Preliminary Datasheet TCB702FNG (Toshiba) - 10

Preliminary
TCB702FNG
6.4. Change of Amplifier Operation Mode (Power Amplifier Mode / Line Driver Mode)
It is possible to set the internal amplifier operation mode via I2C bus for speaker output (power amplifier mode) and for a line driver mode. The amplifier operation mode should be changed during the hardware or software standby state. Please do not change the mode during operating the amplifier. (1) Power amplifier mode The IC operates as the power amplifier mode with high efficiency class TB by setting IB2-D3 data to bit=0. At that time, the output DC voltage of ch1 and ch3 turns to VCC/4, that of ch2 and ch4 turns to 3VCC/4. The GV of ch1, ch3 (Front) and ch2, ch4 (Rear) can be set separately by using the data of IB1-D4 (Front) and IB1- D3 (Rear). It is set to 26 dB by setting each bit=0, and it is set to 16 dB by setting each bit=1. Additionally, the thresholds of open and short detections are for the settings of the power amplifier. For each threshold, refer to Section 9.1.1. (2) Line driver mode (Note1, Note 2 Note 3, and Note 4) The IC operates as the line driver mode by setting IB2-D3 data to bit=1. At that time, the output DC voltage of all channels is the same level, and it operates as the class AB amplifier. The GV setting of 26 dB and 16dB can be changed by using the data of IB1-D4 and IB1-D3. However, The GV of ch1, ch3 (Front) and ch2, ch4 (Rear) cannot be set separately. When both bits of IB1-D4 and IB1-D3 are set to 0, the operation mode is set to 26 dB mode, and other cases are set to 16 dB mode. The output DC voltage is also changed by GV setting. It is VCC/2 in 26 dB setting, and it is VCC/4 in 16 dB setting. For details, refer to Table 6.3. Additionally, the thresholds of open and short detections are for the settings of the Line driver. For each threshold, refer to Section 9.1.2. Note1: GV changing cannot be set per channel. Note2: The thresholds of the open, short, and rare short detections at self-diagnostics are thresholds for the line driver. Note3: The clip detection does not operate in the line driver mode. Note4: In 16-dB line driver mode, when one of two pins of each channel is used as an unbalanced output, the timing of upper and lower clippings deviates because the output DC voltage becomes VCC/4.
Table 6.3 Amplifier operation mode setting
I2C bus setting command ch1 and ch3 (Front) ch2 and ch4 (Rear) Line Driver Self-diagnostics Gv16F Gv16R Output DC Output DC Diagnostics mode Operation mode Operation mode (IB1-D4) (IB1-D3) voltage voltage (IB2-D3) Power amplifier 26 dB power amplifier 26 dB power amplifier 0 0 0 V 3V diagnosis (class TB) CC/4 (class TB) CC/4 Power amplifier 26 dB power amplifier 16 dB power amplifier 0 0 1 VCC/4 3VCC/4 diagnosis (class TB) (class TB) Power amplifier 16 dB power amplifier 26 dB power amplifier 0 1 0 VCC/4 3VCC/4 diagnosis (class TB) (class TB) Power amplifier 16 dB power amplifier 16 dB power amplifier 0 1 1 VCC/4 3VCC/4 diagnosis (class TB) (class TB) 26 dB line driver 26 dB line driver 1 0 0 Line driver diagnosis V V (class AB) CC/2 (class AB) CC/2 16 dB line driver 16 dB line driver 1 0 1 Line driver diagnosis V V (class AB) CC/4 (class AB) CC/4 16 dB line driver 16 dB line driver 1 1 0 Line driver diagnosis V V (class AB) CC/4 (class AB) CC/4 16 dB line driver 16 dB line driver 1 1 1 Line driver diagnosis V V (class AB) CC/4 (class AB) CC/4 10 2018-10-23