LM1108SF5 HTC Korea, LM1108SF5 Datasheet - Page 3

• Manufacturer Part Number: LM1108SF5
• Description: 300mA C-MOS L.D.O. Regulator
• Manufacturer: HTC Korea

0702-01 Taejin Technology Co.,Ltd.
Detail Description
The maximum allowable power dissipation (Equation
2-2) is a function of the maximum ambient
temperature(TAMAX), the maximum allowable die
temperature(TJMAX) and the thermal resistance
from junction-to-air(θJA).
300mA C-MOS L.D.O. Regulator
- The LM1108 is aprecision, fixed output LDO.
Un like bipolar regulators, the LM1108’s supply current does not increase with load current.
In addition,VOUT remains stable and with in regulation over theen tire 0mA to IOUT MAX operating
load currentrange, (an important consideration in RTC and CMOS RAM battery back-up applications).
Figure3-1shows a typical application circuit.
1. Output Capacitor
1uF(min) capacitor from VOUT to ground is required.
The output capacitor hould have an effective series resistance greater than 0.1 Ω and less than .0Ω.
1uF capacitor should be connected from VIN to GND if there is more than 10 inche sofwire between
the regulator and the AC filter capacitor ,or if a battery is used as the power source. Aluminum
electrolytic or tantalum capacitor types can be used. (Since many aluminum electrolytic capacitors
freeze at approximately -30°C, solid tantalums are recommended for applications operating below -25°
C.)
When operating from sources other than batteries,supply-noise rejection and transient response can
be improved by increasing the value of the input and output capacitors and employing passive filtering
techniques.
2. THERMAL CONSIDERATIONS
2.1 Thermal Shutdown
Integrated thermal protection circuitry shuts the regulator off when die temperature exceeds150°C.
The regulator remains off until the die temperature drops to approxi mately 140°C.
2.2 Power Dissipation
The amount of power the regulator dissipate is primarily a function of input and output voltage, and
output current. The following equation is used to calculate worst case actual power dissipation:
EQUATION 2-1:
3
TABLE 2-1 :
LM1108F/SF
HTC