High power speaker amp ICs are optimised for autonomous driving
AEC-Q100-qualified 2.8W output Class AB monaural speaker amplifiers from Rohm Semiconductor are intended for instrumental clusters in vehicles equipped with autonomous driving and advanced driving assistance systems (ADAS).
The BD783xxEFJ-M series (BD78306EFJ-M, BD78310EFJ-M and BD78326EFJ-M)
have been developed for vehicle clusters where various sound outputs at high volume, including warning sounds, turn signals, welcome tones and voice guidance are required. They use a new type of over-current protection (OCP) circuit to protect against output shorts to deliver high 2.8W output, which was difficult to achieve in the past, reports Rohm. In addition to over-current protection, built-in thermal shutdown and under-voltage lock out (UVLO) ensure high reliability protection against abnormal conditions.
The amplifiers can withstand high temperature operation up to 105 degrees C to enable stable voice output without compromising functionality even under severe conditions, Rohm said.
With conventional over current protection circuits, the maximum output is limited, since the operating threshold of the protection circuit must be set to a value smaller than the maximum current the speaker amp can provide. Rohm’s over-current protection circuit eliminates the need to limit the output by preventing waveform distortion even at high output. The BD783xxEFJ-M series provides over-current protection from output shorts with 2.8W maximum output at 4Ohm load and 10 per cent distortion.
The BD783xxEFJ-M series is qualified to withstand automotive reliability standard AEC-Q100 and the power package reduces heat generation even at high volumes, resulting in stable audio output. In addition to over-current protection, thermal shutdown and under-voltage lock-out are built-in, preventing damage caused by abnormal heat generation and unexpected popping (cracking) noise during battery interruptions.
ROHM’s BD783xxEFJ-M series speaker operational amps are mounted on Cypress Semiconductor’s Traveo Cluster microcontroller family S6J3360 series evaluation board for automotive applications.
Rohm offers output gains of +6dB (BD78306EFJ-M), +10dB (BD78310EFJ-M), and +26dB (BD78626EFJ-M). The range will be expanded to include a total of 11 models ranging from +6dB to +26dB in 2dB steps.
