Cirrus Logic CS485xx - Manual (Page 90)

Pin Description
CS485xx Hardware User’s Manual
DS734UM7 Copyright 2009 Cirrus Logic, Inc. 9-10
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.
Table 9-1. Core Supply Pins
LQFP-48
Pin #
Pin Name
Pin
Type
Pin Description
16 VDD1
Input
1.8V DSP Core supply.
This powers all internal logic and
the on-chip SRAMs and ROMs
28 VDD2
42 VDD3
Table 9-2. I/O Supply Pins
LQFP-48
Pin #
Pin Name
Pin
Type
Pin Description
12 VDDIO1
Input 3.3V I/O supply 24 VDDIO2
37 VDDIO3