TB2912HQ Toshiba, TB2912HQ Datasheet - Page 3

• Manufacturer Part Number: TB2912HQ
• Manufacturer: Toshiba

Specifications of TB2912HQ

• No. Of Channels: 4
• Package: HZIP 25-P-1.00F
• Recommended Vcc (v): 13.2
• Rl=2 Ohm: 70W x 4
• Rl=4 Ohm: 43W x 4
• Rl=8 Ohm: -
• Features/built-in Functions: 4 BTL channels, standby switch, mute, BiCD process, I2C self-diagnosis, tweeter diagnostics, low standby current
• Operating Voltage (v): 9 to 18

Caution and Application Information
channel.)
1. Voltage Gain Adjustment
2. Stand by and muting (
The capacitor C4 at pin 16 is for muting time constant to suppress the pop noise. The larger value capacitor
is used, the lower pop noise becomes but the longer the muting time from the mute ON command sent to
muting an output sound actually.
The charge period, which makes the delay of muting after "Mute On" command is written, is MIN=30msec,
As the V
basically.
Use the transistor which has the current capacitance more than 1mA to control the pin 16 in stable.
MAX=180msec in case of C4 (Pin 16) = 1 uF, Vcc=9 to 18V and Tj =-40 to 150 degrees condition..
software). However, this feature makes possible space and cost saving.
dynamic range is reduced as the output of Amp.1 is attenuated.
① I2C bus circuit awake as the pin 16 is 2.5V and more.
② Control the mute / standby function via I2C as I2C
To turning off (Standby on)
① Control muting circuit to mute ON via I2C control or the pin 16 is set at M position
② Control the standby circuit to turn off via I2C bus and it become in standby mode after 53200 x C2(sec)
③ The pop noise generates if the pin 16 is set at L position in advance to the ②step, or from the ① step
At turning on(Stand by off)
This IC has no NF (negative feedback) Pins. Therefore, the voltage gain can not be adjusted (except by
The amplifier gain, G
Therefore, the total voltage gain is decided by expression below.
In the case when G
The below procedure can make the pop noise suppress.
The voltage of pin 16 is pulled up to Vcc after this.
command can be received after ① condition.
later from sending the standby ON command.
to the ③ step directly.
Therefore, the diode insertion is necessary between pin 16
and micro controller to stop the reverse current if the
micro controller control the pin 16 of this IC.
The voltage gain of amp.1: G
The voltage gain of amp.2A, B: G
The voltage gain of BTL connection: G
G
CC
V
= G
is rapidly falling, the IC internal low voltage muting operates to eliminate the large pop noise
V1
+ G
V2
V
+ G
= 12dB selected via I
V
= 26dB, is calculated using the expression below:
V (BTL)
Input
pin 16)
Figure 1 Block Diagram
= 0 + 20 + 6 = 26dB
V1
= 0dB
V2
Amp. 1
= 20dB
(description is made referring only on the single
V (BTL)
2
C, G
3
V1
= 6dB
changed from 0dB to −14dB so that the output
Amp. 2A
Amp. 2B
Figure 2 Stand by and Mute
16
Start Up
TB2912HQ
2006-04-28
From low voltage
muting circuit
To mute circuit