Analog Audio Group Recommended Circuitry; Creating An Analog Ground; Figure 25: Creating An Analog Reference Voltage; Figure 26: Bias/Vana R - Wavecom CM52 Integrator's Manual

3.4

Analog Audio Group Recommended Circuitry

Creating an analog ground

3.4.1
An analog ground plane should be generated which connects to GND in one point so that high
frequency digital current is not floating through the analog ground. Connecting the analog ground
in only one point avoids ground currents from power supplies and other high current circuitry from
creating noise in the analog circuitry. This common point should be located where the analog
supply voltage (VANA) is generated (at filter (A), or regulator (B) depending on implementation).
The BIAS reference should be generated from the analog supply voltage (VANA) and be referenced
to the analog ground. This reference shall be used to bias all analog circuitry in the application.
The bias can be tapped directly from the resistor voltage divider, but the amplifier will make the
bias more stable and less susceptible to noise.
CM52 Integrators' Manual
WI_DEV_CM52_UGD_001-001
Page 44 of 53
A
5V
Figure 25: Creating an analog reference voltage (BIAS)
VANA
Figure 26: BIAS/VANA Reference
This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without prior written agreement.
Ce document est la propriété exclusive de WAVECOM. Il ne peut être communiqué ou divulgué à des tiers sans son autorisation préalable
B
12V
VANA
100k
0
-
+
100k
CM52 Integrators' Manual
VANA
Regulator
BIAS