ADP7118ARDZ-5.0 vs LM3940IS-3.3
| Part Number |
|
|
| Category | PMIC - Voltage Regulators - Linear | PMIC - Voltage Regulators - Linear |
| Manufacturer | Analog Devices Inc. | Texas Instruments |
| Description | IC REG LINEAR 5V 200MA 8SOIC | IC REG LIN 3.3V 1A DDPAK/TO263-3 |
| Package | Cut Tape (CT) | Bulk |
| Series | - | - |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Package / Case | 8-SOIC (0.154\", 3.90mm Width) Exposed Pad | TO-263-4, D²Pak (3 Leads + Tab), TO-263AA |
| Supplier Device Package | 8-SOIC-EP | DDPAK/TO-263-3 |
| Output Type | Fixed | Fixed |
| Voltage - Output (Min/Fixed) | 5V | 3.3V |
| Voltage - Output (Max) | - | - |
| Current - Output | 200mA | 1A |
| Output Configuration | Positive | Positive |
| Control Features | Enable, Soft Start | - |
| Voltage - Input (Max) | 20V | 7.5V |
| Number of Regulators | 1 | 1 |
| Voltage Dropout (Max) | 0.42V @ 200mA | 0.2V @ 100mA |
| Current - Quiescent (Iq) | 140 µA | - |
| Current - Supply (Max) | 320 µA | - |
| PSRR | 88dB ~ 50dB (10kHz ~ 1MHz) | - |
| Protection Features | Over Current, Over Temperature | Over Temperature, Short Circuit |
-
1. What is a linear regulator?
A linear regulator is an electronic device that is primarily used to maintain a specified output voltage stable when the input voltage or load conditions change. It is an important component in electronics that acts as a buffer to protect the components of the circuit from damage. A linear regulator works by using an active device (such as a BJT or MOSFET) controlled by a high-gain amplifier, using the variable conductivity of the active pass device to maintain the output voltage. This regulator acts as a voltage divider to produce a regulated output voltage, where a linear element (such as a resistive load) is used to regulate the output voltage. The transistor stays in its active region of operation during voltage regulation. To maintain a constant output voltage, the internal resistance can be varied, providing a variable resistance by using a transistor controlled by the amplifier feedback loop.
A linear regulator is also called a buck converter, where the output voltage is always -
2. What problems will linear regulators bring to the circuit?
The problems that linear regulators bring to the circuit mainly include low efficiency and a lot of heat.
Linear The main working principle of the voltage regulator is to control the output voltage of the transistor through a current amplifier to keep the output voltage stable. This working mode causes the linear regulator to control the regulating tube through a differential voltage when adjusting the output voltage. The control tube needs to absorb part of the input voltage, which makes the efficiency of the linear regulator relatively low. In practical applications, this means that the linear regulator will convert the difference between the input voltage and the output voltage into heat energy, causing serious heating of the device, especially when the input and output voltage difference is large, this power loss will further increase, causing the device to heat up. -
3. What are the three types of voltage regulator?
The three types of voltage regulators include the contact voltage regulator, the transistor regulator and the integrated circuit regulator.
Contact voltage regulator: This is the type of voltage regulator used earlier. Its working principle is based on the vibration of the contact, but there is mechanical inertia and electromagnetic inertia, resulting in low voltage adjustment accuracy. Large, poor reliability, and short life, so it has been eliminated.
Crystal tube regulator: With the development of semiconductor technology, the transistor regulator becomes the mainstream. It uses a triode for voltage adjustment. Compared with the contact -type voltage regulator, the advantages of the transistor regulator is that the response speed, high efficiency, small volume, light weight, and not easily affected by external magnetic fields are widely used.
Integrated circuit regulator: Integrated circuit regulator is a new type of voltage regulator developed in recent years. It integrates mult -
4. Can a linear regulator be up?
Linear regulators cannot be boost.
The main function of a linear regulator is to stabilize the output voltage, protecting the electrical equipment from high or unstable voltage effects. It realizes a stable output voltage by adjusting the gap between the output voltage and the input voltage, but this process is limited to lowering the voltage, not including the voltage. The working principle of a linear regulator is to regulate the voltage by converting excess voltage into heat loss, thereby realizing the voltage regulation. This feature determines that it does not have the voltage function.
