A voltage regulator is an IC, used to provide a fixed and stable output voltage apart from a change within the input voltage or load. Similarly, a low-dropout regulator is a DC linear voltage regulator that works even when the voltage supply is extremely close to the o/p voltage. The benefits of an LDO regulator compared to another voltage regulator mainly include smaller device size, lack of switching noise, better design simplicity, etc. So the LDO voltage regulator like LP2985 from Texas Instruments is a voltage regulator IC that provides low noise, low dropout & stable output voltage. This family of LDOs provides fixed output and excellent and gainful performance. This article discusses an overview of LP2985 IC, pinout, specifications, circuit, working, and its applications.
What is LP2985 IC?
LP2985 is a 150mAmps low-noise and fixed output LDO regulator with flexible shutdown and low-noise performance features for reduced power consumption. It supports 2.5 V to 16 V input voltage and up to 150 mAmps load current. This IC has over-temperature and over-current protection that provides cost-effective & outstanding performance for portable & non-portable applications. This IC is suited for applications that need power supplies like; wireless systems, portable devices, precision instrumentation, and automotive electronics.
This IC’s over-current protection feature performs as a protect, detecting extreme current & triggering a protective shutdown to avoid overheating and extend the lifetime of connected components. So the thermal protection feature ensures the unit shuts down automatically in extreme temperatures by maintaining the stability of the device and avoiding hardware failure because of thermal stress.
LP2985 IC Pin Configuration:
The pin configuration of LP2985 IC is shown below. This IC includes 5-pins which are discussed below.
LP2985 IC Pin Configuration
- Pin-1 (VIN): It is an input supply pin of the voltage regulator IC that provides a voltage supply to this chip.
- Pin-2 (GND): It is a ground pin of the voltage regulator IC.
- Pin-3 (ON/OFF): It is an active-low shutdown pin when this is logic-high then it will be enabled and it will shut down when this pin is logic-low (or) open.
- Pin-4 (BYP): It is a reference bypass pin of IC where a 470 pF capacitor is connected externally to the ground terminal to decrease output noise.
- Pin-5 (OUT): It is an output pin of the voltage regulator.
LP2985 IC Working
The LP2985 IC is a low-noise, wide-input, fixed-output, and low-dropout voltage regulator that supports 2.5 Volts to 16 Volts input voltage and up to 150 mA of load current. This IC supports a 1.2 Volts to 5.0 Volts output range for a new chip. So the significant components of this voltage regulator IC mainly include; the Ref voltage, transistor, and error amplifier.
LP2985 IC mainly includes a CMOS (or) TTL compatible enable (or) shutdown control input. Whenever it is shutting down, then power consumption falls almost to zero. So further the output noise within this IC is decreased by the bypass pin. Thus, this IC is designed especially for use in digital cameras, MP3 players, and portable devices.
Features & Specifications:
The features and specifications of LP2985 IC include the following.
- LP2985 is a low-dropout voltage regulator IC.
- This IC includes 5 pins.
- It is manufactured by Texas Instruments.
- Its mounting style is SMD or SMT.
- The package or Case is SOT-23-5.
- Its output voltage is 3.3 Volts.
- Its output current is 150 mAmps.
- This IC has a single output.
- It has positive polarity.
- Its quiescent current is 850 uAmps.
- Its minimum input voltage is 2.2 Volts.
- The maximum input voltage is 16 Volts.
- Its operating temperature ranges from – 40 C to + 125 C.
- Dropout voltage of this IC is 280 mV.
- Its line regulation is 0.014 %/Volts.
- Accuracy of voltage regulation is 1.5 %.
Equivalents & Alternative LDO Regulators
Equivalent LP2985 ICs are; TPS73633, MIC5205, and TLV713, and alternative LDO regulators are; AP2112K, MIC5225 and AMS1117.
LP2985 LDO Voltage Regulator Circuit
The LP2985 voltage regulator application circuit is shown below. Generally, the input voltage of LP2985 IC ranges from 2.2 volts to 16 volts. This IC includes a TTL or CMOS-compatible enable or shutdown control input. Thus, whenever this control pin shuts down then power consumption falls almost to zero. So the o/p noise within this IC can be decreased through the bypass pin of the IC. LP2985 low dropout regulator IC is available in a 5-pin package. Further in this regulator circuit, an additional bypass pin can be introduced for reduction of output noise.
LP2985 LDO Voltage Regulator Circuit
This pin is connected simply to the GND through an optional 10nf capacitor. Here, a Vin pin is connected to the i/p power supply & a 1µf ceramic capacitor is utilized for input noise cancellation. So the regulated voltage output voltage can be obtained through the Vout pin. The Enable pin of this IC can be utilized to turn ON/OFF the voltage regulator which helps the manufacturers to turn off the voltage regulator and avoid battery utilization whenever not within use, extending both the efficiency and lifespan of the power source. Thus, this main functionality allows designers to make more energy-efficient & sustainable systems.
Advantages
The advantages of LP2985 ICs include the following.
- The LP2985 IC provides two o/p tolerance options 1% for Grade A & 1.5% for Standard. Thus, these two tolerances are necessary in situations that demand very strong voltage regulation.
- This voltage regulator is available within the SOT-23 package for the most space-constrained requirements.
- The LP2985 IC demonstrates an extraordinary ability to protect power by operating with 850μA of low quiescent current at complete load. So less consumption is majorly beneficial in environments where each energy efficiency measure can have a significant impact.
- The LP2985 IC features 0.01μA shutdown current, so such consumption in shutdown ensures there is small power wastage, a prominent benefit in projects wherever energy conservation is a main concern.
- The IC at 30μVRMS maintains noise levels with a 10nF bypass capacitor. So this low noise performance is priceless in sensitive analog circuits, wherever any noise could disturb the precision & stability of the system.
- The LP2985 IC ensures stability in varying operational situations compatible with stable low ESR capacitors. So this compatibility gives reliable performance & prolongs the lifespan of components by supporting demanding situations.
- Its Bypass pin IC permits low-noise operation with 30 µVRMS typical output noise using a 10-nF bypass capacitor.
- Its shutdown feature allows consuming 0.01 µA current only whenever the ON/OFF pin of this IC is pulled low.
Disadvantages
The disadvantages of LP2985 IC include the following.
- This voltage regulator IC can be damaged through ESD.
- These ICs must be handled with suitable precautions
- The capacitance of ceramic capacitors in this IC can differ with temperature.
- Tantalum capacitors can be utilized at the LP2985 IC’s output, but there are major disadvantages that could exclude their utilization.
- Low drop-out voltage regulators typically have a higher GND-pin current as compared to quasi-LDOs or standard regulators.
- LP2985 ICs can provide noise, more expensive & complex.
- These ICs have a slower transient response.
- These ICs are not suitable for sensitive analog circuits because of their ripple and higher output noise.
Applications
The applications of LP2985 IC include the following.
- The LP2985 IC is a low-noise and low-dropout voltage regulator used in different applications like; land mobile radios, washers and dryers, cordless power tools, motor drives, active antenna systems, control boards, etc.
- This IC is used in personal multimedia devices; CD players, portable MP3 players, MP3 players, etc.
- These are used in video recording devices like camcorders, digital cameras, etc.
- It is used in other portable devices like; GPS units, personal medical devices, handheld gaming consoles, etc.
- The reliability and versatility position of LP2985 IC is used in a variety of portable electronic devices.
- These are used in Land mobile radios, dryers and washers, portable devices, consumer electronics, cordless power tools, motor drives and control boards, active antenna systems, power management, audio, etc.
Please refer to this link for the LP2985 IC Datasheet.
Thus, this is an overview of LP2985 IC, pin-out, features, specifications, circuit, working, pros, cons, and applications. This LP2985 IC is a fixed-output and LDO voltage regulator IC that provides cost-effective performance and exceptional performance for both non-portable and portable applications. This IC is available different voltages like 1.8V, 2.5V, 2.8V, 2.9V, 3V, 3.1V, 3.3V, 5V and 10V. This family of IC has a 1% output tolerance for the A version and with 1.5% tolerance for the non-A version. It is capable of delivering continuous 150mAmps load current. Here is a question for you, what is MIC5205 IC?