EVAL6730 STMicroelectronics, EVAL6730 Datasheet - Page 24

• Manufacturer Part Number: EVAL6730
• Description: EVAL BOARD FOR L6730XX
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of EVAL6730

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Power - Output: 66W
• Voltage - Output: 3.3V
• Current - Output: 20A
• Voltage - Input: 4.5 ~ 14V
• Regulator Topology: Buck
• Frequency - Switching: 400kHz
• Board Type: Fully Populated
• Utilized Ic / Part: L6730
• Input Voltage: 8 V to 52 V
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: L6208
• Other names: 497-5501

AN1451 APPLICATION NOTE
Figure 25. Power Dissipation formulae and results.
24/43
Dissipating Pw
Dissipating Pw
pating Power
Current Ripple
Commutation
r.m.s. Current
Average Cur-
Commutatiion
PowerDMOS
Diss. Energy
during Load
Total Dissi-
Duty Cycle
Dissipating
Dissipating
Frequency
Load Time
rent during
Load Time
Load Time
Rise Time
Rise Time
Quiescent
Switching
Fall Time
Fall Time
Energy
Energy
Period
Time
Time
Time
Tcom = 9.60E-08
Tload = 5.97E-04
Erise = 1.50E-04
Eload = 6.50E-05
Ecom = 6.78E-05
Trise = 4.03E-04
Irms = 9.86E-01
Tfall = 3.16E-04
fSW = 2.50E+04
Efall = 3.62E-04
Pq = 1.32E-01
D = 6.25E-01
P = 1.36E+00
T = 2.00E-03
I = 2.85E-02
I = 9.86E-01
Result
[Hz]
[W]
[W]
[A]
[A]
[A]
[s]
[s]
[s]
[s]
[s]
[J]
[J]
[J]
[J]
-
Lm
–
–
ln
ln
2Ron · Irms
Ipk Rm
------------------------------------------------------------------------------------------------------------ -
Ipk Rm
-------------------------------------------------------------------------------------------------------------- -
–
Ipk Rm 2 Ipk Ron Ipk Rs
–
ln
------------------------------------------------------------------------------------------ -
Ipk Rm
+
+
2
-- -
T
Ipk Rs
2
2
· D ·Tload + (Ron · Irms
–
·(Erise + Efall + Eload + Ecom) + Pq
2 V d Tfall
Ipk Ron
2Vs · I · Tcom · Tload · fSW
(Vs - Vb)*D / (Lm* fSW)
+
Vs
+
Vs 2 Vd
2Ron · Irms
Ipk Rs
2Ron Ipk
V s
2Ron Ipk
Ipk
Vs 2 Vd
(Vs + Vb) / 2Vs
Vs / (250V/ s)
–
(1-D) / tOFF
T-Trise-Tfall
–
+
(T/2)-Trise
(3/4)T-rise
Ipk
Vb / Vs
2 / fCK
4 / fCK
2 / fCK
Ipk
Ipk Rs
Vs · Iq
–
------------------------------------- -
+
–
–
Vs 2 Vd
–
V s
2
Rm
2
2
---- -
2
I
· Tload
I
Trise
-------------- -
–
Tfall
------------ -
+
-------------------------------------------------------------------------------- -
+
+
+
1
2
3
3
2 V d
Vs
Rs
+
+ Vd · I) · (1 - D) · Tload
------ -
–
3
I
Vs
exp
2
------------------------------------------------------ -
+
– fal l
--------------- -
Rm
Rm
--------------------------- -
T
--------------------------------------------- -
Rm
Lm
Rm
+
Lm
+
+
+
2 Ron
Rs
Rs
Rs
Lm
Lm
Rm
2
+
2Ron
+
+
Rs
Rs
NORMAL Mode
HALF or WAVE
Mode
Sync. Slow Decay
Quasi-Sync Fast Decay
NORMAL Mode
HALF Mode
WAVE Mode
NORMAL Mode
HALF Mode
WAVE Mode
MORMAL Mode
HALF or WAVE
Mode
Sync. Slow Decay
Quasi-Sync Fast Decay