ISL6551EVAL1 Intersil, ISL6551EVAL1 Datasheet - Page 33

• 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: -

Figures 62 and Figure 63 show the interaction between
master and slave units in two different turn-on sequences.
When the slave unit is turned on first, it acts as a “master”
during the start up of the master unit. It takes a longer time
for both converters to switch back to their proper roles
settling down than that of the master unit is turned on first.
Step Responses
This section summarizes step responses of the converter at
various input lines and output voltages (Figures 64 to 69). In
all the figures of this section, Channel 4 represents the load
step, and channel 1 represents the output voltage. For
transients from 45A to 60A, channel 4 shows only 1/4 of the
load. Table 6 summarizes the transient voltage spikes at
different operating conditions. Note that the measurement is
including the ripple voltage. The actual transient voltages
excluding the ripple voltage should be smaller and not very
different in all cases since the cut-off frequency and the
corresponding phase of the loop for all cases are very close,
as illustrated in the Loop Response section.
INPUT OUTPUT
75V
75V
48V
48V
36V
36V
FIGURE 63. TURN ON MASTER (CHANNEL 3 AND
2.64V
2.64V
3.30V
3.30V
3.63V
3.63V
TABLE 6. TRANSIENT RESPONSE
CHANNEL 1) FIRST. SLAVE: CHANNEL 4 AND
CHANNEL 2
2
1
45-60A, 1A/us
45-60A, 1A/us
LOAD STEP
0-15A, 1A/us
0-15A, 1A/us
0-15A, 1A/us
45-60, 1A/us
4
3
33
TRANSIENT
353mV
350mV
328mV
319mV
316mV
306mV
Vp-p
Application Note 1002
1/2 Vp-p
175mV
160mV
177mV
164mV
158mV
153mV
FIGURE 64. TRANSIENT RESPONSE FOR V
FIGURE 66. TRANSIENT RESPONSE FOR V
FIGURE 65. TRANSIENT RESPONSE FOR V
V
V
V
OUT
OUT
OUT
= 2.64V AT 0A-15A STEP, 1A/us
= 3.3V AT 0A-15A STEP, 1A/us
= 2.64V AT 45A-60A STEP, 1A/us
IN
IN
IN
=75V AND
=48V AND
=75V AND