L6728 STMicroelectronics, L6728 Datasheet - Page 12

• Manufacturer Part Number: L6728
• Description: IC PWM CTLR 1PH PWRGOOD 10-DFN
• Manufacturer: STMicroelectronics

Specifications of L6728

• 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
• Output Voltage: 0.8 V
• Output Current: 30 A
• Input Voltage: 1.5 V to 13.2 V
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• For Use With: 497-8228 - BOARD EVALUATION W/L6728497-6418 - BOARD EVAL BASED ON L6728
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Over current protection
8
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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, L6728 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
st
level over current is detected. If four 1
st
level
st
level OC
L6728