MAX8887EZK27+ vs MAX8878EUK28+
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| Category | PMIC - Voltage Regulators - Linear | PMIC - Voltage Regulators - Linear |
| Manufacturer | Maxim Integrated | Maxim Integrated |
| Description | IC REG LIN 2.7V 300MA TSOT23-5 | IC REG LINEAR 2.8V 150MA SOT23-5 |
| Package | Strip | Strip |
| Series | - | - |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Package / Case | SOT-23-5 Thin, TSOT-23-5 | SC-74A, SOT-753 |
| Supplier Device Package | TSOT-23-5 | SOT-23-5 |
| Output Type | Fixed | Fixed |
| Voltage - Output (Min/Fixed) | 2.7V | 2.8V |
| Voltage - Output (Max) | - | - |
| Current - Output | 300mA | 150mA |
| Output Configuration | Positive | Positive |
| Control Features | Enable | Enable |
| Voltage - Input (Max) | 5.5V | 6.5V |
| Number of Regulators | 1 | 1 |
| Voltage Dropout (Max) | - | 0.165V @ 150mA (Typ) |
| Current - Quiescent (Iq) | 100 µA | 180 µA |
| Current - Supply (Max) | 65 µA | 100 µA |
| PSRR | 60dB (1kHz) | - |
| Protection Features | Over Current, Over Temperature, Short Circuit | Over Current, Over Temperature, Reverse Polarity, Short Circuit |
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1. What are the disadvantages of linear regulators?
The disadvantage of linear regulators is that they are not efficient and can only be used in voltage reduction applications. The efficiency of a linear regulator depends on the ratio of output voltage to input voltage: turbidity = Vo: Vi. For example, for ordinary linear regulators, when the input voltage is 5V and the output voltage is 2.5V, the efficiency is only 50%. For ordinary linear regulators, about 50% of the electrical energy is converted into "heat" and lost, which is also the main reason why ordinary linear regulators are prone to heat when working. For LDO, due to its low voltage difference, the efficiency is much higher. For example, when the input voltage is 3.3V and the output voltage is 2.5V, its efficiency can reach 76%. Therefore, in LCD color TVs, in order to improve the utilization rate of electrical energy, ordinary linear regulators are used less, while LDOs are used more.
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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 is the difference between a linear regulator and a resistor?
Linear regulators and resistors have significant differences in function, working principle and application scenarios.
Function and working principle:
A linear regulator is an electronic device that achieves a stable voltage output by adjusting linear elements (such as resistors, transistors, etc.) in the circuit. It uses the negative feedback principle. When the input voltage changes, the regulator senses this change and adjusts the parameters of the circuit elements (such as the resistance value or the conduction state of the transistor) accordingly to keep the output voltage stable within the required range. Linear regulators can provide lower output noise and fluctuations, and have better responsiveness to load changes.
Resistors are a basic electronic component used to limit current and divide voltage. It works by hindering the flow of current, has a fixed resistance value, and does not have the function of adjusting the output voltage.
Application scenarios:
Linear regulator -
4. 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
