Ny audiochip skal give elbiler 'motorlyd'
Toshiba står bag en single-chip audio effektforstærker, der kan give elektriske og hybride køretøjer en 'egenlyd', der minder om en traditionel forbrændingsmotor (in english).
In 2011 the European Commission adopted a resolution amendment that manufacturers shall be required to install acoustic vehicle alerting system (AVAS) in electric vechicles (EVs) and hybrid electric vehicles (HEVs), that the sound should be easily indicative of vehicle behavior, and should sound similar to the sound of a vehicle of the same category equipped with an internal combustion engine.Toshiba Electronics Europe (TEE) is now offering a single-chip amplifier to support safety designs that add the sound of a conventional internal combustion engine to EVs and HEVs. The TB2909FNG is a compact and integrated power amplifier that also supports other external audible output including reversing alarms and ‘answerback’ confirmation for keyless remote entry security.
EVs and HEVs operating in all-electric mode are much quieter than vehicles driven by internal combustion engines. As a result, pedestrians, cyclists and other road users may be less aware of their presence – especially at low speeds. Because of this a number of manufacturers already equip their vehicles with an acoustic vehicle alerting system. It is anticipated that such systems will become more prevalent as legislators seek to establish a minimum level and type of sound for low-speed, all-electric operation. Due to road users’ familiarity with traditional vehicles, a preferred sound is that of a normal vehicle engine.
Toshiba’s TB2909FNG power IC is a single-channel, Class-AB, single-ended push-pull (SEPP) amplifier specifically developed to amplify the simulated sound of a conventional engine. The device operates from a supply of between 6V and 16V and can deliver a maximum output power of 5W (Vcc = 16V, RL = 8Ω). Total harmonic distortion (THD) is rated at 0.08% (for an output power of 0.125W) and output noise voltage is just 50μV. Guaranteed operation between -40° and 110°C supports use in EV warning sound systems where stable performance at extended temperatures is required.
The new device is supplied in a TSSOP16 package with dimensions of just 4.4mm x 5.0mm x 1.0mm. Despite its compact size, the IC provides high levels of integrated functionality including a variety of mute capabilities and a built-in standby switch. Abnormality detection and protection for thermal overload, over-voltage, short circuits to GND or VCC, and speaker-open conditions are provided as standard, supporting functional safety.
Toshiba has developed the TB2909FNG using its BiCD-0.13 process. This process allows the integration of bipolar transistors, CMOS FETs and high-voltage DMOS elements on the same die.
