L5981 STMicroelectronics, L5981 Datasheet - Page 29

• Manufacturer Part Number: L5981
• Description: IC REG SW STEP DOWN 1A 8-VFQFPN
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L5981

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.6 ~ 18 V
• Current - Output: 1A
• 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
• Output Voltage: 3 V
• Output Current: 1 A
• Input Voltage: 2.9 V to 18 V
• Switching Frequency: 220 KHz to 275 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 100 %
• Low Dropout Operation: 100 % duty cycle
• For Use With: 497-6385 - BOARD EVAL FOR L5981
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L5981
5.7
Application circuit
In
Figure 18. Demonstration board application circuit
Table 9.
VIN=3.3V to 18V
VIN=3.3V to 18V
VIN=3.3V to 18V
VIN=3.3V to 18V
Figure 18
10uF
10uF
10uF
10uF
C1
C1
C1
C1
Reference
C1
C2
C3
C4
C5
C6
R1
R2
R3
R4
R5
D1
L1
68nF
68nF
68nF
68nF
the demonstration board application circuit is shown.
C6
C6
C6
C6
Component list
GRM31CR61E106KA12
GRM32ER61E226KE15
STPS2L25V
7447779115
GND
GND
GND
GND
VCC
VCC
VCC
VCC
INH
INH
INH
INH
R5 100K
R5 100K
Part number
8
8
8
8
7
7
7
7
3
3
3
3
FSW
FSW
FSW
FSW
Doc ID 13004 Rev 6
6
6
6
6
L5985
L5981
L5985
L5981
COMP
COMP
COMP
COMP
COMP
COMP
COMP
COMP
4
4
4
4
R4 3.9K
R4 3.9K
1
1
1
1
1
1
1
1
2
2
2
2
5
5
5
5
C5 150pF
C5 150pF
10 μF, 25 V
22 μF, 25 V
3.3 nF, 50 V
10 nF, 50 V
150 pF, 50 V
68 nF, 25 V
4.99 kΩ, 1 %, 0.1 W 0603
1.1 kΩ, 1 %, 0.1 W 0603
180 Ω, 1 %, 0.1 W 0603
3.9 kΩ, 1 %, 0.1 W 0603
100 kΩ, 1 %, 0.1 W 0603
2 A, 25 V
15 μH, 20 %, 2.2 A
OUT
OUT
OUT
OUT
SYNCH
SYNCH
SYNCH
SYNCH
FB
FB
FB
FB
C4 10nF
C4 10nF
C4 10nF
C4 10nF
Description
R2 1.1K
R2 1.1K
R2 1.1K
R2 1.1K
D1
D1
D1
D1
STPS2L25U
STPS2L25U
STPS2L25U
STPS2L25U
L1 15uH
L1 15uH
R3 180
R3 180
R1 4.99K
R1 4.99K
R1 4.99K
R1 4.99K
Application information
MURATA
MURATA
STMicroelectronics
Wurth elektronik
C3 3.3nF
C3 3.3nF
Manufacturer
Vout=3.3V
Vout=3.3V
Vout=3.3V
Vout=3.3V
22uF
22uF
22uF
22uF
C2
C2
C2
C2
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