ZHCS891G April 2012 – December 2017 TPA3116D2 , TPA3118D2 , TPA3130D2
PRODUCTION DATA.
The TPA31xxD2 family has a built-in voltage limiter that can be used to limit the output voltage level below the supply rail, the amplifier simply operates as if it was powered by a lower supply voltage, and thereby limits the output power. Add a resistor divider from GVDD to ground to set the voltage at the PLIMIT pin. An external reference may also be used if tighter tolerance is required. Add a 1 µF capacitor from pin PLIMIT to ground to ensure stability. It is recommended to connect PLIMIT to GVDD when using 1SPW-modulation mode.
The PLIMIT circuit sets a limit on the output peak-to-peak voltage. The limiting is done by limiting the duty cycle to a fixed maximum value. This limit can be thought of as a "virtual" voltage rail which is lower than the supply connected to PVCC. This "virtual" rail is approximately 4 times the voltage at the PLIMIT pin. This output voltage can be used to calculate the maximum output power for a given maximum input voltage and speaker impedance.
where
PVCC (V) | PLIMIT VOLTAGE (V)(1) | R to GND | R to GVDD | OUTPUT VOLTAGE (Vrms) |
---|---|---|---|---|
24 V | GVDD | Open | Short | 17.9 |
24 V | 3.3 | 45 kΩ | 51 kΩ | 12.67 |
24 V | 2.25 | 24 kΩ | 51 kΩ | 9 |
12 V | GVDD | Short | Open | 10.33 |
12 V | 2.25 | 24 kΩ | 51 kΩ | 9 |
12 V | 1.5 | 18 kΩ | 68 kΩ | 6.3 |