L99H01 datasheet(25/53 Pages) STMICROELECTRONICS

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L99H01

Device description

3.1

Dual power supply: VS and VCC

The power supply voltage VS supplies the charge-pump. An internal charge-pump is used to

drive the high-side switches and the low-side switches. The logic supply voltage VCC

(3.3 V / 5 V) is used for the logic part and the SPI of the device. Due to the independent logic

supply voltage the control and status information is not lost, even if the supply voltage VS is

switched-off. In case of power-on (VCC increases from undervoltage to

VPOR OFF = 2.5 V, typical) the circuit is initialized by an internally generated power-on reset

(POR). If the voltage VCC decreases under the minimum threshold (VPOR ON =2.2 V,

typical), the outputs are switched-off and the status registers are cleared.

3.2

Standby mode (EN)

The L99H01 is activated with enable input high signal. For enable input floating (not

connected) or VEN = 0 V the device is in standby mode. All latched data are cleared and the

inputs and outputs are switched-off. In the standby mode the current at VS is less than 5 µA

(1 µA) for CSN = high (DO in tristate). If VCC > VPOR OFF and EN = high the device enters

the active mode. In the active mode the charge-pump and the diagnostic functions are

active.

3.3

H-bridge control (DIR, PWM, bit FW)

The DIR and PWM inputs control the drivers of the external H-bridge transistors. The motor

direction can be chosen with the DIR input, the duty cycle and frequency with the PWM

input. With the SPI registers FW and FW-PAS 4 different free wheeling modes (2 active and

2 passive) can be selected using the high-side transistors or the low-side transistors.

Unconnected inputs are defined by internal pull-down current.

L99H01 データシート(PDF) 25 Page - STMicroelectronics