The device is capable of compensating for voltage drops in the cables, can be easily paralleled with higher currents or spread across the circuit board, and can be configured as a three-terminal floating regulator. The LT3091's input voltage range is -1.5V to -36V. A single resistor programs the adjustable rail-to-rail output voltage between 0V and -32V, and the dropout voltage is only 300mV (typical at full load).
The device features a 50µA tuned current source reference with an accuracy of ±1% and offers an output voltage tolerance of ±2% over the input voltage, load, and temperature range. Output voltage regulation, bandwidth, transient response, and output noise (18µVRMS from 10Hz to 100kHz) remain independent of the output voltage due to the device's unity-gain voltage follower architecture. The LT3091 is ideal for negative logic sources, low-noise instrumentation and RF sources, rugged industrial power supplies, and post-regulator switching power supplies.
The LT3091 boasts excellent stability due to its wide range of output capacitors, including small, low-cost ceramic capacitors. It remains stable with a minimum output capacitor of 10µF. A single resistor is used to precisely adjust the programmable current limit. The device's bipolar current monitor can supply or drain a current proportional to the output current, which is useful for control systems. The LT3091's bidirectional turn-off capability allows it to operate with both positive and negative logic levels. Furthermore, the precision of the LT3091's turn-off thresholds enables a programmable UVLO limit that can be used for both the regulator's input supply and the output voltage of a positive system. The IC's internal protection circuitry includes precise current limiting with foldback (level reduction proportional to the current level) and thermal shutdown with hysteresis.
The LT3091 is available in a low-profile (0.75mm) 3mm x 4mm DFN package with 14 pins and a 16-pin TSSOP package, both with thermal pads on the back. The device is also offered in TO-220-7 and DD-Pak-7 power packages. The junction temperature for Grade E and I chips is between -40°C and 125°C, for Grade H it is between -40°C and 150°C, and for Grade MP it is specified over the widest available operating range of -55°C to 150°C.
Summary of features: LT3091
• Output current: 1.5A
• Output voltage is fixed with a single resistor
• 50µA SET pin current: Initial accuracy of ±1%
• Programmable current limit
• Positive or negative output current monitor
• Can be matched for higher currents or to distribute heat
• Low dropout voltage: 300mV
• Low output noise: 18µVRMS (10Hz to 100kHz)
• Configurable as a 3-terminal regulator
• Wide input voltage range: -1.5V to -36V
• Rail-to-rail output voltage: 0V to 32V
• Positive/negative UVLO or shutdown logic
• Programmable compensation for voltage drop in cable
• Load regulation: 1.2V (1mA to 1.5A)
• Stable with a minimum output capacitance of 10µF
• Stable with ceramic or tantalum capacitors
• Packages: Thermally enhanced 16-pin TSSOP, 14-pin 3mm x 4mm x 0.75mm DFN, DD-Pak-7 and TO-220-7
Reverse output protection
