L6722TR STMicroelectronics, L6722TR Datasheet - Page 25

• Manufacturer Part Number: L6722TR
• Description: IC BUCK ADJ 2A TRPL 36VFQFPN
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L6722TR

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 3
• Voltage - Output: Adj to 0.8V
• Current - Output: 2A
• Frequency - Switching: 100kHz
• Voltage - Input: 12V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 36-VFQFN, 36-VFQFPN
• Power - Output: 3.5W
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-5904-2

L6722
Where V
threshold is crossed, all mosfets are turned off, the FAULT pin is driven high and the device
stops working. Cycle the power supply or the INH pin to restart operation.
The maximum average current during the Constant-Current behavior results:
in this particular situation, the switching frequency for each phase results reduced. The ON time
is the maximum allowed T
The trans-conductance resistor R
bottom of the inductor current ripple and also considering the additional current delivered
during the quasi-constant-current behavior as previously described in the worst case
conditions.
Figure 14. Constant current operation
I
I
PEAK
OCPx
I
MAX
PEAK
T
ON(max)
outMIN
=
R
I
T
ISENx
OCPx
SW
is the UVP threshold, (inductor saturation must be considered). When that
LS ON Skipping
Clock Cycles
+
T
=
V
------------------------------------------ -
OFF
MAX tot
I
-------------------------------------------------------------------- -
IN
OCPx max
–
,
=
ON(max)
V
L
OUT min
L
(
⋅
I
OCTH min
=
T
ON(max)
I
------------------------------------ -
(
PEAK
)
3
ISENx
⋅
while the OFF time depends on the application:
⋅
T
V
(
R
)
SW
I
⋅
MAX
OUT
dsON max
–
can be designed considering that the device limits the
T
I
)
OCPx
ON max
=
(
(
3
⋅
)
)
where
⎛
⎝
I
=
OCPx
I
OCPx
f
I
=
OCPx
+
9 Output voltage monitor and protections
--------------------------------------------- -
T
I
------------------------------------ -
0.40 V
+
PEAK
ON max
V
V
------------------------------------------ -
OUT
(
=
IN
IN
(I
2
–
–
I
--------------------------- -
DROOP
OUT OCP
I
1
OCP
V
I
)
OCPx
+
Constant Current (Exploded)
Limted-T
Resulting Out. Char.
UVP Threshold
OUT min
L
= N x I
T
3
(
= N x 35µA)
OFF
(
⎞
⎠
OCPx
ON
)
–
)
Char.
⋅
∆I
----------- -
2
0.40
PP
Droop Effect
⋅
I
MAX,tot
T
SW
25/34
I
OUT