EVAL6730 STMicroelectronics, EVAL6730 Datasheet - Page 4
![EVAL BOARD FOR L6730XX](/photos/9/30/93060/eval6730_sml.jpg)
EVAL6730
Manufacturer Part Number
EVAL6730
Description
EVAL BOARD FOR L6730XX
Manufacturer
STMicroelectronics
Type
Motor / Motion Controllers & Driversr
Datasheets
1.L6730TR.pdf
(52 pages)
2.L6730DTR.pdf
(50 pages)
3.EVAL6730.pdf
(9 pages)
4.EVAL6732.pdf
(43 pages)
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
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
AN1451 APPLICATION NOTE
above V
as the current reverses direction and flows into the bulk capacitor. It turns out that, in fast decay, the highest
differential voltage is observed between the two OUT pins of the same bridge, at the beginning of the off-time,
and this must always be kept below 60V [3]. The same high voltage condition exists when a step is made and
the direction of current flow reverses in the bridge.
Figure 3. Currents and voltages during the dead time at the beginning of the off-time .
Figure 4 shows the voltage waveforms at the two OUT pins referring to a possible practical situation, with a peak
output current of 2.8A, V
ground spike amplitude is -2.65V for one output; the other OUT pin is at about 57V. In these conditions, total
differential voltage reaches almost 60V, which is the absolute maximum rating for the DMOS. Keeping differen-
tial voltage between two Output pins belonging to the same Full Bridge within rated values is a must that can
be accomplished with proper selection of Bulk capacitor value and equivalent series resistance (ESR), accord-
ing to current peaks and chopping style and adopting good layout practices to minimize PCB parasitic induc-
tances (see below) [3].
4/43
S
, due to the PCB inductance and voltage drop across the high-side (integrated) freewheeling diode,
Equivalent Circuit
Bulk Capacitor
S
= 52V, R
ESR
ESL
SENSE
R
PCB Parasitic
Inductance
SENSE
= 0.33 , T
*I+V
R
SENSE
F(Diode)
*I
J
SENSE
= 25°C (approximately) and a good PCB layout. Below
V
R
S
SENSE
High Differential Voltage
PCB Parasitic
Inductance
Dangerous
OUT
OUT
2
1
V
S
+V
F(Diode)