ADAS1000-4BSTZ datasheet(48/80 Pages) AD

48 / 80 page

ADAS1000-3/ADAS1000-4

Data Sheet

Common Mode

The ADAS1000-3/ADAS1000-4 have a dedicated CM_OUT

pin serving as an output and a CM_IN pin as an input. In

gang mode, the master device determines the common-mode

voltage based on the selected input electrodes. This common-

mode signal (on CM_OUT) can then be used by subsequent

slave devices (applied to CM_IN) as the common-mode

reference. All electrodes within the slave device are then

measured with respect to the CM_IN signal from the master

device. See the CMREFCTL register in Table 32 for more

details on the control via the serial interface. Figure 74 shows

the connections between a master and slave device using

multiple devices.

Right Leg Drive

The right leg drive comes from the master device. If the

internal RLD resistors of the slave device are to contribute

to the RLD loop, tie the RLD_SJ pins of master and slave

together.

Sequencing Devices into Gang Mode

When entering gang mode with multiple devices, both

devices can be configured for operation, but the conver-

sion enable bit (ECGCTL register, Bit 2, Table 28) of the

master device should be set after the conversion enable bit

of the slave device. When the master device conversion

signal is set, the master device generates one edge on its

SYNC_GANG pin. This applies to any slave SYNC_GANG

inputs, allowing the devices to synchronize ADC conversions.

Rev. B | Page 48 of 80

ADAS1000-4BSTZ 数据表(PDF) 48 Page - Analog Devices