Design Note 4 Issue 2 June 1995 Temperature Effects On Silicon Semiconductor Devices Many applications require reliable circ uit operation over a wide temperature range. Automotive environments for example may experience a range of -40°C to +125°C, while a more usual industrial range may b e - 1 0 ° C t o 8 5 ° C . T o e ns u r e t h a t electronic components and systems behave satisfactorily, the design process must include consideration of device parameter variation with temperature, in particular those parameters which affect leakage currents, drive conditions, on-state loss es, and switching performance. This design note provides a general indication of the effects of temperature on silicon devices, and lists typical temperature coefficients for the main parameters. This information is based on known physical effects, and measurements conducted previously. The latter applies when either the device textbooks do not consider the de vice/parameter of interest, or a product specific measurement is required. Obviously for such a general guide, these values must be considered as approximate, but will probably be adequate in many cases. BIPOLAR (except Darlingtons) Parameter Temp. Coefficient Comment hFE +0.3 to 0.6%/°C In active region at low to medium currents Negative At high currents. Cross over point falls as IC and Breakdown Voltage Increases -0.25%/°C In saturation region VBE(sat) -0.15%/°C VBE(on) -1.9 to 2.2 mV/°C VCE(sat) +0.23 to 0.4%/°C Small signal devices (eg ZTX300) 0.12 to 0.15%/°C Medium power devices (eg ZTX650) VCBO(VCES) +0.07 to 0.09%/°C VCEO + or - about zero VEBO +0.04%/°C ICBO. x2 per 11°C PNP tend to be higher than NPN (Eg. can be small, but very device dependent) Design Note 4 Issue 2 June 1995 DARLINGTONS Parameter Temperature Coefficient Comment hFE +0.5 to 1.6%/°C In active region at low to medium currents + or - about zero (small) (due to inability to saturate fully) In saturation region VCE(sat) + or - about zero (small) VBE(on) -0.2%/°C VCBO +0.08%/°C VEBO +0.04%/°C ICEO Approx x2 per 8-10 °C rise. Dependent on voltage as well as temperature MOSFETS Parameter Temperature Coefficient Comment VDSS +0.04 to 0.1%/°C Increases with resistivity (BVDSS) RDS(ON) +0.7 to 1.0%/°C VGS(TH) -0.1 to 0.2%/°C IDSS Approx x2 per 11°C rise gfs Small ( say -0.2% / °C) Vf (of body diode) -2 to 2.5mV/°C dV/dT capability falls as temperature increases. Switching speed does not alter significantly. DIODES Parameter Temperature Coefficient VSS -1.9 to 2.2mV/°C BSS +0.7 to 0.09%/°C Comment VARICAP/VARACTOR DIODES Parameter Temperature Coefficient Comment Capacitance Abrupt:280 ppm @ 4V; 100 ppm @ 20V Very dependent on bias voltage Hyperabrupt:350 ppm @ 3V; 80 ppm @ 20V VOLTAGE REFERENCE DIODES Parameter Temperature Coefficient Comment VZ -0.06%/°C Nominally zero +0.075%/°C 0.2%/°C 3.3V(Field effect) 5.0V 12.0V (Avalanche effect) 24.0V (Avalanche effect) ICEO Approx x4 per11°C rise ICER(10k) Approx x3 per 11°C rise td and tr Independent ts +1.4 to 1.6%/°C Parameter Temperature Coefficient tf +1.0 to 2.5%/°C VF -1.2mV/°C Very dependent on hFE SCHOTTKY DIODES DN4-1 Comment DN4-2 Design Note 4 Issue 2 June 1995 Temperature Effects On Silicon Semiconductor Devices Many applications require reliable circ uit operation over a wide temperature range. Automotive environments for example may experience a range of -40°C to +125°C, while a more usual industrial range may b e - 1 0 ° C t o 8 5 ° C . T o e ns u r e t h a t electronic components and systems behave satisfactorily, the design process must include consideration of device parameter variation with temperature, in particular those parameters which affect leakage currents, drive conditions, on-state loss es, and switching performance. This design note provides a general indication of the effects of temperature on silicon devices, and lists typical temperature coefficients for the main parameters. This information is based on known physical effects, and measurements conducted previously. The latter applies when either the device textbooks do not consider the de vice/parameter of interest, or a product specific measurement is required. Obviously for such a general guide, these values must be considered as approximate, but will probably be adequate in many cases. BIPOLAR (except Darlingtons) Parameter Temp. Coefficient Comment hFE +0.3 to 0.6%/°C In active region at low to medium currents Negative At high currents. Cross over point falls as IC and Breakdown Voltage Increases -0.25%/°C In saturation region VBE(sat) -0.15%/°C VBE(on) -1.9 to 2.2 mV/°C VCE(sat) +0.23 to 0.4%/°C Small signal devices (eg ZTX300) 0.12 to 0.15%/°C Medium power devices (eg ZTX650) VCBO(VCES) +0.07 to 0.09%/°C VCEO + or - about zero VEBO +0.04%/°C ICBO. x2 per 11°C PNP tend to be higher than NPN (Eg. can be small, but very device dependent) Design Note 4 Issue 2 June 1995 DARLINGTONS Parameter Temperature Coefficient Comment hFE +0.5 to 1.6%/°C In active region at low to medium currents + or - about zero (small) (due to inability to saturate fully) In saturation region VCE(sat) + or - about zero (small) VBE(on) -0.2%/°C VCBO +0.08%/°C VEBO +0.04%/°C ICEO Approx x2 per 8-10 °C rise. Dependent on voltage as well as temperature MOSFETS Parameter Temperature Coefficient Comment VDSS +0.04 to 0.1%/°C Increases with resistivity (BVDSS) RDS(ON) +0.7 to 1.0%/°C VGS(TH) -0.1 to 0.2%/°C IDSS Approx x2 per 11°C rise gfs Small ( say -0.2% / °C) Vf (of body diode) -2 to 2.5mV/°C dV/dT capability falls as temperature increases. Switching speed does not alter significantly. DIODES Parameter Temperature Coefficient VSS -1.9 to 2.2mV/°C BSS +0.7 to 0.09%/°C Comment VARICAP/VARACTOR DIODES Parameter Temperature Coefficient Comment Capacitance Abrupt:280 ppm @ 4V; 100 ppm @ 20V Very dependent on bias voltage Hyperabrupt:350 ppm @ 3V; 80 ppm @ 20V VOLTAGE REFERENCE DIODES Parameter Temperature Coefficient Comment VZ -0.06%/°C Nominally zero +0.075%/°C 0.2%/°C 3.3V(Field effect) 5.0V 12.0V (Avalanche effect) 24.0V (Avalanche effect) ICEO Approx x4 per11°C rise ICER(10k) Approx x3 per 11°C rise td and tr Independent ts +1.4 to 1.6%/°C Parameter Temperature Coefficient tf +1.0 to 2.5%/°C VF -1.2mV/°C Very dependent on hFE SCHOTTKY DIODES DN4-1 Comment DN4-2