L5983TR STMicroelectronics, L5983TR Datasheet - Page 21

• Manufacturer Part Number: L5983TR
• Description: IC REG SW 1.5A STEPDOWN 8-VFQFPN
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L5983TR

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.6 ~ 18 V
• Current - Output: 1.5A
• Frequency - Switching: 250kHz ~ 1MHz
• Voltage - Input: 2.9 ~ 18 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-VFQFN, 8-VFQFPN
• Power - Output: 1.5W
• For Use With: 497-6386 - BOARD EVAL FOR L5983
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6860-2; L5983TR

L5983
Equation 19
4.
Equation 20
5.
Equation 21
The suggested maximum system bandwidth is equal to the switching frequency divided by
3.5 (F
For example, with V
mΩ, the type III compensation network is:
In
77 kHz and the phase margin is 47°.
R
1
Figure 12
=
Calculate C
Set the first pole also at four times the system bandwidth and also the second zero at
the output filter double pole:
4.99kΩ
SW
/3.5), but lower than 100 kHz if the F
,
the module and phase of the open loop gain is shown. The bandwidth is about
R
5
2
by placing the second pole at four times the system bandwidth (BW):
=
OUT
1.1kΩ
= 3.3 V, V
R
,
3
R
=
3
Doc ID 13005 Rev 7
-------------------------- -
4 BW
----------------- 1
=
⋅
f
C
LC
120Ω
5
R
IN
1
=
= 12 V, I
–
------------------------------------------------------------- -
2π R
C
,
4
,
R
⋅
=
4
4
=
-------------------------- -
π R
O
⋅
SW
⋅
4.99kΩ
C
= 1.5 A, L = 22 μH, C
C
C
4
1
4
4
⋅
3
is set higher than 500 kHz.
⋅
4 BW
=
f
LC
⋅
,
---------------------------------------- -
2π R
⋅
C
–
3
3
1
=
1
⋅
4 BW
4.7nF
⋅
,
Application information
OUT
C
4
=
= 22 μF, ESR < 1
10nF
,
C
5
=
68pF
21/43