VLA500K-01R

VLA500K-01R Powerex, Inc., 200 E. Hillis Street, Youngwood, Pennsylvania 15697-1800 (724) 925-7272 A Hybrid IC IGBT Gate Driver + DC/DC Converter C B D E F D 19 VCC 1 VD G 30 1 2 REGULATOR DETECT CIRCUIT DC-AC CONVERTER 29 ttrip CONTROL PIN 30 DETECT PIN 20 GND Gi 3 LATCH 4 TIMER & RESET CIRCUIT Vl + 6 INTERFACE Vl – 7 26 COLLECTOR 23 VO 24 180Ω OPTO COUPLER 25 GATE SHUTDOWN CIRCUIT SHUTDOWN 27 SPEED CONTROL 28 FAULT OUTPUT 21 VEE 22 5 , 17 , 18 : N.C. Outline Drawing and Circuit Diagram Dimensions A B C D E F G Inches 3.27 1.3 0.67 0.2 0.1 0.45 0.24 Millimeters 83.0 33.0 17.0 5.0 2.54 11.5 6.0 Note: All dimensions listed are maximums except E. Rev. 5/07 Description: VLA500K-01R is a hybrid integrated circuit designed for driving IGBT modules. This device is a fully isolated gate drive circuit consisting of an optimally isolated gate drive amplifier and an isolated DC-to-DC converter. The gate driver provides an over-current protection function based on desaturation detection. Features: £ Built-in Isolated DC-to-DC Converter for Gate Drive £ SIP Outline Allows More Space on Mounting Area £ Built-in Short-Circuit Protection (With Fault Output) £ Variable Fall Time on Short Circuit Protection £ Electrical Isolation Voltage Between Input and Output (4000 Vrms for 1 Minute) £ TTL Compatible Input Application: To drive IGBT modules for inverter or AC servo systems applications Recommended IGBT Modules: 600V module up to 600A 1200V module up to 1400A 1700V module up tp 1000A  Powerex, Inc., 200 E. Hillis Street, Youngwood, Pennsylvania 15697-1800 (724) 925-7272 VLA500K-01R Hybrid IC IGBT Gate Driver + DC/DC Converter Absolute Maximum Ratings, Ta = 25°C unless otherwise specified Characteristics Symbol VLA500K-01R Units VD -1 ~ 16.5 Volts Input Signal Voltage (Applied between Pin 6 - 7, 50% Duty Cycle, Pulse Width 1ms) Vi -1 ~ 7 Volts Output Voltage (When the Output Voltage is "H") VO VCC Volts Output Current IOHP -12 Amperes (Pulse Width 2µs) IOLP 12 Amperes Isolation Voltage (Sine Wave Voltage 60HZ, for 1 Minute, R.H. VCES of IGBT being used (Note 1) Detect input pin surge voltage protection (Note 2) Gate surge voltage protection VD supply decoupling – Electrolytic, long life, low Impedance, 105°C (Note 3) DC/DC output filter – Electrolytic, long life, low Impedance, 105°C (Note 3,4) Fault feedback signal noise filter Adjust soft shutdown – Multilayer ceramic or film (see application note) Adjust trip time – Multilayer ceramic or film (see application note) Fault sink current limiting resistor Fault signal noise suppression resistor Fault feedback signal noise filter Fault feedback signal pull-up Opto-coupler for fault feedback signal isolation 74HC04 or similar – Must actively pull high to maintain noise immunity Notes: (1) The VCE detection diode should have a blocking voltage rating equal to or greater than the VCES of the IGBT being driven. Recovery time should be less than 200ns to prevent application of high voltage to Pin 30. (2) DZ1 is necessary to protect Pin 30 of the driver from voltage surges during the recovery of D1. (3) Power supply input and output decoupling capacitors should be connected as close as possible to the pins of the gate driver. (4) DC-to-DC converter output decoupling capacitors must be sized to have appropriate ESR and ripple current capability for the IGBT being driven.  Rev. 5/07 Powerex, Inc., 200 E. Hillis Street, Youngwood, Pennsylvania 15697-1800 (724) 925-7272 VLA500K-01R Hybrid IC IGBT Gate Driver + DC/DC Converter General Description The VLA500K-01R is a hybrid integrated circuit designed to provide gate drive for high power IGBT modules. This circuit has been optimized for use with Powerex NFSeries and A-Series IGBT modules. However, the output characteristics are compatible with most MOS gated power devices. The VLA500K-01R features a compact single-in-line package design. The upright mounting minimizes required printed circuit board space to allow efficient and flexible layout. The VLA500K-01R converts logic level control signals into fully isolated +15V/-8V gate drive with up to 12A of peak drive current. Isolated drive power is provided by a built in DC-to-DC converter and control signal isolation is provided by an integrated high speed opto-coupler. Short circuit protection is provided by means of destauration detection. Short Circuit Protection Figure 1 shows a block diagram of a typical desaturation detector. In this circuit, a high voltage fast recovery diode (D1) is connected to the IGBT’s collector to monitor the collector to emitter voltage. When the IGBT is in the off state, VCE is high and D1 is reverse biased. With D1 off the (+) input of the comparator is pulled up to the positive gate drive power supply (V+) which is normally +15V. When the IGBT turns on, the comparators (+) input is pulled down by D1 to the IGBT’s VCE(sat). The (-) input of the comparator is supplied with a fixed voltage (Vtrip). During a normal on-state condition the comparator’s (+) input will be less than Vtrip and it’s output will be low. During a normal off-state condition the comparator’s (+) input will be larger than Vtrip and it’s output will be high. If the IGBT turns on into a short circuit, the high current will cause the IGBT’s collector-emitter voltage to rise above Vtrip even though the gate of the IGBT is being driven on. This abnormal presence of high VCE when the IGBT is supposed to be on is often called desaturation. Desaturation can be detected by a logical AND of the driver’s input signal and the comparator output. When the output of the AND goes high a short circuit is indicated. The output of the AND can be used to command the IGBT to shut down in order to protect it from the short circuit. A delay (ttrip) must be provided after the comparator output to allow for the normal turn on time of the IGBT. The ttrip delay is set so that the IGBT's VCE has enough time to fall below Vtrip during normal turn on switching. If ttrip is set too short, erroneous desaturation detection will occur. The maxi- Rev. 5/07 mum allowable ttrip delay is limited by the IGBT’s short circuit withstanding capability. In typical applications using Powerex IGBT modules the recommended limit is 10µs. Operation of the VLA500K-01R Desaturation Detector The Powerex VLA500K-01R incorporates short circuit protection using desaturation detection as described above. A flow chart for the logical operation of the shortcircuit protection is shown in Figure 2. When a desaturation is detected the hybrid gate driver performs a soft shutdown of the IGBT and starts a timed (ttimer) 1.5ms lock out. The soft turn-off helps to limit the transient voltage that may be generated while interrupting the large short circuit current flowing in the IGBT. During the lock out the driver pulls Pin 28 low to indicate the fault status. Normal operation of the driver will resume after the lock-out time has expired and the control input signal returns to its off state. Adjustment of Trip Time The VLA500K-01R has a default short-circuit detection time delay (ttrip) of approximately 3µs. This will prevent erroneous detection of short-circuit conditions as long as the series gate resistance (RG) is near the minimum recommended value for the module being used. The 3µs delay is appropriate for most applications so adjustment will not be necessary. However, in some low frequency applications it may be desirable to use a V+ D1 + DELAY ttrip COMPARE Vtrip C AND IGBT MODULE SHUTDOWN INPUT GATE DRIVE RG G E E Figure 1. Desaturation Detector  Powerex, Inc., 200 E. Hillis Street, Youngwood, Pennsylvania 15697-1800 (724) 925-7272 VLA500K-01R Hybrid IC IGBT Gate Driver + DC/DC Converter START IS VCE > VSC NO YES IS INPUT SIGNAL ON NO YES DELAY ttrip YES IS VCE > VSC Adjustment of Soft Shutdown Speed NO YES SLOW SHUTDOWN DISABLE OUTPUT SET FAULT SIGNAL WAIT ttimer YES IS INPUT SIGNAL OFF larger series gate resistor to slow the switching of the IGBT, reduce noise, and limit turn-off transient voltages. When RG is increased, the switching delay time of the IGBT will also increase. If the delay becomes long enough so that the voltage on the detect Pin 30 is greater than VSC at the end of the ttrip delay the driver will erroneously indicate that a short circuit has occurred. To avoid this condition the VLA500K-01R has provisions for extending the ttrip delay by connecting a capacitor (Ctrip) between Pin 29 and VEE (Pins 21 and 22). A curve showing the effect of adding Ctrip on time is given in the characteristic data section of this data sheet. The waveform defining trip time (ttrip) is shown in Figure 3. If ttrip is extended care must be exercised not to exceed the short-circuit withstanding capability of the IGBT module. Normally this will be satisfied for Powerex NF and A-Series IGBT modules as long as the total shut-down time does not exceed 10µs. NO As noted above the VLA500K-01R provides a soft turnoff when a short circuit is detected in order to help limit the transient voltage surge that occurs when large short circuit currents are interrupted. The default shutdown speed will work for most applications so adjustment is usually not necessary. In this case CS can be omitted. In some applications using large modules or parallel connected devices it may be helpful to make the shutdown even softer. This can be accomplished by connecting a capacitor (CS) at Pin 27. A curve showing the effect of CS on short circuit fall time (t1, t2) is given in the characteristic data section of this data sheet. The waveform defining the fall time characteristics is shown in Figure 3. ttimer FAULT SIGNAL (PIN 28) 10V ttrip YES CLEAR FAULT SIGNAL ENABLE OUTPUT 10V SHORT CIRCUIT PROTECTION TIMING DIAGRAM (PIN 30 OPEN) t1 t2 90% 50% Figure 2. VLA500K-01R Desaturation Detector -5V VO (PIN 23) 10% Figure 3. Adjustment of ttrip and Slow Shutdown Speed  Rev. 5/07