150 mA C-MOS L.D.O. Regulator
LM1185SF
SOT-23-5L(SOT-25)
FEATURES
• Extremely Low Supply Current(50µA,Typ.)
• Very Low Dropout Voltage
• 150mA Output Current
• High Output Voltage Accuracy +/- 1.4 %
• Standard or Custom Output Voltages
• Over Currentand Over Temperature Protection
• Small input/output differential : 0.165V at 150mA
APPLICATIONS
• Battery Operated Systems
• Portable Computers
• Portable Cameras and Video Recorders
• Medical Instruments
• Instrumentation
• Cellular/GSM/PHS Phones
• Linear Post-Regulators for SMPS
• Pagers
1.Vin 2.Gnd 3.
SHDN
4.Bypass 5.Vout
ORDERING INFORMATION
Device
Marking
Package
HAXX
LM1185 SF5
SOT-25
(Note : "XX" is Output Voltage for SOT-25 Pkg,
1.5V=HA15, 1.8V=HA18….3.3V=HA33)
DESCRIPTION
The LM1185 series is a low-dropout linear regulators.
There are devices designed specifically for battery-operated Systems. Ground current is very small (2µA -
Typ), that significantly extending battery life.
Low power consumption and high accuracy is achieved through CMOS and programmable fuse
technologies. Output voltage: 1.5V to 6.0V.
The LM1185 consists of a high-precision voltage reference, an error correction circuit, and a current
limited output driver. With good transient responses, output remains stable even during load changes.
The SHDN input enables the output to be turned off, resulting in reduced power consumption. Also, the
LM1185 having high ripple rejection ratios, the series can be used with power supply noise. A 470pF
capacitor from the Bypass input to ground reduces noise present on the internal reference, which in turn
significantly reduces output noise.
If output noise is not a concern, this input may be left unconnected. Larger capacitor values Cbp be used,
but results in a longer time period to rated output voltage when power is initially applied. The LM1185
incorporates both over-temperature and over-current protection. SOT23-5 (300mW) and SOT-89-5
(500mW) packages are available.
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150 mA C-MOS L.D.O. Regulator
LM1185SF
ABSOLUTE MAXIMUM RATING (Note 1)
Supply Voltage (Vin)
Output Current (Iout)
Output Voltage (Vout)
Total Power Dissipation (Pd) SOT-23-5L
SOT-89-5L
Operating Ambient Temperature (Topr)
Lead Temperature (soldering, 5 sec)
Storage Temperature (Tstg)
+6.5V
150 mA
Vss-0.3 to Vin+0.3V
300 mW
500 mW
-30 ~ +80 °C
260°C
-40 ~ +125 °C
ELECTRICAL CHARACTERISTICS
(at Ta = 25℃, VIN = Vout+0.5V, unless otherwise noted)
0702 Taejin Technology Co.,Ltd.
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150 mA C-MOS L.D.O. Regulator
Typical Application Circuit
•
+
+
Battery
(To CMOS
Logic or Tie to
Vin if unused)
1uF
Gnd
+
470pF
Reference
Bypass
Cap(Optional)
Vin
SHDN
LM1185SF
Vout
BP
+
•
1uF
Vout
Detail Description
1. Output Capacitor
1uF(min) capacitor from V
OUT
to Gnd 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. Bypass Input
470pF capacitor connected from the Bypass input to ground reduces noise present on the internal
reference,which in turn significantly reduces output noise. If output noise is not aconcern, this input
maybe left unconnected. Larger capacitor values maybe used,but results in alonger time period to
rated output voltage when power is initially applied.
3. THERMAL CONSIDERATIONS
3.1 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.
3.2 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:
0702 Taejin Technology Co.,Ltd.
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150 mA C-MOS L.D.O. Regulator
EQUATION 3-1:
LM1185SF
The maximum allowable power dissipation (Equation
3-2) is a function of the maximum ambient
temperature(T
AMAX
), the maximum allowable die
temperature(T
JMAX
) and the thermal resistance from
junction-to-air(θ
JA
).
EQUATION 3-2:
Equation 3-1 can be used in conjunction with
Equation 4-2 to ensure regulator thermal operation
is within limits.Forexample:
3.3 Layout Considerations :
The primary path of heat conduction out of the package is via the package leads. Therefore,layouts
having a ground plane,wide traces at the pads,and wide power supply bus lines combine to lower
θ
and therefore increase the maximum allow able power dissipation limit.
JA
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