EVAL6730 STMicroelectronics, EVAL6730 Datasheet - Page 21

• 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

L6730C - L6730D
Figure 13. OVP latched
Figure 14. OVP with sink enabled: the low-side MOSFET is turned-on in advance.
It must be taken into account that there is an electrical network between the output terminal and
the FB pin and therefore the voltage at this pin is not a perfect replica of the output voltage. If
the converter can sink current, in the most of cases the low-side will be turned-on before the
output voltage exceeds the over-voltage threshold, because the error amplifier will throw off
balance in advance. Even if the device doesn’t report an over-voltage, the behaviour is the
same, because the low-side is turned-on immediately. Instead, if the sink-mode is disabled, the
low-side will be turned-on only when the over-voltage-protection (OVP) operates and not
before, because the current can’t be reversed. In this case a delay between the output voltage
rising and the FB voltage rising can appear and the OVP can operate on late. The following two
figures show an over-voltage event in case of sink enabled and disabled. The output voltage
rises with a slope of 100mV/µs, emulating in this way the breaking of the high-side MOSFET as
an over-voltage cause.
109%
V
LGate
V
FB
OUT
Device description
LGate
OSC
FB
21/50