Dual Boost Plus Inverting DC/DC Converter for CCD/LCD Applications in a 3mm × 3mm QFN
Linear Technology announces the LT3587, a triple channel (dual boost plus inverter), ±32V, 1MHz DC/DC converter with output disconnect. Its internal 800mA boost and 900mA inverter can deliver up to 50mA at 15V and 100mA at –8V from a Li-Ion cell, providing bias for the latest generation of CCD (Charge-Coupled Device) imagers and LCD displays. Additionally, its second 400mA boost channel generates either a constant current to a string of up to six 20mA white LEDs for LCD backlighting, or a constant voltage to bias an OLED display. Its input voltage range of 2.5V to 6V enables it to be powered from Li-Ion to multiple cell Alkaline/NiMH batteries. Switching at a constant 1MHz, the LT3587 uses tiny, low profile capacitors and inductors and generates low noise outputs that are easy to filter. Output voltages can be set with only one resistor per channel, reducing external component count. Packaged in a 3mm × 3mm QFN, the entire solution has less than a 1mm profile and occupies just 50mm2.
The LT3587 uses an intelligent soft-start circuit that allows for the sequential powering of the Boost1 output, followed by the Inverting output with a single capacitor. Internal sequencing circuitry also disables the inverter until the Boost1 output has reached 87% of its final value, optimizing system reliability.
The LT3587EUD is available from stock in a 20-lead 3mm × 3mm QFN package. Pricing starts at $2.95 each for 1,000-piece quantities.
Summary of Features: LT3587
- Ideal for CCD, LCD, LED Backlight & OLED Applications
- Easy Generation of 15V (50mA), –8V (100mA) & 20V (20mA) from a Li-Ion Cell
- VIN Range: 2.5V to 6V
- Wide Output Ranges: Up to 32V for the Boosts & Up to –32V for the Inverter
- Output Disconnect for the Boost Channels
- Boost3 Allows Voltage Programming and/or Current Programming for a "One Wire Current Source"
- Overload Fault Protection with Fault I/O Pin Indicator
- Combined Soft-Start & Enable Pins
- Small 20-Pin 3mm × 3mm QFN Package
Dual Boost & Inverting DC/DC Converter for CCD/LCD Applications
Editor's Contact Information
- Doug Dickinson