A6986ITR datasheet(43/62 Pages) STMICROELECTRONICS

Part #	A6986ITR

Description	Automotive 38 V, 5 W synchronous iso-buck converter for isolated applications

PDF	62 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

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Application example

The target of this section is to show a typical application example as well as to describe the expected

performances.

The schematic below depicts a typical application where an isolated voltage (single) together with a not isolated

voltage is required.

Figure 49. Typical schematic with load applied to both the isolated and not isolated outputs

This application generates 5 V at the primary output (not isolated) with a switching frequency of 500 kHz. The

secondary voltage (isolated) is generated by a transformer with a 1:5.8 turn ratio. The voltage between VOUT_sec+

and VOUT_sec- changes with the current drawn from the load. A post-regulation is necessary to keep this voltage

stable.

Maximum deliverable current in an iso-buck topology must take into account equations (5) and (6). According to

how much current is drawn from the isolated and not isolated outputs, IPEAKHS or IPEAKLS is the most stringent

parameter.

A6986I

Application example

DS13481 - Rev 2

page 43/62

A6986ITR Datasheet(PDF) 43 Page - STMicroelectronics