AD7608BSTZ - 18-Bit 8-Ch Simultaneous Sampling ADC | Analog Devices
MPN: AD7608BSTZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $65.4545 | $65.45 |
| 10 | $47.2727 | $472.73 |
| 100 | $41.8182 | $4,181.82 |
| 500 | $40 | $20,000.00 |
| 1,000 | $38.1818 | $38,181.80 |
AD7608BSTZ Overview
What is a data acquisition system? A DAS is a complete signal chain that conditions, samples, and converts analog signals into digital data. The AD7608 integrates all essential analog front-end functions — clamping, filtering, track-and-hold, SAR conversion, and digital interface — reducing external circuitry. As part of the simultaneous sampling ADC family, it captures all channels at the same instant, preserving phase relationships that are critical in three-phase power analysis, vibration monitoring, and motor current sensing.
Key features include 18-bit resolution, 200 kSPS per channel, true simultaneous sampling across eight channels, and bipolar input ranges that eliminate external level-shifting. The second-order antialias filter has a 22 kHz 3 dB cutoff and provides 40 dB rejection at 200 kSPS. The programmable pin-driven digital filter trades bandwidth for improved SNR. The integrated 2.5 V reference and buffer maintain gain stability over temperature. Both parallel and SPI/DSP serial interfaces are available, simplifying connection to MCUs, DSPs, and FPGAs.
Architecturally, the charge redistribution SAR approach provides excellent linearity and low power for a multi-channel precision converter. The input clamp protection and antialias filter simplify front-end design in harsh industrial environments. The flexible digital filter allows engineers to optimize noise versus output data rate for each application.
Typical applications include power-line monitoring, protective relays, motor control, multi-phase energy metering, vibration analysis, and test and measurement instrumentation. The simultaneous sampling capability is essential for accurate phase measurement and multi-axis synchronization. The 18-bit resolution enables detection of small signal variations that 16-bit systems miss.
When designing with the AD7608, place decoupling capacitors close to the AVCC and DVCC pins, and route the reference decoupling capacitor adjacent to REFIN/REFOUT. Balance the oversampling ratio against settling time so the increased digital filtering does not reduce the effective throughput below system requirements.
Drop-in alternatives for AD7608BSTZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD7608BSTZ (same form factor and footprint) — differing in Architecture, Input Clamp Protection, Interface, Internal Reference, Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7606BSTZ
✓ In Stock
$16.9 / Unit
View Datasheet →AD7609BSTZ
✓ In Stock
$33.2 / Unit
View Datasheet →AD7606CSTZ
📋 Reference alternative (not in catalog)
AD7607BSTZ
📋 Reference alternative (not in catalog)
AD7606-6BSTZ
📋 Reference alternative (not in catalog)
AD7606-4BSTZ
📋 Reference alternative (not in catalog)
AD7608BSTZ Maximum Ratings & Electrical Characteristics
| Resolution | 18 bit |
| Number of Channels | 8 |
| Sampling Rate | 200 kSPS per channel |
| Architecture | SAR (charge redistribution successive approximation) |
| Input Voltage Ranges | ±10 V, ±5 V, ±2.5 V |
| Interface | Parallel; Serial (SPI/DSP) |
| Analog Supply Voltage (AVCC) | 5 V |
| Internal Reference | 2.5 V with buffer (REFIN/REFOUT) |
| Antialias Filter | Second-order, 22 kHz 3 dB cutoff, 40 dB rejection at 200 kSPS |
| Digital Filter | Flexible, pin-driven, programmable oversampling |
| Input Clamp Protection | Yes |
| Package | 64-LQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40°C to +85°C |
| Lifecycle Status | Active (Production) |
AD7608BSTZ 64-lqfp (10x10 mm) Pin Configuration Guide
Pin configuration for AD7608BSTZ (64-lqfp (10x10 mm) package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for AD7608BSTZ.
Refer to the datasheet for full pin configuration.
Typical Applications
AD7608BSTZ is suitable for 6 applications: Power-Line Monitoring, Motor Control, Protective Relays, Multi-Phase Energy Metering, Vibration Analysis, Test and Measurement.
Power-Line Monitoring
The AD7608BSTZ's 18-bit resolution and 200 kSPS simultaneous sampling on eight channels preserve phase relationships between voltage and current. Its ±10 V bipolar input directly connects to CTs and PTs through scaling resistors, while the second-order antialias filter rejects out-of-band noise. In power monitoring, the high dynamic range improves harmonic and disturbance detection.
Recommended
Motor Control
In servo and VFD motor drives, the AD7608BSTZ senses currents and bus voltages simultaneously, enabling accurate angle estimation. The 200 kSPS sampling and 18-bit resolution provide sufficient bandwidth for fast current loops, while the ±5 V and ±10 V input ranges match common sensor outputs. Integrated input clamp protection reduces external protection circuitry.
Recommended
Protective Relays
Protective relays require precise phase-coherent sampling of six current and two voltage channels. The AD7608BSTZ meets this with eight simultaneous channels, 18-bit resolution, and ±10 V input range, while the pin-driven digital filter rejects transients. Its 200 kSPS throughput supports burst measurements during fault events. Bipolar inputs handle CT saturation inrush without additional conditioning.
Recommended
Multi-Phase Energy Metering
For three-phase energy metering, the AD7608BSTZ simultaneously digitizes three voltages and three currents plus neutral, retaining phase integrity. The 18-bit resolution improves active and reactive power accuracy at low current levels, and the internal 2.5 V reference with buffer maintains gain stability over temperature. 200 kSPS allows harmonic analysis beyond the 50/60 Hz fundamentals.
Recommended
Vibration Analysis
Vibration monitoring needs synchronized multi-axis sampling; the AD7608BSTZ's simultaneous track-and-hold ensures zero skew between accelerometer channels. The ±2.5 V input range matches MEMS sensor outputs, while 200 kSPS captures high-frequency vibration components. The flexible digital filter can trade bandwidth for noise performance, aiding condition monitoring and bearing fault detection.
Recommended
Test and Measurement
General-purpose data acquisition systems use the AD7608BSTZ as a front end for multiple analog channels. The parallel or SPI/DSP interface connects directly to MCUs and FPGAs; 18-bit resolution supports precision instrumentation. The integrated input clamp and antialias filter simplify board design, while 200 kSPS is adequate for transient capture and sensor scanning.
Recommended
Recommended Products Summary
Engineering reference data for AD7608BSTZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7606BSTZ | AD7607BSTZ | AD7609BSTZ | AD7606-6BSTZ |
|---|---|---|---|---|---|
| Package | 64-LQFP (10x10) | 64-LQFP (10x10) - same | 64-LQFP (10x10) - same | 64-LQFP (10x10) - same | 64-LQFP (10x10) - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 18-bit | 16-bit | 14-bit | 18-bit | 16-bit |
| Number of Channels | 8 | 8 | 8 | 8 | 6 |
| Max Sampling Rate | 200 kSPS (all channels) | 200 kSPS (all channels) | 200 kSPS (all channels) | 200 kSPS (all channels) | 200 kSPS (all channels) |
| Input Ranges | ±10 V, ±5 V, ±2.5 V | ±10 V, ±5 V, ±2.5 V | ±10 V, ±5 V, ±2.5 V | ±10 V, ±5 V, ±2.5 V | ±10 V, ±5 V, ±2.5 V |
| Interface | Parallel; Serial (SPI/DSP) | Parallel | Parallel | Parallel | Parallel |
| Internal Reference | 2.5 V with buffer | 2.5 V with buffer | 2.5 V with buffer | 2.5 V with buffer | 2.5 V with buffer |
Key Differentiators
- True 18-bit resolution in an 8-channel simultaneous sampling DAS (vs AD7606BSTZ)
- Four extra bits versus 14-bit family variants (vs AD7607BSTZ)
- Eight simultaneously sampled channels (vs AD7606-6BSTZ)
Design Notes
The AD7608BSTZ operates from a single 5 V AVCC supply. Place a 10 uF bulk capacitor and a 100 nF ceramic capacitor close to the AVCC pin, and a similar combination on DVCC if used. The VDRIVE pin sets the digital interface voltage; ensure it does not exceed the host I/O supply and is decoupled with a 100 nF capacitor. Excessive input voltage beyond ±16.5 V can trigger the internal clamp protection, but external series resistance should still be considered for severe overvoltage transients.
For best noise performance, place the 1 uF reference decoupling capacitor as close as possible to REFIN/REFOUT and the REGCAP decoupling capacitors near the corresponding pins. Use a solid analog ground plane beneath the 64-LQFP and avoid routing digital traces under the analog input paths. The AD7608's second-order antialias filter reduces the need for external RC filtering, but keep the analog input traces short and shielded from the parallel data bus to preserve 18-bit SNR.
Do not confuse the flexible digital filter oversampling with the ADC sampling rate. Setting a high oversampling ratio improves noise rejection but reduces the output data rate because each conversion requires multiple samples. For 200 kSPS continuous throughput, use a minimal oversampling setting. Also verify STBY and RANGE pin logic levels during power-up; incorrect settings can place the part in standby or change the analog input scale unexpectedly.
Compliance Information
Compliance data was not explicitly provided in the verified web data. The 'Z' suffix in ADI part numbers often indicates RoHS-compliant lead-free finish, but this should be confirmed on the Analog Devices product page before production use.
