AN557 Datasheet, PDF (1/52 Pages) STMicroelectronics – EASY APPLICATION DESIGN WITH THE L4970A

AN557
APPLICATION NOTE
EASY APPLICATION DESIGN WITH THE L4970A,
MONOLITHIC DC-DC CONVERTERS FAMILY
The L497XA series of high current switching regulator ICs exploit Multipower-BCD technology to
achieve very high output currents with low power dissipation – up to 10A in the Multiwatt power package
and 3.5A in a DIP package .
THE TECHNOLOGY
The technology architecture is based on the vertical DMOS silicon gate process that allows a channel
length of 1.5 micron ; using a junction isolation technique it has been possible to mix on the same chip
Bipolar and CMOS transistors along with the DMOS power components (Fig. 2). Figure 1 shows how this
process brings a rapid increase in power IC complexity compared to conventional bipolar technology. In
the 70’s class B circuits and DC circuits allowed output power in the range of 70W. By 1980, with the in-
troduction of switching techniques in power ICs, output powers up to 200W were reached ; with BCD tech-
nology the output power increased up to 400W.
November 2003
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