MP1580HS-LF Monolithic Power Systems (MPS), MP1580HS-LF Datasheet - Page 8

• Manufacturer Part Number: MP1580HS-LF
• Description: Switching Converters, Regulators & Controllers 2A 380kHz Step-Down Converter
• Manufacturer: Monolithic Power Systems (MPS)

Specifications of MP1580HS-LF

• Rohs: yes
• Output Voltage: 21 V
• Output Current: 2 A
• Input Voltage: 4.75 V to 25 V
• Switching Frequency: 380 kHz
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-8

Determine
capacitor, C6, is required. It is required if the
ESR zero of the output capacitor happens at
less than four times the crossover frequency.
Or:
or
If
compensation capacitor. Determine the value
by the equation:
Where R
output capacitor.
For example:
V
C2= 22μF Ceramic (ESR = 10mΩ)
Use the nearest standard value of 10kΩ.
Use a standard value of 2nF
which is less than 1, therefore no second
compensation capacitor is required.
MP1580 Rev. 3.0
10/10/2007
OUT
Table 5—Recommended Components for
R
this
3
1.22V
= 3.3V
V
1.5V
1.8V
2.5V
3.3V
5.0V
≈
OUT
C
(
3
. 1
ESR(MAX)
Standard Output Voltages
is
>
37
2
. 7
. 0
π
TM
×
if
34
8
×
22
the
C
10
π
C
6
×
×
×
8
2
10
the
=
is the maximum ESR of the
C
)
(
×
10
2.32kΩ
4.75kΩ
10.5kΩ
16.9kΩ
30.9kΩ
22
2
×
C
R
−
V
case,
×
5
(
R1
0Ω
2
OUT
×
22
ESR
×
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
R
×
×
10
10
second
R
ESR
R
×
R
3
3
×
10
−
ESR
6
3
×
f
×
)
C
−
R
add
×
(
6
f
MAX
=
C
ESR
)
3
×
3 .
. 0
≥
)
(
014
L1 Minimum
. 3
1
≥
=
compensation
the
) 3
1
1
6.8μH
6.8μH
6 .
10μH
10μH
15μH
22μH
=
nF
. 9
© 2007 MPS. All Rights Reserved.
second
k 9
www.MonolithicPower.com
Ω
MP1580 – 2A, 380KHz STEP-DOWN CONVERTER
Negative Output Voltage
The MP1580 can be configured as a buck-
boost regulator to supply negative output
voltage.
Because the GND pin of the IC is now
connected to the negative output voltage, the
maximum allowable input voltage is the IC input
voltage rating (25V) minus the negative output
voltage value. A typical application circuit is
shown in Figure 3.
External Bootstrap Diode
It is recommended that an external bootstrap
diode be added when the system has a 5V
fixed input or the power supply generates a 5V
output. This helps improve the efficiency of the
regulator. The bootstrap diode can be a low
cost one such as IN4148 or BAT54.
This diode is also recommended for high duty
cycle operation (when
output voltage (V
Figure 2—External Bootstrap Diode
MP1580
OUT
>12V) applications.
SW
BS
V
V
OUT
IN
MP1580_F02
5V
10nF
>65%) and high
8