L5985 STMicroelectronics, L5985 Datasheet - Page 21

• Manufacturer Part Number: L5985
• Description: IC REG SW STEP DOWN 2A 8-VFQFPN
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L5985

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.6 ~ 18 V
• Current - Output: 2A
• 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: 2 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: 497-6387 - BOARD EVAL FOR L5985
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L5985
Application information
The suggested maximum system bandwidth is equals to the switching frequency divided by
3.5 (F
/3.5), anyway lower than 100 kHz if the F
is set higher than 500 kHz.
SW
SW
= 2 A, L = 15 μH, C
= 22 μF, ESR < 1 mΩ,
For example with V
= 3.3 V, V
= 12 V, I
OUT
IN
O
OUT
the type III compensation network is:
,
,
,
,
,
,
R
4.99kΩ
R
1.1kΩ
R
150Ω
R
4.99kΩ
C
3.3nF
C
10nF
C
100pF
=
=
=
=
=
=
=
1
2
3
4
3
4
5
In
Figure 12
is shown the module and phase of the open loop gain. The bandwidth is about
75 kHz and the phase margin is 47°.
Doc ID 13006 Rev 5
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