L6728D STMicroelectronics, L6728D Datasheet - Page 13

• Manufacturer Part Number: L6728D
• Description: IC CTLR PWM 1PH POWERGOOD 10DFN
• Manufacturer: STMicroelectronics

Specifications of L6728D

• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Frequency - Max: 330kHz
• Duty Cycle: 80%
• Voltage - Supply: 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

L6728D
8
Overcurrent protection
The overcurrent 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 the LS MOSFET is turned on with the programmed OCP threshold voltages,
internally held. If the monitored voltage is higher than these thresholds, an overcurrent event
is detected.
For maximum safety and load protection, the L6728D implements a dual-level overcurrent
protection system:
●
●
When overcurrent protection is triggered, the device turns off both the LS and HS MOSFETs
in a latched condition.
To recover from an overcurrent protection-triggered condition, the VCC power supply must
be cycled.
1
on PHASE exceeds this threshold, a 1
OC events are detected in four consecutive switching cycles, overcurrent protection is
triggered.
2
threshold multiplied by a factor 1.5. If the monitored voltage on PHASE exceeds this
threshold, overcurrent protection is triggered immediately.
st
nd
level threshold: This is the user externally-set threshold. If the monitored voltage
level threshold: This is an internal threshold whose value is equal to the 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 16498 Rev 1
st
level overcurrent is detected. If four 1
Overcurrent protection
st
st
level
level
13/33