Features: `Ultra-high efficiency up to 96%
`4V to 14V input voltage range
`Internal high-side MOSFET with low RDS(ON) = 0.033W
`300 kHz fixed frequency internal oscillator
`Low-side drive for synchronous operation
`Guaranteed less than 12 A shutdown current
`Patented current sensing for current mode control
`Programmable soft-start
`Input undervoltage lockout
`Output overvoltage shutdown protection
`Output undervoltage shutdown protection
`Thermal Shutdown
`16-pin TSSOP packageApplication·Hard disk drives
·Internet appliances
·TFT monitors
·Computer peripherals
·Battery powered devicesPinout
Specifications
| Output Current |
2500 mA |
| Input Min Voltage |
4 Volt |
| Input Max Voltage |
14 Volt |
| Output Min |
3.3, 1.24 Volt |
| Output Max |
3.3, 13 Volt |
| Frequency Min |
300 kHz |
| Frequency Max |
300 kHz |
| Efficiency (peak) |
90 % |
| On/Off Pin |
Yes |
| Error Flag |
No |
| SoftStart |
Yes |
| Sync Pin |
No |
| Inverting |
No |
| Flyback |
No |
| RegType |
Switching Regulator |
| Temperature Min |
-40 deg C |
| Temperature Max |
125 deg C |
| Adjustable Output |
Yes, No |
| Adj Switch Frequency |
No |
| PWM Mode |
Current |
| Topology |
Synchronous Buck |
| Special Features |
Max. Iq at shutdown is 20uA over full temp range |
| Step-Down |
Yes |
| Multiple Output Capability |
No |
| Output Voltage |
3.3 Volt |
| Output Range |
1.24V to 13V |
| Switching Frequency |
300 kHz |
| Feedback Voltage |
Undefined Volt |
| Regulator Family |
Undefined |
| Synchronous Rectification |
Yes |
| View Using Catalog |
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (PVIN) .....................3.8V VIN 14V
Supply Voltage (AVIN)..................... 4.0V VIN 14V
Feedback Pin Voltage ......................-0.4V VFB 5V
VCB Voltage, (Note 7) .............................................7V
CSS Voltage .........................................................2.5V
Comp Voltage ..................................................... 2.5V
LDELAY Voltage .....................................................2.5V
LDR Voltage ............................................................5V
VSW, (Note 8) ........................................................14V
Power Dissipation (TA =25),
(Note 2)
TSSOP-16 Package JA ..................................140/W
Power Dissapation.......................................... 893mW
Lead Temperature
Vapor Phase (60 sec.)........................................ 215
Infrared (15 sec.) ................................................220
ESD Susceptibility(Note 3)
Human Body Model(Note 4) ...................................1kV
Machine Model .....................................................200V
DescriptionThe LM2655 is a current-mode controlled PWM step-down switching regulator. It has the unique ability to operate in synchronous or asynchronous mode. This gives the designer flexibility to choose between the high efficiency of synchronous operation, or the low solution cost of asynchronous operation. Along with flexibility, the LM2655 offers high power density with the small footprint of a TSSOP-16 package.
High efficiency (>90%) is obtained through the use of an internal low ON-resistance (33m) MOSFET, and an external N-Channel MOSFET. This feature, together with its low quiescent current, makes the LM2655 an ideal fit in portable applications.
Integrated in the LM2655 are all the power, control, and drive functions for asynchronous operation. In addition, a low-side driver output allows easy synchronous operation. The IC uses patented current sensing circuitry that eliminates the external current sensing resistor required by other current-mode DC-DC converters. A programmable soft-start feature limits start up current surges and provides a means of sequencing multiple power supplies.
Reliability Metrics
| Part Number |
Process |
EFR Reject |
EFR Sample Size |
PPM |
LTA Rejects |
LTA Device Hours |
FITS |
MTTF (Hours) |
| LM2655MTC-3.3 |
ABCD150 |
0 |
31520 |
0 |
0 |
3739000 |
1 |
1060951459 |
| LM2655MTC-ADJ |
ABCD150 |
0 |
31520 |
0 |
0 |
3739000 |
1 |
1060951459 |
| LM2655MTCX-3.3 |
ABCD150 |
0 |
31520 |
0 |
0 |
3739000 |
1 |
1060951459 |
| LM2655MTCX-ADJ |
ABCD150 |
0 |
31520 |
0 |
0 |
3739000 |
1 |
1060951459 |
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 |
|
|
|
| Power Reference Design Library |
0 Kbytes |
28-Mar-2006 |
View |
|
|
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
Application Notes
| Title |
Size in Kbytes |
Date |
|
| AN-1215: Application Note 1215 LM2655 2.5A Synchronous Switching Regulator Evaluation Board |
307 Kbytes |
10-May-04 |
Download |
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
More Application Notes
| Title |
Size in Kbytes |
Date |
|
| AN-1143: Application Note 1143 LM2651_3.3V_EVAL 1.5A High Efficiency Synchronous Switching Regulator Evaluation Board |
150 Kbytes |
24-Jul-08 |
Download |
| AN-1147: Application Note 1147 LM2651_EVAL 1.5A High Efficiency Synchronous Switching Regulator Evaluation Board |
149 Kbytes |
2-Oct-07 |
Download |
| AN-1133: Application Note 1133 LM2653EVAL 1.5A Synchronous Switching Regulator Evaluation Board |
76 Kbytes |
4-Oct-04 |
Download |
| AN-1520: Application Note 1520 A Guide to Board Layout for Best Thermal Resistance for Exposed Packages |
2176 Kbytes |
7-Sep-06 |
Download |
AN-1520 (Chinese): Application Note 1520 A Guide to Board Layout for Best Thermal Resistance for Exposed Packages
|
849 Kbytes |
|
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
| AN-1071: Application Note 1071 Information About the LM2650 Evaluation Board Rev. 1 |
105 Kbytes |
4-Oct-04 |
Download |
AN-1071 (Japanese): Application Note 1071 Information About the LM2650 Evaluation Board Rev. 1
640){this.height=this.height*640/this.width;this.width=640;}' border="0" alt=" Connection Diagram"> |
279 Kbytes |
|
|
If you have trouble printing or viewing PDF file(s), see Printing Problems.
|
LM2655 Data Sheet
