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IZ2H Tech Notes

IZ2 Critical Failure

TN0983

Product: IZ2, IZ2H, LZ48
Version: All
Date Added: 2016-12-05

Issue

We discovered a failure mode in the IZ2 electrical stimulator / LZ48 battery pack that can lead to improper device output. Although the failure occurrence is relatively rare, this failure mode can result in the unintended delivery of high current to the research subject and thereby potentially cause injury or death. As such, we are taking every step possible to address the issue and ensure the best possible safety for your research subjects.

We strongly recommend that you verify proper device operation prior to connecting any research subjects and initiating any stimulation protocols. If an LZ48 battery is fully discharged while still connected to the IZ2, under some operating conditions electrical components in the IZ2 stimulator can be damaged. After the failure of these electrical components, higher than intended stimulation current can be delivered to the research subject during subsequent device operation. In this condition, IZ2 devices must be returned to TDT for repair or replacement of the damaged components.

Solution

  1. To minimize risk, never allow the LZ48 battery to fully discharge. When the battery charge indicator is getting low, stop the experiment, disconnect the subject, and recharge before further use.

  2. Always verify proper operation of your device before connecting to a research subject. If you observe red LED status lights on your IZ2 during setup, do not connect a research subject or proceed with the experiment. Please see the IZ2 Operation Guide for additional details. If you encounter any problems or need help verifying proper device operation, please contact TDT Technical Support for assistance.

  3. Contact TDT for a free LZ48PC protection cable. This new cable will monitor line voltages and protect the IZ2 from electrical component damage even if the battery is inadvertently allowed to fully discharge. The cable will replace the LZ48 to IZ2 cable that shipped with your device and can be easily installed in a matter of seconds.

  4. Consider upgrading your current LZ48 battery to a newer LZ48M battery pack that includes several additional protections and safety features including medical grade isolation from mains power when charging.

Building a custom headstage to use with SI, PZ, IZ, or ACO

TN0896

Product: PZA (SI), PZD (SI), IZV (SI), PZ5, PZ2, PZ3, IZ2, IZ2H, IZ2M, IZ2MH, ACO32, ACO64
Version: All
Date Added: 2012-02-08

Issue

This tech note provides the information needed to wire a custom or third-party headstage to TDT amplifiers, stimulus isolators, and commutators.

Solution

The PZA (SI), IZV (SI), PZ5 analog, PZ2, PZ3, IZ2, IZ2H, IZ2M, IZ2MH, ACO32, and ACO64 all use the same female mini-DB26 connectors. The mating male connector is made by TE Connectivity (previously Tyco), part number 5749621-2, and can be purchased from Newark, Digikey, or similar vendors. The part number for the connector's backshell kit is 749608-2.

The SI, PZ5, PZ2, PZ3, IZ2, and IZ2H are all battery powered. To conserve power, each bank of channels will not turn on unless a headstage is connected. The device detects whether a headstage is connected through the HSD (HeadStage Detect) pins: pins 18 and 19. These pins should be shorted together on the headstage connector. If pins 18 and 19 are not shorted the headstage will not be detected and the bank that it is connected to will power off.

Important

This does not apply to the IZ2M and IZ2MH. In those devices all banks are always powered.

The pins on the headstage should be made to match the connector on the intended device. The pinouts for each device are shown below.

Note

The user must increment the channel numbers by 16 (or 8) according to the amp, mode and position of the connector. So, for the connector labeled 'A', A1 is channel 1 while on the connector labeled 'B', A1 may be channel 17.

PZA (SI) and PZ5 Analog Connector Pinout for Building Headstages

PZA (SI) and PZ5 Analog banks have 26-pin headstage connectors. The connectors are labeled alphabetically from bottom to top. Each connector carries signal for one bank of channels with ground and reference. The corresponding channel numbers depend on:

  1. the reference mode configurations

  2. the position of the bank in a logical amplifier.

For simplicity sake, the diagrams below assume channels for that connector begin with channel 1. For example, A1 - A16 represent the 16 channels coming from the connected headstage.

Local Mode

Pin Name Description Pin Name Description
1 A1 Analog Input Channels 14 V+ Positive Voltage (+2.5V)
2 A2 15 GND Ground
3 A3 16 GND
4 A4 17 V- Negative Voltage (-2.5V)
5 Ref Reference 18 HSD Headstage Detect
6 DNC Do Not Connect 19 HSD
7 A5 Analog Input Channels 20 A6 Analog Input Channels
8 A7 21 A8
9 A9 22 A10
10 A11 23 A12
11 A13 24 A14
12 A15 25 A16
13 RefA Alternate Reference 26 DNC Do Not Connect

Local Mode Notes

  • Short pins 18 and 19 together.

  • Pins 14 and 17 can be used to power an active headstage. Each amp board on the PZ5 / PZA can source up to 100mA through the V+/V- power pins. If you have a higher current draw (over 100mA) then you will need an external battery pack to power your load.

None Mode

Pin Name Description Pin Name Description
1 A1 Analog Input Channels 14 V+ Positive Voltage (+2.5V)
2 A2 15 GND Ground
3 A3 16 GND
4 A4 17 V- Negative Voltage (-2.5V)
5 DNC Do Not Connect 18 HSD Headstage Detect
6 DNC 19 HSD
7 A5 Analog Input Channels 20 A6 Analog Input Channels
8 A7 21 A8
9 A9 22 A10
10 A11 23 A12
11 A13 24 A14
12 A15 25 A16
13 GND Ground 26 DNC Do Not Connect

None Mode Notes

  • Short pins 18 and 19 together.

  • Do NOT connect pin 5.

  • Pins 14 and 17 can be used to power an active headstage. Each amp board on the PZ5 / PZA can source up to 100mA through the V+/V- power pins. If you have a higher current draw (over 100mA) then you will need an external battery pack to power your load.

Shared Mode

Pin Name Description Pin Name Description
1 A1 Analog Input Channels 14 V+ Positive Voltage (+2.5V)
2 A2 15 GND Ground
3 A3 16 GND
4 A4 17 V- Negative Voltage (-2.5V)
5 Ref Reference 18 HSD Headstage Detect
6 DNC Do Not Connect 19 HSD
7 A5 Analog Input Channels 20 A6 Analog Input Channels
8 A7 21 A8
9 A9 22 A10
10 A11 23 A12
11 A13 24 A14
12 A15 25 A16
13 GND Ground 26 DNC Do Not Connect

Shared Mode Notes

  • Short pins 18 and 19 together.

  • In Shared reference mode, only Pin 5 of the first bank of the logical amplifier is connected to the reference. It is shared internally among the other banks of the logical amplifier.

  • Pins 14 and 17 can be used to power an active headstage. Each amp board on the PZ5 / PZA can source up to 100mA through the V+/V- power pins. If you have a higher current draw (over 100mA) then you will need an external battery pack to power your load.

Differential Mode

Pin Name Description Pin Name Description
1 A1(+) Analog Input Channel 14 V+ Positive Voltage (+2.5V)
2 A1(-) Differential Analog Input Channel 15 GND Ground
3 A2(+) Analog Input Channel 16 GND Ground
4 A2(-) Differential Analog Input Channel 17 V- Negative Voltage (-2.5V)
5 NA Not Used 18 HSD Headstage Detect
6 DNC Do Not Connect 19 HSD Headstage Detect
7 A3(+) Analog Input Channels 20 A3(-) Differential Input Channels
8 A4(+) 21 A4(-)
9 A5(+) 22 A5(-)
10 A6(+) 23 A6(-)
11 A7(+) 24 A7(-)
12 A8(+) 25 A8(-)
13 GND Ground 26 DNC Do Not Connect

Differential Mode Notes

  • There are 8 (+) channels and 8 (-) channels per DB26 connector. Subsequent banks are indexed by an additional 8 channels.

  • Short pins 18 and 19 together.

  • Pins 14 and 17 can be used to power an active headstage. Each amp board on the PZ5 / PZA can source up to 100mA through the V+/V- power pins. If you have a higher current draw (over 100mA) then you will need an external battery pack to power your load.

PZ2 Connector Pinout for Building Headstages

Pin Name Description Pin Name Description
1 A1 Analog Input Channels 14 V+ Positive Voltage (+1.5V)
2 A2 15 GND Ground
3 A3 16 DNC Do Not Connect
4 A4 17 V- Negative Voltage (-1.5V)
5 Ref Reference 18 HSD Headstage Detect
6 DNC Do Not Connect 19 HSD
7 A5 Analog Input Channels 20 A6 Analog Input Channels
8 A7 21 A8
9 A9 22 A10
10 A11 23 A12
11 A13 24 A14
12 A15 25 A16
13 RefA Alternate Reference 26 DNC Do Not Connect

PZ2 Notes

  • Short pins 18 and 19 together.

  • Do NOT connect pins 6, 13, 16, or 26.

  • Pins 14 and 17 can be used to power an active headstage. Each amp board on the PZ5 / PZA can source up to 100mA through the V+/V- power pins. If you have a higher current draw (over 100mA) then you will need an external battery pack to power your load.

PZ3 Connector Pinout for Building Headstages

Pin Name Description Pin Name Description
1 A1(+) Analog Input Channel 14 V+ Positive Voltage (+1.5V)
2 A1(-) Differential Analog Input Channel 15 GND Ground
3 A2(+) Analog Input Channel 16 DNC Do Not Connect
4 A2(-) Differential Analog Input Channel 17 V- Negative Voltage (-1.5V)
5 Ref* Shared Reference 18 HSD Headstage Detect
6 DNC Do Not Connect 19 HSD Headstage Detect
7 A3(+) Analog Input Channels 20 A3(-) Differential Input Channels
8 A4(+) 21 A4(-)
9 A5(+) 22 A5(-)
10 A6(+) 23 A6(-)
11 A7(+) 24 A7(-)
12 A8(+) 25 A8(-)
13 DNC Do Not Connect 26 DNC Do Not Connect

PZ3 Notes

  • * The PZ3 can operate in Shared or Individual (True Differential) mode.

    • If operating in Shared mode: do NOT connect differential analog input channels, pins 2, 4, 20-25.

    • If operating in Individual mode: do NOT connect pin 5.

  • There are 8 (+) channels and 8 (-) channels per DB26 connector. Subsequent banks are indexed by an additional 8 channels.

  • Short pins 18 and 19 together.

  • Do NOT connect pins 6, 13, 16, 26.

  • Pins 14 and 17 can be used to power an active headstage. Each amp board on the PZ5 / PZA can source up to 100mA through the V+/V- power pins. If you have a higher current draw (over 100mA) then you will need an external battery pack to power your load.

IZ2, IZ2M, IZ2MH, IZV Subject Interface (SI) Connector Pinout for Building Headstages

Pin Name Description Pin Name Description
1 A1 Analog Output Channels 14 DNC Do Not Connect
2 A2 15 GND Ground
3 A3 16 DNC Do Not Connect
4 A4 17 DNC Do Not Connect
5 DNC Do Not Connect 18 HSD Headstage Detect
6 DNC Do Not Connect 19 HSD
7 A5 Analog Output Channels 20 A6 Analog Output Channels
8 A7 21 A8
9 A9 22 A10
10 A11 23 A12
11 A13 24 A14
12 A15 25 A16
13 DNC Do Not Connect 26 DNC Do Not Connect

IZ2 and IZV Notes

  • Short pins 18 and 19 together.

  • Do NOT connect pins 5, 6, 13, 14, 16, 17, or 26.

  • Only passive headstages can be used with the IZ2 and IZV.

IZ2H Connector Pinout for Building Headstages

Pin Name Description Pin Name Description
1 A1 Analog Output Channels 14 DNC Do Not Connect
2 A2 15 GND Ground
3 A3 16 DNC Do Not Connect
4 A4 17 DNC Do Not Connect
5 DNC Do Not Connect 18 HSD Headstage Detect
6 DNC Do Not Connect 19 HSD
7 A5 Analog Output Channels 20 A6 Analog Output Channels
8 A7 21 A8
9 DNC Do Not Connect 22 DNC Do Not Connect
10 DNC 23 DNC
11 DNC 24 DNC
12 DNC 25 DNC
13 DNC 26 DNC

IZ2H Notes

  • Short pins 18 and 19 together.

  • Do NOT connect pins 5, 6, 9-14, 16, 17, or 22-26.

  • Only passive headstages can be used with the IZ2H.

The ACO passes signals from each header to the pins on the associated DB26 connector on the face of the commutator. The unused pins should not be connected. The pins on the headstage should be made to map to the connected amplifier/stimulator via the header as follows:

ACO Headers - Pinout for Building Active Headstages

For PZ2, PZ5 Analog, or PZA Subject Interface (SI)

For PZ3

ACO Headers - Pinout for Building Passive Headstages

For IZ2, IZ2M, IZ2MH, or IZV Subject Interface (SI)

For IZ2H

Leakage current on output of IZ2 in Current mode.

TN0894

Product: IZ2, IZ2H
Version: IZ2 SN < 3000, IZ2H SN < 2000
Date Added: 2011-12-06

Issue

In current mode, there may be a leakage current on the output of the stimulator. This DC offset depends on the temperature.

This issue has been addressed in new IZ2s. A fan has been added to the unit for better cooling and resistor changes in the output stage reduce the effectiveness of the offset error. An ACC16-Z coupler is also available to eliminate the offset.

Solution

If you experience this problem, contact Support to request an RMA for return and upgrade.

IZ2 Output Drops Unexpectedly

TN0890

Product: IZ2, IZ2H, RZ
Version: TDT Drivers < 72
Date Added: 2011-07-15

Issue

In voltage mode, the output of the IZ2 can go to zero for approximately 300-350 milliseconds and then return to the originally intended output. In current mode, a similar drop will appear to occur on the monitor ADC, but the output does not actually drop.

Solution

This error is caused by the IZ2 DSP Card installed in the controlling RZ device. If you experience this problem, contact TDT Support to request an RMA for return and repair of your RZDSP-I card.