LM2575-3.3WU Micrel Inc, LM2575-3.3WU Datasheet - Page 9

• Manufacturer Part Number: LM2575-3.3WU
• Description: 1A Step-Down SMPS Regulator ( )
• Manufacturer: Micrel Inc
• Type: Step-Down (Buck)r

Specifications of LM2575-3.3WU

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3.3V
• Current - Output: 1A
• Frequency - Switching: 42kHz ~ 63kHz
• Voltage - Input: 4 ~ 40 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: D²Pak, TO-263 (5 leads + tab)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Functional Characteristics
Functional Diagrams
Micrel, Inc.
May 2009
V
Voltage
Change
Current
Output
Output
OUT
= 5V
+100mV
–100mV
1.0A
0.5A
0
0
Load Transient Response
V IN
V IN
FB
FB
1
4
1
4
Note: Pin numbers are for the TO-220 package
100µs/div.
REFERENCE
REFERENCE
BAND-GAP
BAND-GAP
1.23V
1.23V
3.1k
1.0k
(circuit of Figure 1)
+
-
+
-
FIXED GAIN
ERROR AMP
FIXED GAIN
ERROR AMP
OSCILLATOR
OSCILLATOR
52 kHz
52 kHz
Adjustable Regulator
+
+
-
-
Fixed Regulator
REGULATOR
COMPARATOR
COMPARATOR
REGULATOR
RESET
RESET
INTERNAL
INTERNAL
SHUTDOWN
SHUTDOWN
9
THERMAL
THERMAL
ON/OFF
ON/OFF
DRIVER
DRIVER
A
B
C
D
A: Output pin voltage 10V/div
B: Output pin current 1A/div
C: Inductor current 0.5A/div
D: Output ripple voltage 20 mV/div. AC coupled
Horizontal Time Base: 5µs/div
CURRENT
CURRENT
LIMIT
LIMIT
V
10V
.5A
OUT = 5V
1A
1A
0
0
0
1 AMP
SWITCH
SWITCH
1 AMP
V
IN = 20V
Switching Waveforms
5
2
3
5
2
3
ON/OFF
OUT
GND
ON/OFF
OUT
GND
M9999-051209-B
LM2575