L6756D STMicroelectronics, L6756D Datasheet - Page 25
L6756D
Manufacturer Part Number
L6756D
Description
IC CTLR 2/3/4PH BUCK 40-VFQFPN
Manufacturer
STMicroelectronics
Datasheet
1.L6756DTR.pdf
(36 pages)
Specifications of L6756D
Applications
Controller, Intel VR10, VR11, VR11.1
Voltage - Input
12V
Number Of Outputs
4
Voltage - Output
0.3 ~ 1.6 V
Operating Temperature
0°C ~ 70°C
Mounting Type
Surface Mount
Package / Case
40-VFQFN, 40-VFQFPN
Output Voltage
3 V
Input Voltage
- 0.3 V to + 15 V
Switching Frequency
185 KHz to 215 KHz
Operating Temperature Range
- 40 C to + 150 C
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
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L6756D
5.6.1
LSLESS start-up
In order to avoid any kind of negative undershoot on the load side during start-up, L6756D
performs a special sequence in enabling the drivers for both sections: during the soft-start
phase, the LS driver results to be disabled (LS = OFF - Gx set to HiZ and DRVON = 0) until
the first PWM pulse. After the first PWM pulse, Gx outputs switches between logic “0” and
logic “1” and DRVON is set to logic “1”.
This particular sequence avoids the dangerous negative spike on the output voltage that
can happen if starting over a pre-biased output.
Low-side MOSFET turn-on is masked only from the control loop point of view: protections
are still allowed to turn-ON the low-side MOSFET in case of overvoltage if needed.
Figure 10. LSLESS start-up: enabled (left) and disabled (right)
Output voltage positioning
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