LINEAR Manuals

The LTC3401 is a high-efficiency, fixed-frequency, step-up DC/DC converter that operates from an input voltage below 1V. The device includes a 0.16Ω N-channel MOSFET switch and a 0.18Ω P-channel synchronous rectifier. Switching frequencies up to 3MHz are programmed with an external timing resistor and the oscillator can be synchronized to an external clock. An external Schottky diode is optional but will slightly improve efficiency. Quiescent current is only 38µA 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 has either a clock or is driven low, then fixed frequency switching is enabled. Other features include 1µA shutdown, antiringing control, open-drain power good output, thermal shutdown and current limit. The LTC3401 is available in the 10-lead thermally enhanced MSOP package. Higher current applications should use the 2A rated LTC3402 synchronous boost converter. Applications that require VOUT < 2.6V should use the LTC3423. All-Ceramic-Capacitor 2-Cell to 3.3V at 500mA Step-Up Converter.

The LTC1702 is a dual switching regulator controller opti- mized for high efficiency with low input voltages.

The LT1533 is a new class of switching regulator designed to reduce conducted and radiated electromagnetic interference (EMI). It features ultralow noise and EMI, high efficiency, and independent control of switch voltage and current slew rates.

The LTC3559/LTC3559-1 are USB battery chargers with dual high efficiency buck regulators. The parts are ideally suited to power single-cell Li-Ion/Polymer based handheld applications needing multiple supply rails. Battery charge current is programmed via the PROG pin and the HPWR pin, with capability up to 950mA at the BAT pin. The battery charger has an NTC input for temperature qualified charging. The CHRG pin allows battery status to be monitored continuously during the charging process. An internal timer controls charger termination. Each monolithic synchronous buck regulator provides up to 400mA of output current while operating at efficiencies greater than 90% over the entire Li-Ion/Polymer range. A MODE pin provides the flexibility to place both buck regulators in a power saving Burst Mode operation or a low noise pulse skip mode. The LTC3559/LTC3559-1 are offered in a low profile thermally enhanced 16-lead (3mm × 3mm) QFN package.

The LTC3720 is a synchronous step-down switching regulator controller for CPU power. It supports programmable output voltage between 1.05V and 1.825V, does not require a sense resistor, and has features such as wide input voltage range, adjustable current limit, and switching frequency.

The LTC ®1759 Smart Battery Charger is a single chip charging solution that dramatically simplifies construc- tion of an SBS compliant system. The LTC1759 imple- ments a Level 2 charger function whereby the charger can be programmed by the battery or by the host. A thermistor on the battery being charged is monitored for tempera- ture, connectivity and battery type information. The SMBus interface remains alive when the AC power adapter is removed and responds to all SMBus activity directed to it, including thermistor status (via the ChargerStatus com- mand). The charger also provides an interrupt to the host whenever a status change is detected (e.g., battery removal, AC adapter connection). Charging current and voltage are restricted to chemistry specific limits for improved system safety and reliability. Limits are programmable by two external resistors. Addi- tionally, the maximum average current from the AC adapter is programmable to avoid overloading the adapter when simultaneously supplying load current and charging cur- rent. When supplying system load current, charging cur- rent is automatically reduced to prevent adapter overload.

LTC4006 is a 4A high efficiency Li-ion battery charger

The LTC1483 is an ultra-low power differential line transceiver designed for data transmission standard RS485 applications with extended common-mode range (–7V to 12V). It will also meet the requirements of RS422. The LTC1483 features output drivers with controlled slew rate, decreasing the EMI radiated from the RS485 lines, and improving signal fidelity with misterminated lines. The CMOS design offers significant power savings over its bipolar counterparts without sacrificing ruggedness against overload or ESD damage. Typical quiescent current is only 80µA while operating and less than 1µA 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. I/O pins are protected against multiple ESD strikes of over ±10kV. The LTC1483 is fully specified over the commercial and extended industrial temperature range and is available in 8-pin DIP and SO packages.

The LT1884/LT1885 op amps provide high accuracy input performance to amplifiers with rail-to-rail output swing and faster response compared to other precision amplifiers. The input offset voltage is trimmed to less than 50µV, and the low drift ensures accuracy over the operating temperature range. The maximum input bias currents are ultralow at 400pA. The amplifiers can operate on any total power supply voltage between 2.7V and 36V (fully specified from 5V to ±15V). The output voltage swings to within 40mV of the negative supply and 220mV of the positive supply, making them suitable for low voltage single supply operation. With a supply current of less than 1mA per amplifier, they offer superior response and settling time performance in a low power precision amplifier. The dual LT1884 is available in 8-pin SO and PDIP packages with standard pinouts. The quad LT1885 is also available in the standard pinout 14-pin SO package.

The LT6013/LT6014 is a single/dual 145µA, 9.5nV/√Hz, AV≥5, rail-to-rail output precision op amp. It features low noise, high precision input performance, low power consumption and rail-to-rail output swing. The amplifier is stable in a gain of 5 or more and features greatly improved CMRR and PSRR versus frequency compared to other precision op amps. Input offset voltage is factory-trimmed to less than 35µV. The low drift and excellent long-term stability ensure a high accuracy over temperature and time. The 250pA maximum input bias current and 145µA supply current make this amplifier very suitable for battery-powered precision systems and low-voltage precision systems. It can be used for thermocouple amplifiers, precision photodiode amplifiers, instrumentation amplifiers, micro-power sensor interfaces and other applications.

The LTC1487 is an ultra-low power differential line transceiver designed with high impedance inputs allowing up to 256 transceivers to share a single bus. It meets the requirements of RS485 and RS422. The LTC1487 features output drivers with controlled slew rate, decreasing the EMI radiated from the RS485 lines, and improving signal fidelity with misterminated lines. The CMOS design offers significant power savings without sacrificing ruggedness against overload or ESD damage. Typical quiescent cur- rent is only 80µA while operating and 1µA 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. I/O pins are protected against multiple ESD strikes of over ±10kV using the Human Body Model. The LTC1487 is fully specified over the commercial tem- perature range and is available in 8-pin DIP and SO packages.

LT6700-1/LT6700-2/LT6700-3/LT6700HV-1/LT6700HV-2/LT6700HV-3 are low power, low voltage, dual comparators with a 400mV reference in a 6-lead SOT-23 or tiny DFN package. Operating with supplies from 1.4V up to 18V, these devices draw only 6.5μA, making them ideal for low voltage system monitoring. Hysteresis is included in the comparators, easing design requirements to insure stable output operation. The comparators each have one input available externally; the other inputs are connected internally to the reference. The comparator outputs are open collector and the output load can be referred to any voltage up to 18V (36V for LT6700HV), independent of supply voltage. The output stage sinking capability is guaranteed to be greater than 5mA over temperature. The three versions of this part differ by the polarity of the available comparator inputs. The LT6700-1/LT6700HV-1 has one inverting input and one noninverting input, making it suitable for use as a window comparator. The LT6700-2/LT6700HV-2 has two inverting inputs and the LT6700-3/LT6700HV-3 has two noninverting inputs. All versions are offered in commercial, industrial and automotive temperature ranges.

The document introduces the LTC3713 low input voltage, high power, No RSENSE synchronous buck DC/DC controller. The controller adopts true current mode control, the input voltage can be as low as 1.5V, without 5V auxiliary power supply, using standard 5V logic level N-channel MOSFETs, adjustable current limit, frequency, switch time, duty cycle, reference voltage, output overvoltage protection, etc., suitable for telecom card 3.3V, 2.5V, 1.8V step-down, bus termination (DDR memory, SSTL), synchronous buck with general purpose boost, low VIN synchronous boost and other applications.

The LTC6240/6241/LTC6242 series are low noise, low offset, unity gain stable CMOS op amps featuring 1pA of input bias current. Input bias current is guaranteed to be 1pA max on the single LTC6240. The 0.1Hz to 10Hz noise of only 550nVP-P, along with an offset of just 125µV are significant improvements over traditional CMOS op amps. Additionally, noise is guaranteed to be less than 10nV/√Hz at 1kHz. An 18MHz gain bandwidth, and 10V/µs slew rate, along with the wide supply range and low input capacitance, make them perfect for use as fast signal processing amplifiers. These op amps have an output stage that swings within 30mV of either supply rail to maximize the signal dynamic range in low supply applications. The input common mode range extends to the negative supply. They are fully specified on 3V and 5V, and an HV version guarantees operation on supplies up to ±5V. The LTC6240 is available in the 8-pin SO and the 5-pin SOT-23 packages. The LTC6241 is available in the 8-pin SO, and for compact designs it is packaged in a tiny dual fine pitch leadless (DFN) package. The LTC6242 is available in the 16-Pin SSOP as well as the 5mm × 3mm DFN package.

The LTC1153 is an auto-reset electronic circuit breaker with programmable trip delay, trip current and auto-reset time, which can drive low RDS(ON) N-channel MOSFETs and achieve thermal action via PTC thermistor.