My Inquiry
My Account
Analog Devices Inc. AD1555BPZ
- Part No.:
- AD1555BPZ
- Manufacturer:
- Analog Devices Inc.
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 28-LCC (J-Lead)
- Datasheet:
-
AD1555BPZ.pdf
- Description:
- IC ADC 24BIT SIGMA-DELTA 28PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:148
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AD1555BPZ from Analog Devices is a 24-bit sigma-delta modulator with integrated programmable gain amplifier (PGA), designed for high-precision, low-frequency measurement systems. It delivers 116.5 dB minimum dynamic range at 1 ms output word rate, 80 nV rms input noise at 4 ms with PGA gain of 128, and supports five PGA gains (1, 2.5, 8.5, 34, 128) for scalable input ranges down to ±12.4 mV rms. It is used in seismic data acquisition where ultra-low noise and wide dynamic range are critical.
For engineers reviewing the AD1555BPZ datasheet, AD1555BPZ pinout, AD1555BPZ application, or AD1555BPZ equivalent, key selection considerations include its 28-lead PLCC package, –55°C to +85°C extended temperature rating, fourth-order continuous-time modulator architecture eliminating external antialias filtering, and compatibility with AD1556 digital filter/decimator for full 24-bit ADC functionality.
Technical Context
The AD1555BPZ implements a fourth-order continuous-time sigma-delta modulator operating at 256 kHz sampling frequency, with internal clock generation synchronized to external CLKIN via MCLK. Its fully differential PGA provides five discrete gain settings controlled by CB0–CB4 logic inputs, enabling precise signal conditioning before modulation.
It features robust analog input architecture with 140 MΩ differential input impedance, 93 dB min CMRR at PGA gain = 1, and overvoltage detection circuitry. The modulator outputs a return-to-zero bitstream on MDATA, validated for jitter tolerance up to 300 ps, and includes MFLG error flag for overrange monitoring.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Dynamic Range | 116.5 dB min @ 1 ms output word rate, enabling >17-bit effective resolution in low-noise DC-coupled measurements |
| Input Noise | 79 nV rms @ 4 ms FO with PGA gain = 128, supporting sub-microvolt-level signal detection |
| PGA Gains | 1, 2.5, 8.5, 34, 128 - selectable via CB0–CB4 pins to match input signal amplitude without external amplification |
| Modulator Sampling Rate | 256 kSPS nominal, internally derived from 1.024 MHz CLKIN (÷4), ensuring stable timing without external oscillator |
| Supply Voltages | +VA = ±5 V (±5%), VL = 5 V (±5%) - dual analog supply enables rail-to-rail common-mode handling and low distortion |
| Operating Temperature | –55°C to +85°C - qualified for harsh industrial and geophysical environments |
| Power Dissipation | 77 mW typical active, 650 µW in power-down mode - suitable for battery-powered remote sensing nodes |
Pinout & Package
AD1555BPZ is housed in a 28-lead Plastic Lead Chip Carrier (PLCC, package option P-28A), with exposed thermal pad not electrically connected. Pin 1 identifier located at top-left corner; body material is flame-retardant thermoplastic.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 27 | AGND1 / AGND2 | Analog ground references for PGA and MODIN paths - must be star-connected to minimize ground loop noise |
| 2 | PGAOUT | PGA output node - directly connects to MODIN (Pin 28) in standard configuration; accessible for external signal routing |
| 3, 20, 21 | +VA | Positive analog supply - powers PGA and modulator core; requires local 10 µF + 0.1 µF decoupling |
| 4 | –VA | Negative analog supply - symmetric to +VA for true differential operation; same decoupling requirements |
| 5–8 | AIN(+), AIN(–), TIN(+), TIN(–) | Differential input pairs - AIN for primary measurement, TIN for calibration/test; both support ±2.25 V full-scale |
| 10–14 | CB0–CB4 | Configuration bus - sets PGA gain (CB0–CB2) and input mux selection (CB3–CB4); logic levels define operating mode at power-up |
| 15 | MFLG | Modulator overrange flag - open-drain output pulsed high during saturation; used for real-time fault detection |
| 17 | MDATA | Modulator bitstream output - return-to-zero format, valid for ~50% of MCLK cycle; interfaces directly to AD1556 MDATA input |
| 18 | MCLK | Modulator clock input - 256 kHz nominal; static state forces power-down mode |
| 19, 22 | VL, AGND3 | Digital supply and reference ground - powers internal logic and REFIN divider; isolated from analog grounds |
| 23–25 | REFCAP1, REFCAP2, REFIN | Reference interface - REFIN accepts 3.0 V ±10 mV; REFCAP1 requires 22 µF tantalum cap to AGND3 for low-noise modulator reference |
| 28 | MODIN | Modulator analog input - typically tied to PGAOUT; accepts ±2.25 V differential or single-ended signals |
Key Features
| Feature | Design Value |
|---|---|
| No external antialias filter required | Continuous-time modulator architecture inherently suppresses aliasing above Nyquist, reducing BOM count and board area |
| Programmable gain front end | Five discrete PGA gains enable optimal ADC utilization across five decades of input signal amplitude without recalibration |
| High CMRR and input impedance | 93 dB min CMRR at DC–1 kHz and 140 MΩ differential input impedance minimize sensor loading and common-mode interference |
| Jitter-tolerant clocking | 300 ps jitter tolerance allows use with low-cost crystal oscillators or microcontroller-generated clocks without SNR degradation |
| Low-power standby modes | 650 µW power-down current and PGA-specific standby (56 mW) extend battery life in intermittent-sampling applications |
Applications
| Seismic Data Acquisition | Chromatography Systems |
|---|---|
Use Scenario: High-resolution recording of ground motion using geophone arrays deployed in remote field locations. IC Role / Device Role / Timing Role: Primary sigma-delta modulator capturing low-frequency (<100 Hz), microvolt-level seismic signals with >116 dB DR and minimal thermal drift. Use Value: Enables detection of sub-10 nV signals at 250 Hz output word rate, supporting 146 dB system dynamic range when paired with AD1556 at FO = 250 Hz. | Use Scenario: Precision analog signal digitization from electrochemical detectors in gas/liquid chromatographs. IC Role / Device Role / Timing Role: Front-end modulator converting picoampere-level detector currents (via transimpedance amp) into noise-immune bitstream for digital filtering. Use Value: 80 nV rms input noise at PGA gain = 128 ensures accurate peak integration of low-amplitude analyte elution signals. |
| Automatic Test Equipment | High-Accuracy Calibration Standards |
Use Scenario: Modular instrumentation for metrology-grade voltage/current source verification and DMM calibration. IC Role / Device Role / Timing Role: Reference-grade modulator in self-calibrating ADC subsystem, leveraging internal full-scale reference and test inputs (TIN). Use Value: ±3.5% absolute gain error and <6 µV/°C offset drift support traceable calibration without frequent external reference updates. | Use Scenario: Embedded reference in portable calibrators requiring long-term stability and low power in battery-operated field tools. IC Role / Device Role / Timing Role: Low-drift, low-noise modulator serving as primary digitizer for precision voltage standards with 0.001% accuracy targets. Use Value: –55°C to +85°C operation with <15 ppm/°C gain stability ensures specification compliance across environmental chambers and field deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar sigma-delta modulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AD7768-1BCPZ | 8-channel, 24-bit, 128 kSPS per channel; integrated buffer and reference; SPI interface only; no PGA | Multi-sensor synchronous acquisition; eliminates need for external multiplexing but lacks programmable gain | Select AD7768-1BCPZ when channel density and integrated buffering outweigh need for on-chip PGA flexibility |
| ADS127L11IPWR | Single-channel, 24-bit, 400 kSPS; fixed gain of 1; lower noise (4.2 µV rms) but no PGA; uses external reference | Ultra-low-noise DC measurements where signal amplitude is tightly constrained and external gain is acceptable | Select ADS127L11IPWR when maximum SNR at fixed gain is prioritized over input range adaptability |
Compared with AD1555BPZ, AD7768-1BCPZ offers higher channel count and integrated resources but sacrifices PGA configurability, while ADS127L11IPWR achieves lower noise at fixed gain but requires external signal conditioning - making AD1555BPZ uniquely suited for variable-amplitude, low-frequency, single-channel precision measurement with minimal external components.
Availability
AD1555BPZ is available at Aetrix Electronics and suitable for seismic monitoring, chromatography instrumentation, and automatic test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for AD1555BPZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.
The AD1555BPZ belongs to Analog Devices' precision sigma-delta converter product line, engineered specifically for geophysical, analytical, and metrology applications demanding ultra-low noise, wide dynamic range, and robust operation in extreme environments.
FAQ
What is the operating temperature range specified for the AD1555BPZ?
The AD1555BPZ is rated for operation from –55°C to +85°C, meeting extended industrial and geophysical environmental requirements. This grade (B) differs from the AD1555AP (0°C to +85°C) and is verified per the ordering guide and specifications table on page –9 of the AD1555/AD1556 Rev. B datasheet. Thermal performance data, including dynamic range vs. temperature (TPC 4), confirms stable operation across this full range.
Does the AD1555BPZ require an external antialias filter?
No, the AD1555BPZ does not require an external antialias filter. Its continuous-time analog modulator architecture inherently attenuates out-of-band signals, as confirmed in the General Description ("continuous-time analog modulator input architecture avoids the need for an external antialias filter") and Functional Block Diagram. This eliminates passive filter components and associated phase distortion or board space.
How is the PGA gain configured on the AD1555BPZ?
The PGA gain on AD1555BPZ is configured using digital logic levels applied to pins CB0 through CB4. Specifically, CB0–CB2 set the gain value (1, 2.5, 8.5, 34, or 128) per Table III, while CB3–CB4 select the input mux source (AIN, TIN, internal ground, or internal reference). Configuration occurs at power-up or after RESET, and is detailed in the AD1555 PIN FUNCTION DESCRIPTIONS section (page –10).
What reference voltage does the AD1555BPZ require?
The AD1555BPZ requires a 3.0 V ±10 mV reference voltage applied to the REFIN pin (Pin 25). This voltage is internally divided to generate the modulator reference. The datasheet recommends the AD780BR as a compatible reference, and specifies that a 22 µF tantalum capacitor must be connected from REFCAP1 (Pin 23) to AGND3 (Pin 22) to ensure low-noise operation.
Can the AD1555BPZ operate independently without the AD1556?
Yes, the AD1555BPZ can operate independently as a standalone sigma-delta modulator, outputting a ones-density bitstream on MDATA (Pin 17). However, it does not perform digital filtering or decimation - those functions require the AD1556 or an external FPGA/DSP. The AD1555BPZ is optimized for use with AD1556 to form a complete 24-bit ADC, but bitstream output enables custom digital processing if needed.
AD1555BPZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Number of Bits:
- 24
- Sampling Rate (Per Second):
- 256k
- Number of Inputs:
- 2
- Input Type:
- Differential
- Data Interface:
- SPI
- Configuration:
- MUX-PGA-ADC
- Ratio - S/H:ADC:
- -
- Number of A/D Converters:
- 1
- Architecture:
- Sigma-Delta
- Reference Type:
- External, Internal
- Voltage - Supply, Analog:
- ±5V
- Voltage - Supply, Digital:
- 5V
- Features:
- PGA
- Operating Temperature:
- -55°C ~ 85°C
- Supplier Device Package:
- 28-PLCC (11.51x11.51)
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
AD1555BPZ FAQ
1.How can I place an order for AD1555BPZ through Aetrix?
Please submit a Request for Quotation (RFQ) for AD1555BPZ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AD1555BPZ reliable?
The price and inventory of AD1555BPZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AD1555BPZ is usually 5 days.
3.What payment methods are accepted for AD1555BPZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AD1555BPZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AD1555BPZ?
AD1555BPZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AD1555BPZ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AD1555BPZ?
For technical support, including AD1555BPZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AD1555BPZ requirements.
6.How does Aetrix verify that AD1555BPZ is sourced from the original manufacturer or authorized distributors?
All AD1555BPZ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AD1555BPZ meets industry standards.
7.What is the process for return or replacement of AD1555BPZ?
All AD1555BPZ units undergo pre-shipment inspection (PSI). If there is an issue with AD1555BPZ, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AD1555BPZ part is unused and in its original packaging.
Return procedure for AD1555BPZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AD1555BPZ Tags
-
ADC081C021CIMKX/NOPB
Texas Instruments
-
MCP3021A5T-E/OT
Microchip Technology
-
TLA2024IRUGR
Texas Instruments
-
MCP3221A5T-E/OT
Microchip Technology
-
MCP3221A5T-I/OT
Microchip Technology
-
MCP3221A4T-E/OT
Microchip Technology
-
MCP3221A6T-E/OT
Microchip Technology
-
MCP3221A0T-E/OT
Microchip Technology
-
MCP3221A1T-E/OT
Microchip Technology
-
ADC121S021CIMFX/NOPB
Texas Instruments
-
MCP3001-I/MS
Microchip Technology
-
MCP3001-I/SN
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
