Analog Devices Inc./Maxim Integrated

The LT1618 step-up DC/DC converter combines a traditional voltage feedback loop and a unique current feedback loop to operate as a constant-current, constant-voltage source. This fixed frequency, current mode switcher operates from a wide input voltage range of 1.6V to 18V, and the high switching frequency of 1.4MHz permits the use of tiny, low profile inductors and capacitors. The current sense voltage is set at 50mV and can be adjusted using the IADJpin.Available in the 10-Pin (3mm x 3mm) Exposed Pad DFN and 10-pin MSOP packages, the LT1618 provides a complete solution for constant-current applications.ApplicationsLED Backlight DriversUSB Powered Boost/SEPIC ConvertersInput Current Limited Boost/SEPIC ConvertersBattery Chargers

The LT1620 simplifies the design of high performance, controlled current battery charging circuits when used in conjunction with a current mode PWM controller IC.The LT1620 regulates average output current independent of input and output voltage variations. Output current can be easily adjusted via a programming voltage applied to the LT1620’s PROG pin.Most current mode PWM controllers have limited output voltage range because of common mode limitations on the current sense inputs. The LT1620 overcomes this restriction by providing a level-shifted current sense signal, allowing a 0V to 32V output voltage range.The 16-pin version of the LT1620 contains a programmable low charging current flag output. This output flag can be used to signal when a Li-Ion battery charging cycle is nearing completion.The LT1621 incorporates two fully independent current control circuits for dual loop applications.ApplicationsHigh Current Battery ChargersHigh Output Voltage DC/DC ConvertersConstant Current SourcesOvercurrent Fault Protectors

The LT1630/LT1631 are dual/quad, rail-to-rail input and output op amps with a 30MHz gain-bandwidth product and a 10V/μs slew rate.The LT1630/LT1631 have excellent DC precision over the full range of operation. Input offset voltage is typically less than 150μV and the minimum open-loop gain of one million into a 10k load virtually eliminates all gain error. To maximize common mode rejection, the LT1630/LT1631 employ a patented trim technique for both input stages, one at the negative supply and the other at the positive supply, that gives a typical CMRR of 106dB over the full input range.The LT1630/LT1631 maintain their performance for supplies from 2.7V to 36V and are specified at 3V, 5V and ±15V supplies. The inputs can be driven beyond the supplies without damage or phase reversal of the output. The output delivers load currents in excess of 35mA.The LT1630 is available in 8-pin PDIP and SO packages with the standard dual op amp pinout. The LT1631 features the standard quad op amp configuration and is available in a 14-pin plastic SO package. These devices can be used as plug-in replacements for many standard op amps to improve input/output range and performance.ApplicationsActive FiltersRail-to-Rail Buffer AmplifiersDriving A/D ConvertersLow Voltage Signal ProcessingBattery-Powered Systems

The LT1632/LT1633 have excellent DC precision over the full range of operation. Input offset voltage is typically less than 400µV and the minimum open-loop gain of 0.8 million into a 10k load virtually eliminates all gain error. Common mode rejection is typically 83dB over the full rail-to-rail input range when on a single 5V supply for excellent noninverting performance.The LT1632/LT1633 maintain their performance for supplies from 2.7V to 36V and are specified at 3V, 5V and ±15V supplies. The inputs can be driven beyond the supplies without damage or phase reversal of the output. The output delivers load currents in excess of 35mA.The LT1632 is available in 8-pin PDIP and SO packages with the standard dual op amp pinout. The LT1633 features the standard quad op amp configuration and is available in a 14-pin plastic SO package. These devices can be used as plug-in replacements for many standard op amps to improve input/output range and performance.ApplicationsActive FiltersRail-to-Rail Buffer AmplifiersDriving A/D ConvertersLow Voltage Signal ProcessingBattery-Powered Systems