SLAS724A September 2008 – November 2014 PCM3070
PRODUCTION DATA.
To power up the device, a 3.3V system rail (1.9V to 3.6V) can be used. The IOVDD voltage can be in the range of 1.1V – 3.6V. Internal LDOs can generate the appropriate digital and analog core voltages when configured to do so. For maximum flexibility, the respective voltages can also be supplied externally, bypassing the built-in LDOs. To support high-output drive capabilities, the output stages of the output amplifiers can be driven from the analog core voltage or the 1.9…3.6V rail used for the LDO inputs (LDO_in).
The AVDD and LDOIN power inputs are used to power the analog circuits including analog to digital converters, digital to analog converters, programmable gain amplifiers, headphone amplifiers, etc. The analog blocks in PCM3070 have high power supply rejection ratio, however it is recommended that these supplies be powered by well regulated power supplies like low dropout regulators (LDO) for optimal performance. When these power terminals are driven from a common power source, the current drawn from the source will depend upon blocks enabled inside the device. However as an example when all the internal blocks powered are enabled the source should be able to deliver 150mA of current.
The DVDD powers the digital core of PCM3070, including the miniDSP, the audio serial interface, control interfaces (SPI or I2C), clock generation and PLL. The DVDD power can be driven by high efficiency switching regulators or low drop out regulators. When the miniDSP_A and miniDSP_D are enabled in programmable mode and operated at peak frequencies, the supply source should be able to able to deliver approx 100mA of current. When the PRB modes are used instead of programmable miniDSP mode, then the peak current load on DVDD supply source could be approximately 20 mA.
The IOVDD powers the digital input and digital output buffers of PCM3070. The current consumption of this power depends on configuration of digital terminals as inputs or outputs. When the digital terminals are configured as outputs, the current consumption would depend on switching frequency of the signal and the load on the output terminal, which depends on board design and input capacitance of other devices connected to the signal.
Refer to Figure 19 for recommendations on decoupling capacitors.
For more detailed information see the PCM3070 Application Reference Guide, SLAU332.