Achieve premium audio quality with LM4811 and MK64FN1M0VDC12
Unleash your headphones' full potential with our amplifier
Published Oct 22, 2023
Click board™
Headphone AMP Click
Dev Board
Clicker 2 for Kinetis
Compiler
NECTO Studio
MCU
MK64FN1M0VDC12
Experience the true power of your headphones with our amplifier, designed to maximize every detail and bring your music to life like never before
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Hardware Overview
How does it work?
Headphone AMP Click is based on the LM4811, a stereo, analog input headphone amplifier with digital volume control from Texas Instruments. This headphone amplifier is designed to provide high-quality output power using few external components and does not require bootstrap capacitors or snubber networks for stability improvement. The maximum power delivered by the LM4811 headphone amplifier is 105mW per channel into 16Ω and 70mW with 16Ω load impedance. Other prominent features of the ML4811 also include digital volume control, "Click and Pop" suppression circuitry, and a low shutdown current of 0.3μA. This Click board™ communicates with MCU using several GPIO pins.
The signals from the CLK and U/D pins routed to the PWM and INT pins of the mikroBUS™ socket control the LM4811's gain. The gain will increase or decrease by a 3dB step depending on the logic voltage level applied to the U/D pin at each rising edge of the CLK signal. A logic high voltage level applied to the U/D pin causes the gain to increase by 3dB at each rising edge of the CLK signal and vice versa. The amplifier's gain is set to a default value of 0dB upon the devices' Power-On features. Sixteen discrete gain settings range from +12dB maximum to −33dB minimum. The unity-gain stable LM4811 also features an externally controlled, active-high, micro-power consumption Shutdown mode, available on the RST pin of the
mikroBUS™ socket, to reduce power consumption while not in use. However, when coming out of Shutdown mode, the LM4811 will revert to its previous gain setting. Alongside all these features, the LM4811 also has an internal thermal shutdown protection mechanism. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.
Features overview
Development board
Clicker 2 for Kinetis is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit ARM Cortex-M4F microcontroller, the MK64FN1M0VDC12 from NXP Semiconductors, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a JTAG programmer connector, and two 26-pin headers for interfacing with external electronics. Its compact design with clear and easily recognizable silkscreen markings allows you to build gadgets with unique functionalities and
features quickly. Each part of the Clicker 2 for Kinetis development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Clicker 2 for Kinetis programming method, using a USB HID mikroBootloader or an external mikroProg connector for Kinetis programmer, the Clicker 2 board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Micro-B cable, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or
using a Li-Polymer battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several user-configurable buttons and LED indicators. Clicker 2 for Kinetis is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M4
MCU Memory (KB)
1024
Silicon Vendor
NXP
Pin count
121
RAM (Bytes)
262144
You complete me!
Accessories
These standard small stereo earphones offer a high-quality listening experience with their top-notch stereo cable and connector. Designed for universal compatibility, they effortlessly connect to all MIKROE mikromedia and multimedia boards, making them an ideal choice for your electronic projects. With a rated power of 100mW, the earphones provide crisp audio across a broad frequency range from 20Hz to 20kHz. They boast a sensitivity of 100 ± 5dB and an impedance of 32Ω ± 15%, ensuring optimal sound quality. The Φ15mm speaker delivers clear and immersive audio. Cost-effective and versatile, these earphones are perfect for testing your prototype devices, offering an affordable and reliable audio solution to complement your projects.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Clicker 2 for Kinetis as your development board.
Track your results in real time
Application Output via Debug Mode
1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.
2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.
Software Support
Library Description
This library contains API for Headphone AMP Click driver.
Key functions:
headphoneamp_set_sound_volume- Headphone AMP set sound volume functionheadphoneamp_volume_up- Headphone AMP set sound volume up functionheadphoneamp_volume_down- Headphone AMP set sound volume down function
Open Source
Code example
This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.
/*!
* @file main.c
* @brief Headphone AMP Click Example.
*
* # Description
* This library contains API for the Headphone AMP click driver.
* This demo application shows use of a Headphone AMP click board™.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of GPIO module and log UART.
* After driver initialization the app set default settings,
* performs power-up sequence, sets a the sound volume of -12 dB.
*
* ## Application Task
* This is an example that shows the use of Headphone AMP click board™.
* The app performs circles the volume from -12 dB to 3 dB back and forth,
* increase/decrement by 3dB.
* Results are being sent to the Usart Terminal where you can track their changes.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "headphoneamp.h"
static headphoneamp_t headphoneamp; /**< Headphone AMP Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
headphoneamp_cfg_t headphoneamp_cfg; /**< Click config object. */
/**
* Logger initialization.
* Default baud rate: 115200
* Default log level: LOG_LEVEL_DEBUG
* @note If USB_UART_RX and USB_UART_TX
* are defined as HAL_PIN_NC, you will
* need to define them manually for log to work.
* See @b LOG_MAP_USB_UART macro definition for detailed explanation.
*/
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, " Application Init " );
// Click initialization.
headphoneamp_cfg_setup( &headphoneamp_cfg );
HEADPHONEAMP_MAP_MIKROBUS( headphoneamp_cfg, MIKROBUS_1 );
if ( headphoneamp_init( &headphoneamp, &headphoneamp_cfg ) == DIGITAL_OUT_UNSUPPORTED_PIN )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
headphoneamp_default_cfg ( &headphoneamp );
log_info( &logger, " Application Task " );
Delay_ms( 100 );
log_printf( &logger, "-------------------------\r\n" );
log_printf( &logger, " Performs Power-up\r\n" );
headphoneamp_power_up( &headphoneamp );
Delay_ms( 100 );
log_printf( &logger, "-------------------------\r\n" );
log_printf( &logger, " Set volume gain -12dB\r\n", HEADPHONEAMP_SOUND_VOLUME_NEG_12_dB );
headphoneamp_set_sound_volume( &headphoneamp, HEADPHONEAMP_SOUND_VOLUME_NEG_12_dB );
log_printf( &logger, "-------------------------\r\n" );
Delay_ms( 5000 );
}
void application_task ( void )
{
for ( uint8_t n_cnt = 0; n_cnt < 5; n_cnt++ ) {
log_printf( &logger, " Turning volume up\r\n" );
headphoneamp_volume_up ( &headphoneamp );
Delay_ms( 2000 );
}
log_printf( &logger, "-------------------------\r\n" );
Delay_ms( 5000 );
for ( uint8_t n_cnt = 0; n_cnt < 5; n_cnt++ ) {
log_printf( &logger, " Turning volume down\r\n" );
headphoneamp_volume_down ( &headphoneamp );
Delay_ms( 2000 );
}
log_printf( &logger, "-------------------------\r\n" );
Delay_ms( 5000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
