MCP3421 Microchip Technology, MCP3421 Datasheet - Page 11

• Manufacturer Part Number: MCP3421
• Description: 18-Bit Analog-to-Digital Converter with I2C Interface and On-Board Reference
• Manufacturer: Microchip Technology

5.2
The MCP3421 has an 8-bit wide configuration register
to select for: PGA gain, conversion rate, and conver-
sion mode. This register allows the user to change the
operating condition of the device and check the status
of the device operation. The user can rewrite the
configuration byte any time during the device
operation.
register bits.
REGISTER 5-1:
© 2006 Microchip Technology Inc.
bit 7
* Default Configuration after Power-On Reset
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6-5
bit 4
bit 3-2
bit 1-0
R/W-1
RDY
1 *
Configuration Register
Register 5-1
RDY: Ready Bit
This bit is the data ready flag. In read mode, this bit indicates if the output register has been updated
with a new conversion. In One-Shot Conversion mode, writing this bit to “1” initiates a new conversion.
Reading RDY bit with the read command:
1 = Output register has not been updated.
0 = Output register has been updated with the latest conversion data.
Writing RDY bit with the write command:
Continuous Conversion mode: No effect
One-Shot Conversion mode:
1 = Initiate a new conversion.
0 = No effect.
C1-C0: Channel Selection Bits
These are the Channel Selection bits, but not used in the MCP3421 device.
O/C: Conversion Mode Bit
1 = Continuous Conversion Mode. Once this bit is selected, the device performs data conversions
0 = One-Shot Conversion Mode. The device performs a single conversion and enters a low power
S1-S0: Sample Rate Selection Bit
00 =
01 =
10 =
11 =
G1-G0: PGA Gain Selector Bits
00 =
01 =
10 =
11 =
R/W-0
continuously.
standby mode until it receives another write/read command.
C1
0 *
CONFIGURATION REGISTER
240 SPS (12 bits),
60 SPS (14 bits),
15 SPS (16 bits),
3.75 SPS (18 bits)
1 V/V,
2 V/V,
4 V/V,
8 V/V
shows the configuration
W = Writable bit
‘1’ = Bit is set
R/W-0
C0
0 *
R/W-1
O/C
1 *
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R/W-0
S1
0 *
R/W-0
S0
0 *
x = Bit is unknown
R/W-0
MCP3421
G1
0 *
DS22003B-page 11
R/W-0
G0
0 *
bit 0