Explore The PNSA15E7E IC Schematic Diagram, Download the Datasheet, Pinout Configurations, And Repair Ways. Connect With Amplifier ic and Charging ic. And More Details And Connections.
A15E7E Circuit Diagram
➔ Charging Section
5V from Charger: The input for charging the battery.
D1 (Diode): Connected to protect the circuit from reverse polarity or current flow.
B1 (PNP Transistor): Acts as a switch to control battery charging.
E (Emitter): Connected to the battery.
C (Collector): Connected to ground.
330Ω Resistor and LED CHG: The resistor and LED serve as an indicator for the charging state.
4.7k Resistor: Controls the current flow.
➔ Power Supply and Battery Charging Section
5V from Charger: The 5V input is used to charge the battery. It passes through a diode (D1), likely a Schottky diode, to prevent reverse current flow from the battery.
PNP Transistor (2TY): The PNP transistor serves as a switch in the charging circuit. When the charger is plugged in, it activates the LED indicator (labelled "LED CHG") via the 330Ω resistor, indicating the charging process. The base of the PNP transistor is connected to a 4.7kΩ resistor, which controls its switching state.
Battery Connection: The battery is connected via the output of the charging circuit, receiving regulated power through the diode.
➔ Main IC (A15E7E)
The system's core is a Bluetooth processor responsible for managing Bluetooth communication, SD card access, audio output, and various control functions.
ANT Pin: Antenna for Bluetooth signal transmission.
This pin is likely connected to an antenna or an internal trace acting as an antenna, which is essential for Bluetooth communication.
XTAL Pins (26 MHz Crystal): Provides a clock signal to the Bluetooth IC.
This crystal oscillator provides the clock signal required for the IC to function correctly. The IC uses this clock for timing and data transmission.
VDD (Power Supply): Powered by the battery, typically 3.7V.
DM/DP Pins (USB Interface): Likely used for communication or charging.
These pins are connected to the USB data lines via a pair of resistors (likely 15kΩ each). The USB interface is used for data transfer or firmware updates. The DM and DP lines are the differential pairs for USB communication.
VDD (Power Pin): This pin is connected to the battery voltage (3.7V). It powers the main IC, ensuring that all internal circuits receive stable voltage.
3.3V Output Pin: This pin provides a 3.3V regulated output to power other components in the system, such as the SD card and microphone. The 3.3V is derived internally from the 3.7V battery supply.
SD Card Interface (SD Pins): There are four connections for the SD card.
For reading an SD card. This diagram shows two SD connections, indicating a possible external memory interface (PINs may be custom or proprietary).
SD VDD (Pin 4): The SD card is powered by the 3.3V line.
GND (Pin 3): Connected to ground.
SD Data and Clock Pins: These data and clock pins are connected to the IC’s respective pins to manage SD card communication.
Mic In: This is connected to an external microphone through a 10kΩ resistor and a capacitor (providing DC blocking). The microphone captures audio signals, likely used for voice calls or recording.
Audio Out: This is the audio signal output from the IC, which is further amplified before being sent to the speaker. It may connect to an amplifier IC or directly to a speaker in small, low-power designs.
Button (BTN Pin): This pin is connected to an external button or switch through a 4.7kΩ pull-up resistor. It may be used for various functions like play/pause or Bluetooth pairing.
Enable (EN Pin): This EN pin enables or disables certain parts of the circuit. This pin may be tied to a power management function that shuts down non-essential components to conserve battery life.
➔ MOSFET Power Control Section
➻ A1SHB (P-Channel MOSFET)
D (Drain): Connected to the positive terminal of the battery.
G (Gate): Controlled by resistors (10k and 100k) and NPN transistor Q1 (J3Y).
S (Source): Provides power to the load when the MOSFET is switched on.
A1SHB P-Channel MOSFET controls the power to the main IC. The Drain (D) is connected to the 3.7V battery-positive terminal, and the Source (S) is connected to the load (IC and other components). The gate (G) is driven by an NPN transistor (J3Y), which controls when the MOSFET turns on or off based on the switching control signal.
J3Y (NPN Transistor): Controls the MOSFET operation, allowing or cutting off power from the battery.
NPN Transistor (J3Y): The base of the NPN transistor is connected through a 1kΩ resistor, and the emitter is grounded. This transistor acts as a switch for controlling the MOSFET, which in turn controls the main power supply. The MOSFET allows efficient switching of the battery supply.
Resistor Network: A set of resistors (100kΩ, 1kΩ, 18kΩ) forms a voltage divider to control the gate drive of the MOSFET, ensuring proper switching thresholds.
➔ Audio Amplification Circuit or Section (NS8002)
NS8002 Audio Amplifier IC amplifies the audio signal from the Bluetooth IC and drives the speakers (SPK1 and SPK2).
IN+ and IN-: These are the differential audio inputs. The audio signal from the main IC is fed here, possibly filtered or amplified before reaching the speakers.
SPK1 and SPK2 (Speaker Outputs): These pins drive the external speakers.
SB Pin: This is likely a shutdown or standby pin that controls the amplifier’s operating state. When pulled low, the amplifier is disabled, conserving power.
Bypass Pin: Connected to a capacitor, this pin reduces noise during power-up and ensures stability in the amplifier circuit.
VDD: 3.7V supply voltage pins power the amplifier.
GND: Ground connection.
➔ Push the Button and Switch the Control
Switch Control: This push button (labelled "PWR") is connected through a network of resistors and capacitors. It likely serves as the power button for the system. When pressed, it may either enable the MOSFET to turn on the main IC or trigger a software-based power control signal.
Capacitor Network (12kΩ, 4.7kΩ, 0.8kΩ): These components help debounce the switch or provide filtering to stabilize the power-on signal, ensuring the system powers on cleanly without noise interference.
➔ RGB LED Circuit And Indicator Light Section
RGB LED: This RGB LED is used for status indication (e.g., Bluetooth pairing, battery charging status). Each colour (red, green, blue) is controlled by transistors or directly by the main IC.
NPN Transistor (J3Y): This transistor controls the current flow to the RGB LED. The base of the transistor is controlled by the main IC through a 100Ω current-limiting resistor.
Resistor Network: These resistors (1kΩ, 10kΩ, etc.) limit the current and set the brightness for each colour channel of the RGB LED.
➔ Miscellaneous Components
Capacitors and Resistors: Various resistors and capacitors are scattered throughout the circuit to filter noise, stabilize voltages, and set biasing conditions for transistors and amplifiers.
100kΩ Resistor (Connected to the MOSFET): This resistor provides a weak pull-up to ensure the MOSFET stays off when no signal is present, preventing accidental power-on conditions.
➔ Connections and Signals
USB Power (3.7V): This USB input is connected to provide charging power to the battery. The data lines (DM and DP) allow communication with external devices, possibly for data transfer or firmware updates.
Audio Signal Flow: The audio signal originates from the main IC’s audio out pin, passes through passive components like capacitors and resistors, and then enters the NS8002 amplifier before being sent to the speakers.
Control Signals: Buttons, pins and power switches are used to control various functions such as turning the system on/off, enabling the amplifier, and interacting with the Bluetooth pairing functions.
➔ Summary of the Circuit Operation through Schematic Diagram
↬ Power Management and Charging:
The 5V input from a charger charges the battery through the PNP transistor and diode combination. A P-Channel MOSFET controlled by an NPN transistor manages the power supply from the battery to the main IC.
↬ Bluetooth Module and Control:
The main IC, powered by this battery, manages Bluetooth communication, SD card reading, and audio processing. It sends out control signals to various components, like the RGB LED for status indication and the audio amplifier for driving speakers.
↬ Audio Amplification:
This NS8002 audio amplifier boosts the audio signal received from the main IC and sends it to the external speakers.
↬ User Controls:
A push button controls power, and an additional button is connected to the IC for Bluetooth pairing or other functions. The RGB LED provides visual feedback for the system status.
↬ SD Card and USB Interface:
The SD card is used for audio storage, while the USB interface allows data transfer or firmware updates. Both are integrated into the Bluetooth IC for managing audio files and playback.
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