Analog Devices ADuCM356 User Manual

Reference Manual ADuCM356
USE CASE CONFIGURATIONS
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The ADuCM356 is primarily designed for controlling and measuring
electrochemical sensors. This section gives suggested setup details
for the main use cases of the ADuCM356 with an electrochemical
sensor.
HIBERNATE MODE WHILE MAINTAINING A DC
BIAS TO THE SENSOR
In this mode, the digital die and analog die are in hibernate mode.
Digital Die
On the digital die, the low-power LDO regulator and low power, 32
kHz oscillator are active. This LDO regulator and oscillator support
retention of the SRAM contents and maintains the configuration of
the digital input/output pins while minimizing current consumption.
Analog Die
On the analog die, the low-power LDO regulator and low-power,
32 kHz oscillator are active. The low-power reference, low-power
DAC, low-power potentiostat amplifier, and low-power TIAs are
also active to maintain a DC bias voltage to an external sensor.
The switches connecting the low-power amplifiers to the external
sensor are also unaffected when entering or exiting this mode. For
code examples on how to enter and exit hibernate mode, see the
Hibernate Mode, Mode 2 section.
To maintain a bias voltage to an electrochemical sensor, the
recommended analog die configuration setting for the low-power
potentiostat amplifier and low-power TIA is LPTIASWx = 0x302C.
Figure 38 shows how the switches are configured in the low-power
potentiostat amplifier with this value.
Minimize leakage in the unused switches in the switch matrix by
tying an unused pin to the internal 1.8 V digital LDO regulator rail.
Tying the unused pin also ties the excitation amplifier P, N, and D
nodes to a fixed level. See the PL, PL2, NL2, and NL switches in
Figure 37 to understand which signal paths must be tied to 1.8 V to
minimize leakage current effects. To close these switches, use the
following code:
SWCON &= 0xEFFFF; // Clear SWCON[16] to
allow access to NSWFULLCON/PSWFULLCON
NSWFULLCON |= 0xC00; // Close NL2 and NL
switches
PSWFULLCON |= 0x6000; // Close PL2 and PL
switches
SWCON |= 0x10000; // Set SWCON[16] to up►
date switches

Analog Devices ADuCM356 Specifications

General

Brand	Analog Devices
Model	ADuCM356
Category	Microcontrollers
Language	English