Datasheet

MCP3204/3208
DS21298E-page 20 © 2008 Microchip Technology Inc.
FIGURE 5-1: Communication with the MCP3204 or MCP3208.
FIGURE 5-2: Communication with MCP3204 or MCP3208 in LSB First Format.
CS
CLK
D
IN
D
OUT
D1D2 D0
HI-Z
Don’t Care
Null
Bit
B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0*
HI-Z
t
SAMPLE
t
CONV
SGL/
DIFF
Start
t
CYC
t
CSH
t
CYC
D2
SGL/
DIFF
Start
* After completing the data transfer, if further clocks are applied with CS low, the A/D converter will output LSB
first data, followed by zeros indefinitely (see Figure 5-2 below).
** t
DATA
: during this time, the bias current and the comparator power down while the reference input becomes
a high impedance node, leaving the CLK running to clock out the LSB-first data or zeros.
t
DATA
**
t
SUCS
Null
Bit
B11
B10
B9
B8 B7 B6 B5 B4 B3 B2 B1 B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10B11
CS
CLK
D
OUT
HI-Z
HI-Z
(MSB)
t
CONV
t
DATA
**
Power Down
t
SAMPLE
Start
SGL/
DIFF
D
IN
t
CYC
t
CSH
D0D1D2
* After completing the data transfer, if further clocks are applied with CS low, the A/D converter will output zeros
indefinitely.
** t
DATA
: During this time, the bias circuit and the comparator power down while the reference input becomes a
high impedance node, leaving the CLK running to clock out LSB first data or zeroes.
t
SUCS
Don’t Care
*