L6728HTR STMicroelectronics, L6728HTR Datasheet - Page 12

• Manufacturer Part Number: L6728HTR
• Description: IC CTLR PWM SGL PHASE 10-DFN
• Manufacturer: STMicroelectronics

Specifications of L6728HTR

• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Frequency - Max: 330kHz
• Duty Cycle: 80%
• Voltage - Supply: 4.5 V ~ 12 V
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 10-DFN
• Frequency-max: 330kHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-8978-2

Over current protection
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Over current protection
The over current function protects the converter from a shorted output or overload, by
sensing the output current information across the low side MOSFET drain-source on-
resistance, R
avoiding the use of expensive and space-consuming sense resistors.
The low side R
node when LS MOSFET is turned on with the programmed OCP thresholds voltages,
internally held. If the monitored voltage is bigger than these thresholds, an over current
event is detected.
For maximum safety and load protection, L6728H implements a dual level over current
protection system:
●
●
When over current protection is triggered, the device turns off both LS and HS MOSFETs in
a latched condition.
To recover from over current protection triggered condition, VCC power supply must be
cycled.
1
PHASE exceeds this threshold, a 1
events are detected in four consecutive switching cycles, over current protection will be
triggered.
2
threshold multiplied by a factor 1.5. If the monitored voltage on PHASE exceeds this
threshold, over current protection will be triggered immediately.
st
nd
level threshold: it is the user externally set threshold. If the monitored voltage on
level threshold: it is an internal threshold whose value is equal to 1
DS(on)
DS(on)
. This method reduces cost and enhances converter efficiency by
current sense is implemented by comparing the voltage at the PHASE
Doc ID 15725 Rev 1
st
level over current is detected. If four 1
st
level
st
level OC
L6728H