Details

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BUY 7905 https://www.utsource.net/itm/p/12610552.html

Parameter	Description	Value
Part Number	7905
Type	Negative Voltage Regulator
Output Voltage	Fixed Output Voltage	-5V
Input Voltage	Minimum Input Voltage	-7V
	Maximum Input Voltage	-35V
Output Current	Continuous Output Current	1A
Quiescent Current	Current Consumption at No Load	8mA (Typical)
Dropout Voltage	Voltage Difference Between Input and Output	2V (Typical)
Operating Temperature	Range for Normal Operation	-40掳C to +85掳C
Storage Temperature	Range for Storage	-65掳C to +150掳C
Package	Common Packages	TO-220, TO-92
Mounting Type	Through-Hole

Instructions for Use

1. Circuit Connection:

   • Input Pin (Pin 1): Connect to the negative input voltage.
   • Ground Pin (Pin 2): Connect to the common ground.
   • Output Pin (Pin 3): Connect to the load or circuit requiring the regulated -5V output.

2. Capacitors:

   • Input Capacitor: Place a 0.33 渭F ceramic capacitor between the input pin and ground as close as possible to the regulator to ensure stability.
   • Output Capacitor: Place a 0.1 渭F ceramic capacitor between the output pin and ground to filter out noise and improve transient response.

3. Heat Dissipation:

   • For applications where the input voltage is significantly higher than the output voltage, or the current draw is high, consider using a heatsink to dissipate heat effectively.
   • The thermal resistance from junction to ambient (胃JA) can be found in the datasheet and should be used to calculate the required heatsink size.

4. Power Supply:

   • Ensure the input voltage is within the specified range to avoid damage to the regulator.
   • Use a power supply with sufficient current capacity to meet the load requirements.

5. PCB Layout:

   • Keep the traces from the input and output capacitors to the regulator as short as possible to minimize inductance and improve stability.
   • Use wide traces for the ground connection to reduce resistance and improve heat dissipation.

6. Testing:

   • Before connecting the load, test the output voltage with a multimeter to ensure it is stable at -5V.
   • Monitor the temperature of the regulator during operation to ensure it does not exceed the maximum operating temperature.

7. Safety:

   • Always follow proper electrical safety practices when working with circuits.
   • Ensure the circuit is powered down before making any connections or modifications.

(For reference only)