10 Power Control and Regulation
For greater power efficiency the CSR8640 BGA contains 2 switch-mode regulators:
■
1 generates a 1.80V supply rail with an output current of 185mA, see Section 10.1.
■
1 generates a 1.35V supply rail with an output current of 160mA, see Section 10.2.
■
Combining the 2 switch-mode regulators in parallel generates a single 1.80V supply rail with an output
current of 340mA, see Section 10.3.
CSR8640 BGA contains 4 LDO linear regulators:
■
3.30V bypass regulator, see Section 10.4.
■
0.80V to 1.25V VDD_DIG linear regulator, see Section 10.5.
■
1.35V VDD_AUX linear regulator, see Section 10.6.
■
1.35V VDD_ANA linear regulator, see Section 10.7.
The recommended configurations for power control and regulation on the CSR8640 BGA are:
■
3 switch-mode configurations:
■
A 1.80V and 1.35V dual-supply rail system using the 1.80V and 1.35V switch-mode regulators, see
Figure 10.1. This is the default power control and regulation configuration for the CSR8640 BGA.
■
A 1.80V single-supply rail system using the 1.80V switch-mode regulator.
■
A 1.80V parallel-supply rail system for higher currents using the 1.80V and 1.35V switch-mode
regulators with combined outputs, see Figure 10.2.
■
A linear configuration using an external 1.8V rail omitting all regulators
Table 10.1 shows settings for the recommended configurations for power control and regulation on the
CSR8640 BGA.
Supply
Configuration
Regulators
Supply Rail
Switch-mode
VDD_AUX
Linear
Regulator
VDD_ANA
Linear
Regulator
1.8V
1.35V
1.8V
1.35V
Dual-supply
ON
ON
OFF
OFF
Single-supply
ON
OFF
ON
ON
Parallel-
supply SMPS
ON
ON
ON
ON
Linear supply
OFF
OFF
ON
ON
External
Table 10.1: Recommended Configurations for Power Control and Regulation
For more information on CSR8640 BGA power supply configuration see the
Configuring the Power Supplies on
CSR8670
application note.
Advance Information
This material is subject to CSR's non-disclosure agreement
© Cambridge Silicon Radio Limited 2011
Page 60 of 110
CS-209182-DSP1
CSR8640 BGA
Data Sheet
