LP3928 Datasheet, PDF (1/11 Pages) National Semiconductor (TI) – High Speed Bi-Directional Level Shifter and Ultra Low-Dropout CMOS Voltage Regulator

October 2002
LP3928
High Speed Bi-Directional Level Shifter and Ultra
Low-Dropout CMOS Voltage Regulator
General Description
The LP3928 is designed for portable and wireless applica-
tions with demanding performance and space requirements.
The LP3928 provides level shifting and power conversion
needed for applications interfacing differing voltage levels.
The part contains a bi-directional level shifter for three sig-
nals to translate the levels between 1.8V and 2.85V and an
ultra low-dropout CMOS 2.85V voltage regulator.
The three level shifted signals are individually direction con-
trolled. Signals going from 2.85V to 1.8V can also be latched
using an external clock source. The latches are powered
from internal 2.85V. There is also an option to by-pass the
latches.
The built-in low-dropout voltage regulator is ideal for mobile
phone and battery powered wireless applications. It provides
up to 150 mA from a 3.05V to 6.0V input, and is character-
ized by extremely low dropout voltage, low quiescent current
and low output noise voltage. It is stable with small 1.5 µF
±30% ceramic and high quality tantalum output capacitors,
requiring smallest possible PC board area.
A shutdown mode is available for the level shifters and the
regulator. High performance is achieved over various load
conditions with very low rise and fall times.
Key Specifications
Level Shifter:
n 4 ns propagation delay (typ.)
n 2 ns rise and fall times (typ.)
n 20 ns direction switch response time
n 2 µA input/output leakage current
Low-Dropout Regulator:
n 3.05V to 6.0V input range
n 150 mA guaranteed output
n Fast Turn-On time: 200 µs (typ.)
n 100 mV maximum dropout with 150 mA load
Features
n Ultra small micro SMD package
n Bi-directional level-shifter for three individual signals:
1.8V to 2.85V and 2.85V to 1.8V signal level translation
n Logic controlled enable pins: 4 different operation
modes
n LDO stable with ceramic and high quality tantalum
capacitors
n Thermal shutdown
Applications
n Multi-Media Cards for Cellular Phones
n SD Cards for Cellular Handsets
n Logic Level Translation
n Portable Information Appliances
© 2002 National Semiconductor Corporation DS200391
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