Step Down Charge Pumps Use No Inductors

Requiring few external capacitors and no inductors, the TPS6050x charge pumps allow for a complete converter to be built in an area measuring just 0.155 in.2. With a quiescent current of 40 µA, the devices provide regulated output voltages from 0.8V to 3.3V and an output current drive of 250 mA, said to be the highest in the industry. Via a fractional conversion topology, peak efficiencies of 90% can be achieved, resulting in the elimination of the need for a heat sink. The charge pumps can be powered by three or four NiCad, NiMH or alkaline batteries, or by a single Li-ion cell. Four devices with varied output voltages are available: TPS60500 with adjustable output from 0.8 to 3.3V; TPS60501 with fixed 3.3V output; TPS60502 with fixed 1.8V output; and the TPS60503 with fixed 1.5V output. In 10-pin MSOPs, price is $1.35 each/1,000. TEXAS INSTRUMENTS INC., Santa Clarita, CA. (800) 477-8924, ext. 4500.