ISL6551EVAL1 Intersil, ISL6551EVAL1 Datasheet - Page 19

• 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: -

VOPOUT
Feedback
Secondary Control - In secondary side control systems,
only a few resistors and capacitors are required to complete
the feedback loop.
Primary Control - This feedback loop configuration for
primary side control systems requires an optocoupler for
isolation. The bandwidth is limited by the optocoupler.
VOPOUT
FIGURE 16A. SECONDARY CONTROL
FIGURE 16B. PRIMARY CONTROL
TL431
IL207
19
VREF = 5V
EAI
EAO
EAI
ISL6551
EAO
Rectifiers
Current Doubler Rectifiers -
Conventional Rectifiers -
Self-Driven Rectifiers - For low output voltage applications,
both FETs can be driven by the voltage across the
secondary winding. This can work with all kinds of main
transformer configurations as shown in Figures 18A-D.
1. Synchronous FETs are used for low output voltage, high
2. Schottky diodes are used for lower current applications.
1. Synchronous FETs are used for low output voltage, high
2. Schottky diodes are used for lower current applications.
output current and/or high efficiency applications.
Pins S+ and S- are connected to the output filter and the
main transformer with current doubler configurations.
output current and/or high efficiency applications.
Pins S+ and S- are connected to the main transformer
with conventional configurations.
FIGURE 17A. CURRENT DOUBLER RECTIFIERS
FIGURE 17B. CONVENTIONAL RECTIFIERS
SYNCHRONOUS FETs
S+
S–
FIGURE 17C. SELF-DRIVEN RECTIFIERS
S+
S–
SYNP
SYNN
SYNCHRONOUS FETs
SYNN
S–
S+
SYNP
S+
S–
S+
S–
SCHOTTKY
SCHOTTKY
January 3, 2006
FN9066.5