PI3303-00-EVAL1 Datasheet, PDF (36/42 Pages) Vicor Corporation – Cool-Power® ZVS Switching Regulators

PI33xx-x0
Inductor Pairing
The PI33xx-x0 utilizes an external inductor. This inductor has been
optimized for maximum efficiency performance. Table 4 details
the specific inductor value and part number utilized for each
PI33xx-x0 device which are available from Coiltronics and Eaton.
Data sheets are available at:
http://www.cooperindustries.com
Device
Inductor
[nH]
Inductor
Part Number
PI3311-x0
125
FPV1006-125-R
PI3318-x0
150
FPV1006-150-R
PI3312-x0
200
FPT705-200-R
PI3301-x0
200
FPT705-200-R
PI3302-x0
200
FPT705-200-R
PI3303-x0
230
FPT705-230-R
PI3305-x0
230
FPT705-230-R
Table 4 — PI33xx-x0 Inductor pairing
Manufacturer
Eaton
Eaton
Coiltronics
Coiltronics
Coiltronics
Coiltronics
Coiltronics
Thermal Derating
Thermal de-rating curves are provided that are based on
component temperature changes versus load current, input
voltage and air flow. It is recommended to use these curves as a
guideline for proper thermal de-rating. These curves represent the
entire system and are inclusive to both the Picor regulator and the
external inductor. Maximum thermal operation is limited by
either the MOSFETs or inductor depending upon line and
load conditions.
Thermal measurements were made using a standard PI33xx-x0
Evaluation board which is 3 x 4 inches in area and uses 4-layer,
2oz copper. Thermal measurements were made on the three
main power devices, the two internal MOSFETs and the external
inductor, with air flows of 0, 200, and 400LFM.
Filter Considerations
The PI33xx-x0 requires input bulk storage capacitance as well as
low impedance ceramic X5R input capacitors to ensure proper
start up and high frequency decoupling for the power stage. The
PI33xx-x0 will draw nearly all of the high frequency current from
the low impedance ceramic capacitors when the main high side
MOSFET is conducting. During the time the high side MOSFET
is off, they are replenished from the bulk capacitor. If the input
impedance is high at the switching frequency of the converter,
the bulk capacitor must supply all of the average current into the
converter, including replenishing the ceramic capacitors. This value
has been chosen to be 100µF so that the PI33xx-x0 can start up
into a full resistive load and supply the output capacitive load with
the default minimum soft start capacitor when the input source
impedance is 50Ω at 1MHz. The ESR for this capacitor should be
approximately 20mΩ. The RMS ripple current in this capacitor is
small, so it should not be a concern if the input recommended
ceramic capacitors are used. Table 5 shows the recommended
input and output capacitors to be used for the various models
as well as expected transient response, RMS ripple currents per
capacitor, and input and output ripple voltages.
Table 6 includes the recommended input and output
ceramic capacitors.
Device
V_IN
(V)
I_LOAD
(A)
C_INPUT
Ceramic
X5R
C_INPUT
Bulk
Elec.
C_OUTPUT
Ceramic
X5R
PI3311
24
10
5
4 x 4.7µF
50V
100µF
50V
8 X 100µF
2 X 1µF
1 X 0.1µF
PI3318
24
10
5
4 x 4.7µF
50
100µF
50V
6 X 100µF
2 X 1µF
1 X 0.1µF
PI3312
24
10
5
4 x 4.7µF
100µF
50V
4 X 100µF
2 X 1µF
1 X 0.1µF
PI3301
24
10
5
4 x 4.7µF
100µF
50V
4 X 100µF
2 X 1µF
1 X 0.1µF
PI3302
24
10
5
4 x 4.7µF
100µF
50V
4 X 47µF
2 X 1µF
1 X 0.1µF
PI3303
24
8
4
4 x 4.7µF
100µF
50V
4 X 22µF
2 X 1µF
1 X 0.1µF
PI3305
24
8
4
4 x 4.7µF
100µF
50V
4 X 22µF
2 X 1µF
1 X 0.1µF
Table 5 — Recommended input and output capacitance
C_INPUT
Ripple
Current
(I_RMS)
C_OUTPUT
Ripple
Current
(I_RMS)
0.5
0.8
0.5
0.8
1
1.75
1.05
1.625
1.2
1.5
1.3
1.36
1.38
1.2
Input
Ripple
(mVpp)
120
100
120
100
150
100
200
125
220
140
275
150
280
160
Output
Ripple
(mVpp)
20
15
20
15
50
24
40
33
50
30
100
60
150
75
Output
Ripple
(mVpp)
Recovery
Time
(µs)
Load
Step
(A)
(Slew/µs)
-/+40
40
5
(5A/µs)
-/+40
40
5
(5A/µs)
-/+80
25
5
(10A/µs)
-/+100
20
5
(10A/µs)
-/+170
30
5
(5A/µs)
-/+300
30
4
(10A/µs)
-/+400
30
4
(10A/µs)
Cool-Power^® ZVS Switching Regulators
Page 36 of 42
Rev 2.4
02/2017
vicorpower.com
800 927.9474