LM3444MM/NOPB National Semiconductor, LM3444MM/NOPB Datasheet - Page 14

• Manufacturer Part Number: LM3444MM/NOPB
• Description: IC LED DRIVER AC-DC 10MSOP
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LM3444MM/NOPB

• Constant Current: Yes
• Constant Voltage: Yes
• Internal Driver: No
• Type - Primary: General Purpose
• Type - Secondary: High Brightness LED (HBLED)
• Mounting Type: Surface Mount
• Topology: AC DC Offline Switcher, PWM, Step-Down (Buck)
• Number Of Outputs: 1
• Frequency: Adjustable/Selectable
• Voltage - Supply: 8 V ~ 13 V
• Package / Case: 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
• No. Of Outputs: 1
• Output Current: 100mA
• Operating Temperature Range: -40°C To +125°C
• Driver Case Style: MSOP
• No. Of Pins: 10
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Operating Temperature: -
• Other names: LM3444MM/NOPB; LM3444MM/NOPBTR

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3.
4.
5.
6.
7.
Calculate t
Calculate t
t
Calculate C11 and R4:
Choose current through R4: (between 50 µA and 100 µA)
70 µA
Use a standard value of 365 kΩ
ON(MIN)
> 200 ns:
OFF
ON(MIN)
at V
at high line to ensure that
BUCK
nominal line voltage:
14
8.
9.
10. Use standard value of 120 pF
11. Calculate ripple current: 400 mA X 0.30 = 120 mA
12. Calculate inductor value at t
13. Choose C10: 1.0 µF 200V
14. Calculate valley-fill capacitor values: V
Calculate C11:
90V
maximum at full load and low line.
i) equals P
2.77 ms, and then C
C9 = 22 µF
AC
, V
BUCK
OUT
/V
minimum equals 60V. Set droop for 20V
BUCK
TOTAL
(270 mA), dV equals 20V, dt equals
equals 37 µF. Therefore C7 =
OFF
= 3 µs:
AC
low line =