L99LD02 datasheet(7/66 Pages) STMICROELECTRONICS

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DS12448 Rev 3

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L99LD02

Introduction

The L99LD02 is a dual-phase, constant frequency, current mode boost controller that drives

N-channel power MOSFETs providing a regulated voltage on BST_OUT pin.

The boost controllers of more devices can be stacked, in order to operate in multi-phase for

high power applications. Multi-phase operation is supported by SYNC I/O pin, providing the

phase shifted clock signal. Special care has been taken for the current balancing between

the different phases and for the switching activity of the boost MOSFETs with proper phase

shift.

The device offers a high level of flexibility, without any change of the external components,

thanks to its programmability through the ST SPI interface. This feature supports generic

platform approaches, which require a software configuration of several parameters.

Moreover, this robust interface offers a detailed diagnostic of the device itself.

The L99LD02 features a timeout watchdog, a monitoring of the watchdog counter and a

Limp Home function. The device is fully configurable in Limp Home through OTP bits,

allowing stand-alone operation.

The L99LD02 integrates a 10 V LDO to supply the gate drivers for standard level MOSFETs

and features a supply option from boost output to supply the device when battery level is not

enough to guarantee fully Ron external MOSFETs and to fulfill cold cranking requirement.

The input of the boost stage must be connected to the battery voltage through a reverse

polarity protection.

The output of the L99LD02 can reach up to 80 V. This allows system designers to drive LED

strings up to 60 V.

L99LD02 Datenblatt(PDF) 7 Page - STMicroelectronics