Details

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Parameter	Symbol	Conditions	Min	Typ	Max	Unit
Input Voltage	VIN	Continuous	1.0	-	20	V
Output Voltage	VOUT	Regulation Range	1.23	-	15	V
Dropout Voltage	VDROPOUT	IOUT = 10 mA, VIN = 1.23V + VOUT	-	0.2	0.4	V
Quiescent Current	IQ	VIN = 2.0V to 20V	-	60	100	μA
Shutdown Current	ISD	VIN = 2.0V to 20V, SHDN = 0V	-	0.1	1	μA
Load Current	IOUT	Continuous	-	150	300	mA
Output Voltage Accuracy	ΔVOUT	VIN = 2.0V to 20V, IOUT = 0mA to 150mA	-	±1	-	%
Line Regulation	ΔVOUT/ΔVIN	VIN = 2.0V to 20V, IOUT = 0mA to 150mA	-	0.01	-	%/V
Load Regulation	ΔVOUT/ΔIOUT	VIN = 2.0V to 20V, IOUT = 0mA to 150mA	-	0.05	-	%/mA
Thermal Shutdown Temperature	TSD	-	160	-	°C
Operating Junction Temperature	TJ	-	-40	-	125	°C
Storage Temperature	TSTG	-	-65	-	150	°C

Instructions for Using the LM2991S

1. Input Voltage (VIN):

   • Ensure the input voltage is within the range of 1.0V to 20V.
   • The input voltage should be at least 0.2V to 0.4V higher than the desired output voltage to maintain regulation.

2. Output Voltage (VOUT):

   • The output voltage can be set using external resistors R1 and R2 according to the formula: [ V_ = 1.23 left(1 + fracright) ]
   • Choose resistor values to achieve the desired output voltage within the range of 1.23V to 15V.

3. Quiescent Current (IQ):

   • The quiescent current is typically 60μA and can go up to 100μA. This is the current consumed by the regulator when no load is applied.

4. Shutdown Pin (SHDN):

   • To shut down the regulator, pull the SHDN pin low (0V). The shutdown current is typically 0.1μA.
   • To enable the regulator, pull the SHDN pin high (VIN).

5. Load Current (IOUT):

   • The maximum continuous load current is 300mA, but it is recommended to stay below 150mA for optimal performance and stability.

6. Thermal Considerations:

   • Ensure proper heat dissipation if operating at high load currents or high ambient temperatures.
   • The thermal shutdown temperature is 160°C to protect the device from overheating.

7. Operating and Storage Temperatures:

   • The operating junction temperature range is -40°C to 125°C.
   • The storage temperature range is -65°C to 150°C.

8. Capacitors:

   • Use a 1μF ceramic capacitor on the input (CIN) and a 1μF to 10μF ceramic capacitor on the output (COUT) for stability and noise reduction.
   • Place these capacitors as close as possible to the respective pins.

9. PCB Layout:

   • Ensure a good ground plane to minimize noise and improve thermal performance.
   • Keep the traces short and wide to reduce resistance and inductance.

By following these guidelines, you can ensure the LM2991S operates efficiently and reliably in your application.

(For reference only)