Description:
The MIC37501 and MIC37502 are 5A, low dropout linear voltage regulators that provide low-voltage, high-current outputs with a minimum of external components. They offer high precision, ultra-low dropout (500mV), and low ground current.
The MIC37501and MIC37502 operate from an input of 2.3V to 6.0V. They are designed to drive digital circuits requiring low voltage at high currents (i.e., PLDs, DSPs, microcontrollers, etc.). They are available in fixed and adjustable output voltages. Fixed voltages include 1.5V, 1.65V, 1.8V, 2.5V, and 3.3V. The adjustable version is capable of 1.24V to 5.5V.
MIC37501 and MIC37502 LDOs feature thermal and current limit protection, and reverse current protection. Logic-enable and error flag pins are available.
Junction temperature range of the MIC37501/02 is -40°C to 125°C.
For applications requiring input voltage greater than 6.0V, see MIC3910x, MIC3915x, MIC3930x, and MIC3950x LDOs.
Features：
5A minimum guaranteed output current
Ideal for 3.0V to 2.5V conversion
Ideal for 2.5V to 1.8V, 1.65V, or 1.5V conversion
Stable with ceramic or tantalum capacitor
±1.0% initial output tolerance
Fixed and adjustable output voltages: MIC37501 -7 terminal fixed voltage
Excellent line and load regulation specifications
Logic controlled shutdown
Thermal shutdown and current-limit protection
Reverse leakage protection
Low-profile S-Pak and TO-263 packages
Applications:
LDO linear regulator for low-voltage digital lC
PC add-in cards
High efficiency linear power supplies
SMPS post regulator
Battery charger
Notes:
Exceeding the ratings in the“Absolute Maximum Ratings” section may damage the device.
2.The device is not guaranteed to function outside its operating rating.
3.Devices are ESD sensitive.Handling precautions recommended.Human body model, 1.5kΩ in series with 100pF.
4. Pp(max) = (Tj(max) – Ta) / θjc, where θjc depends upon the printed circuit layout.See“Applications Information” section.
5. Specification for packaged product only
6.VDo = VIN- Vour when Vour decreased to 98% of its nominal output voltage with VIN= Vour +1V. For output voltages below 1.75V,dropout voltage specification does not apply dut to a minimum input operating voltage of 2.3V.
7. lGnD is the quiescent current.IN = lGND +lOUT.
8. For a 2.5V device,VIN =2.3V (device is in dropout).
Application Information
The MIC37501/02 is a high-performance, low dropout voltage regulator suitable for moderate to high-current regulator applications. Its 500mV dropout voltage at full load makes it especially valuable in battery-powered systems and as a high-efficiency noise filter in post-regulator applications. Unlike older NPN-pass transistor designs, where the minimum dropout voltage is limited by the based-to-emitter voltage drop and collector-to-emitter saturation voltage,dropout performance of the PNP output of these devices is limited only by the low Vce saturation voltage.
A trade-off for the low dropout voltage is a varying base drive requirement. Micrel’s Super Beta PNP process reduces this drive requirement to only 2% to 5% of the load current.
The MIC37501/02regulator is fully protected from damage due to fault conditions. Current limiting is provided. This limiting is linear; output current during overload conditions is constant. Thermal shutdown disables the device when the die temperature exceeds the maximum safe operating temperature.
The output structure of these regulators allows voltages in excess of the desired output voltage to be applied without reverse current flow.
Input Capacitor
An input capacitor of 1.0μF or greater is recom-mended when the device is more than 4 inches away from the bulk supply capacitance, or when the supply is a battery. Small, surfacemount chip capacitors can be used for the bypassing. The capacitor should be placed within 1″ of the device for optimal performance.Larger values will help to improve ripple rejection by bypassing the input to the regulator, further improving the integrity of the output voltage.
Minimum Load Current
The MIC37501/02regulator is specified between finite loads. If the output current is too small,leakage currents dominate and the output voltage rises. A 10mA minimum load current is necessary for proper operation.
