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 70 80 90 100 110 120 130 140 150 160 170 180
Switching Frequency – kHz
Resistance – kΩ
An onboard electrolytic input capacitor may be added at C1.
1.3.1 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 below
show how to select the different ways of power sequencing.
Equation 1–3.
R6
R7
+
R1
R2
–core voltage tracks I/O voltage;
Equation 1–4.
R6
R7
+
ǒ
V
IńO
* 0.891
Ǔ
8.891
– 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 seconde
at power down.