Features: · Requires few external components
· Family of standard inductors and transformers
· NPN output switches 3.0A, can stand off 65V
· Wide input voltage range: 4V to 40V
· Current-mode operation for improved transient response, line regulation, and current limit
· 100 kHz switching frequency
· Internal soft-start function reduces in-rush current during start-up
· Output transistor protected by current limit, under voltage lockout, and thermal shutdown
· System Output Voltage Tolerance of ±4% max over line and load conditionsApplication·Flyback regulator
· Multiple-output regulator
· Simple boost regulator
· Forward converterSpecifications
| Output Range |
1.23V min, 5V, 12V, 3.3V |
| Switch Current |
3 Amp |
| Input Min Voltage |
4 Volt |
| Input Max Voltage |
40 Volt |
| Feedback Voltage |
3.3, 1.23, 12, 5 Volt |
| Frequency Max |
100 kHz |
| Efficiency (peak) |
93, 80, 76 % |
| Sync Pin |
No |
| Adj Switch Frequency |
No |
| Frequency Min |
100 kHz |
| On/Off Pin |
No |
| Error Flag |
No |
| SoftStart |
Yes |
| Special Features |
SIMPLE SWITCHER regulator |
| Topology |
Boost, Flyback |
| Step-Up |
Yes |
| Inverting |
No |
| Flyback |
Yes |
| RegType |
Switching Regulator |
| Adjustable Output |
Yes, No |
| Temperature Min |
-40 deg C |
| Temperature Max |
125 deg C |
| Regulator Family |
SIMPLE SWITCHER |
| View Using Catalog |
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
Input Voltage ................................................−0.4VVIN 45V
Switch Voltage.................................................. .−0.4V 65V
Switch Current (Note 2) Internally Limited
Compensation Pin Voltage .....................−0.4V VCOMP 2.4V
Feedback Pin Voltage ...............................−0.4VVFB 2 VOUT
Storage Temperature Range ...........................−65 to +150
Lead Temperature
(Soldering, 10 sec.) ..........................................................260
Maximum Junction Temperature(Note 3) ..........................150
Power Dissipation (Note 3) Internally Limited
Minimum ESD Rating
(C = 100 pF, R = 1.5 k).................................................... 2kVDescriptionThe LM2585 series of regulators are monolithic integrated circuits specifically designed for flyback, step-up (boost), and forward converter applications. The device is available in 4 different output voltage versions: 3.3V, 5.0V, 12V, and adjustable.
Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Included in the datasheet are typical circuits of boost and flyback regulators. Also listed are selector guides for diodes and capacitors and a family of standard inductors and flyback transformers designed to work with these switching regulators.
The power switch is a 3.0A NPN device that can stand-off 65V. Protecting the power switch are current and thermal limiting circuits, and an undervoltage lockout circuit. This IC contains a 100 kHz fixed-frequency internal oscillator that permits the use of small magnetics. Other features include soft start mode to reduce in-rush current during start up, current mode control for improved rejection of input voltage and output load transients and cycle-by-cycle current limiting. An output voltage tolerance of ±4%, within specified input voltages and output load conditions, is guaranteed for the power supply system.
Reliability Metrics
| Part Number |
Process |
EFR Reject |
EFR Sample Size |
PPM |
LTA Rejects |
LTA Device Hours |
FITS |
MTTF (Hours) |
| LM2585S-12 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585S-3.3 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585S-5.0 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585S-ADJ |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585SX-12 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585SX-3.3 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585SX-5.0 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585SX-ADJ |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585T-12 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585T-3.3 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585T-5.0 |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
| LM2585T-ADJ |
SLM |
0 |
42786 |
0 |
0 |
3352500 |
2 |
951281028 |
Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.For more information on Reliability Metrics, please click here.
Design Tools
| Title |
Size in Kbytes |
Date |
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| SimpleSwitcher® DC-DC Converters Design Software |
|
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View |
|
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If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
Application Notes
| Title |
Size in Kbytes |
Date |
|
| AN-1082: Application Note 1082 Adjust or Synchronize LM2586/88 Switching Frequency |
50 Kbytes |
4-Oct-04 |
Download |
AN-1082 (Japanese): Application Note 1082 Adjust or Synchronize LM2586/88 Switching Frequency
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
85 Kbytes |
|
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| AN-1061: Application Note 1061 Power Conversion in Line-Powered Equipment |
162 Kbytes |
1-Oct-02 |
Download |
AN-1061 (Japanese): Application Note 1061 Power Conversion in Line-Powered Equipment
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
215 Kbytes |
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If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
More Application Notes
| Title |
Size in Kbytes |
Date |
|
| AN-1095: Application Note 1095 Design of Isolated Converters Using Simple Switchers |
398 Kbytes |
1-May-04 |
Download |
AN-1095 (Japanese): Application Note 1095 Design of Isolated Converters Using Simple Switchers
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
403 Kbytes |
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AN-1095 (Chinese): Application Note 1095 Design of Isolated Converters Using Simple Switchers
|
436 Kbytes |
|
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
| AN-116: Application Note 116 Use the LM158/LM258/LM358 Dual, Single Supply Op Amp |
101 Kbytes |
1-Oct-02 |
Download |
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
LM2585 Data Sheet
