LM2574MX-ADJ/NOPB National Semiconductor, LM2574MX-ADJ/NOPB Datasheet - Page 10

• Manufacturer Part Number: LM2574MX-ADJ/NOPB
• Description: IC REG SIMPLE SWITCHER 14-SOIC
• Manufacturer: National Semiconductor
• Series: SIMPLE SWITCHER®r
• Type: Step-Down (Buck)r

Specifications of LM2574MX-ADJ/NOPB

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.23 ~ 37 V
• Current - Output: 500mA
• Frequency - Switching: 52kHz
• Voltage - Input: 4 ~ 40 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 14-SOIC (7.5mm Width)
• Power - Output: 750mW
• Dc To Dc Converter Type: Inverting/Step Down
• Pin Count: 14
• Input Voltage: 40V
• Output Voltage: 1.23 to 37V
• Switching Freq: 47 TO 58KHz
• Output Current: 500mA
• Efficiency: 77%
• Package Type: SOIC W
• Output Type: Adjustable
• Switching Regulator: Yes
• Mounting: Surface Mount
• Input Voltage (min): 4V
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Leaded Process Compatible: Yes
• Rohs Compliant: Yes
• Peak Reflow Compatible (260 C): Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM2574MX-ADJ; *LM2574MX-ADJ/NOPB; LM2574MX-ADJ; LM2574MX-ADJTR

www.national.com
Test Circuit and Layout Guidelines
C
C
D1 — Schottky, 11DQ06
L1 — 330 µH, 52627
R1 — 2k, 0.1%
R2 — 6.12k, 0.1%
As in any switching regulator, layout is very important. Rap-
idly switching currents associated with wiring inductance
generate voltage transients which can cause problems. For
minimal inductance and ground loops, the length of the leads
indicated by heavy lines should be kept as short as pos-
sible. Single-point grounding (as indicated) or ground plane
construction should be used for best results. When using the
Adjustable version, physically locate the programming resis-
tors near the regulator, to keep the sensitive feedback wiring
short.
IN
OUT
— 22 µF, 75V
— 220 µF, 25V
Aluminum Electrolytic
Aluminum Electrolytic
(for 5V in, 3.3V out, use
100 µH, RL-1284-100)
Adjustable Output Voltage Version
Fixed Output Voltage Versions
FIGURE 2.
10
DS011394-11
DS011394-12