An Intelligent Power Module (IPM) is an advanced power switch device adapted to the current development trends of power devices - modularity, composite, and power integrated circuits (PIC), which is becoming more and more widely used in the field of power electronics. This paper will describe the features of IPMs, as well as IPM products launched by ON Semiconductor.
An IPM generally uses a high-speed, low-power insulated gate bipolar transistor (IGBT) as its power switch component, with an integrated current sensor, protection circuit, and gate drive circuit. IPMs are winning an increasingly large market with their high reliability and ease of use, and are especially suitable for the frequency converters of drive motors and various inverters, and are an ideal power electronic device for frequency conversion and speed adjustment, metallurgical machinery, electric traction, servo drives, and inverter appliances.
IPMs integrate power switch devices with drive circuits, and also integrate logic, control, and fault detection circuits for overvoltage, overcurrent, and overheating, and can send detection signals to the CPU. They are composed of a high-speed and low-power consumption die, optimized gate drive circuit, and fast protection circuit, and are easy to use, which not only reduces the system size and development time, but also greatly enhances system reliability. Even if a load accident or improper use occurs, the IPM itself will be undamaged.
In an IPM, the IGBT is a composite of a giant transistor (GTR) and metal-oxide-semiconductor field effect transistor (MOSFET), and the GTR is driven by the MOSFET. Therefore, an IGBT has the advantages of both a GTR and MOSFET. A GTR has the advantages of high current density, low saturation voltage, and high voltage resistance, while a MOSFET has the advantages of high input impedance, high switching frequency, and low drive power.
Compared with the components of the previous IGBT module and drive circuit, an IPM contains the drive circuit which sets the optimum IGBT drive conditions. With a very short distance between the drive motor and IGBT, and very low output impedance, reverse bias is not required. IPMs contain functions such as over-current (OC) protection and under-voltage (UV) protection to ensure stable operation of the system.
ON Semiconductor is a leader in the field of power semiconductors and has released a number of IPM products, here are some of key products for industrial equipment.
The NFAM1012L5B (1200 V, 10 A) and NFAM2012L5B (1200 V, 20 A), which are included in the SPM31 series, are fully integrated inverter power modules. They are composed of an independent high-end gate driver, a low-voltage integrated circuit (LVIC), six IGBTs, and a temperature sensor (TSU by LVIC) and are suitable for driving permanent magnet synchronous motors (PMSM), brushless direct current (BLDC) motors, and alternate current asynchronous motors. An IGBT is configured in a three-phase bridge, and provides a separate emitter connection for the lower legs to provide the maximum flexibility in selecting the control algorithm. The power stage has under-voltage lockout protection (UVP), and an internal boost diode is used for high-side gate boost drive.
The NFAM1012L5B/NFAM2012L5B has an active logic interface, built-in UVP, integrated bootstrap diode and resistor, a separate low-side IGBT emitter connection for individual current sensing for each phase, a temperature sensor (TSU output by LVIC), meets UL certification, and is a Pb-free device.
In addition, the SPM31 series also includes many devices that support different powers and have similar characteristics, including the NFAM2065L4B (650 V, 20 A), NFAM3065L4B (650 V, 30 A), and NFAM5065L4B (650 V, 50 A), which are available for selection by customers according to different specifications they need.
The NFAL5065L4B (650 V, 50 A) and NFAL7565L4B (650 V, 75 A) intelligent power modules, which are included in the SPM49 series, can provide full-featured high-performance inverter output stages for AC induction, BLDC, and PMSM motors. These modules integrate optimized gate drivers with built-in IGBTs to minimize EMI and losses, and also provide multiple on-module protection features, including under-voltage lockout, over-current shutdown, temperature sensing, and fault reporting. The built-in high-speed high-voltage integrated circuit (HVIC) only needs a power supply voltage to convert the input logic-level gate input into a high-voltage and high-current drive signal to properly drive the module's internal IGBTs. Each phase has independent negative IGBT terminals to support the widest range of control algorithms.
The SPM31/ SPM49 Series contain a control integrated circuit for gate drive and protection, with low loss and short circuit rated IGBT, uses an Al2O3 DBC (direct bonded copper) substrate with extremely low thermal resistance, has a built-in bootstrap diode/resistor and an open-emitter pin separate from the low-side IGBT for three-phase current sensing, and provides adjustable over-current protection via an integrated sensing IGBT, with an isolation rating of 2500 Vrms/1 min, which is UL certified and RoHS compliant.
The NFAQ0860L36T (600 V, 8 A) and NFAQ1060L36T(600 V, 10 A), which are included in the DIP-S6 series, are fully integrated inverter power stages and is composed of a high-voltage driver, six IGBTs, and a thermistor, is suitable for driving a PMSM, BLDC motor, and alternate current asynchronous motor. An IGBT is configured in a three-phase bridge, and the lower legs of each bridge with a separate emitter connection to provide the maximum flexibility in selecting the control algorithm. The power stage has a full range of protection functions, including cross-conduction protection, external shutdown and under-voltage lockout. The internal comparator and the reference voltage source connected to the over-current protection circuit allow designers to set the level of over-current protection.
The NFAQ0860L36T/NFAQ1060L36T with an integrated driver and uses DBC substrate, The NFAQ0860L36T with typical values at 8A being VCE(sat) = 2,4V, VF = 2.1V, and ESW = 280 'J, and the NFAQ1060L36T with typical values at 10A being VCE(sat) = 1.9V, VF = 2.4V, and ESW = 400 'J. Both with a compact 29.6mm x 18.2mm dual in-line package and adjustable over-current protection level, it is integrated with a bootstrap diode and resistor, and thermistor for substrate temperature measurement, internally installed with under-voltage protection, cross-conduction protection, and shutdown pins. All IGBTs can be turned off through an ITRIP input. The lead from the bottom of the module to the pin end is only 3.4mm, and is compliant with UL1557 certification.
The DBC substrate used by the NFAQ0860L36T/NFAQ1060L36T has good heat dissipation (low thermal resistance). The NFAQ1060L36T uses the latest technology to optimize losses and has good EMI. With a compact package, it reduces the PCB size. With an adjustable over-current protection level, it integrates multiple functions. It is characterized by compact design and optimized cost. Through an embedded NTC thermistor, it can measure the module temperature more accurately. The module is more tightly assembled with the PCB to reduce vibration stress.
ON Semiconductor also provides IPM products in various specifications to meet the different needs of various applications. The applications of IPM products include industrial fans, washing machines, air conditioners, pumps, etc.