EVAL6730 STMicroelectronics, EVAL6730 Datasheet - Page 37

• 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

L6730 - L6730B
6.5
Two quadrant or one quadrant operation mode (L6730)
After the soft-start phase the L6730 can work in source only (one quadrant operation mode)
or in sink/source (two quadrant operation mode), depending on the setting of the
multifunction pin (see
operation mode is related to the application. One quadrant operation mode permits to have
a higher efficiency at light load, because the converter works in discontinuous mode (see
Figure
frequency, it’s preferable to work in two quadrants, even at light load. In this way the
reduction of the switching frequency due to the pulse skipping is avoided. To parallel two or
more modules is requested the one quadrant operation in order not to have current sinking
between different converters. Finally the two quadrant operation allows faster recovers after
negative load transient. For example, let’s consider that the load current falls down from I
to 0A with a slew rate sufficiently greater than L/V
considering that the converter reacts instantaneously setting to 0% the duty-cycle, the
energy ½*L*I
increasing the output voltage. If the converter can sink current this overvoltage can be faster
eliminated.
Figure 31. Efficiency in discontinuous-current-mode and continuous-current-mode
0.7
0.6
0.5
0.4
0.3
0.2
0.1
31). Nevertheless in some cases, in order to maintain a constant switching
0
OUT
0.2
2
stored in the inductor will be transferred to the output capacitors,
0.4
Chapter 5.10 on page
0.6
OUTP UT CURRENT (A)
EFFIC IENCY: D C M vs. C CM
0.8
Doc ID 11938 Rev 3
1
1.2
27). The choice of one or two quadrant
1.4
OUT
1.6
(where L is the inductor value). Even
1.8
2
Application details
E FFICIENCY DCM
E FFICIENCY CCM
37/52
OUT