Many "6V max" LDOs will fail at 6.2V. If your supply is a 5V USB that can spike to 5.5V, you are safe. But if you use a 9V wall adapter, the 8681L will be destroyed instantly.
If the 8681L is an LDO, the pinout will typically be: 8681l ic datasheet
| Pin # | Name | Description | |-------|------|-------------| | 1 | VIN | Unregulated input voltage | | 2 | GND | Ground | | 3 | EN | Enable control (active high) | | 4 | NC | No connect (or bypass cap pin) | | 5 | VOUT | Regulated output voltage | Many "6V max" LDOs will fail at 6
Note: Some 3-pin SOT-89 versions omit the EN pin and NC. If the 8681L is an LDO, the pinout
Once you secure the official datasheet, here are the key specifications you should verify. Below is a representative table based on common 8681L-type LDO regulators.
| Parameter | Symbol | Test Condition | Min | Typ | Max | Unit | |-----------|--------|----------------|-----|-----|-----|------| | Input Voltage | VIN | – | 2.0 | – | 6.0 | V | | Output Voltage | VOUT | Fixed option | 3.267 | 3.3 | 3.333 | V | | Output Current | IOUT | – | 0 | – | 300 | mA | | Dropout Voltage | VDROP | IOUT = 200 mA | – | 120 | 180 | mV | | Quiescent Current | IQ | No load | – | 25 | 50 | µA | | Shutdown Current | ISD | EN = GND | – | 0.1 | 1 | µA | | Line Regulation | ΔVOUT / ΔVIN | VIN = (VOUT+1) to 6V, IOUT=10mA | – | 0.05 | 0.2 | %/V | | Load Regulation | ΔVOUT / ΔIOUT | IOUT = 1 to 250 mA | – | 0.1 | 0.5 | % | | Power Supply Ripple Rejection | PSRR | f = 1 kHz, IOUT = 100 mA | – | 65 | – | dB | | Thermal Shutdown | TSD | – | 150 | 160 | 170 | °C |
The datasheet will show a PSRR curve. To improve ripple rejection: