ISL8200AMMREP View Datasheet(PDF) - Renesas Electronics
Part Name
Description
Manufacturer
ISL8200AMMREP Datasheet PDF : 24 Pages
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ISL8200AMM
shown in these graphs is the average output current and not the
inductor ripple current.
VIN = 4.5V TO 20V
VIN
VOUT
PVIN ISL8200AMMREP
POWER MODULE
VOUT_SET
EN
FF
ISHARE
PHASE
OCSET
5k
FIGURE 30. ISL8200AMMREP USING RISEN-EX BETWEEN
OCSET and PHASE
16
14
1.8VOUT
12
2.5VOUT
10
8
1.2VOUT
6
4
2
0
0
5
10
15
20
RISEN-EX(kΩ)
FIGURE 31. 5VIN
16
14 5.0VOUT
12
10
1.2VOUT
1.8VOUT
8
6
2.5VOUT
4
2
0
0
10
20
30
40
50
RISEN-EX (kΩ)
FIGURE 32. 12VIN
16
1.8VOUT
14
12
10
1.2VOUT
8
6
2.5VOUT
4 5.0VOUT
2
0
0
20
40
60
RISEN-EX (kΩ)
80
100
FIGURE 33. 20VIN
In a high input voltage, high output voltage application, such as
20V input to 5V output, the inductor ripple becomes excessive
due to the fixed internal inductor value. In such applications, the
output current will be limited from the rating to approximately
70% of the module’s rated current.
When OCP is triggered, the controller pulls EN low immediately to
turn off UGATE and LGATE.
For overload and hard short conditions, the overcurrent
protection reduces the regulator RMS output current much less
than full load by putting the controller into hiccup mode. A delay
time, equal to 3 soft-start intervals, is entered to allow the
disturbance to be cleared out. After the delay time, the controller
then initiates a soft-start interval. If the output voltage comes up
and returns to the regulation, PGOOD transitions high. If the OC
trip is exceeded during the soft-start interval, the controller pulls
EN low again. The PGOOD signal will remain low and the
soft-start interval will be allowed to expire. Another soft-start
interval will be initiated after the delay interval. If an overcurrent
trip occurs again, this same cycle repeats until the fault is
removed.
Fault Handshake
In a multi-module system, with the EN pins wired OR’ed together,
all modules can immediately turn off, at one time, when a fault
condition occurs in one or more modules. A fault would pull the
EN pin low, disabling all the modules and therefore not creating
current bounce. Thus, no single channel would be over stressed
when a fault occurs.
Since the EN pins are pulled down under fault conditions, the
pull-up resistor (RUP) should be scaled to sink no more than 5mA
current from EN pin. Essentially, the EN pins cannot be directly
connected to VCC.
Oscillator
The Oscillator is a sawtooth waveform, providing for leading edge
modulation with 350ns minimum dead time. The oscillator
(sawtooth) waveform has a DC offset of 1.0V. Each channel’s
peak-to-peak of the ramp amplitude is set to be proportional to
the voltage applied to its corresponding FF pin.
FN8287 Rev 2.00
June 3, 2015
Page 17 of 24
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