Product overview
Description
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 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.
Using L pin is possible to sense key switch and a pre-excitation duty cycle is applied on the field coil in order to start phase voltage sensing. In the case L connection gets lost, device starts to generate using residual magnetism of the generator.
Field, lamp and relay drivers are protected against short circuit.
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All features
- IC regulator for 12 V type alternator
- Fixed frequency regulation loop
- 130 mΩ high 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
EDA Symbols, Footprints and 3D Models
Quality and Reliability
Part Number | Marketing Status | Package | Grade | RoHS Compliance Grade | Material Declaration** |
---|---|---|---|---|---|
L9409F | NRND | MW 8L | Automotive | Ecopack1 | |
L9409F
Package:
MW 8LMaterial Declaration**:
(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.
Sample & Buy
Part Number | Marketing Status | Budgetary Price (US$)*/Qty | Order from ST | Order from distributors | Package | Packing Type | RoHS | Country of Origin | ECCN (US) | ECCN (EU) | Operating temperature (°C) | Operating Temperature (°C) (max) | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
min | max | |||||||||||||
L9409F | | | distributors No availability of distributors reported, please contact our sales office |
L9409F NRND
(*) Suggested Resale Price (USD) per defined quantity for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office or our Distributors