L9409F STMicroelectronics

L9409 Alternator voltage regulator with load response control Features IC regulator for 12 V type alternator Fixed frequency regulation loop 130 m high side field driver Fail safe device with double sensing of battery voltage (VB and VS) Load response control (LRC) function activates 0 03 after an initial time delay Multiwatt8 Self start function from phase frequency Z shaped regulation curve compliant with VW specification. of sudden electrical loads during alternator low speed operations (f < 310 Hz). Both the analog Key recognition from L input and digital duty cycle are applied to a high side Field driver, lamp driver and relay driver short driver. protection The device is able to regulate the voltage either Complex diagnostics using a feedback signal from B pin or from S pin Thermal shutdown at 175 C 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 Description lost the device will regulate voltage using B pin The L9409 is a monolithic multifunction alternator giving a fail safe functionality. voltage regulator intended for use in automotive Using L pin is possible to sense key switch and a applications. pre-excitation duty cycle is applied on the field coil The device regulates the output of an automotive in order to start phase voltage sensing. In the generator by controlling the field winding current case L connection gets lost, device starts to by means of either an analog fixed frequency generate using residual magnetism of the PWM signal or digital fixed frequency PWM signal generator. (LRC). The Load Response Control function is Field, lamp and relay drivers are protected activated in order to eliminate IC engine speed against short circuit. fluctuation and vibrations caused by the insertion Order codes Table 1. Device summary Order code Junction temp range, CPackage Packing L9409F -40 to 150 Multiwatt8 Tube September 2013 Doc ID 022665 Rev 2 1/13 www.st.com 13Contents L9409 Contents 1 Block and application diagram 3 2 Pin description . 4 3 Maximum ratings 5 3.1 Voltage maximum ratings 5 3.2 Thermal data . 5 4 Device description 6 4.1 Voltage regulation 6 4.1.1 Description 6 4.1.2 Electrical characteristic 6 4.2 Load response control (LRC) . 8 4.2.1 Description 8 4.2.2 Electrical characteristics . 8 4.3 Lamp and relay driver . 9 4.3.1 Description 9 4.3.2 Electrical characteristic 9 4.3.3 Relay driver description 9 4.3.4 Electrical characteristic 9 4.4 Protection and diagnosis . 10 4.4.1 Diagnostic electric parameters . 10 5 Package information 11 6 Revision history . 12 2/13 Doc ID 022665 Rev 2