Maxim Integrated MAXQ7666 - Manual (Page 83)

2.3 Supply Configuration
The MAXQ7665/MAXQ7666 use three supplies to power the internal analog, digital core, and digital I/O circuits. The supplies are con-
figured as listed:
• AVDD = +5V
• DVDD = +3.3V (with internal linear regulator enabled or through an external supply)
• DVDDIO = +5V
Figure 2-2 and Figure 2-3 show the recommended supply configurations. Bypass capacitors should be mounted as close as possible
to the body of the MAXQ7665/MAXQ7666 to reduce noise. Note: If AVDD is a separate supply, no voltage monitoring is applied and
the supply voltage should not deviate more than ±300mV from DVDDIO. For PCB layout guidelines, refer to
Application Note 801
( www.maxim-ic.com/AN801 ) and Application Note 637 ( www.maxim-ic.com/AN637 ).
Figure 2-2. Supply Configuration 1 (Using Internal Linear Regulator)
0.1 μF
DVDD
REGEN
4.7 μF 0.1 μF
NOTE: USE A LOW-ESR CAPACITOR SIMILAR TO VISHAY TYPE 591D.
DGND
DGND
DGND
DVDDIO
DVDDIO
GNDIO
DRIVEN FROM
INTERNAL LDO
1 μF
MAIN SUPPLY
GENERATION
0.1 μF
AGND
AVDD
AGND
+5.0V
GND
(SEE NOTE)
Figure 2-3. Supply Configuration 2 (External DVDD)
0.1 μF
DVDD
DGND
0.1 μF
NOTE: USE A LOW-ESR CAPACITOR SIMILAR TO VISHAY TYPE 591D.
DGND
DGND
DVDDIO
DVDDIO
GNDIO
1 μF
MAIN SUPPLY
GENERATION
0.1 μF
AGND
AVDD
AGND
+5.0V
EXTERNAL LDO
+3.3V
GND
+5.0V
GND
(SEE NOTE)
REGEN
MAXQ7665/MAXQ7666 User’s Guide
2-11
Maxim Integrated