ISL6551EVAL1 Intersil, ISL6551EVAL1 Datasheet - Page 9

• Manufacturer Part Number: ISL6551EVAL1
• Description: EVALUATION BOARD ISL6551
• Manufacturer: Intersil

Specifications of ISL6551EVAL1

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Isolated
• Voltage - Output: 3.3V
• Current - Output: 60A
• Voltage - Input: 36 ~ 75V
• Regulator Topology: Buck
• Frequency - Switching: 470kHz
• Board Type: Fully Populated
• Utilized Ic / Part: ISL6551
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -

Shutdown Timing Diagrams
Shutdown Timing Descriptions
A (ON/OFF) - When the ON/OFF is pulled low, the soft-start
capacitor is discharged and all the drivers are disabled.
When the ON/OFF is released without a fault condition, a
soft-start is initiated.
B (OVERCURRENT) - If the output of the converter is over
loaded, i.e., the PKILIM is above the bandgap reference
voltage (BGREF), the soft-start capacitor is discharged very
quickly and all the drivers are turned off. Thereafter, the soft-
start capacitor is charged slowly, and discharged quickly if
the output is overloaded again. The soft-start will remain in
hiccup mode as long as the overload conditions persist.
Once the overload is removed, the soft-start capacitor is
charged up and the converter is then back to normal
operation.
C (LATCHING SHUTDOWN) - The IC is latched off
completely as the LATSD pin is pulled high, and the soft-start
capacitor is reset.
D (ON/OFF) - The latch cannot be reset by the ON/OFF.
LATSD
ON/OFF
ILIM_OUT
SOFT
START
DRIVER
ENABLE
SOFT-START
SHUTDOWN
VDD
FAULT
OFF
A
9
PKILIM < BGREF
PKILIM > BGREF
OVER
CURRENT
B
ISL6551
LATCHED
C
E (LATCH RESET) - The latch is reset by removing the
VDD. The soft-start capacitor starts to be charged after VDD
increases above the turn-on threshold VDD
F (VDD UVLO) - The IC is turned off when the VDD is below
the turn-off threshold VDD
incorporated in the undervoltage lockout (UVLO) circuit.
OFF/ON
D
LATCH CANNOT BE RESET BY ON/OFF
E
LATCH RESET BY
REMOVING VDD
VDD
LATCH
RESET
FAULT
ON
OFF
. Hysteresis VDD
UNDER VOLTAGE
LOCKOUT
F
VDD
ON
OFF
.
HYS
January 3, 2006
is
FN9066.5