L5983TR STMicroelectronics, L5983TR Datasheet - Page 20

• 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

Application information
20/43
Figure 10. Type III compensation network
In
and the open loop gain (G
Figure 11. Open loop gain: module Bode diagram
The guidelines for positioning the poles and the zeros and for calculating the component
values can be summarized as follows:
1.
2.
Equation 18
where K is the feed forward constant and 1/K is equal to 9.
3.
Figure 11
Choose a value for R
Choose a gain (R
Calculate C
the Bode diagram of the PWM and LC filter transfer function (G
4
by placing the zero at 50 % of the output filter double pole frequency (f
4
/R
1
1
LOOP
) in order to have the required bandwidth (BW), that means:
, usually between 1 kΩ and 5 kΩ.
Doc ID 13005 Rev 7
(f) = G
PW0
R
4
=
· G
BW K
----------------- - R
f
LC
LC
⋅
(f) · G
⋅
1
TYPEIII
(f)) is given.
PW0
· G
LC
L5983
(f))
LC
):