From Newsgroup: sci.electronics.design
Putting this to Google AI gets this:
The specific component you are looking for is the internal multi-rail power supply circuit (or voltage regulator IC) typically found inside Ford premium radio head units, such as the Ford Audio Control Module (ACM) from the Sony or Shaker premium sound systems.Where These Specific Voltages Are UsedIn a standard automotive environment, a vehicle's battery only supplies a single, nominal 12 VDC to 14.5 VDC rail. To power complex internal electronics, the car stereo utilizes an onboard step-up/step-down multi-channel power supply management IC (PMIC) to split and convert that single input into these exact sub-rails:-# 5.0 VDC: Powers the digital logic, the main microcontroller unit (MCU), the USB ports, and the CAN-bus communication chips.-# 8.0 VDC: Dedicated strictly to clean audio processing, including the AM/FM tuner circuitry, pre-amplifier stages, and Digital Signal Processing (DSP) operational amplifiers (op-amps).-# 13.5 VDC: Replicates stable battery-level voltage to power the internal CD/DVD changer motors, display backlighting, and cooling fans.30.0 VDC: Generated by an internal DC-to-DC boost converter specifically to drive Vacuum Fluorescent Displays (VFD) or high-voltage liquid crystal display (LCD) bias gates.Common Integrated Circuits (ICs) to CheckIf you are repairing or testing a Ford stereo PCB board, look for the following multi-output automotive power supply ICs (often manufactured by STMicroelectronics or NXP) located near the main power input connector block:L9779 / L9780 Series: Automotive multi-voltage regulators commonly deployed in Ford infotainment platforms.ST75185 / TDA-series regulators: Multi-channel voltage regulators that manage 5V, 8V, and boosted display lines on a single chip.If you are trying to bench-test this Ford stereo outside of the car, note that you do not need a power supply that outputs all of these voltages. You only need to feed a standard 12VrCo13.8V DC (at least 5 to 10 Amps) power supply into the stereo's main harness pins (BATT+ and ACC/Ignition), and the radio's internal circuitry will generate the 5V, 8V, 13.5V, and 30V rails on its own.To help you find the exact schematic or chip placement, could you share the model number or part number (usually starting with letters like AA8T, BL3T, or HC3T) printed on the radio's metal sticker?
End Quote
If you identify the particular multi-rail regulator chip or chips, the manu will have an app note or datasheet typical from which inferring the schematic is a trivial exercise.
--
For full context, visit
https://www.electrondepot.com/electrodesign/multiple-output-dc-dc-converter-4405051-.htm
--- Synchronet 3.22a-Linux NewsLink 1.2
