★ Board Specifications
↳ Board Number: 777
↳ Board Full Number: SM-777
↳ Board Version: V1.3
↳ Board Type: Audio Amplifier
The board described here is an audio amplifier that boosts low-power audio signals to a level suitable for driving speakers. The specific board model is SM-777, version 1.3.
▶ Component /Circuit / Parts Name /Explore Details
★ Audio Connector
↳ Type: Auxiliary (AUX)
↳ Total Pin: 4 Pin (Connection Pin: 3 Pin)
The auxiliary (AUX) connector is typically used to connect external audio sources, such as phones or media players, to the amplifier. Even though the connector has 4 pins, only 3 of them are used for connections:
Left Audio Channel (L)
Right Audio Channel (R)
Ground (GND)
The fourth pin might be unused or reserved for grounding or shielding purposes.
★ Memory Card Slot
↳ Memory Card Slot Install Quantity: 1
↳ Type: Mini Slot
This memory card slot is designed to hold a memory card. Given it's described as a "Mini Slot," it's likely to be compatible with either a miniSD or microSD card, which can be used to store audio files, configuration data, or firmware.
★ Crystal IC
↳ Frequency: 24.000 MHz
↳ Crystal IC Type: SMD
Crystal IC Total Pin: 4 Pin
Crystals are used to provide a precise clock frequency to control timing in circuits. The 24.000 MHz crystal oscillator is surface-mounted (SMD) and has 4 pins, likely including connections for power (Vcc), ground (GND), and output.
★ Power IC / Control IC / CPU / Audio Generator IC
↳ Total Install IC Quantity: 1 piece
↳ Other Number: A15E7E
↳ Serial Number: UM6244
↳ Power IC: Manages the distribution of power across the board.
↳ Control IC / CPU: Acts as the brain of the system, processing input signals and controlling various operations.
↳ Audio Generator IC: Generates or processes the audio signals before amplification.
The IC number PNSA15E7E is the specific identifier, while 777 might refer to a broader family of chips.
★ Audio Amplifier IC
↳ Total Install IC Quantity: 1 piece
↳ Total Channel: 2 Channels
↳ Other Number: NS8002
The audio amplifier IC, 2307, is responsible for amplifying audio signals. It is a 2-channel amplifier, meaning it can drive two separate audio oṇ outputs, typically used in stereo applications (left and right channels). The IC number 2307 might be a batch or version number.
★ Types and Colors of LEDs
↳ Charging LED: Red
↳ Audio Running and On LED: Blue Blinking
The Red LED indicates that the device is charging, while the Blue LED blinks when the device is powered on or when audio is running. These LEDs provide a simple visual indication of the device's status.
★ Charging IC
↳ IC Number: LP4054 (Same IC: LTH7)
↳ Other Name: 5-Pin Charging IC
↳ Total Pin Quantity: 5 Pins
↳ Functionality: 5V to 4V Converter, LED Indicator, and Battery Connector
The charging IC converts a 5V input (typically from a USB or power supply) to the 4.2V necessary to charge the battery. It also manages the charging process, including indicating the charging status through the red LED, and connects directly to the battery.
★ Buttons
↳ Total Install Button Quantity: 4 Buttons
↳ Power Button (P/P): On/Off switch with 4 pins: 2 connected to ground (GND), 1 not connected (NC), and 1 providing a signal to the control IC.
↳ Previous Button (PREV): Used for navigating to the previous track or function, also with 4 pins: 2 connected to GND, 1 NC, and 1 providing a signal.
↳ Next Button (NEXT): Functions similarly to the previous button but for moving to the next track or function.
↳ Mode Select Button (MODE): Used to switch between different modes (e.g., AUX, Bluetooth, Radio), following the same 4-pin configuration.
★ Microphone
↳ Type: SMD (Surface Mounted Device)
↳ Total Pin: 2 Pins
This microphone is used to pick up audio, typically for voice commands, hands-free calls, or recording. The 2 pins are for power and output.
★ Audio Output Speaker
↳ Audio Output Slot: 2-Slot
↳ Total Install Speaker Quantity: 2 Speakers
↳ Single Speaker Power: 5W
↳ Total Power: 10W
The board drives two speakers, each rated at 5W, providing a total output power of 10W. This is sufficient for small to medium-sized audio systems.
★ Battery Section
↳ Total Install Battery Slot Quantity: 1
↳ Battery Voltage: 4.2V
↳ Battery Capacity: 5Ah
The battery slot holds a rechargeable battery with a nominal voltage of 4.2V and a capacity of 5Ah (ampere-hours). This battery provides power for the entire system when it's not connected to an external power source.
★ Capacitors
↳ Total Install Polar Capacitor Quantity: 2 Polar Capacitors
↳ Voltage: 10V
↳ Capacitance: 470uF
Polar capacitors are used for energy storage, filtering, and voltage smoothing in power supply circuits. The 10V rating indicates the maximum voltage the capacitors can safely handle, while the 470uF (microfarad) value indicates the amount of charge they can store.
▶ Explain Extra Information
★ Audio Signal Processing:
The Audio Generator IC (PNSA15E7E) handles the generation or processing of audio signals. These signals are then passed to the 2307 Audio Amplifier IC, which boosts them to a level sufficient to drive the speakers.
★ Control and User Interaction:
The board includes four buttons for user interaction, allowing power control, track navigation, and mode selection. Each button connects to the control IC, providing signals that trigger specific functions.
★ Connectivity and Inputs:
The AUX connector allows external audio input, while the memory card slot supports stored audio playback. The microphone enables voice input for additional functionality.
★ Output and Indicators:
The dual speakers output the amplified audio signals, while the LEDs provide a visual status of power, audio activity, and charging.