Datasheet

Pin connections and functions L6730 - L6730B
10/52 Doc ID 11938 Rev 3
11 OCL
A resistor connected from this pin to ground sets the valley- current-limit.
The valley current is sensed through the low-side MOSFET(s). The
internal current generator sources a current of 100μA (I
OCL
) from this pin
to ground through the external resistor (R
OCL
). The over-current threshold
is given by the following equation:
Connecting a capacitor from this pin to GND helps in reducing the noise
injected from V
CC
to the device, but can be a low impedance path for the
high-frequency noise related to the GND. Connect a capacitor only to a
“clean” GND.
12 OCH
A resistor connected from this pin and the high-side MOSFET(s) drain
sets the peak-current-limit. The peak current is sensed through the high-
side MOSFET(s). The internal 100μA current generator (I
OCH
) sinks a
current from the drain through the external resistor (R
OCH
). The over-
current threshold is given by the following equation:
13 PHASE
This pin is connected to the source of the high-side MOSFET(s) and
provides the return path for the high-side driver. This pin monitors the
drop across both the upper and lower MOSFET(s) for the current limit
together with OCH and OCL.
14 HGATE This pin is connected to the high-side MOSFET(s) gate.
15 BOOT
The high-side driver is supplied through this pin. Connect a capacitor from
this pin to the PHASE pin, and a diode from V
CCDR to this pin (cathode
versus BOOT).
16 PGND
This pin has to be connected closely to the low-side MOSFET(s) source
in order to reduce the noise injection into the device. Connect to the PCB
power ground plane.
17 LGATE This pin is connected to the low-side MOSFET(s) gate.
18
V
CCDR
5V internally regulated voltage. It is used to supply the internal drivers
and as a voltage reference. Filter it to GND with at least a 1µF ceramic
cap.
19
V
CC
Supply voltage pin. The operative supply voltage range is from 4.5V to
14V.
20 PGOOD
This pin is an open collector output and it is pulled low if the output
voltage is not within the specified thresholds (90%-110%). If not used it
may be left floating. Pull up this pin to V
CCDR
with a 10K resistor to obtain
a logical signal.
- Thermal PAD
Thermal Pad connects the silicon substrate and makes good thermal
contact with the PCB. Connect to the PCB power ground plane.
Table 4. Pin connection (continued)
Pin n. Name Description
DSonLS
R2
OCL
R
OCL
I
VALLEY
I
⋅
⋅
=
DSonHS
R
OCH
R
OCH
I
PEAK
I
⋅
=