ISL6115A Datasheet, PDF (6/10 Pages) Intersil Corporation – 12V Power Distribution Controllers

ISL6115A
region) high r_DS(ON) state. Strike a balance between the CR
limit and the timing requirements to avoid periods when the
external N-Channel MOSFETs may be damaged or destroyed
due to excessive internal power dissipation. Refer to the
MOSFET SOA information in the manufacturer’s data sheet.
When driving particularly large capacitive loads a longer
soft-start time to prevent current regulation upon charging
and a short CR time may offer the best application solution
relative to reliability and FET MTF.
Physical layout of R_SENSE resistor is critical to avoid the
possibility of false overcurrent occurrences. Ideally, trace
routing between the R_SENSE resistors and the IC is as direct
and as short as possible with zero current in the sense lines
(see Figure 1).
Typical Performance Curves
3.5
3.4
3.3
3.2
3.1
3.0
2.9
2.8
-40
0
25
70
85
125
TEMPERATURE (°C)
FIGURE 2. V_DD BIAS CURRENT
.
CORRECT
INCORRECT
TO ISEN AND
R_ISET
CURRENT
SENSE RESISTOR
FIGURE 1. SENSE RESISTOR PCB LAYOUT
22.0
21.5
21.0
20.5
20.0
19.5
19.0
18.5
18.0
-40
0
25
70
85
125
TEMPERATURE (°C)
FIGURE 3. I_SET SOURCE CURRENT
20.8
20.6
20.4
20.2
20.0
19.8
19.6
19.4
19.2
19.0
18.8
-40
C_TIM - 0V
0
25
70
85
125
TEMPERATURE (°C)
FIGURE 4. C_TIM CURRENT SOURCE
1.82
1.81
1.80
1.79
1.78
1.77
-40
0
25
70
85
125
TEMPERATURE (°C)
FIGURE 5. C_TIM OC VOLTAGE THRESHOLD
6
FN6855.0
February 25, 2009