l6730cqtr STMicroelectronics, l6730cqtr Datasheet - Page 25

• Manufacturer Part Number: l6730cqtr
• Description: Adjustable Step-down Controller With Synchronous Rectification
• Manufacturer: STMicroelectronics

L6730C - L6730D
5.9
5.10
Figure 20. External resistor
During the constant-current-protection if the Vout becomes lower than 80% of the programmed
value an UV (under-voltage) is detected and the device enters in HICCUP mode. The under-
voltage-lock-out (UVLO) is adjustable by the multifunction pin (see
It’s possible to set two different thresholds:
●
●
Working with a 12V BUS, setting the UVLO at 8.6V can be very helpful to limit the input current
in case of BUS fall.
Adjustable masking time
By connecting the masking-time pin to V
values for the peak -current-protection leading edge blanking time. This is useful to avoid any
false OCP trigger due to spikes and oscillations generated at the turn-on of the high-side
MOSFET(s). The amount of this noise depends a lot on the layout, MOSFETs, free-wheeling
diode, switched current and input voltage. In case of good layout and medium current, the
minimum masking time can be chosen, while in case of higher noise, it’s better to select to
maximum one. Connecting Tmask pin to V
connecting it to GND the resulting masking time is about 260ns.
Multifunction pin (S/O/U L6730C) (CC/O/U L6730D)
With this pin it is possible:
●
●
●
Table 6
4.2V for 5V Bus
8.6V for 12V Bus
To enable-disable the sink-mode-current capability (L6730C) or the constant current
protection (L6730D) at the end of the soft-start;
To enable-disable the latch-mode for the OVP;
To set the UVLO threshold for 5V BUS and 12V BUS.
shows how to set the different options through an external resistor divider:
R2
R1
CCDR
CCDR
CC/O/U
VCCDR
S/O/U
or GND it is possible to select two different
L6730C/D
the masking time is about 400ns while
L6730/B
Chapter 5.10 on page
Device description
25).
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