MCP3901A0-I/SS Microchip Technology, MCP3901A0-I/SS Datasheet - Page 26

• Manufacturer Part Number: MCP3901A0-I/SS
• Description: IC AFE 24BIT 64KSPS 20-SSOP
• Manufacturer: Microchip Technology

Specifications of MCP3901A0-I/SS

• Number Of Bits: 24
• Number Of Channels: 2
• Power (watts): 10mW
• Voltage - Supply, Analog: 4.5 V ~ 5.5 V
• Voltage - Supply, Digital: 2.7 V ~ 5.5 V
• Package / Case: 20-SSOP
• Ic Function: Analog Front End Device IC
• Supply Voltage Range: 4.5V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SSOP
• No. Of Pins: 20
• Supply Voltage Max: 5.5V
• Output Voltage: 0.4 V
• Output Power: 14 mW
• Input Voltage: 4.5 V to 5.5 V, 2.7 V to 5.5 V
• Switching Frequency: 4 MHz
• Mounting Style: SMD/SMT
• Number Of Outputs: 2
• No. Of Channels: 2
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: MCP3901AO-I/SS; MCP3901AO-I/SS

MCP3901
5.3.2
For a specified voltage reference value of 2.4V, the
modulators specified differential input range is
±500 mV. The input range is proportional to V
scales according to the V
guaranteeing the stability of the modulator over
amplitude and frequency. Outside of this range, the
modulator is still functional, however its stability is no
longer guaranteed and therefore it is not recommended
to exceed this limit. The saturation point for the
modulator is V
ADC includes a gain of 3 by default (independent from
the PGA setting. See Section 5.6 “ADC OUTPUT
CODING”).
5.3.3
The
independent BOOST mode for each channel. If the
corresponding BOOST<1:0> bit is enabled, the power
consumption of the modulator is multiplied by 2 and its
bandwidth is increased to be able to sustain AMCLK
clock frequencies up to 8.192 MHz while keeping the
ADC accuracy. When disabled, the power consumption
is back to normal and the AMCLK clock frequencies
can only reach up to 5 MHz without affecting ADC
accuracy.
5.4
If the user wishes to use the modulator output of the
device the appropriate bits to enable the modulator
output must be set in the configuration register.
When MODOUT<1:0> is enabled, the modulator
output of the corresponding channel is present at the
corresponding MDAT output pin as soon as the
command is placed.
Since the sigma-delta modulators have a 5-level output
given by the state of 4 comparators with thermometer
coding, their outputs can be represented on 4 bits, each
bit giving the state of the corresponding comparator
(See
register and are updated at the DMCLK rate.
In order to output the comparators result on a separate
pin (MDAT0 and MDAT1), these comparator output bits
have been arranged to be serially output at the AMCLK
rate (See
This 1-bit serial bitstream is the same that would be
produced by a 1-bit DAC modulator with a sampling
frequency of AMCLK. The modulator can either be
considered like a 5 level-output at DMCLK rate or 1-bit
output at AMCLK rate. These two representations are
interchangeable. The MDAT outputs can therefore be
used in any application that requires 1-bit modulator
outputs. These applications will often integrate and
filter the 1-bit output with SINC or more complex
decimation filters computed by a MCU or a DSP.
DS22192B-page 26
Table
Delta-Sigma
Modulator Output Block
Figure
MODULATOR INPUT RANGE AND
SATURATION POINT
BOOST MODE
5-2). These bits are present on the MOD
REF
5-2).
/3 since the transfer function of the
modulators
REF
voltage. This range is
also
include
REF
and
an
TABLE 5-2:
FIGURE 5-2:
Function of the Modulator Output Code.
Since the reset and shutdown SPI commands are
asynchronous, the MDAT pins are resynchronized with
DMCLK after each time the part goes out of reset and
shutdown.
This means that the first output of MDAT after RESET
is always 0011 after the first DMCLK rising edge.
AMCLK
DMCLK
MDAT+2
MDAT+1
MDAT+0
MDAT-1
MDAT-2
Comp<3:0>
Code
1111
0111
0011
0001
0000
COMP
<3>
DELTA-SIGMA MODULATOR
CODING
Output Code
Modulator
MDAT Serial Outputs in
COMP
© 2009 Microchip Technology Inc.
<2>
+2
+1
-1
-2
0
COMP
<1>
MDAT Serial
COMP
<0>
Stream
1111
0111
0011
0001
0000