STMicroelectronics L9409
The L9409 is a monolithic multifunction alternator voltage regulator intended for use in automotive applications. The device regulates the output of an automotive generator by controlling the field winding current by means of either an analog fixed frequency PWM signal or digital fixed frequency PWM signal (LRC). The Load Response Control function is activated in order to eliminate IC engine speed fluctuation and vibrations caused by the insertion Order codes Table 1.| Part No. | L9409 |
|---|---|
| Datasheet | L9409 Download |
| Manufacturer |  STMicroelectronics |
| Description | Alternator voltage regulator |
| Buy | Stock & Price |
FEATURES
● IC regulator for 12 V type alternator● Fixed frequency regulation loop
● 130 mhigh side field driver
● Fail safe device with double sensing of battery voltage (VB and VS)
● Load response control (LRC) function activates after an initial time delay
● Self start function from phase frequency
● “Z” shaped regulation curve compliant with VW specification.
● Key recognition from L input
● Field driver, lamp driver and relay driver short protection
● Complex diagnostics
● Thermal shutdown at 175 °C
DESCRIPTION
Device summary Order code Junction temp range, C L9409F -40 to 150 '!0'03 Multiwatt8 of sudden electrical loads during alternator low speed operations (f < 310 Hz). Both the analog and digital duty cycle are applied to a high side driver. The device is able to regulate the voltage either using a feedback signal from B pin or from S pin depending on application needs. S pin is intended to have a clear direct connection with the positive terminal of the car battery. If this connection gets lost the device will regulate voltage using B pin giving a fail safe functionality.
