Datasheet

Modifications
1-5
Introduction
Figure 1−1. Frequency Trimming Resistor Selection Graph
250
300
350
400
450
500
550
600
650
700
750
60 80 100 120 140 160 180
Switching Frequency − kHz
R − Resistance − kΩ
An onboard electrolytic input capacitor may be added at C1.
1.3.3 Power Sequencing
By selecting different R6−R7 resistor divider ratios, different power
sequencing scenarios can be set. The Equations 1−3, 1−4, and 1−5 show how
to select the different ways of power sequencing.
Equation 1−3.
R6
R7
+
R1
R2
* Core voltage tracks IńO voltage
Equation 1−4.
R6
R7
+
ǒ
V
IńO
* 0.891
Ǔ
0.891
− Ratiometric relation between core and I/O
voltage
Equation 1−5.
R6
R7
t
R1
R2
− Core voltage rises first at power up and falls second
at power down