EVAL6730 STMicroelectronics, EVAL6730 Datasheet - Page 22

• 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
2.13.1 Maximum output current vs. selectable devices
Figure 22 reports a performance comparison between L6228 (std. power) and L6208 (high power) for different
packages, with the following assumptions:
- Normal Drive Mode (two-phase on)
- Supply voltage: 24 V; Switching frequency: 30 kHz.
- T
- Maximum R
- Maximum quiescent current I
- PCB is a FR4 with a dissipating copper surface on the top side of 6 cm
SO and PowerDIP packages (D, N suffixes).
- PCB is a FR4 with a dissipating copper surface on the top side of 6 cm
via holes and a ground layer for the PowerSO package (PD suffix).
- For each device (on the x axis) y axis reports the maximum output current.
Figure 22. Maximum output current vs. selectable devices.
2.13.2 Power Dissipation Formulae for different sequences
Figure 23 to Figure 26 are screenshots of a spreadsheet that helps calculating power dissipation in specified
conditions (application and motor data), and estimates the resulting junction temperature for a given package
and copper area available on the PCB [6]. The model considers power dissipation during the on-time and the
off-time, taking into account the selected decay, rise and fall time (when a phase change occurs) considering
the operating sequence, the switching losses and the quiescent current power dissipation.
22/43
Load Current
amb
[A]
= 25 °C, T
DS(ON)
1 .7 0
1 .5 0
1 .3 0
1 .1 0
0 .9 0
0 .7 0
0 .5 0
J
= 125 °C.
(taking into account process spread) has been considered, @ 125 °C.
Q
(taking into account process spread) has been considered.
2
2
(with a thickness of 35 µm), 16
(with a thickness of 35 µm) for