L99MD01 datasheet(7/54 Pages) STMICROELECTRONICS

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L99MD01

Detailed description

Doc ID 17242 Rev 6

7/54

Detailed description

2.1

Power supply: VCC

The supply voltage VCC (3.3 V / 5 V) supplies the whole device. In case of power-on (VCC

increases from undervoltage to VPOR OFF = 2.75 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 = 2.55 V, typical), the outputs are switched off in 3-state (high

impedance). The status registers are cleared and the control registers are reset to their

default.

Figure 2.

Power on reset

2.2

Power supply: VSA, VSB

Each VSA and VSB supplies 4 half bridges independently.

VSA  Out 1 to Out 4

VSB  Out 5 to Out 8

2.3

Standby mode

The standby mode of the L99MD01 is activated by EN pin to low. The inputs and outputs are

switched off. The status registers are cleared and the control registers are reset to their

default values.

In the standby mode the current consumption is typ. 5 µA.

2.4

PWM mode

The PWM Mode is intended to generate a hold current for stepper motors.

PWM frequency typ. 100 Hz.

Duty cycle (SPI 2bit): 15 %, 30 %, 45 % and 60 %.

Each half-bridge is independently addressable (SPI 8bit).

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