l9958 STMicroelectronics, l9958 Datasheet - Page 22

• Manufacturer Part Number: l9958
• Description: Low Rdson Spi Controlled H-bridge
• Manufacturer: STMicroelectronics

Diagnostics and protections
5.2.7
5.2.8
5.2.9
22/38
Figure 17. Battery voltage monitoring
Table 13.
Vdd over-voltage detection
Although the Vdd input pin and all I/O's are able to withstand up to 19 V, an over-voltage
circuitry is implemented to ensure that the bridge is kept in tri-state when the Vdd voltage is
higher than the Vdd overvoltage threshold "Vdd_ov_off" for duration longer than
"Tov_Vdd". The information is detected and stored into the SPI register in a bit called
"VDD_OV". The bridge is kept in tri-state as long as an appropriate reset is not requested
(see
Table 14.
Vdd under-voltage detection
When the Vdd voltage falls below the under-voltage detection threshold "Vdd_uv_off" for
duration longer than "Tuv_vdd", the bridge is switched to tri-state. In such a condition, the
L9958 is going in sleep mode. When the voltage increases above the threshold (hysteresis
implemented), the L9958 starts with all the settings reset to their default values (Power On
Reset).
Output short protection
The L9958 can sustain short on the outputs. In case of short to GND, short to battery or
short between outputs the battery voltage cannot exceed 18 V. The connection of a 100 µF
decoupling capacitor as close as possible to V
the exposed pad is mandatory to improve the robustness.
VS_UV
Bridge
Section
Vs_ uv
0 (default)
0 (default)
VDD_OV
State
VS_UV
Vs
1
1
Vs under-voltage
Vdd over-voltage detection
5.1).
Vdd > Vdd_ov_off
Vdd < Vdd_ov_on
Vs < Vs_uv_off
Vs > Vs_uv_on
ON-STATE
Comments
Comments
Doc ID 17269 Rev 1
t<Tuv_vs
s
pin and the GND connection of the slug or of
Bridge state
Bridge state
Hi Z
Hi-Z
Tuv_vs
TRI-STATE
-
-
1 (not latched)
ON-STATE
1 (latched)
FSI
FSI
0
0
AC00667
L9958