Charge Recovery Measurements with TLP

Transcription

1 Charge Recovery Measurements with TLP High Power Pulse Instruments (HPPI) February 11, 218 1/4

2 Outline Definitions TLP Setup Various Generic Setups Measurement Setup With Discrete Current Sensor 2/4

3 Outline Definitions TLP Setup Various Generic Setups Measurement Setup With Discrete Current Sensor 3/4

4 Charge Recovery Phenomenon of Diodes V DUT V R -V F t I DUT DUT V DUT I DUT Forward Recovery Phenomenon Reverse Recovery Phenomenon I R t -I F 4/4

5 Reverse Recovery Time of Diodes Various Definitions V DUT Reverse Recovery Time Definition by M. Reisch t rr V R 9 % of reverse voltage V R DUT I DUT (t) V DUT (t) - V F I DUT I R t Reverse Recovery Time Definition by AVTECH Corp. t rr 25 % of nom. peak rev. current 1 % of nom. peak rev. current t - I F t rr 1 % of nom. peak rev. current defined by MIL-STD-75D, METHOD /4

6 Reverse Recovery Time of Diodes Various Definitions Reverse Recovery Setup: and 1 Ω Reverse Recovery Definition - I: 25 % of nominal peak reverse current [1] Reverse Recovery Definition - II: 1 % of nominal peak reverse current [2] MIL-STD-75D, method Reverse Recovery Definition - III: 9 % of reverse voltage [3] Reverse Recovery Definition - IV: Reverse recovered charge [4] 6/4

7 Outline Definitions TLP Setup Various Generic Setups Measurement Setup With Discrete Current Sensor 7/4

8 General 1 Ω Measurement Setup Reverse and Forward Recovery SMU Sampling Oscilloscope Ch3 5Ω TLP Bias-T Pick-Off-T 5Ω DUT Bias-T ATT Ch1 5Ω V DUT = V Ch3 k PT V Ch1 k ATT I DUT = V Ch1 k ATT 8/4

9 Detailed 1 Ω Measurement Setup Reverse and Forward Recovery System Control PC GPIB and or TLP-812A5 GPIB GPIB GPIB AUX Trigger Output RG188-2m AUX Trigger Input GPIB TLP-311C Pulse Width Extender HVN-3A PWE-9A TLP-81C Pulse Output Control CH 1 V CH1 (t) Digital Oscilloscope High Voltage Pulse Generator Keithley SMU DUT DC Bias Bias-Tee BT-11A SF14-1m Overload Protection TVS-7MF-1 RG188-2m SF14-2m A3 CH 3 V CH3 (t) (optional) Overload Protection TVS-7MF-1 SF14-1m PCC-2A Switch Control A1 (optional) RG188-2m Keithley SMU DUT DC Test DC Test DUT Switch S-3C-LT SF14-2m SF14-2m Pulse Force SF14-1m Pulse Sense Pickoff-Tee PT-45A Bias-Tee BT-11A Picoprobe Cable.1 m I(t) V 3 (t) GND DUT Picoprobe Cable 1 m V 1 (t) 9/4

10 General 1 Ω TDR Measurement Setup Sub-ns Recovery Time Measurement Source Meter TLP Generator V (t) I F Forward Current Bias Tee 3 khz - 6 GHz Pickoff Tee L D Delay Line DUT V A (t) I DUT (t) V DUT (t) Oscilloscope V I (t), V R (t) V DUT (t) = V I (t) + V R (t) - V A (t) I DUT (t) = V A (t) Z = V I (t) - V R (t) Z V A (t) 1/4

11 Reverse Recovery Time of Diodes t rr Extraction Procedure Set the pulse parameters to minimum available rise time of 1 ps and a pulse width which is approximately two to three times the expected reverse recovery time. Operate diode in forward mode with a defined forward bias current I F. Apply a reverse mode TLP pulse with a defined reverse voltage V R = V TLP V F. The pulse width of the TLP has to be increased until the voltage V R remains steady state. Measurement of the nominal peak reverse current. Extract 25 % (or 1 % according MIL-STD) of the nominal peak reverse current. The time where the current I DUT decreases down to 25 % (or 1 % according MIL-STD) of the nominal peak reverse current, is the reverse recovery time. 11/4

12 Reverse Recovery Transient Waveforms Example: 39.7 ns V DUT (V) I DUT (A) t rr = 39.7 ns Time (ns) 12/4

13 Reverse Recovery Transient Waveforms Example: 2.5 ns V DUT (V) I DUT (A) t rr = 2.5 ns Time (ns) 13/4

14 Reverse Recovery Transient Waveforms Example:.6 ns V DUT (V) I DUT (A) 5 t rr =.6 ns Time (ns) 14/4

15 Reverse Recovery Measurement Setup Example: Reverse Recovery Measurement Result of a Silicon Diode Reverse Recovery Time t rr [ns] J F = 1.4E-6 A/µm 2 J F = 4.1E-6 A/µm 2 J F = 6.8E-6 A/µm Reverse Voltage V R [V] 15/4

16 Outline Definitions TLP Setup Various Generic Setups Measurement Setup With Discrete Current Sensor 16/4

17 Reverse Recovery Time of Diodes Reverse Recovery Measurement Setup Source Meter I F Forward Current TLP Generator Bias Tee 3 khz - 6 GHz Current Sensor V (t) Oscilloscope I DUT (t) High Impedance Probe DUT I DUT (t) V DUT (t) V DUT (t) 17/4

18 Reverse Recovery Setup with Shunt Current Sense Resistor SMU Sampling Oscilloscope Ch3 5Ω TLP Bias-T Pick-Off-T 5Ω DUT Ch1 5Ω R<< V DUT = V Ch3 k PT V Ch1 I DUT = V Ch1 R 18/4

19 Reverse Recovery Time of Diodes 1 Ω Reverse Recovery Measurement Setup Source Meter TLP Generator I F Forward Current Bias Tee 3 khz - 6 GHz V DUT (t) = V C (t) - V A (t) I DUT (t) = V A (t) / V (t) Oscilloscope Pickoff Tee V C (t) DUT V A (t) I DUT (t) V DUT (t) V C (t) V A (t) 19/4

20 Forward Recovery +RS Setup Sampling Oscilloscope TLP Pick-Off-T Ch3 5Ω 5Ω RS DUT Ch1 5Ω R<< V DUT = V Ch3 k PT V Ch1 I DUT = V Ch1 R 2/4

21 Forward Recovery +RS Setup Sampling Oscilloscope TLP Pick-Off-T Ch3 5Ω 5Ω RS DUT V DUT = V Ch3 k PT 21/4

22 Forward Recovery 1 Ω Setup Sampling Oscilloscope Ch3 5Ω TLP Pick-Off-T 5Ω DUT ATT Ch1 5Ω V DUT = V Ch3 k PT V Ch1 k ATT I DUT = V Ch1 k ATT 22/4

23 Forward Recovery 1 Ω+RS Setup Sampling Oscilloscope Ch3 5Ω TLP Pick-Off-T 5Ω RS DUT ATT Ch1 5Ω V DUT = V Ch3 k PT V Ch1 k ATT I DUT = V Ch1 k ATT 23/4

24 Outline Definitions TLP Setup Various Generic Setups Measurement Setup With Discrete Current Sensor 24/4

25 Measurement Setup with Discrete Current Sensor Transformer-based Current Sensor Source Meter I F Forward Current TLP Generator Bias Tee BT-11A 3 khz - 6 GHz Cable L Current Sensor CS-V5A Interconnection Cable L 1 ~.15m GGB 5 kω Model 1 R PP = 4.95 kω V PULSE (t) I DUT (t) Oscilloscope DUT V DUT (t) I READOUT (t) V DUT (t) The transformer-based current sensor does not readout the initial DC current 25/4

26 Setup and Polarity Definition Source Meter I F Forward Current TLP Generator Bias Tee BT-11A 3 khz - 6 GHz Cable L Current Sensor CS-V5A Interconnection Cable L 1 ~.15m GGB 5 kω Model 1 R PP = 4.95 kω V PULSE (t) I DUT (t) Oscilloscope DUT V DUT (t) I READOUT (t) V DUT (t) Voltage and current polarities are defined as shown in this schematic Therefore the diode forward current is considered as a negative value, e.g. IF = 45 ma I DUT,CALC = I READOUT + I F 26/4

27 Measurement Setup with Discrete Current Sensor Transformer-based Current Sensor Because of the transformer, the current sensor will not read out the DC forward bias current IF The sensor will read out the difference in the time domain: Read Out Current = IDUT - IF This means we need to correct the result by post processing to get the correct IDUT value: IDUT = Read Out Current + IF In addition the readout signals shows a delay and a plateau due to the cable L 1 27/4

28 1 A, 3 GHz,,.5 V/A Current Sensor CS-V5-A SPICE Equivalent Model CS-V5-A Simplified SPICE Equivalent Model Current Sensor Output (PORT 3) R1 L1 Ideal Transformer L2 R2 Pulse Input (PORT 1) RS LP N : 1 Pulse Output (PORT 2) 5 Current Sensor Output (PORT 3) 5 Pulse Output (PORT 2) 5 Pulse Input (PORT 1) N = 18 k =.9999 RS = 11 Ω R1 =.1 Ω LP = mh ( ) 1 L1 = LP k 1 = nh L2 = L1 =.48 nh N2 R2 =.1 Ω 28/4

29 How to Correct the Current Sensor Readout Signal? Current [ma] I DUT I READOUT -2-6 I CALC -3-8 V DUT Time [ns] V DUT [V] 29/4

30 How to Correct the Current Sensor Readout Signal? Step 1: Shift down the readout signal by IF Step 2: Shift left the readout signal by the delay time due to 2 L1 3/4

31 Probe Parasitics and Cable De-Embedding Required to avoid wrong readouts Voltage attenuation factor of the 5k Picoprobe model 1: 49 + = 1 Probe Parasitic Shunt Resistance: 49 + = 5 Ω Activate correct cable de-embedding and offset correction 31/4

32 Maximum Peak Reverse Current I DUT (t) V PULSE (t) Bias Tee DUT V DUT (t) The maximum peak reverse current is limited by the pulse voltage: I DUT,max = V PULSE + I F Example: V PULSE = 5 V, I F = 45 ma Maximum possible peak reverse current: I DUT,max = 55 ma 32/4

33 Readout Detail A V PULSE = 5 V, I F = 45 ma Current [ma] A I DUT -4 I READOUT -2-6 I DUT,CALC = I DUT + I F -3-8 V DUT Time [ns] V DUT [V] The amplitude of the plateau A results from: I A = V PULSE 2 1 = 5 ma 33/4

34 Readout Detail B V PULSE = 5 V, I F = 45 ma Current [ma] B I DUT -4 I READOUT -2-6 I DUT,CALC = I DUT + I F -3-8 V DUT Time [ns] V DUT [V] The pulse width B of the plateau results from: t B = 2 L 1 v 2 L 1 ɛ r c 34/4

35 Readout Detail C V PULSE = 5 V, I F = 45 ma Current [ma] C I DUT -4 I READOUT -2-6 I DUT,CALC = I DUT + I F -3-8 V DUT Time [ns] V DUT [V] The amplitude of the plateau C results from: I C,max = V PULSE 1 = 1 ma The value can be lower if Q rr is low, but not higher than I C,max 35/4

36 Readout Detail D V PULSE = 5 V, I F = 45 ma Current [ma] D I DUT -4 I READOUT -2-6 I DUT,CALC = I DUT + I F -3-8 V DUT Time [ns] V DUT [V] The time D is depending on Q rr 36/4

37 Readout Detail E V PULSE = 5 V, I F = 45 ma Current [ma] E I DUT -4 I READOUT -2-6 I DUT,CALC = I DUT + I F -3-8 V DUT Time [ns] V DUT [V] The decay E is depending on C jo 37/4

38 Calculation of the DUT Current Out of the Readout Current Post-processing procedure: I DUT,CALC = I READOUT + I F I DUT,CALC is valid after t B, this means that the time t B needs to be blanked (set I DUT,CALC = I F ) in order to get the right peak reverse current of the diode. Precise evaluation of t B is necessary for this purpose In all cases for I F and V PULSE the calculated peak reverse current and decay give the right result, despite the current sensor delay. 38/4

39 Example With Very Low Q rr C B D E All details A-E as described before 39/4

40 References [1] AVTECH Electrosystems LTD, A comparison of reverse recovery measurement systems, Nov. 26. [2] MIL-STD-75D, method 431.3, reverse recovery characteristics, [3] M. Reisch, Elektronische Baulemente, 2nd ed.: Springer, 27, ISBN: [4] N. Shammas, D. Chamund, and P. Taylor, Forward and reverse recovery behaviour of diodes in power converter applications, in Microelectronics, th International Conference on, vol. 1, May 24, pp /4