New DC/DC Controllers Conserve Battery Life and Board Space in Cost-Sensitive Applications.
Sept. 16, 2003 - Texas Instruments Incorporated (TI) announced a family of non-synchronous DC/DC step-down controllers with low quiescent current and up to 95 percent power efficiency. The tiny controllers help conserve battery life in battery-powered applications with input voltages between 1.8 V and 6.5 V that must be stepped down to a regulated voltage to 1.2 V and provide output currents from 1 A to 3 A. The new devices are ideal for applications such as personal digital assistants (PDAs), digital cameras, notebooks and medical and industrial appliances. (See:'power.ti.com/sc03186.)'
TI's TPS6420x family of step-down controllers feature a quiescent current of only 20 µA and drive an external P-channel MOSFET, which allows for added design flexibility with the application's output current. The controllers are ideally suited for systems powered from a 5-V or 3.3-V bus or for battery-powered applications using a single-cell lithium-ion (Li-Ion) battery or two- to four-cell alkaline, nickel metal-hydride (NiMH) or nickel cadmium (NiCd) batteries.
The TPS6420x controllers achieve highest efficiency over a wide range offload current by using a minimum on-time and off-time control scheme. The minimum on time of typical 600 nanoseconds (ns) allows the use of small inductors and capacitors. When disabled, the current consumption is reduced to less than 1 µA.'
Additional Features
- Adjustable and Fixed Voltage Options from 1.2 V to Vin'
- 100 Percent Maximum Duty Cycle for Lowest Drop-out'
- High Efficiency at Light Load Currents'
- Internal Soft-Start'
- Over-Current Protection
Pricing and Availability
The TPS6420x devices are available today in volume from TI and its authorized distributors. The DC/DC controllers come in a six-pin SOT-23 (DBV) package, and are priced in quantities of 1,000 at $0.50 per unit. Evaluation modules of the TPS64200 are available in less than 24 hours through'power.ti.com.
