LM3351 Datasheet | National Semiconductor

Description The LM3351 is a CMOS charge-pump voltage converter which efficiently provides a 3.3V to 5V step-up, or 5V to 3.3V step-down. The LM3351 is pin for pin patible with the LM3350 but consumes 66% less quiescent current. The LM3351 uses four small, low cost capacitors to provide the voltage conversion. It eliminates the cost, size and radiated EMI related to inductor based circuits, or the power loss of a linear regulator. Operating power conversion efficiency greater than 90% provides ideal performance for battery powered portable systems. The architecture provides a fixed voltage conversion ratio of 3/2 or 2/3. Thus it can be used for other DC-DC conversions as well. n n n n n 4.2Ω typical step-up output impedance 1.8Ω typical step-down output impedance 95% typical power conversion efficiency at 50 m A 250 n A typical shutdown current Low quiescent current extends battary life Features n Conversion of 3.3V to 5V, or 5V to 3.3V n Small Mini SO-8 package n No inductor required Applications n n n n Any mixed 5V and 3.3V system Laptop puters and PDAs Handheld instrumentation PCMCIA cards Key Specifications n 200 k Hz switch frequency allows use of very small, inexpensive capacitors. Ordering Information Order Number LM3351MMX LM3351MM Package Type Mini SO-8 Mini SO-8 NSC Package Drawing MUA08A MUA08A Package Marking S05A S05A Supplied As 3500 Units on Tape and Reel 1000 Units on Tape and Reel Basic Operating Circuits Step-Up Converter Step-Down Converter DS100146-1 DS100146-2 Connection Diagram Mini SO8 Package DS100146-3 Top View © 1999 National Semiconductor Corporation DS100146 .national. Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Maximum Input Voltage, Step-Down Maximum Input Voltage, Step-Up Power Dissipation (PD) (TA=25˚C, (Note 2)) θja (Note 2) Tj Max (Note 2) 5.5V 3.65V 500 m W 250˚C/W...