ISL6551EVAL1 Intersil, ISL6551EVAL1 Datasheet - Page 34

• 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: -

FIGURE 68. TRANSIENT RESPONSE FOR V
FIGURE 69. TRANSIENT RESPONSE FOR V
FIGURE 67. TRANSIENT RESPONSE FOR V
V
V
V
OUT
OUT
OUT
= 3.63V AT 0A-15A STEP, 1A/us
= 3.63V AT 45A-60A STEP, 1A/us
= 3.3V AT 45A-60A STEP, 1A/us
34
IN
IN
IN
=36V AND
=36V AND
=48V and
Application Note 1002
Loop Response
The experimental results presented in this section are
measured with a 350 Venable system. The injection point is
at R131 instead of R76 since R76 is located at noise
sensitivity nodes.
Since it is a current mode control system, the transfer
function of the plant is mainly determined by the
characteristic of the load including the output resistive,
capacitive, and inductive impedance, all of which varies with
different applications.
We had only five 25W 0.1
for testing in our lab. A 38A load was constructed with these
five resistors for 3.3V output. As shown in Figure 70, the load
can be characterized as a 0.086Ω resistor in series with 260
nH inductance induced by the two 5.0” 10AWG wires that
connect to the load. The open loop response slightly varies
with the input voltage, as shown in Figure 71.
FIGURE 71. OPEN LOOP RESPONSE FOR 3.3V@38A
FIGURE 70. RESISTIVE LOAD CHARACTERISTIC
-10
-20
-30
90
80
70
60
50
40
30
20
10
1.0E+02
0
RESISTIVE LOAD. RED-48V, BLUE-75V, AND
BLACK-36V
GAIN
1.0E+03
Fre que ncy (Hz)
Ω
1.0E+04
“pure” resistive loads available
1.0E+05
1.0E+06
PHASE
Measured
Gain
Measured
Phase
Model
Gain
Model
Phase