Description
The LTC®1481 is an ultralow power differential line transceiver designed for data transmission standard RS485 applications. It will also meet the requirements of RS422.
The CMOS design offers significant power savings over its bipolar counterparts without sacrificing ruggedness against overload or ESD damage. Typical quiescent current is only
80mA while operating and less than 1mA in shutdown.
The driver and receiver feature three-state outputs, with the driver outputs maintaining high impedance over the entire common mode range. Excessive power dissipation caused by bus contention or faults is prevented by a thermal shutdown circuit which forces the driver outputs into a high impedance state. The receiver has a fail-safe feature which guarantees a high output state when the inputs are left open.
The LTC1481 is fully specified over the commercial and extended industrial temperature range and is available in 8-pin PDIP and SO packages.

Features
*Low Power: ICC = 120mA Max with Driver Disabled
*Drivers/Receivers Have ±10kV ESD Protection
*1mA Quiescent Current in Shutdown Mode
*High Speed: Up to 2.5Mbits/s Data Rate
*ICC = 500mA Max with Driver Enabled, No Load
*Single 5V Supply
*–7V to 12V Common Mode Range Permits ±7V Ground Difference Between Devices on the Data Line
*Thermal Shutdown Protection
*Power Up/Down Glitch-Free Driver Outputs Permit Live Insertion or Removal of Transceiver
*Driver Maintains High Impedance in Three-State or with the Power Off
*Up to 32 Transceivers on the Bus
*30ns Typical Driver Propagation Delays with 5ns Skew
*Pin Compatible with the LTC485

Applications
*Battery-Powered RS485/RS422 Applications
*Low Power RS485/RS422 Transceiver
*Level Translator

LTC1481CN8, LTC1481IN8, LTC1481CS8, LTC1481IS8

 

LTC1481 - Ultralow Power RS485 Transceiver with Shutdown

DESCRIPTION
The LT®1373 is a low supply current high frequency current mode switching regulator.
It can be operated in all standard switching configurations including boost, buck, flyback, forward, inverting and “Cuk.”
A 1.5A high efficiency switch is included on the die, along with all oscillator, control and protection circuitry.
All functions of the LT1373 are integrated into 8-pin SO/PDIP packages.
Compared to the 500kHz LT1372, which draws 4mA of quiescent current, the LT1373 switches at 250kHz, typically consumes only 1mA and has higher efficiency.
High frequency switching allows for small inductors to be used.
All surface mount components consume less than 0.6 square inch of board space.
New design techniques increase flexibility and maintain ease of use.
Switching is easily synchronized to an external logic level source.
A logic low on the shutdown pin reduces supply current to 12mA.
Unique error amplifier circuitry can regulate positive or negative output voltage while maintaining simple frequency compensation techniques.
Nonlinear error amplifier transconductance reduces output overshoot on start-up or overload recovery.
Oscillator frequency shifting protects external components during overload conditions.


FEATURES
*1mA IQ at 250kHz
*Uses Small Inductors: 15mH
*All Surface Mount Components
*Only 0.6 Square Inch of Board Space
*Low Minimum Supply Voltage: 2.7V
*Constant Frequency Current Mode
*Current Limited Power Switch: 1.5A
*Regulates Positive or Negative Outputs
*Shutdow*Supply Current: 12mA Typ
*Easy External Synchronization
*8-Pi*SO or PDIP Packages

APPLICATIOUS
*Boost Regulators
*CCFL Backlight Driver
*Laptop Computer Supplies
*Multiple Output Flyback Supplies
*Inverting Supplies

LT1373CN8
LT1373HVCN8
LT1373CS8

 

LT1373-250kHz Low Supply Current High Efficiency 1.5A Switching Regulator

FEATURES
* Complete Switch Mode Power Supply
* Wide Input Voltage Range: 4.5V to 20V
* 10A DC, 14A Peak Output Current
* Parallel Two μModule™ DC/DC Converters for 20A Output Current
* 0.6V to 5V Output Voltage
* 1.5% Output Voltage Regulation
* Ultrafast Transient Response
* Current Mode Control
* Pb-Free (e4) RoHS Compliant Package with Gold- Pad Finish
* Up to 92% Effi ciency
* Programmable Soft-Start
* Output Overvoltage Protection
* Optional Short-Circuit Shutdown Timer
* Small Footprint, Low Profi le (15mm × 15mm × 2.8mm) Surface Mount LGA Package

APPLICATIONS
* Telecom and Networking Equipment
* Servers
* Industrial Equipment
* Point of Load Regulation

DESCRIPTION
The LTM®4600 is a complete 10A, DC/DC step down power supply. Included in the package are the switching controller, power FETs, inductor, and all support components.
Operating over an input voltage range of 4.5V to 20V, the LTM4600 supports an output voltage range of 0.6V to 5V, set by a single resistor. This high effi ciency design delivers 10A continuous current (14A peak), needing no heat sinks or airfl ow to meet power specifi cations. Only bulk input and output capacitors are needed to fi nish the design.
The low profi le package (2.8mm) enables utilization of unused space on the bottom of PC boards for high density point of load regulation. High switching frequency and an adaptive on-time current mode architecture enables a very fast transient response to line and load changes without sacrifi cing stability. Fault protection features include integrated overvoltage and short circuit protection with a defeatable shutdown timer. A built-in soft-start timer is adjustable with a small capacitor.
The LTM4600 is packaged in a thermally enhanced, compact (15mm × 15mm) and low profi le (2.8mm) over-molded Land Grid Array (LGA) package suitable for automated assembly by standard surface mount equipment. The LTM4600 is Pb-free and RoHS compliant.

LTM4600EV
LTM4600IV

 

LTM4600 - 10A High Effi ciency DC/DC μModule

FEATURES
* Regulated Output with Input Above, Below or Equal to the Output
* Single Inductor, No Schottky Diodes
* High Efficiency: Up to 96%
* 28μA Quiescent Current in Burst Mode® Operation
* Up to 1.2A Continuous Output Current from a Single Lithium-Ion
* True Output Disconnect in Shutdown
* 2.4V to 5.5V Input Range
* 2.4V to 5.25V Output Range
* 600kHz Fixed Frequency Operation
* Synchronizable Oscillator
* Selectable Burst Mode or Fixed Frequency Operation
* <1μA Quiescent Current in Shutdown
* Small, Thermally Enhanced 12-Lead (4mm × 3mm × 0.8mm) DFN package

APPLICATIOUS
* Handheld Computers
* Handheld Instruments
* MP3 Players
* Digital Cameras

DESCRIPTION
The LTC®3443 is a high efficiency, fixed frequency, buckboost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The part is pin for pin compatible with its predecessor, the LTC3441, with a lower operating frequency (600kHz), and a VC pin clamp circuit during Burst Mode operation. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for single Lithium Ion or multicell applications where the output voltage is within the battery voltage range.
The device includes two 0.10Ω N-channel MOSFET switches and two 0.11Ω P-channel switches. External Schottky diodes are optional, and can be used for a moderate efficiency improvement. The operating frequency is internally set to 600kHz and can be synchronized up to 1.2MHz. Quiescent current is only 28μA in Burst Mode operation, maximizing battery life in portable applications.
Burst Mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high. If the MODE/ SYNC pin is driven low or with a clock, then fixed frequency switching is enabled.
Other features include a 1μA shutdown, soft-start control, thermal shutdown and current limit. The LTC3443 is available in a thermally enhanced 12-lead (4mm × 3mm) DFN Package.

LTC3443EDE

 

LTC3443 - High Current Micropower 600kHz Synchronous Buck-Boost DC/DC Converter

FEATURES
* Dual Output Boost for Dual Display Devices
* Drives Up to Six White LEDs and OLED/LCD Bias
* Internal Power Switches and Schottky Diodes
* Independent Dimming and Shutdown
* 200mV High Side Sense on LED Driver Allows
“One-Wire Current Source”
* Wide Input Voltage Range: 2.5V to 12V
* Wide Output Voltage Range: Up to 32V
* 2.3MHz PWM Frequency for LED Driver
* PFM for OLED Driver is Non-Audible Over Entire Load Range
* Open LED Protection (27V Maximum on CAP1 Pin)
* OLED Output Disconnect
* Available in 12-Pin DFN Package
* 1mm Tall Solution Height

APPLICATIONS
* Cellular Phones
* PDAs, Handheld Computers
* Digital Cameras
* MP3 Players
* GPS Receivers

DESCRIPTION
The LT®3498 is a dual output boost converter featuring a 2.3MHz PWM LED Driver and PFM OLED Driver. It includes an internal power switch and Schottky diode for each driver. Both converters can be independently shut down and modulated. This highly integrated power solution is ideal for dual display electronic devices.
The 2.3MHz step-up converter is designed to drive up to six white LEDs in series from a Li-Ion cell. The device features a unique high side LED current sense that enables the part to function as a “one-wire” current source—one side of the LED string can be returned to ground anywhere. Traditional LED drivers use a grounded resistor to sense LED current, requiring a 2-wire connection to the LED string.
The PFM OLED driver is a low noise boost converter that features a novel control technique.
The converter controls power delivery by varying both the peak inductor current and switch off time. This technique results in low output voltage ripple, as well as, high effi ciency over a wide load range. The off time of the switch is not allowed to exceed a fi xed level, guaranteeing a switching frequency that stays above the audio band.

 

LT3498 - 20mA LED Driver and OLED Driver with Integrated Schottky in 3mm x 2mm DFN