Delta-Sigma Modulator; Figure 2. Quad Group Routing Of Rc Filter Components - Cirrus Logic CDB5378 Manual

The CS3301A/02A amplifier outputs require a differential anti-alias RC filter, which is created by connect-
Ω
ing external 680 series resistors with 20 nF of high-linearity differential capacitance (2x 10 nF C0G) be-
tween each half of the rough and fine signals.
INR+
INF+
INF-
INR-
2.2.3

Delta-Sigma Modulator

The CS5373A ∆Σ modulator performs the A/D function for the differential analog signal from the
CS3301A/02A amplifier. The digital output from the modulator is an oversampled ∆Σ bit stream.
Analog Signals
INR, INF
VREF
Digital Signals
MDATA
MFLAG
MCLK
MSYNC
2.2.3.1 Rough-Fine Inputs - INR, INF
The modulator analog inputs are separated into rough and fine signals, each of which has a differential
anti-alias RC filter to limit the input signal bandwidth.
20

Figure 2. Quad Group Routing of RC Filter Components

Description
Modulator analog rough / fine inputs
Voltage reference analog inputs
Description
Modulator delta-sigma data output
Modulator over-range flag output
Clock input
Synchronization input
CDB5378
INR+
INF+
INF-
INR-
DS639DB4