EL7563 INTERSIL [Intersil Corporation], EL7563 Datasheet - Page 12

• Manufacturer Part Number: EL7563
• Description: Monolithic 4 Amp DC:DC Step-Down Regulator
• Manufacturer: INTERSIL [Intersil Corporation]

Power Tracking
The power tracking pins STP and STN are the inputs to a
comparator, whose HI output forces the PWM controller to
skip switching cycle.
1. Linear Tracking
In this application, it is always the case that the lower voltage
supply V
C
tracks the higher output supply V
V
R
R
IN
A
B
10
10
10
10
1
2
6
7
8
9
1
2
6
7
8
9
1
2
6
7
8
9
1
2
6
7
8
9
12
STP
STN
STP
STN
EL7563
EL7563
EL7563
EL7563
+
+
+
+
-
-
-
-
P
20
19
15
14
13
12
20
19
15
14
13
12
11
11
20
19
15
14
13
12
20
19
15
14
13
12
11
11
. See Figure 23.
FIGURE 24. OFFSET POWER TRACKING
FIGURE 23. LINEAR POWER TRACKING
EL7563
V
V
V
V
C
P
C
P
2. Offset Tracking
The intended start-up sequence is shown in Figure 24. In
this configuration, V
value of:
--------------------- -
R
A
R
+
B
R
B
×
V
V
V
IN
OUT
OUT
C
will not start until V
TIME
TIME
V
V
V
V
P
C
P
C
P
reaches a preset
May 13, 2005
FN7296.2