L5981 STMicroelectronics, L5981 Datasheet - Page 24

• 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

Application information
24/37
Equation 25
For example with V
ESR = 100 mΩ, the type II compensation network is:
In
33 kHz and the phase margin is 46°.
Figure 15
is shown the module and phase of the open loop gain. The bandwidth is about
R
1
OUT
=
1.1kΩ
= 3.3 V, V
,
R
Doc ID 13004 Rev 6
2
C
IN
=
5
= 12 V, I
249Ω
=
------------------------------------------------------------- -
2π R
,
⋅
4
R
O
⋅
4
= 1 A, L = 33 μH, C
C
=
C
4
10kΩ
4
⋅
4 BW
⋅
,
–
C
1
4
=
10nF
OUT
,
C
= 220 μF,
5
=
100pF
L5981