AN937 Datasheet, PDF (25/29 Pages) STMicroelectronics – The L4971 is a 1.5 A monolithic dc-dc converter

AN937
Figure 30. Phase Bode plot open loop
EXTERNAL LOOP GAIN PHASE
180
157.5
135
112.5
90
67.5
45
22.5
0
0.1
1
Vout=3.3V
Vout=5V
Vout=12V
Vout=15V
Vout=18V
Vout=24V
10
100
1 ^.10³
1 ^.10⁴
Frequency [Hz]
Typical application
1 ^.10⁵
1 ^.10⁶
Table 1. Component list (fsw = 200 kHz, V_OUT= 5 V)
Reference
Description
Part number
Manufacturer
R1
Resistor 12 KΩ 1% 1/4W
R2
Resistor 2.7 KΩ 1% 1/4W
R3
Resistor 4.99 KΩ 1% 1/4W
R4
Resistor 15 KΩ 1% 1/4W
R5
Not mounted
C1
Capacitor 180 μF 63V
EKY-630ELL181MJ20S Nippon Chemi-con
C2 - C6
Capacitor 220 nF 63V
C3
Capacitor 2.2 nF 100V
C4
Capacitor 22 nF 50V
C5
Capacitor 82 pF 50V
C7 - C11
Capacitor 100 nF 100V
C8
Not mounted
C9
Capacitor 4.7 nF 50V
C10
Capacitor 150 μF 35V
EKY-350ELL151MHB5D Nippon Chemi-con
L1
120 μH I_RMS = 1.85A I_SAT = 1.92A
MSS1260-124KLD
Coilcraft
U1
L4971
STMicroelectronics
Doc ID 5655 Rev 15
25/29