LM2576SX-3.3/NOPB National Semiconductor, LM2576SX-3.3/NOPB Datasheet - Page 13

• Manufacturer Part Number: LM2576SX-3.3/NOPB
• Description: IC REG SW 3.3V 3A STP DN TO263-5
• Manufacturer: National Semiconductor
• Series: SIMPLE SWITCHER®r
• Type: Step-Down (Buck)r

Specifications of LM2576SX-3.3/NOPB

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3.3V
• Current - Output: 3A
• Frequency - Switching: 52kHz
• Voltage - Input: 4 ~ 40 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: D²Pak, TO-263 (5 leads + tab)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Other names: *LM2576SX-3.3; *LM2576SX-3.3/NOPB; LM2576SX-3.3

LM2576 Series Buck Regulator Design Procedure
Given: V
Maximum Input Voltage I
Current F = Switching Frequency (Fixed at 52 kHz)
1. Programming Output Voltage (Selecting R1 and R2,
as shown in Figure 2) Use the following formula to select
the appropriate resistor values.
coefficient and stability with time, use 1% metal film resis-
tors)
PROCEDURE (Adjustable Output Voltage Versions)
R
1
can be between 1k and 5k. (For best temperature
OUT
= Regulated Output Voltage V
LOAD
(Max) = Maximum Load
IN
(Max) =
FIGURE 7. LM2576(HV)-ADJ
13
Given: V
52 kHz
1. Programming Output Voltage (Selecting R1 and R2)
R
2
EXAMPLE (Adjustable Output Voltage Versions)
= 1k (8.13 − 1) = 7.13k, closest 1% value is 7.15k
OUT
= 10V V
(Continued)
01147613
IN
(Max) = 25V I
LOAD
(Max) = 3A F =
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