Features: ` Regulated VOUT with ±3% accuracy
` Standard output voltage of 4.1V
` Custom output voltages available from 1.8V to 4.1V in 100 mV increments
` 2.5V to 5.5V input voltage
` Up to 50 mA output current
` >75% average efficiency
`Uses few, low-cost external components
` Very small solution size
` 375 A typical operating current
` 2.3 A typical shutdown current
` 1 MHz switching frequency (typical)
` Architecture and control methods provide high load current and good efficiency
` MSOP-10 package
` Over-temperature protection
Application· White LED display backlights
· 1-cell Lilon battery-operated equipment including PDAs, hand-held PCs, cellular phones
· Flat panel displays
· Hand-held instruments
· NiCd, NiMH, or alkaline battery powered systems
Pinout
SpecificationsIf Military/Aerospace specified devices are required, please contact the National Semiconductor Salesffice/Distributors for availability and specifications.
All Pins .............................................−0.5V to 5.6V
Power Dissipation (TA = 25)
(Note 2) .....................................Internally Limited
TJMAX (Note 2) ..............................................150
JA (Note 2) .............................................250/W
Storage Temperature ..................−65 to +150
Lead Temperature (Soldering, 5 sec.) ..........260
ESD Rating (Note 3)
Human Body Model .....................................1.5 kV
Machine Model ..............................................100V
Input Voltage (VIN) ............................2.5V to 5.5V
Output Voltage (VOUT) .......................1.8V to 4.1V
Ambient Temperature (TA) (Note 2) −40 to +85
Junction Temperature (TJ) (Note 2) −40 to +125
| Output Current |
50 mA |
| Output Min |
4.1 Volt |
| Output Max |
4.1 Volt |
| Adjustable Output |
No |
| Input Min Voltage |
2.5 Volt |
| Input Max Voltage |
5.5 Volt |
| Efficiency (peak) |
75 % |
| Frequency Min |
1000 kHz |
| Frequency Max |
1000 kHz |
| Adj Switch Frequency |
No |
| On/Off Pin |
Yes |
| Quiescent Current |
0.375 mA |
| Special Features |
Auto buck/boost multi-gain architecture |
| PWM Mode |
Multi-gain Switched Capacitor |
| Topology |
Boost, Buck |
| Step-Down |
Yes |
| Step-Up |
Yes |
| Inverting |
No |
| RegType |
Switched Cap Regulator |
| Temperature Min |
-40 deg C |
| Temperature Max |
85 deg C |
| View Using Catalog |
DescriptionThe LM3355 is a CMOS switched capacitor DC/DC converter that produces a regulated output voltage by automatically stepping up (boost) or stepping down (buck) the input voltage. It accepts an input voltage between 2.5V and 5.5V.
The LM3355 is available with a standard output voltage of 4.1V (ideal for white LED applications). If other output voltage options between 1.8V and 4.1V are desired for other applications, please contact your National emiconductor representative.
The LM3355's proprietary buck-boost architecture enables up to 50 mA of load current at an average efficiency reater than 75%. Typical operating current is only 375 A and the typical shutdown current is only 2.3 A.
The LM3355 is available in a 10-pin MSOP package. This package has a maximum height of only 1.1 mm.
The high efficiency of the LM3355, low operating and shutdown currents, small package size, and the small size of the overall solution make this device ideal for battery powered, portable, and hand-held applications.
See the LM3352 for up to 200mA of output current.
LM3355 Data Sheet
