Linear Technology Launches 1.5A Negative LDO
Provides fast transient response, low output noise, and precise current limiting

June 22, 2011 – Linear Technology Korea (CEO Hong Sa-kwak, www.linear.com ) announced the release of the LT3015, a 1.5A negative low-dropout linear regulator featuring fast transient response, low noise, and precise current limiting. Providing a wide input voltage range of -1.8V to -30V and an adjustable output voltage range of -1.220V to -29.5V, the device's common emitter NPN power transistor design requires only a single input and offers a low dropout voltage of just 310mV (typically at full load). Output voltage noise is only 60µVrms across a bandwidth of 10Hz to 100kHz. The LT3015 features an operating current of 1.1mA and a standby current of less than 1µA during shutdown, with the standby current well controlled by dropout. The LT3015 is a negative LDO that complements Linear’s popular positive LDO (1.5A LT1963A) and is ideal for negative logic inputs, low-noise devices, industrial supplies, and post-regulating switching supply outputs.

The LT3015's reference amplifier topology is characterized not only by providing precise DC characteristics but also by excellent loop stability with a very wide range of output capacitors, including small, low-cost ceramic output capacitors. The LT3015 is stable with output capacitors as small as 10µF. These ultra-small external capacitors can be used without adding the series resistance (ESR) commonly used in many other regulators. The LT3015 features a bidirectional shutdown function, allowing the device to operate at positive or negative logic levels. Additionally, due to the LT3015's high-precision shutdown threshold, the SHDN pin can be used for setting a programmable low-voltage lockout (UVLO) threshold for a regulator input supply. Internal circuit protection features for the IC include reverse output protection, precision current limiting with a foldback function to protect power transistors in the safe operating region, and thermal limiting with hysteresis.

The LT3015 is currently available in a rear thermal pad low-profile (0.75mm) 3mm x 3mm 8-pin DFN package, a rear thermal pad 12-pin MSOP package, a through-hole power TO-220 package, and a surface mount power DD-Pak package. The operating junction temperature range for Grades E and I is -40°C to +125°C, while the MP grade is -55°C to +125°C. Pricing for Grades E, I, and MP starts at $2.67 for DFN, MSOP, and TO-220/DD-Pak packages in 1,000-piece quantities and is currently available. For more information, please refer to www.linear.com/product/LT3015 .

Photo Caption: LT3015 1.5A Negative LDO

Product Features: LT3015

• VIN Range: -1.8V ~ -30V
• VOUT Range: -1.22V ~ -29.5V (Adjustable)
• Dropout voltage: 310mV
• Output current: 1.5A
• Precision current limiting of foldback
• Stable with 10µF ceramic output capacitor
• Low dropout noise (without additional bypass capacitor): 60µVrms
• Precision bidirectional SHDN logic
• Rapid transient response
• Operating current: 1.1mA
• Shutdown current: <1µA
• Reverse output voltage acceptance
• Hysteresis-enabled heat limiting function
• 3mm x 3mm x 0.75mm DFN-8, MSOP-12, DD-Pak-5 & TO-220-5 packages

Linear Technology Company Introduction
Linear Technology Corporation, an S&P 500 company, has been designing, manufacturing, and selling a wide range of high-performance analog integrated circuits for major global companies for over 30 years. Linear Technology's products play a vital role in bridging the digital world with the analog world in communications, networking, industrial, automotive, computer, medical, instrumentation, consumer electronics, military, and aerospace systems. Linear Technology currently produces power management, data conversion, signal conditioning, RF, interface ICs, and µModule® subsystems.