6
Don’t Care
B5
X
11
B5
X
X
B4
12
B4
X
B3
13
B3
Figure
X
B2
14
B2
X
B1
15
B1
6-1, the first byte transmitted to the
X
B0
16
B0
Data is clocked out of
A/D Converter on falling edges
X
MCU latches data from A/D Converter
on rising edges of SCLK
MCP3002
DS21294D-page 19