MAS 3507D
PRELIMINARY DATA SHEET
2.6.4. Start-up Sequence
µController
The DC/DC converter starts from a minimum input
voltage of 0.9 V. There should be no output load during
startup. In case WSEN is active, the MAS 3507D is in
the DSP operation mode. The start-up script should be
as follows:
DSP
operation
=1
1. Enable the DC/DC-converter with a high signal
(VDD, AVDD) at pin DCEN.
WSEN > 2 V
> 0.9 V
2. Wait until PUP goes “high”.
DC/DC
On
3. Wait one more millisecond to guarantee that the out-
put voltage has settled (recommended).
DCEN
button
4. Enable the MAS 3507D with a “high” signal at pin
“WSEN”.
Fig. 2–2: DC/DC operation
Please also refer to Figure 2–2.
optional
filter
CLKI
VDD
AVDD
22 µH
DCSO
DCSG
Start-up
oscillator
Cout
330 µF
Low ESR
+
Frequency
divider
−
DC/DC
converter
Power-On
Push Button
64...94
x2
+
−
DCEN
PUP
Cin
Vin
≥0.9 V
330 µF
32...47
voltage monitor
+32
10 kΩ
0...15
WSEN
DCCF
$8e
VSENSE
9
10
16
10 nF
47 kΩ 47 kΩ
VSS
AVSS
µController
Fig. 2–3: DC/DC converter connections
10
Micronas
MICRONAS [ MICRONAS ]
