Neural Recording Chips: A Guide to DAQ ASICs

Every NeuroNexus headstage and DAQ system is built around one recording chip — a DAQ chip ↗. It performs the first step of acquisition, and it sets the channel count, the noise floor and whether the system can stimulate. This guide compares the families and says how to choose between them.

Research use only. NeuroNexus products and the procedures described here are for non-clinical research use, and must not be used in human or veterinary medical procedures.

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What Is a DAQ Chip?#

A DAQ chip (neural recording ASIC) is the integrated circuit inside a headstage ↗ or recording system. It amplifies, bandpass-filters and digitizes many channels on silicon, before the data leaves the implant site.

Why on-chip processing matters:

• Lower noise: Neural signals are 50–500 µV. Amplifying at the source prevents pickup from cables and connectors
• Reduced cable mass: One SPI or LVDS link replaces dozens of analog wires. That matters most in freely moving work
• Power efficiency: Modern recording ASICs consume 0.1–0.5 mW per channel, enabling battery-powered or implantable systems

Position in the recording chain:

Neural tissue → Silicon Probe → Package → Headstage [DAQ chip] → DAQ system → Host computer

The chip's analog front-end amplifies each electrode's signal, the on-chip ADC digitizes it, and the digital output is streamed to the data acquisition system ↗.

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Chip Families#

Intan RHD Series — Record-Only#

The Intan RHD family is the workhorse of extracellular recording. The three variants share one analog front-end and differ only in channel count.

Shared specifications:

• Input-referred noise: 2.4 µV RMS
• ADC resolution: 16-bit
• Sampling rate: 12–30 kHz (programmable)
• Bandwidth: 0.02 Hz – 20 kHz (programmable high and low cutoffs)
• Input signal range: ±5 mV
• Digital interface: SPI
• Supply voltage: 3.2–3.6 V

Best for: Acute and chronic extracellular recording in rodents and large animals. The 32-channel RHD2132 appears in more NeuroNexus headstages than any other chip. The RHD2164 doubles the channel density per headstage.

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Intan RHS2116 — Record + Stimulate#

The RHS2116 adds stimulation to the same 16-channel front-end. Each channel independently records or delivers a constant-current pulse, which is what makes closed-loop protocols possible on one electrode.

Key specifications:

• Recording channels: 16 (same analog front-end as RHD series)
• Stimulation channels: 16 (constant-current, per-channel)
• Stimulation range: 0.01–2500 µA (programmable in 0.01 µA steps)
• Pulse width: 10–1000 µs
• Frequency: 0.1–5000 Hz
• Compliance voltage: ±10.7 V
• Input noise: 2.4 µV RMS (recording)
• Power: 18 mW

Best for: Closed-loop stimulation experiments, intracortical microstimulation (ICMS), deep brain stimulation (DBS) research, and any protocol requiring simultaneous stimulation and recording on the same electrodes.

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Neuropixels — High-Density Recording#

Neuropixels probes integrate the recording ASIC into the probe shank. That places hundreds of sites on one shank, spanning cortical layers in a single penetration.

Neuropixels 1.0 (NP-1):

• Channels: 384
• ADC resolution: 10-bit
• Input noise: 5.0 µV RMS
• Sampling rate: 30 kHz (fixed)
• Bandwidth: 300 Hz – 10 kHz
• Input range: ±0.6 mV
• Digital interface: LVDS
• Power: 70 mW

Neuropixels 2.0 (NP-2):

• Channels: 384 (across 4 shanks)
• ADC resolution: 14-bit (improved from NP-1)
• Input noise: 3.5 µV RMS (improved from NP-1)
• Sampling rate: 30 kHz (fixed)
• Bandwidth: 300 Hz – 10 kHz
• Input range: ±0.3 mV
• Digital interface: LVDS
• Power: 70 mW

Best for: Large-scale single-unit recording across cortical layers in one penetration. NP-2.0 has better ADC resolution and lower noise than NP-1.0.

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SiNAPS-1 — High-Density Penetrating Arrays#

The SiNAPS-1 is a custom ASIC used in NeuroNexus SiNAPS active probes. Amplification and digitization happen on the shank itself, which is what allows site counts into the thousands on a penetrating probe. Catalog SiNAPS designs run from one to eight shanks at 5–5.5 mm.

Key specifications:

• Channels: 256
• ADC resolution: 10-bit
• Sampling rate: 20–30 kHz
• Bandwidth: 100 Hz – 10 kHz
• Input range: ±5 mV
• Digital interface: SiNAPS DAQ (proprietary)
• Amplifier gain: 40 dB (AC differential)

Best for: High-density laminar and multi-shank recording where site count matters more than per-channel ADC resolution.

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Comparison Table#

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Choosing the Right Chip#

Step 1 — How many channels do you need?

• 16–64 channels, standard extracellular: → Intan RHD series (scale from 16 to 64 per headstage)
• 256–1,024+ channels, high-density penetrating: → SiNAPS-1
• 384 channels, high-density laminar: → Neuropixels

Step 2 — Do you need stimulation?

• Yes, on the same electrodes as recording: → Intan RHS2116 (16 ch, constant-current)
• No: → any record-only chip

Step 3 — What ADC resolution and noise floor do you need?

• Highest resolution for spike detection: → RHD series (16-bit, 2.4 µV) or NP-2.0 (14-bit, 3.5 µV)
• Standard: → NP-1.0 (10-bit, 5.0 µV) or SiNAPS-1 (12-bit, 6.5 µV)

Step 4 — What is your weight / cable budget?

• Freely-moving rodent: → RHD2216 or RHD2132 headstages (lightest, SPI interface)
• Head-fixed or tethered: any chip is suitable

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DAQ Chips in NeuroNexus Products#

Each headstage is built around one DAQ chip, and that chip sets the headstage's channel count, noise floor and stimulation capability. The chip model appears on every headstage and DAQ datasheet page.

• Browse Headstages — filter by channel count, stimulation capability, and weight
• Browse DAQ Systems — filter by total channels and throughput

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Further Reading#

• DAQ Chip ↗ — glossary definition
• Headstage ↗ — glossary definition
• Data Acquisition System ↗ — glossary definition
• Silicon Probes ↗ — glossary definition
• NeuroNexus Data Acquisition Systems Overview — system-level overview