INTERNATIONAL Rectifier (IR) has introduced a series of high-voltage IGBT control ICs with a sophisticated set of protection functions.
These devices feature high noise immunity with up to 30% fewer components in half the footprint compared with discrete opto-coupler or transformer-based solutions.
The series consists of 1200V and 600V gate driver ICs and current sense interface ICs for a variety of applications including inverterised motor drives, general-purpose inverter circuits, switch-mode power supplies (SMPS) and uninterruptible power supplies (UPS).
"This new suite of gate driver and sensor ICs made with IR's high-voltage IC technology enables small circuits with full protection, including ground fault protection, which was once available only in high-end systems," said senior vice president of sales at IR, Stephen Tsang.
"The new ICs blaze a new path for low-end industrial or servo drives as well as cost-competitive appliances."
Power stages using IGBTs or MOSFETs must be protected from failures such as short circuits, over-current conditions and ground faults. In addition to protection circuits, the fault conditions must be detected, or sensed, in order to enable the protection functions. IR's new line of driver ICs and sensor ICs fill this requirement, while reducing component count and simplifying circuits.
There are five 1200V gate drivers made with IR's HVIC technology. The IR22381 is an analogue, three-phase IGBT gate driver. With a deadtime of 0.5µsec, the device is 10 times faster than comparable opto-coupler-based drivers. Also, the IR22381 minimises temperature drift and changes in performance over time.
An integrated de-saturation feature provides for all modes of over-current protection, including ground fault, shoot-through and short to supply rails protection.
Soft shutdown is initiated in the event of an over-current condition followed by the turn-off of all six outputs. A shutdown input is included to enable custom shutdown functions.
The IR22381 includes programmable deadtime and the output drivers have separate turn-on/turn-off pins with a two-stage turn-on output to achieve the desired IGBT dv/dt switching level.
Voltage feedback provides accurate measurements and a bootstrap power supply eliminates an auxiliary power supply.
The IR2277 and IR22771 are high speed, single-phase current sense interface ICs with synchronous sampling for motor drive applications.
The current is sensed through an external shunt resistor which converts the analogue voltage into a time interval through a precise dual ramp system. The time interval is level-shifted and provides digital PWM output suitable for digital signal processor (DSP) and analogue-to-digital interfaces without additional logic circuits.
The maximum throughput is 40k samples/second, suitable for up to 20kHz asymmetrical PWM modulation and maximum delay is less than 7.5μsec at 20kHz.
A noise immune bi-directional level-shifting circuit is used to avoid false common mode dV/dt noise up to 50V/ns. The IR2277 provides both analogue and PWM output, while the IR22771 provides PWM output.
The IR2214 and IR22141 are designed to drive single half-bridge circuits in power switching applications, as well as three-phase 380VAC circuits at up to 50A at 80°C.
Unlike solutions using opto-couplers, the IR2214 and IR22141 gate drivers deliver stability during their lifetime and include parameter matching, such as propagation delay for high- and low-side channels as well as deadtime insertion.
Their low quiescent current on the high-side enables economical and space-saving bootstrap supply topology. Fault feedback on IGBT de-saturation is included which automatically shuts down the IGBT when used in multi-phase configurations.
Desaturation detection for both sides plus internal biasing resistor are included in the IR2214, while an active de-saturation diode bias is included in the IR22141.
The IR2214 and IR22141 can be connected together via a dedicated pin to protect the drive system from phase-to-phase short circuits. Input and output pins are 3.3V CMOS-compatible to simplify microprocessor interfacing. Separate power and signal ground pins enable emitter shunt configurations to simplify low-side IGBT current sensing. These devices are housed in a SSOP-24 package.
For appliance motor drives and a wide range of general-purpose inverter circuits, the 1200V HVICs are available in 600V versions.
The IR21381 is an analogue three-phase driver, similar to the IR22381. The IR2177 and IR21771 are 600V versions of the IR2277 and IR22771. Rounding out the set, the IR2114 and IR21141 are 600V versions of the IR2214 and IR22141.
Data sheets for these new HVICs are available on the IR website. Additional design assistance is available:
* IRMD22381Q demo board for the IR22381 and IR21381, a complete ac and brushless motor driver used with a 30A power module
* IRMD2214SS evaluation board for IR2214, IR22141, IR2114 and IR21141
* IRCS2277S - reference design kit for IR2277 and IR2177.
IR's proprietary HVIC technology is suitable for designing products to drive MOSFETs and IGBTs. Gate drive outputs are designed using a latch-immune CMOS circuit. The technology integrates a low-voltage driver with a high-voltage level shifter for high-side and low-side gate drivers in one monolithic IC.