NATIONAL SEMICONDUCTOR LAUNCHES ULTRA-COMPACT DUAL OUTPUT SWITCHED CAPACITOR REGULATOR

LM2685 Delivers ?5V Supplies to Cellular Phones, Handheld PCs and Personal Organizers

July 26, 1999 - National Semiconductor Corporation? (NYSE: NSM) today announced the LM2685, a dual output switched capacitor regulator designed for the high-growth portable communications market. The LM2685 integrates a switched capacitor doubler, a low dropout (LDO) regulator and a switched capacitor inverter in a low profile, TSSOP-14 package. This product establishes National as an excellent source of medium scale power supply integration components for a wide range of portable applications, including cellular phones, handheld PCs, global positioning systems (GPS) and GSM phones that require subscriber identification modules (SIMs).

"The LM2685 is National's first dual output switched capacitor component and also its first to integrate a low noise LDO regulator," said Jim Schuessler, product marketing manager for National's Power Management Group. "Many products in the fast growing portable application market require small 'legacy' 5V supplies, and the LM2685 meets this need in a minimum of space, without inductors."

The LM2685 provides a dual output (+5V regulated and -5V unregulated) power supply by using switched capacitor and LDO techniques. The +5V regulated power supply is required for components such as audio CODECs, amplifiers and SIMs. Additionally, the -5V can be used for contrast bias for liquid crystal displays (LCDs), and to increase the dynamic range of operational amplifiers used for analog inputs. By powering these functions, the LM2685 is a perfect adjunct to the main DC/DC conversion for many portable devices, especially those that incorporate audio I/O and LCDs. The LM2685's 50mA output current is ten times higher than competitive solutions, making it better suited to address the audio component of portable devices. The LM2685 accommodates an input voltage range from 2.85V to 5.5V. This matches the voltage delivered from the increasingly popular lithium ion battery.

The LM2685 achieves its functionality by using five cost-effective capacitors and no inductors. The absence of inductors offers higher manufacturing reliability and lower radiated EMI as compared to inductive switching techniques.

Price and Availability
The LM2685 is available now in a TSSOP-14 package and priced at $1.75 in 1000-piece quantities. For more information on the LM2685 visit http://www.national.com/pf/LM/LM2685.html.

About National Semiconductor
National Semiconductor provides system-on-a-chip solutions for the information age. Combining real-world analog and state-of the-art digital technology, the company's chips lead many sectors of the personal computer, communications and consumer markets. With headquarters in Santa Clara, Calif., National has annual sales of $2 billion and 11,500 employees worldwide. Additional company and product information is available on the World Wide Web at www.national.com.