L9949 Ver la hoja de datos (PDF) - STMicroelectronics
Número de pieza
componentes Descripción
Fabricante
L9949 Datasheet PDF : 20 Pages
| |||
L9949
Temperature Warning and Thermal Shutdown
When the junction temperature rises above Tj TW a temperature warning flag is set and is available via the SPI.
If the junction temperature increases above the second threshold Tj SD, the thermal shutdown bit will be set and
the power DMOS transistors of the output stages are switched off to protect the device. In order to reactivate
the output stages the junction temperature must decrease below Tj SD - Tj SD HYS and the thermal shutdown bit
has to be cleared by the microcontroller.
Open Load Detection
The open load detection monitors the voltage drop of current sense resistors in each highside and lowside driver
of the output stage. The output signal of an open load comparator has to be valid for at least 0.5 ms (tdOL) to
set the open load bit (bit 1-11) in the status register 1.
Over Load Detection
In the case of an overcurrent condition an overcurrent flag (bit 1-11) is set in the status register 0 in the same
way as open load detection. If the overcurrent signal is valid for at least tISC = 10µs, the overcurrent flag is set
and the corresponding driver is switched off to reduce the power dissipation and to protect the integrated circuit.
The microcontroller has to clear the status bits to reactivate the corresponding driver.
Current monitor
The current monitor output sources a current image at the current monitor output which has a fixed ratio (1/
10000) of the instantaneous current of the selected highside driver. The bits 12 and 13 of the Input Data register
controls which of the outputs OUT1, OUT2 and OUT6 will be multiplexed to the current monitor output. The cur-
rent monitor output allows a more precise analyse of the actual state of the load rather than the detection of an
open- or overload condition. For example this can be used to detect the motor state (free-running, loaded or
blocked) or the temperature of the heating element.
Figure 1. Pin Connection (Top view)
GND
OUT3
OUT4
OUT5
VS
CLK
DI
VS
OUT1
GND
1
20
2
19
3
18
4
17
5
16
6
15
7
14
8
13
9
12
10
11
D99AT455Amod
GND
OUT6
VS
DO
CM
VCC
CSN
VS
OUT2
GND
3/20
Share Link: 