LM2597, LM2597HV
SNVS119C –MARCH 1998–REVISED APRIL 2013
www.ti.com
Table 1. LM2597/LM2597HV Fixed Voltage Quick Design Component Selection Table (continued)
Conditions
Inductor
Output Capacitor
Surface Mount
Through Hole
Panasonic Nichicon
HFQ Series
Voltage
Output
(V)
Current
Load
(A)
Voltage
Max Input
(V)
AVX TPS
Series
(μF/V)
Sprague
595D Series
(μF/V)
Inductance
Inductor
(#)
PL Series
(μF/V)
(μH)
(μF/V)
8
47
L13
L21
L20
L19
L10
L9
180/16
180/16
120/25
120/25
82/16
120/16
120/16
82/25
82/25
82/25
82/25
82/25
82/25
82/25
180/16
180/16
120/25
120/25
82/16
120/16
120/16
82/25
82/25
82/25
82/25
82/25
82/25
82/25
100/16
100/16
100/16
100/16
100/16
100/16
100/16
100/16
100/16
100/16
100/16
100/16
100/16
100/16
33/25
33/25
33/25
33/25
33/25
33/25
33/25
15/25
15/25
15/25
15/25
15/25
15/25
15/25
10
15
40
9
68
0.5
0.2
0.5
0.2
100
150
150
220
330
68
5
20
40
15
18
30
40
15
20
40
L8
L21
L19
L27
L26
L11
L9
150
220
330
100
220
330
12
L17
LM2597/LM2597HV Series Buck Regulator Design Procedure (Adjustable Output)
PROCEDURE (Adjustable Output Voltage Version)
EXAMPLE (Adjustable Output Voltage Version)
Given:
Given:
VOUT = Regulated Output Voltage
VOUT = 20V
VIN(max) = Maximum Input Voltage
VIN(max) = 28V
ILOAD(max) = 0.5A
ILOAD(max) = Maximum Load Current
F = Switching Frequency (Fixed at a nominal 150 kHz).
F = Switching Frequency (Fixed at a nominal 150 kHz).
1. Programming Output Voltage (Selecting R1 and R2, as shown in 1. Programming Output Voltage (Selecting R1 and R2, as shown in
Figure 31)
Figure 31)
Use the following formula to select the appropriate resistor values.
Select R1 to be 1 kΩ, 1%. Solve for R2.
Select a value for R1 between 240Ω and 1.5 kΩ. The lower resistor
values minimize noise pickup in the sensitive feedback pin. (For the
lowest temperature coefficient and the best stability with time, use
1% metal film resistors.)
R2 = 1k (16.26 − 1) = 15.26k, closest 1% value is 15.4 kΩ.
R2 = 15.4 kΩ.
14
Submit Documentation Feedback
Copyright © 1998–2013, Texas Instruments Incorporated
Product Folder Links: LM2597 LM2597HV
TI [ TEXAS INSTRUMENTS ]
