L7981 STMicroelectronics, L7981 Datasheet - Page 26

• Manufacturer Part Number: L7981
• Description: Switching Converters, Regulators & Controllers 3A Step-Down Reg 3A DC 4.5-28V 250Khz
• Manufacturer: STMicroelectronics

Specifications of L7981

• Output Voltage: 0.6 V to 3 V
• Output Current: 3 A
• Input Voltage: 4.5 V to 28 V
• Switching Frequency: 250 KHz
• Operating Temperature Range: - 55 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 100 %
• Package / Case: QFPN-8
• Low Dropout Operation: 100% duty cycle
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Application informations
26/44
Equation 28
For example with V
type II compensation network is:
In
21 kHz and the phase margin is 45°.
Figure 15
is shown the module and phase of the open loop gain. The bandwidth is about
R
1
OUT
=
1.1kΩ
=5 V, V
,
IN
R
Doc ID 15182 Rev 3
2
=24 V, I
C
=
5
150Ω
=
------------------------------------------------------------- -
2π R
O
,
⋅
=3 A, L=18 μH, C
R
4
4
⋅
C
=
C
4
4.99kΩ
4
⋅
4 BW
⋅
,
–
1
C
OUT
4
=
=330 μF, ESR=35 mΩ, the
82nF
,
C
5
=
68pF
L7981