PAM8902 Datasheet, PDF (9/13 Pages) Power Analog Micoelectronics – 30-Vpp Mono Class-D Audio Amplifier for Piezo/Ceramic Speakers

PAM8902
30-Vpp Mono Class-D Audio Amplifier for Piezo/Ceramic Speakers
Application Information
good low equivalent series-resistance (ESR) ceramic capacitor, typically 1 μF, is placed as close as
possible to the device AVDD pin for the best operation. For filtering lower frequency noise signals , a large
ceramic capacitor of 10μF or greater placed near the AVDD supply trace is recommended.
External Schottky Diode
Use external schottky diode can get the best driving capability and efficiency.
Since internal power diode has limited driving capability ,only in following conditions customer can remove
the external schottky diode to reduce the cost.
1. Vset = GND or Floating and C_L less than 1uF.
2. The signal frequency less than 4KHz.
3. Haptic application (50-500Hz)
Shutdown operation
In order to reduce power consumption while not in use, the PAM8902 contains shutdown circuitry amplifier
off when a logic low is placed on the ENA pin. By switching the ENA pin connected to GND, the PAM89 02
supply current draw will be minimized in idle mode.
Under Voltage Lock-out (UVLO)
The PAM8902 incorporates circuitry designed to detect supply voltage. When the supply voltage dro ps to
2.2V or below, the PAM8902 goes into a state of shutdown, and the device comes out of its shutdown state
and restore to normal function only when reset the power supply or ENA pin.
Short Circuit Protection (SCP)
The PAM8902 has short circuit protection circuitry on the outputs to prevent the device from damage when
output-to-output shorted or output-to-GND shorted occurs. When a short circuit occurs, the device goes
into a latch state and must be reset by cycling the voltage on the ENA pin to a logic low and then back to the
logic high state for normal operation. This will clear the short-circuit flag and allow for normal operation if
the short was removed. If the short was not removed, the protection circuitry will again activate.
Over Temperature Protection (OTP)
Thermal protection on the PAM8902 prevents the device from damage when the internal die temperature
exceeds 150°C. There is a 15°C tolerance on this trip point from device to device. Once the die tem perature
exceeds the set point, the device will enter the shutdown state and the outputs are disabled,in this
condition both OUT+ and OUT- will become high impedance. This is not a latched fault. The thermal f ault is
cleared once the temperature of the die decreased by 30°C. This large hysteresis will prevent motor
boating sound well and the device begins normal operation at this point with no external system interaction.
Power Analog Microelectronics, Inc
www.poweranalog.com
9
01/2012 Rev1.4