ISL97516 Intersil Corporation, ISL97516 Datasheet - Page 5

• Manufacturer Part Number: ISL97516
• Description: PWM Step-Up Regulator
• Manufacturer: Intersil Corporation

Typical Performance Curves
Applications Information
The ISL97516 is a high frequency, high efficiency boost
regulator operated at constant frequency PWM mode. The
boost converter stores energy from an input voltage source
and deliver it to a higher output voltage. The input voltage
range is 2.3V to 5.5V and output voltage range is 5V to 25V.
The switching frequency is selectable between 600kHz and
1.2MHz allowing smaller inductors and faster transient
response. An external compensation pin gives the user
greater flexibility in setting output transient response and
tighter load regulation. The converter soft-start characteristic
can also be controlled by external C
allows the user to completely shutdown the device.
Boost Converter Operations
Figure 11 shows a boost converter with all the key
components. In steady state operating and continuous
conduction mode where the inductor current is continuous,
the boost converter operates in two cycles. During the first
cycle, as shown in Figure 12, the internal power FET turns
FIGURE 9. PACKAGE POWER DISSIPATION vs AMBIENT
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
V
IN
1
0
0
JEDEC JESD51-7 HIGH EFFECTIVE THERMAL
CONDUCTIVITY TEST BOARD
= 3.3V
FIGURE 7. TRANSIENT RESPONSE
TEMPERATURE
870mW
25
AMBIENT TEMPERATURE (°C)
V
O
= 12V
50
f
s
= 600kHz
5
SS
75
I
O
capacitor. The EN pin
= 50mA to 300mA
85
(Continued)
100
125
ISL97516
on and the Schottky diode is reverse biased and cuts off the
current flow to the output. The output current is supplied
from the output capacitor. The voltage across the inductor is
V
the inductance. The inductance is magnetized and energy is
stored in the inductor. The change in inductor current is:
ΔT1
ΔV
ΔI
D
IN
FIGURE 10. PACKAGE POWER DISSIPATION vs AMBIENT
L1
=
O
and the inductor current ramps up in a rate of V
Duty Cycle
=
=
=
----------- -
F
--------------- -
C
ΔT1
I
SW
D
OUT
OUT
0.6
0.5
0.4
0.3
0.2
0.1
V
IN
0
×
0
JEDEC JESD51-3 LOW EFFECTIVE THERMAL
CONDUCTIVITY TEST BOARD
= 3.3V
FIGURE 8. TRANSIENT RESPONSE
×
TEMPERATURE
V
---------
486mW
L
IN
ΔT
1
25
AMBIENT TEMPERATURE (°C)
V
O
= 12V
50
f
s
= 1.2MHz
75
I
O
= 50mA to 300mA
85
100
December 22, 2006
(EQ. 1)
125
IN
/L, L is
FN9261.1