L9958SB STMicroelectronics, L9958SB Datasheet - Page 16

• Manufacturer Part Number: L9958SB
• Description: IC H-BRIDGE SPI POWERSO16
• Manufacturer: STMicroelectronics

Specifications of L9958SB

• Applications: DC Motor Driver, Brushless (BLDC)
• Number Of Outputs: 2
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: PowerSO-16 Exposed Bottom Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Voltage - Load: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Current regulation
4
4.1
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Current regulation
To protect the actuator and limit power dissipation, a two-level chopper current limitation is
integrated as shown in figure below. The current is measured by sense cells integrated in
the low-side switches. As soon the upper current limit “IH” is reached, both low-side drivers
are switched on to allow free-wheeling recirculation, until the lower current limit “IL” is
reached. During the current regulation, all the slew rate controls are disabled in order to
minimize the power dissipation. Four current limit levels can be set by the SPI control bits 0
and 1. In order to achieve very precise current threshold and ripple, an external resistance is
required (1 % accuracy on all temp range/lifetime) to generate a current reference. Detailed
values for current thresholds and ripple are reported in
Figure 11. Current limitation
Table 9.
Temperature-dependent current regulation
In order to reduce power dissipation and thus the junction temperature, above a temperature
Twarn = 160 °C, current regulation high limit linearly decreases with temperature, to reach
about 2.5 A at Tsd = 175 °C (shutdown temperature).
When this thermal threshold is reached during a current limitation phase, the information is
stored and latched in a coding of bits called "Twarn". This bit can be reset only if the settings
conditions (T
reduce the power dissipation and thus the junction temperature.
CL_2
0
0
1
1
Current limitation programmability
j
> Twarn and I
CL_1
0
1
0
1
LIM
2.5 A
4 A
6.6 A (default value)
8.6 A
Doc ID 17269 Rev 2
= 0) are not present anymore. This feature is mainly used to
Current limit (typical values)
Table
9.
L9958