l99dz80ep STMicroelectronics, l99dz80ep Datasheet - Page 42

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

Application information
3.21
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Table 27.
Controller of electrochromic glass
The voltage of an electrochromic element connected at pin ECV can be controlled to a
target value, which is set by the bits EC<5:0>. Setting bit ECON enables this function. An
on-chip differential amplifier and an external MOS source follower, with its gate connected to
pin ECDR, and which drives the electrochrome mirror voltage at pin ECV, form the control
loop. The drain of the external MOS transistor is supplied by OUT10. A diode from pin ECV
(anode) to pin ECDR (cathode) has been placed on the chip to protect the external MOS
source follower. A capacitor of at least 5 nF has to be added to pin ECDR for loop-stability.
The target voltage is binary coded with a full-scale range of 1.5 V. If Bit EC_HV s set to '0',
the maximum controller output voltage is clamped to 1.2 V without changing the resolution
of bits EC<5:0>.
When programming the ECVLS driver to on-state, the voltage at pin ECV is pulled to ground
by a 1.6 Ω low-side switch until the voltage at pin ECV is less than dV
target voltage (fast discharge). The status of the voltage control loop is reported via SPI. Bit
ECV_VHI is set, if the voltage at pin ECV is higher, whereas Bit ECV_VNR in the same
status register is set, if the voltage at pin ECV is lower than the target value. Both status bits
are valid, if they are stable for at least the ECV
Since OUT10 is the output of a high-side driver, it contains the same diagnose functions as
the other high-side drivers (e.g. during an overcurrent detection, the control loop is switched
off). In electrochrome mode, OUT10 cannot be controlled by PWM mode. For EMS reasons,
the loop capacitor at pin ECDR as well as the capacitor between ECV and GND have to be
placed to the respective pins as close as possible (see
COPT<3>
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Cross-current protection time
COPT<2>
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Doc ID 18260 Rev 4
COPT<1>
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
HI
COPT<0>
/ECV
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
NR
Figure 20
– filter time and are not latched.
1000
1210
1420
1630
1830
2050
2250
2460
2660
2880
3080
3200
Min
150
390
590
800
for details).
1000
1250
1500
1750
2000
2250
2500
2750
3000
3250
3500
3750
4000
Typ
250
500
750
ECVhi
higher than the
1280
1600
1910
2220
2540
2850
3120
3450
3760
4100
4370
4680
5000
Max
360
670
980
L99DZ80EP
unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns