DATA SHEET
MAS 35x9F
2.6.3. Power Supply Configurations
If DC/DC converter 1 is used, it must supply the analog
circuits (pins AVDD0, AVDD1) of the MAS 35x9F.
One of the following supply configurations may be
used:
If only one DC/DC converter is required, DC/DC1 must
be used. Pin DCSO2 must be left vacant, pin VSENS2
should be connected to pin VSENS1.
– Power-optimized solution (recommended opera-
tion). DC/DC 1 (e.g. 2.2 V) drives the MAS 35x9F
DSP and the audio circuitry, DC/DC 2 (e.g. 2.7 V)
supplies controller and flash (see Fig. 2–8 on
page 14)
If the DC/DC converters are not used, pin DCEN must
be connected to VSS, DCSOx must be left vacant.
– Volume-optimized solution. DC/DC 1 (e.g. 2.7 V)
supplies controller, flash and MAS 35x9F audio
parts, DC/DC 2 generates e.g. 2.2 V for the
MAS 35x9F DSP (see Fig. 2–9 on page 14).
– Minimized external components. DC/DC 1 operates
on, e.g., 2.7 V and feeds all components, DC/DC 2
remains off (see Fig. 2–10 on page 14).
– External power supply. All components are powered
by an external source, no DC/DC converter is used
(see Fig. 2–11 on page 14).
battery
voltage
monitor
VBAT
supply
I2CVDD
2
to I C interface
output 1
DCCF (76
)
L1
hex
DCSO2
DCSG2
15
8
22 µH
DC/DC
converter 2
D1
VSENS2
+
C1
330 µF
−
set voltage
voltage
monitor
PUP2
Start
DCEN
PUP
S
Vin
+
−
frequency
divider
R
+
system
or crystal
clock
−
factor
voltage
monitor
3
0
DCFR (77
)
hex
DC/DC
converter 1
DCCF (76
)
hex
7
0
VSS
Fig. 2–7: DC/DC converter overview. The DCEN input must be connected to pin I2CVDD via start-up push button.
Micronas
June 30, 2004; 6251-505-1DS
13
MICRONAS [ MICRONAS ]
