A Complete Guide to IR2104 Half-Bridge Driver
11 April 2024
Ⅱ. IR2104 half-bridge driver circuit characteristics
Ⅲ. IR2104 half-bridge driver working principle
Ⅳ. Practical application of IR2104
Ⅴ. Recommended operating conditions of IR2104
Ⅵ. What are the heat dissipation measures for IR2104?
IR2104 is a high-performance half-bridge driver whose main function is to drive MOSFET or IGBT, so it is widely used in power inverters and input filter circuits. This article will discuss around IR2104, covering its characteristics, working principle and practical applications, aiming to help you understand this device more deeply. So, let’s get started!
The IR2104 is a half-bridge driver that accepts a low power input to output a high current drive and supplies the gate of a high power transistor such as a power MOSFET. Additionally, the IR2104 gate driver can be used as a level shifter and power amplifier. The output channels of the IGBT and MOSFET drivers operate on high-side and low-side references, while the logic inputs operate on 3.3V logic and are compatible with LSTTL and CMOS outputs. None of these technologies are subject to proprietary HVCs and latches, so it enables monolithic construction.
The IR2104 drive circuit is mainly composed of three parts: input stage, logic control and output stage. The input stage includes an input isolator and an input filter circuit to isolate the control signal and power supply noise. Logic control includes a logic input stage and a logic output stage, which are used to receive control signals and generate drive signals. The output stage includes driver and power stages for driving MOSFETs or IGBTs.
Alternative models:
• IR2101S
• IR2102S
• IR2103
• IR2103S
1. Wide operating voltage range: IR2104 supports a wide operating voltage range, from 10V to 20V, suitable for different driving needs.
2. Internal current detection: IR2104 has an internal current detection function that can measure and feedback the current of the low-side MOSFET to achieve closed-loop control.
3. High efficiency: IR2104 adopts a highly integrated design, and the driver circuit has the characteristics of high efficiency and low power consumption. Charge pump technology can provide high-frequency driving signals, allowing MOSFETs to switch quickly and reduce energy loss.
4. Protection functions: IR2104 has a variety of protection functions, including over-temperature protection, over-current protection and under-voltage lockout functions. These protection functions can effectively protect the circuit and improve system reliability.
5. High current driving capability: IR2104 integrates high-side and low-side drivers with strong driving capability. It can provide high peak current and instantaneous current operating capabilities and is suitable for high-power applications.
This driver design is relatively easy to understand based on signal logic analysis, but to achieve in-depth understanding and better application, we need to conduct a more in-depth analysis of the circuit and perform theoretical analysis and calculation to determine the parameters of some peripheral components. Now, we conduct a simple analysis of the internal structure. When the chip is selected, the input signal will pass through the dead zone or breakdown protection circuit, and then be divided into two channels and sent to the upper and lower sets of CMOS circuits respectively. Among them, the lower path is controlled by "0" to conduct, and the signal is sent directly; while the upper path is turned on by "1", the signal will first be controlled by the high pulse current buffer stage to complete the signal buffering and level conversion, and then send enter.
When 0 is initially written: the lower CMOS upper transistor is turned on, and LO is raised from the floating state to the chip power supply potential. Therefore, the conduction voltage VCC is generated between LO and COM, causing the MOS of the lower half bridge to be turned on; at the same time, the upper CMOS lower transistor is turned on, and HO and VS are short-circuited, causing the upper half-bridge MOS to be turned off.
When 1 is initially written: the upper CMOS upper transistor is turned on, and relying on the capacitor bootstrap effect, the conduction voltage VCC is generated between HO and VS, causing the MOS of the upper half-bridge to be turned on; while the lower CMOS lower transistor is turned on, LO and COM are short-circuited, causing the MOS of the lower half bridge to be turned off.
It can be seen that the power supply voltage of IR2104 must be greater than the conduction voltage of the selected MOS or IGBT tube. For example, in the smart car circuit, the 12V power supply voltage used by IR2104 is greater than the turn-on voltage of LR7843, 4.5V. This design ensures the normal operation of the driver and effectively prevents performance degradation or damage caused by insufficient voltage.
IR2104 has a wide range of uses in practical applications. Two typical application circuits are introduced below:
1. Full-bridge drive circuit
Full-bridge driver circuit is one of the most common applications of IR2104. It usually consists of two IR2104 chips and four power MOSFETs and inductors. In this circuit, two IR2104s are responsible for controlling the switches of the MOSFETs on the upper and lower sides respectively to convert DC power to AC power. By precisely controlling the switching speed and duty cycle of the MOSFETs on both sides, it can achieve efficient power conversion and output control. This kind of full-bridge drive circuit is often used in power conversion, inverter and other fields.
2. Half-bridge drive circuit
Half-bridge drive circuit is another important application of IR2104. It usually consists of an IR2104 chip, a power MOSFET and an inductor. In this circuit, IR2104 is responsible for generating the PWM signal and converting DC power to AC power by controlling the switching of the MOSFET. The IR2104 can control the switching speed and duty cycle of MOSFETs to achieve precise control of output voltage and current. This half-bridge drive circuit is widely used in DC motor drives, inverters and other fields.
The input or output logic timing diagram is shown in the following figure. For proper operation the device should be used within the recommended conditions. The VS offset rating is tested with all supplies biased at 15V differential.
The following are some common IR2104 heat dissipation measures:
1. Use of thermally conductive materials
We can use thermally conductive materials, such as thermally conductive silicone or thermal conductive sheets, between the IR2104 and the heatsink or PCB, to significantly improve the efficiency of heat transfer and reduce thermal resistance, thus greatly enhancing the overall heat dissipation effect. Thermally conductive silicone, as an adhesive with high thermal conductivity, can be tightly adhered to the surface of the IR2104 and the heat sink or PCB, effectively filling the small gaps between them, thereby reducing thermal resistance.
2. Reduce workload
We can also reduce the heat generated by the IR2104 by lowering its workload. For example, when the system does not require high power output, we can consider reducing the input voltage of IR2104. Lowering the input voltage can directly reduce the internal power consumption of the chip, which in turn reduces its heat generation. Of course, while lowering the voltage, we need to make sure that the IR2104 still works properly and meets the performance requirements of the system.
3. Heat sink/heatsink: Heat sink or heatsink is a common way to dissipate heat. By installing a heatsink around or above the IR2104, the heat dissipation area can be effectively increased, thus reducing the operating temperature of the chip. When designing the heat sink, we should fully consider the chip's operating current, ambient temperature and other factors to ensure that the heat dissipation effect is optimal.
4. Optimize the PCB layout: In the PCB design, in order to avoid thermal interference with IR2104 caused by other components that generate more heat, we should place these components away from the chip. Components such as power MOSFETs or IGBTs also generate a lot of heat when they are working, and if they are too close to the IR2104, their heat may be transferred to the chip, resulting in an increase in chip temperature. Therefore, when laying out the chip, we should make sure that these components that generate more heat are kept at a certain distance from the IR2104 to minimize the effect of heat on the chip.
As a high-side and low-side driver, IR2104 is specially designed to drive H-bridge circuits. It can effectively solve the dead zone problem in H-bridge circuits. Here are some ways IR2104 solves the dead zone problem in H-bridge drive circuits:
1. Dead time compensation: IR2104 driver provides a dead time compensation pin. By adjusting the voltage of this pin, the compensation amount of the dead time can be set. By increasing or decreasing the dead time compensation, the time difference between the high-end MOS and the low-end MOS can be adjusted to solve the dead zone problem.
2. Bipolar drive: IR2104 driver can control the on and off of high-end MOS and low-end MOS at the same time. This ensures that the time difference between high-end MOS and low-end MOS is accurately controlled to avoid dead zone problems.
3. Delay time setting: The IR2104 driver has a dedicated pin for setting the delay time. By adjusting the capacitance and resistance on the pin, the delay time between the high-end MOS and the low-end MOS can be set. Increasing the delay time can ensure that the high-end MOS and the low-end MOS will not be turned on or off at the same time, thereby avoiding the occurrence of dead zone problems.
Frequently Asked Questions
1. Why do we need MOSFET drivers?
Gate drivers are beneficial to MOSFET operation because the high-current drive provided to the MOSFET gate decreases the switching time between the gate ON/OFF stages which leads to increased MOSFET power and thermal efficiency.
2. What is the maximum voltage of IR2104?
The floating channel can be used to drive an N-channel power MOSFET or IGBT in the high side configuration which operates from 10 to 600 volts.
3. What is IR2104 used for?
The IR2104 is a high voltage, high speed power MOSFET and IGBT driver with dependent high and low side referenced output channels. Proprietary HVIC and latch immune CMOS technologies enable ruggedized monolithic construction. The logic input is compatible with standard CMOS or LSTTL out-puts.
4. What is the difference between IR2101 and IR2104?
The IR2104 is a high voltage, high-speed power MOSFET and IGBT driver with independent high and low side referenced output channels. In comparison, the IR2101 is a high and low side driver. The IRS2104 is a new HVIC product that replaces the IR2101 and is pin-to-pin compatible with its predecessor.
