San Jose, Calif. — Toshiba America Electronic Components, Inc. (TAEC) today announced what it said is the first Class-KB audio power amplifier based on bipolar, complementary metal oxide semiconductor and double-diffused metal oxide semiconductor technology.

Designated TB2905HQ, the linear audio amplifier is intended for demanding car-audio applications, including CD, DVD and navigation applications. The amplifier incorporates four bridge-tied load (BTL) amplifier channels and its many built-in functions include standby switching, muting, offset and clipping detection, and various protective circuits.

Toshiba's proprietary Class-KB (keyed bridge-tied load) high-efficiency amplifier architecture was made for car electronics to overcome the serious shortcomings of competing high-efficiency solutions, said David Cruikshank, business development manager in the ASSP Business Unit at TAEC. “Class-KB completely eliminates the switching noise or electromagnetic interference associated with digital or switched analog amplifier designs,” he said.

Class-KB employs a linear amplifier design rather than a switched analog or digital type — and thus completely eliminates the switching noise found in other designs such as the Class-D architecture, Cruikshank said. Power consumption and heat generation is half that of conventional Class-AB amplifiers under normal driving conditions (when output power is one to four W), he added.

Features of the TB2905HQ include:

• High output power with JEITA maximum power of 47 W x 4 BTL amp channels at 4 Ω and 14.4 V
• High performance at 2 Ω with typical power of 55 W x 4 BTL amplifier channels at 14.4 V and 10 percent total harmonic distortion (THD)
• Low distortion ratio with THD of 0.03 percent typical at 4 Ω, 13.2 V, and 2 W of output power
• Low standby current of 2 μA typically
• Protective circuitry, including thermal shutdown, shorting of output terminal and overvoltage
• Operating voltage of 9 to 18 V
• Housed in a lead-free SPP-25 package that is pin compatible with many Toshiba car amplifiers

 
 
See related block diagram