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
.Adjustable switching frequency: 100 kHz to 200 kHz
.External shutdown capability
. Draws less than 60 A when shut down
.Frequency synchronization
.Current-mode operation for improved transient response, line regulation, and current limit
.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
.Forward converter
.Multiple-output regulator
.Simple boost regulatorSpecificationsIf Military/Aerospace specified devices are required,
pleasecontacttheNationalSemiconductorSalesOffice/
Distributors for availability and specifications.
Input Voltage -0.4V VIN 45V
Switch Voltage -0.4V VSW 65V
Switch Current (Note 2)Internally Limited
Compensation Pin Voltage -0.4V VCOMP 2.4V
Feedback Pin Voltage -0.4V VFB 2VOUT
ON /OFF Pin Voltage -0.4V VSH 6V
Sync Pin Voltage -0.4V VSYNC 2V
Power Dissipation (Note 3) Internally Limited
Storage Temperature Range-65?C to +150
Lead Temperature (Soldering, 10sec.) 260
Maximum Junction Temperature
(Note 3) 150
Minimum ESD Rating
(C = 100 pF, R = 1.5 k) 2kV
| 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 |
200 kHz |
| Efficiency (peak) |
93, 80, 76 % |
| Sync Pin |
Yes |
| Adj Switch Frequency |
Yes |
| Frequency Min |
100 kHz |
| On/Off Pin |
Yes |
| 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 |
DescriptionThe LM2586 series of regulators are monolithic integrated circuitsspecificallydesignedforflyback,step-up(boost),and forward converter applications. The LM2586 is available in 4 differentoutputvoltageversions:3.3V,5.0V,12V,andadjust-able.
Requiring a minimum number of external components,these regulatorsare cost effective, and simple to use. Included in the datasheet are typical circuits of boost and flyback regula- tors.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 an adjustable frequency oscillator that can be pro- grammed up to 200 kHz. The oscillator can also be synchro- nized with other devices, so that multiple devices can oper- ate at the same switching frequency.
Other features of LM2586 include soft start mode to reduce in-rush cur- rent during start up, and current mode control for improved rejection of input voltage and output load transients and cycle-by-cycle current limiting. The device also has a shut- down pin, so that it can be turned off externally. An output voltagetoleranceof ±4%,withinspecifiedinputvoltagesand output load conditions, is guaranteed for the power supply system.
LM2586 Data Sheet
