L9959S datasheet(23/43 Pages) STMICROELECTRONICS

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L9959S, L9959T

Application information

Figure 13. DIR-change output voltage

The first part of the sequence is identical to the PWM-mode (s.a.). After this has been

finished and the associated low-side driver is on (e.g. Figure 11 LS1), in phase 1 the other

low-side driver is turned on (e.g Figure 11 LS2). Then in phase 2 the low-side output of

OUT2 is switched-off slowly and the current through the load is taken over by the body-

diode of the high-side (e.g. Figure 12 HS2). Depending on the inductance of the load, the

current vanishes more or less quickly. After the low-side driver is turned off, the high-side is

switched on with a slow slew-rate.

This assures, that direction switch occurs while the current over the load has vanished,

which reduces the electromagnetic emission.

4.2

Protection and monitoring

All errors are confirmed after their occurrence by accessing the error condition after time

tdelay_retest a second time. Only after the error is confirmed it is entered into the diagnosis

The device can be enabled again by following actions: Power-on reset, disabling or enabling

the device using the pins /ABE or DIS (e.g. disabling - enabling sequence). The diagnosis

registers can be cleared by sending a reset command by SPI (STATCON_REG) to either

diagnosis register 1 (DIA_REG1) or 2 (DIA_REG2). The bit1 (Reset) of the CONFIG_REG if

forced to zero is resetting both the device registers configuration and diagnosis registers

to default but is not able to restart the device. In order to restart IC is necessary to force a

transition LOW/HIGH/LOW on DIS pin or a transition HIGH/LOW/HIGH on /ABE pin.

The errors in the diagnosis register 1 (DIA_REG1) are transferred to the diagnosis register 2

by setting the bit DIACLR1 in the status and configuration register (STATCON_REG) or by

using the enabling -disabling sequence on /ABE or DIS. This will also clear the diagnosis

L9959S 数据表(PDF) 23 Page - STMicroelectronics