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MIC5231 Micrel
MIC5231
Micropower µCap LDO Regulator
Preliminary Information
General Description
The MIC5231 µCap low-dropout voltage regulator is intended
for low-output-current biasing applications. It features extremely low ground current, not greater than 4µA under all
load and temperature conditions, making it efficient and ideal
for keep-alive applications in devices such as notebook
computers.
The MIC5231 offers better than 2% initial accuracy and low
dropout (typically 150mV at 10mA output current). An output
capacitor is not required for stable operation, decreasing cost
and board space. Tiny ceramic chip capacitors may be used
to improve transient response.
The MIC5231 also features a control pin which allows the
regulator to be shut down when not required. Its shutdownstate draws zero current, benefitting battery-powered applications.
The MIC5231 is available in fixed output voltages of 2.75V,
3.0V, 3.3V and 5V in the small SOT-23-5 IttyBitty™ package.
Contact Micrel for other voltage options.
Features
• Extremely low quiescent current—
• No output capacitor requirement
• Stable with ceramic or tantalum capacitors
• IttyBitty™ SOT-23-5 surface-mount package
• 10mA output drive
• Low 150mV at 10mA dropout voltage
• Tight load and line regulation
• Low temperature coefficient
• Logic-level enable input
only 0.65µA
Applications
• Real time clocks
• SRAM backup
• Cellular telephones
• Laptop, notebook and palmtop computers
• Battery-powered equipment
• Bar code scanners
• SMPS post-regulator and dc-to-dc modules
Typical Application
Ordering Information
Part Number Marking Voltage Temperature Range Package
MIC5231-2.75BM5 LM2H 2.75V –40°C to +125°C SOT-23-5
MIC5231-3.0BM5 LM30 3.0V –40°C to +125°C SOT-23-5
MIC5231-3.3BM5 LM33 3.3V –40°C to +125°C SOT-23-5
MIC5231-5.0BM5 LM50 5.0V –40°C to +125°C SOT-23-5
V
IN
6V
5V Linear Regulator Application
MIC5231-5.0BM5
IN
OUT
EN
GND
V
5V
OUT
IttyBitty is a trademark of Micrel, Inc.
MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970
June 2000 1 MIC5231
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MIC5231 Micrel
Pin Configuration
Pin Description
Pin Number Pin Name Pin Function
1 EN Enable (Input): Active high. Logic high = enable; logic low = shutdown. Do
2 GND Ground
3 IN Supply Input
4 OUT Regulated Output
5 NC not internally connected
GND
2
EN
IN
LM50
45
NCOUT
MIC5231-5.0BM5
not float.
13
Part
Identification
Absolute Maximum Ratings (Note 1)
Supply Voltage (VIN) .................................... –0.6V to +14V
Lead Temperature (soldering, 5 sec.) ....................... 260°C
Storage Temperature (TA) ....................... –60°C to +150°C
ESD, Note 3 .................................................................. 2kV
Operating Ratings (Note 2)
Input Voltage (VIN) ........................................... 3.5V to 12V
Ambient Temperature (TA) ......................... –40°C to +85°C
Junction Temperature (TJ) ....................... –40°C to +125°C
Thermal Resistance, Note 4
MIC5231 2 June 2000
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MIC5231 Micrel
Electrical Characteristics
VIN = V
Symbol Parameter Conditions Min Typ Max Units
V
OUT
∆V
OUT
∆V
OUT/VOUT
∆V
OUT/VOUT
V
DO
I
Q
PSRR Ripple Rejection f = 100Hz, IL = 100µA50dB
Enable Input
V
ENL
I
ENL
I
ENH
Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside its operating rating.
Note 3. Devices are ESD sensitive. Handling precautions recommended.
Note 4: The maximum allowable power dissipation at any TA (ambient temperature) is P
Note 5: Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
Note 6: Regulation is measured at constant junction temperature using low duty cycle pulse testing.
Note 7: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V
+ 1V; IL = 100µA; CL = 0.47µF; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.
OUT
Output Voltage Accuracy variation from nominal V
OUT
–2+2%
–3 +3 %
/∆T Output Voltage Note 5 250 ppm/°C
Temperature Coefficient
Line Regulation VIN = 6V to 12V 0.2 0.25 %
Load Regulation IL = 10µA to 10mA, Note 6 0.2 1 %
Dropout Voltage, Note 7 IL = 1mA 15 mV
IL = 10mA 150 300 mV
Ground Pin Current VIN = 6V, IL = 10mA 0.65 3 µA
VIN = 12V, IL = 10mA 1.1 4 µA
Enable Input Voltage VEN = logic low (regulator off) 0.4 0.18 V
VEN = logic high ((regulator on) 1.4 V
Enable Input Current V
Enable Input Current V
130°C/W. Mounted to a standard PC board, the θJA is approximately 235°C/W.
differential. For outputs below 3.5V, dropout voltage is the input-to-output differential with the minimum input voltage 3.5V. Minimum input
operating voltage is 3.5V.
≤ 0.18V (regulator off) 1 nA
ENL
≥ 1.4V (regulator on) 1 nA
ENH
D(max)
= (T
– TA) ÷ θJA. The θJC of the MIC5231 is
J(max)
June 2000 3 MIC5231