ADAU1701 Datasheet, PDF (16/43 Pages) Analog Devices – SigmaDSP 28/56-Bit Audio Processor with 2ADC/4DAC

ADAU1701
10 uF
100 nF
3.3V
1 kΩ
ADAU1701
DVDD VDRIVE
Figure 18. Voltage Regulator Design
Two specifications need to be taken into consideration when
choosing a regulator transistor. First, the transistor’s current
Preliminary Technical Data
amplification factor (hFE or beta) should be at least 100. Second,
the transistor’s collector needs to be able to dissipate the heat
generated when regulating from 3.3 V to 1.8 V. The maximum
digital current draw of the ADAU1701 is 60 mA. The equation
to determine the transistor’s minimum power dissipation specs
is as follows:
(3.3 V – 1.8 V) × 60 mA = 90 mW
There are many transistors with these specifications available in
small packages (i.e. SOT-23 or SOT-223), such as the 2N3906 or
FZT953.
Rev. PrF | Page 16 of 43