Linear Technology claims an industry first with its LT6001 and LT6002 operational amplifiers (see the figure). These are the first 1.8V dual and quad op amps in what’s best described as tiny DFN package. The devices draw a mere 13μA per amplifier; input offset voltage is 500μV max at 25°C with a maximum drift of 5μV/°C over temperature. Inputs and outputs feature rail-to rail-operation.
Such a combination of low supply voltage, low current consumption, and good dc specifications in a small DFN package means that these parts are well suited to handheld and battery-powered applications. To save more power, the dual LT6001 in 3mm by 3mm package also includes a shutdown pin, allowing current consumption to drop to 1.5μA max when idle.
Cascade up to 84A
The company also recently announced the LTC3415, which is a monolithic synchronous buck regulator that uses a phase-lockable, constant-frequency, currentmode architecture. A single LTC3415 can deliver up to 7A of output current at voltages as low as 0.6V. In addition, the device’s PolyPhase operation enables multiple (up to 12 in total) LTC3415s to be run with interleaved phases while using minimal input and output capacitance.
When twelve LTC3415s are cascaded, they can drive a single load with up to 84A of output current while current sharing equally between the units. An input voltage range of 2.5 to 5.5V suits it for single-cell, Li-Ion-battery and point-of-load applications. Since default switching frequency is internally set at 1.5MHz, tiny surface- mount inductors and capacitors can be used.
Combined with a 5mm by 7mm QFN package, it provides a compact high-current power conversion solution.The LTC3415 uses internal switches with an RDS(on) of 0.025 Ω (n-channel) and 0.032 Ω (p-channel) to deliver efficiencies of 96%.
For noise-sensitive applications, the LTC3415 can be configured to skip pulses, provide forced continuous operation, or use spreadspectrum frequency switching to reduce noise and potential RF interference.