l9958 STMicroelectronics, l9958 Datasheet - Page 17

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

L9958
4.2
4.3
Figure 12. Temperature dependent current regulation
Current regulation with low-inductive loads
Each time output stages are turned off, an internal timing starts for duration Toff-min.
Whenever turn-on is reached in a time Toff that is shorter than Toff-min, output stages are
kept OFF, until Toff-min is reached.
In such case the ripple control could be not so precise as specified.
Figure 13. Current regulation with different loads
Slew rate control in case of current limitation on low-side
The slew rate control can be done on voltage and current or only on voltage. This can be
selected by SPI through the bit ISR_DIS.
The slew rate of each high-side power transistor of the bridge is controlled either during
turn-on and turn-off (current AND voltage slew rate). The same setting is applied for both
switching. Moreover, this slew rate is configurable by SPI in order to get the best trade-off
between conducted/radiated EMI and power dissipation during switching. The slew rate
Current
OUT1,2
IH
IL
High Inductive Load
2.5
8.6
AC00662
I
tb
Doc ID 17269 Rev 1
Toff-min
Toff
tb
Twarn
Toff
Toff-min
Low Inductive Load
Tsd
tb
Tj
Current regulation
time
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