Pin Description; Power And Ground; Power; Copyright 2009 Cirrus Logic - Cirrus Logic CS485 Series User Manual

9.2 Pin Description

9.2.1 Power and Ground

The following sections describe the CS485xx power and ground pins. Decoupling and conditioning of the
power supplies is also discussed. Following the recommendations for decoupling and power conditioning
will help to ensure reliable performance.

9.2.1.1 Power

The CS485xx Family of DSPs take two supply voltages — the core supply voltage (VDD) and the I/O supply
voltage (VDDIO). There is also a separate analog supply voltage required for the internal PLL (VDDA).
These pins are described in the following tables and descriptions.
The DSP Core supply voltage pins require a nominal 1.8V. The DSP I/O supply voltage pins require a
nominal 3.3V.
LQFP-48
Pin #
16
28
42
LQFP-48
Pin #
12
24
37
DS734UM7
Table 9-1. Core Supply Pins
Pin
Pin Name
Type
VDD1
VDD2 Input
VDD3
Table 9-2. I/O Supply Pins
Pin
Pin Name
Type
VDDIO1
VDDIO2 Input
VDDIO3
Copyright 2009 Cirrus Logic, Inc.
CS485xx Hardware User's Manual
Pin Description
1.8V DSP Core supply.
This powers all internal logic and
the on-chip SRAMs and ROMs
Pin Description
3.3V I/O supply
Pin Description
9-10