DS12617 Rev 5

19/35

L99MOD53XP

Application information

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3

Application information

3.1

(stabilized 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, if

there are temporary spikes or glitches on the power supply voltage. In case of power-on

and the status registers are cleared.

3.2

Standby mode

The standby mode of the L99MOD53XP is activated by clearing the bit 23 of the input data

register 0. All latched data are cleared and the inputs and outputs are switched to high

be achieved. If bit 23 is set, the device is switched to active mode.

3.3

Inductive loads

Each half bridge is built by an internally connected high-side and a low-side power DMOS

transistor. Due to the built-in reverse diodes of the output transistors, inductive loads can be

driven at the outputs OUT1 to OUT5 without external free-wheeling diodes. The high-side

drivers OUT6 to OUT8 are intended to drive resistive loads. Hence only a limited energy

(E<1mJ) can be dissipated by the internal ESD diodes in freewheeling condition. For

inductive loads (L>100µH) an external free-wheeling diode connected to GND and the

corresponding output is needed.

3.4

Diagnostic functions

All diagnostic functions (over/open-load, power supply over-/under voltage, temperature

warning and thermal shutdown) are internally filtered and the condition has to be valid for at

least 32 µs (open-load: 1 ms, respectively) before the corresponding status bit in the status

registers is set. The filters are used to improve the noise immunity of the device. Open-load

and temperature warning functions are intended for information purpose and don't change

the state of the output drivers. On the contrary, the overload condition disables the

corresponding driver (over-current) and overtemperature switches off all drivers (thermal

shutdown). Without setting the over-current recovery bits in the input data register, the

microcontroller has to clear the over-current status bits to reactivate the corresponding

drivers.