l99dz80ep STMicroelectronics, l99dz80ep Datasheet - Page 43

• Manufacturer Part Number: l99dz80ep
• Description: Door Actuator Driver
• Manufacturer: STMicroelectronics

L99DZ80EP
Figure 20. Electrochrome mirror driver with mirror referenced to ground
If the electrochrome element is connected between the pins ECV and ECFD instead
between ECV and ground, a negative voltage can be applied to the device by pulling ECFD
to a higher value than ECV, which is connected to ground by a 1.6 Ω low-side switch. In this
mode the voltage at pin ECFD is controlled to the target value defined by the register
EC<5:0>. This is done using an on-chip source-follower transistor (see
details). The negative discharge is enabled by setting bit ECND to ‘1’.
When programming the ECFDLS driver to on-state, the voltage at pin ECFD is pulled to
ground by a 1.6 Ω low-side switch until the voltage at pin ECFD is less than dV
than the target voltage (fast discharge).
During normal (positive) voltage control the low side driver at pin ECFD must be switched on
to connect the electrochrome element to ground.
Pin ECDR is pulled resistively (R
Doc ID 18260 Rev 4
ECDRDIS
) to ground while not in electrochrome mode.
Application information
Figure 21
ECFDhi
for
higher
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