L4974A STMicroelectronics, L4974A Datasheet - Page 10

• Manufacturer Part Number: L4974A
• Description: IC REG SW 3.5A 5.1V-40V 20-DIP
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L4974A

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 5.1 ~ 40 V
• Current - Output: 3.5A
• Frequency - Switching: 100kHz
• Voltage - Input: 15 ~ 50 V
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: 20-DIP (0.300", 7.62mm)
• Power - Output: 1.3W
• Output Voltage: 40 V
• Output Current: 3.5 A
• Input Voltage: 15 V to 50 V
• Switching Frequency: 90 KHz to 110 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: Through Hole
• Duty Cycle (max): 90 %
• No. Of Outputs: 1
• Power Dissipation Pd: 5W
• No. Of Pins: 20
• Filter Terminals: Through Hole
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6699-5; L4974A

L4974A
Figure 6a : Component Layout of fig.5 (1 : 1 scale). Evaluation Board Available
PART LIST
R
R
R
R
R
R
R
R
R
** C
* 2 capacitors in parallel to increase input RMS current capability.
* * 3 capacitors in parallel to reduce total output ESR.
10/22
* C
1
2
3
4
5
6
7
8
9
C
C
C
C
C
C
C
core 58310 MAGNETICS
45 TURNS 0.91mm (AWG 19)
COGEMA 949181
D1 = SB 560 (OR EQUIVALENT)
L1 = 150 H
= 30K
= 10K
= 15K
= 30K
= 22
= 4.7K
= see table A
= OPTION
= 4.7K
3
7
8
9
10
11
12
15
1
= C
= 390pF Film
= 22nF MKT 1837 (ERO)
= C
= 2.7nF KP 1830 (ERO)
= 0.33 F Film
= 1nF
= C
= 1 F Film
4
2
13
= 1000 F 63V EYF (ROE)
= C
= C
5
= C
14
= 100 F 40V EKR (ROE)
6
= 2,2 F 50V
Table A
Table B
SUGGESTED BOOSTRAP CAPACITORS
Operating Frequency
12V
15V
18V
24V
V
f = 100KHz
f = 200KHz
f = 500KHz
f = 20KHz
f = 50KHz
0
4.7k
4.7k
4.7k
4.7k
R
9
Boostrap Cap.c10
680nF
470nF
330nF
220nF
100nF
6.2kW
9.1k
12
18
R
7