公开(公告)号：JPH0778969A

公开(公告)日：1995-03-20

申请号：JP16782294

申请日：1994-07-20

Applicant: ABB MANAGEMENT AG

Inventor： KURISUCHIYAN HAUSUBUIRUTO ,  GERUHARUTO HOTSUHOSHIYUTOUURU ,  BURUUNO HOFUSHIYUTETSUTAA ,  MARUKUSU KERAA

IPC: G01R31/26 ,  G01K7/01 ,  H01L21/66 ,  H01L29/74 ,  H01L29/744

Abstract: PURPOSE: To measure the temperature of a depletion layer of a GTO during operation, by providing a measuring current to a gate circuit during an OFF state of the GTO, and measuring a voltage between the gate and a cathode of the GTO after a switching-off control current is decreased. CONSTITUTION: A depletion layer temperature measuring device constituted by a current source 6, a measuring unit 8 for a cathode gate voltage UGR, and a voltage source 7, are connected in parallel to a switching-on circuit 2 and a switching-off circuit 3. By the depletion layer temperature measuring device 4, a measuring current IM of approximately 100 mA is caused to flow, and the voltage UGR between a cathode and a gate of a GTO is measured. This voltage UGR is measured after a switching-off control current is decreased. This voltage UGR has a specified value dependent on the temperature of the depletion layer, and can learn the temperature of the depletion layer. Thus, the temperature of the depletion layer is accurately measured during operation.