Post History
I am trying to figure out what is causing an Allegro A2982 source driver to burn up. The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil ar...
#13: Post edited
by
mrbean
·
2023-09-14T20:00:40Z (8 months ago)
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor. Three outputs of the source driver are used to drive three separate relay coils.
- 
- Closeup
- 
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- 
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor. Three outputs of the source driver are used to drive three separate relay coils.
- 
- Closeup
- 
#12: Post edited
by
mrbean
·
2023-09-14T19:58:36Z (8 months ago)
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor. Three outputs of the source driver are used to drive three separate relay coils.
- 
- Closeup
- 
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- 
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor. Three outputs of the source driver are used to drive three separate relay coils.
- 
- Closeup
- 
#11: Post edited
by
mrbean
·
2023-09-14T19:51:07Z (8 months ago)
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- 
The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor.- 
- Closeup
- 
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- 
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor. Three outputs of the source driver are used to drive three separate relay coils.
- 
- Closeup
- 
#10: Post edited
by
mrbean
·
2023-09-14T19:49:42Z (8 months ago)
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor.
- Closeup
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- 
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor.
- 
- Closeup
- 
#9: Post edited
by
mrbean
·
2023-09-14T19:49:01Z (8 months ago)
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- 
The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. Note: The relay coils are located near the motor.- 
- Closeup
- 
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- 
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. The output of the relay controls an ON/OFF signal (3.3V or GND). Note: The relay coils are located near the motor.
- 
- Closeup
- 
#8: Post edited
by
mrbean
·
2023-09-14T19:38:07Z (8 months ago)
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
If the spike is causing damage, is there a way to reduce or mitigate the spike?
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- Circuit Schematic
- 
- The circuit is used to turn off a motor. Below is a scope capture. The squared area in red is when the motor turns off. Note: The relay coils are located near the motor.
- 
- Closeup
- 
#7: Post edited
by
rdtsc
·
2023-09-14T14:38:53Z (8 months ago)
Added link to device datasheet.
Burned Source Driver - Noise Spikes from Relay Coil
I am trying to figure out what is causing an Allegro A2982 source driver to burn up.- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
- I am trying to figure out what is causing an [Allegro A2982 source driver](https://www.allegromicro.com/~/media/Files/Datasheets/A2981-2-Datasheet.ashx) to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
#6: Post edited
by
mrbean
·
2023-09-14T01:06:47Z (8 months ago)
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
The the spike is causing damage, is there a way to reduce or mitigate damage from the spike?
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- If the spike is causing damage, is there a way to reduce or mitigate the spike?
#5: Post edited
by
mrbean
·
2023-09-14T01:06:09Z (8 months ago)
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. I am using a differential probe to measure the voltage across the coil.- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- The the spike is causing damage, is there a way to reduce or mitigate damage from the spike?
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. Note: I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- The the spike is causing damage, is there a way to reduce or mitigate damage from the spike?
#4: Post edited
by
mrbean
·
2023-09-14T01:05:47Z (8 months ago)
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
The rail of the source driver (Vs) is 9V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. I am using a differential probe to measure the voltage across the coil.- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- The the spike is causing damage, is there a way to reduce or mitigate damage from the spike?
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9 V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- The the spike is causing damage, is there a way to reduce or mitigate damage from the spike?
#3: Post edited
by
mrbean
·
2023-09-14T01:05:10Z (8 months ago)
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. I am using a differential probe to measure the voltage across the coil.
- 
Also, a couple questions. Is it a valid concern that:- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- The the spike is causing damage, is there a way to reduce or mitigate damage from the spike?
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. I am using a differential probe to measure the voltage across the coil.
- 
- Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- The the spike is causing damage, is there a way to reduce or mitigate damage from the spike?
#2: Post edited
by
mrbean
·
2023-09-14T01:04:48Z (8 months ago)
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. I am using a differential probe to measure the voltage across the coil.
- 
Is there a way to mitigate the voltage spike?- Also, a couple questions. Is it a valid concern that:
1. The 9V supply may see the voltage spike and cause damage?2. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- I am trying to figure out what is causing an Allegro A2982 source driver to burn up.
- The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side.
- The rail of the source driver (Vs) is 9V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. I am using a differential probe to measure the voltage across the coil.
- 
- Also, a couple questions. Is it a valid concern that:
- 1. This voltage spike is causing damage to the source driver?
- 2. The 9V supply may see the voltage spike and cause damage?
- 3. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?
- The the spike is causing damage, is there a way to reduce or mitigate damage from the spike?
#1: Initial revision
by
mrbean
·
2023-09-14T01:03:00Z (8 months ago)
Burned Source Driver - Noise Spikes from Relay Coil
I am trying to figure out what is causing an Allegro A2982 source driver to burn up. The source driver (A2982) is connected to the coil of a Panasonic TXS2-9V relay. The source driver and coil are connected by about 3 feet of wire. The source driver is on the high side and the coil is on the low side. The rail of the source driver (Vs) is 9V. The source driver output is ~7.4 V. The peak voltage of the spike, measured across the inductor, is ~13.2 V. I am using a differential probe to measure the voltage across the coil.  Is there a way to mitigate the voltage spike? Also, a couple questions. Is it a valid concern that: 1. The 9V supply may see the voltage spike and cause damage? 2. The Vbe reverse breakdown voltage of the darlington-pair may be exceeded and cause damage?