Different power bus ◆ Power (VCC) chip analog and digital circuits used in this pin convergence, which makes noise to a minimum. Decoupling capacitors should be as close to the chip. ◆ ground (VSSA, VSSD) chip analog and digital circuits at the confluence of different ground pin. ◆ recording (REC) active high. As long as REC is high (regardless of the chip in a power-saving state or are playing in), the chip start recording. During recording, REC must be held high. REC is low or the memory is full, the recording cycle ends, the chip is automatically written to mark the end of a message (EOM), so that future playback operation can be stopped in time. Then the chip automatically enters power-saving state. Note: There are 84 milliseconds rising REC Anti Shake prevent false triggering button. ◆ edge-triggered playback (PLAYE) rising edge when this end, the chip start playback. Playback continues until the end of the EOM flag or memory, after the chip automatically enters power-saving state. After starting playback, you can release PLAYE. ◆ level-triggered playback (PLAYL) this terminal from low to high, the chip start playback. Playback continued this terminal goes low, or encountered EOM flag, or the end of the memory. After the end of playback chip automatically enters power-saving state. ◆ When the voice instructions (/ RECLED) in the recording mode, this terminal is low, you can drive the LED. In addition, playback encountered EOM flag, the end of the output of a low pulse. This pulse can be used to trigger PLAYE, to achieve recycling playback. ◆ microphone input (MIC) This terminal is connected to the on-chip preamplifier. Chip automatic gain control circuit (AGC) to control the gain of the preamplifier. External microphone should be through the series capacitive coupling to this end. 10KΩ input impedance coupling capacitance and this side of the chip determines the low-frequency cutoff frequency band. ◆ reference microphone (MIC REF) This terminal is the inverting input of the preamplifier. When differentially connected microphone can reduce noise, improve the common mode rejection ratio. ◆ Automatic Gain Control (AGC) AGC dynamically adjusts the pre-gain to compensate for the wide variation microphone input level so that the recording has changed dramatically in volume (from whisper to clamor) distortion can be kept to a minimum. 4.7uF capacitors usually get satisfactory results in most cases. ◆ Speaker Output (SP +, SP-) which output can directly drive 8Ω or more speakers. Must be at the output and speaker of indirect coupling capacitors, and double-ended output using either single-ended capacitor can be increased to four times the power. Between SP + and SP- through a resistor of 50KΩ internal connections tone when the hold is floating. ◆ external clock (XCLK) down elements inside this end, only for testing, do not pick. ◆ vibration resistance (ROSC) the termination oscillation resistor to VSS, decision time sound recording by the oscillation resistor. ◆ through mode (FT) This client allows connected external MIC input speech signal through the AGC circuit inside the chip, filter and horn drive and run directly to the speaker output. FT end is usually low, to achieve straight-through functions, terminating the FT high, while the REC, PLAYE and PLAYL kept low. The use of operating power supply voltage 3-5V, in playback mode, press and hold the record button REC That recording, RECLED lights up, recording stops when the key is released, playback, there are three cases: 1, edge-triggered playback Press PE key voice at the upcoming release of the whole paragraph, unless a power failure or end of speech can not stop playback; 2, level-triggered playback, press and hold the key to when the PL playback, release the button stops; 3, loop playback , set loop playback switch is closed, press the PE key to start the cycle playback, only power to stop.