Datasheet

Description L99MC6
14/32 Doc ID 16523 Rev 2
2.4.1 Direct input IN/PWM
The IN/PWM input allows channel 2 to be enabled without the use of SPI. The IN/PWM pin
is OR-ed with the SPI command bit. This pin can be left open if the channel 2 is controlled
only via the SPI. This input has an internal pull-down.
The IN/PWM signal can also be applied to any other switches by the activation of the PWM
mode.
This input is suited for non-inductive loads that are pulse width modulated. This allows PWM
control without further use of the SPI.
2.4.2 Temperature warning and thermal shutdown
If the junction temperature rises above T
j TW
a temperature warning flag is set and is
detectable via the SPI. If the junction temperature increases above the second threshold
T
jSD
, the thermal shutdown bit is set and power DMOS transistors of all output stages are
switched-off to protect the device. Temperature warning flag and thermal shutdown bits are
latched. In order to reactivate the output stages, the junction temperature must decrease
below T
jSD-
T
jSDHYS
and the thermal shutdown bit has to be cleared by the
microcontroller.
2.4.3 Open-load detection in off-state
The open-load detection monitors the load at each output stage in off mode. A current
source of 150 µA (I
OLD1-6
, I
OLS 1-3
) is connected between drain and source or GND. An
open-load failure is detected if the drain or source voltage reaches an internal V
OLD/S
(2.0 V) for at least 3 ms (t
dOL typ.
). The corresponding open-load bit is set in the status
register. In LED mode the open-load detection is disabled and the current source is
switched-off, which avoids a turn-on of the LEDs in off-state.
2.4.4 Overload detection
In case of an overcurrent condition, a flag is set in the corresponding status register. If the
overcurrent signal is valid for at least t
ISC
= 32 µs, the overcurrent flag is set and the
corresponding driver is switched-off to reduce the power dissipation and to protect the
integrated circuit. If the overcurrent recovery bit of the output is zero the microcontroller has
to clear the status bit to reactivate the corresponding driver.
2.5 Bridge mode
The L99MC6 can be configured as bridge driver. Up to three half bridges can be used. In
Bridge mode the device is crosscurrent protected by an internal delay time. If one driver (LS
or HS) is turned-off the activation of the other driver of the same half bridge is automatically
delayed by the crosscurrent protection time. After the crosscurrent protection time is expired
the slew rate limited switch-off phase of the driver is changed to a fast turn-off phase and the
opposite driver is turned-on with slew-rate limitation. Due to this behavior it is always
guaranteed that the previously activated driver is totally turned-off before the opposite driver
starts to conduct.
Due to the built-in reverse diodes of the output transistors, inductive loads can be driven at
the outputs without external free-wheeling diodes.