L6722TR STMicroelectronics, L6722TR Datasheet - Page 20

• 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

7 Output voltage positioning
7.3
20/34
Maximum duty cycle limitation
To provide proper time for current-reading in order to equalize the current carried by each
phase, the device implements a duty-cycle limitation. This limitation is not fixed but it is linearly
variable with the current delivered to the load as follow:
Duty Cycle limitation is variable with the delivered current to provide fast load transient
response at light load as well as assuring robust over-current protection.
Figure 10
T
the limited-T
cross-point. In this case, the output voltage starts to decrease following the resulting
characteristic (dotted in
Figure 10. Maximum duty-cycle limitation
ON
0.80 V
0.40 V
limitation imposed by the previous relationship. If the desired output characteristic crosses
V
OUT
IN
IN
shows the maximum output voltage that the device is able to regulate considering the
ON
maximum output voltage, the output resulting voltage will start to drop after the
Limted-T
Maximum Output Voltage
I
(I
OCP
Figure
ON
ISENx
T
ON max
Output Char.
= 3 x I
(
= 35µA)
10) until UVP is detected or anyway until I
OCPx
)
=
⎧
⎨
⎩
0.80
0.40
I
OUT
⋅
⋅
0.80 V
0.40 V
T
T
SW
SW
V
OUT
IN
IN
I
I
ISENx
ISENx
Limted-T
Desired output Char.
Resulting Output Char.
UVP Threshold
=
=
0µA
35µA
I
Limited T
(I
OCP
ON
ISENx
Output Char.
= 3 x I
= 35µA)
ISENx
ON
OCPx
= 35µA.
I
OUT
L6722