My Inquiry
My Account
Analog Devices Inc. AD7938BCP-REEL7
- Part No.:
- AD7938BCP-REEL7
- Manufacturer:
- Analog Devices Inc.
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 32-VFQFN Exposed Pad, CSP
- Datasheet:
-
AD7938BCP-REEL7.pdf
- Description:
- IC ADC 12BIT 8CH 1.5MSPS 32LFCSP
- Quantity:
- Payment:
- Shipping:
Inventory:1,500
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AD7938BCP-REEL7 from Analog Devices is a 12-bit, 8-channel, 1.5 MSPS successive approximation register (SAR) analog-to-digital converter with integrated channel sequencer, on-chip 2.5 V reference (±0.2% @ 25°C), and parallel word/byte interface. It operates from a single 2.7 V to 5.25 V supply, consumes 6 mW at 3 V/1.5 MSPS, and supports single-ended, pseudo-differential, and fully differential input configurations. It is used in high-speed data acquisition systems requiring precise multi-channel sampling, such as industrial PLC analog input modules.
For engineers reviewing the AD7938BCP-REEL7 datasheet, AD7938BCP-REEL7 pinout, AD7938BCP-REEL7 application, or AD7938BCP-REEL7 equivalent, key selection criteria include its 12-bit resolution with ±1 LSB INL (differential mode), 69 dB SINAD at 50 kHz, 50 MHz full-power bandwidth, no pipeline delay, and software-configurable input modes via control register - all critical for time-critical, multi-sensor measurement systems.
Technical Context
The AD7938BCP-REEL7 implements a SAR architecture with a wide-bandwidth differential track-and-hold amplifier capable of handling input frequencies up to 50 MHz. Its sequencer enables preprogrammed, automatic conversion across eight analog inputs without host intervention.
It features dual-supply flexibility: VDD powers analog/digital circuitry (2.7–5.25 V), while VDRIVE independently sets I/O logic levels (2.7–5.25 V), enabling direct interfacing with 3 V or 5 V microprocessors. The on-chip 2.5 V reference has 25 ppm/°C max drift and can be overdriven by an external reference.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 12 bits - delivers 1 LSB = VREF/4096 quantization step; supports precise sensor signal digitization in industrial monitoring. |
| Throughput Rate | 1.5 MSPS - enables real-time capture of fast transients across 8 channels with sequenced auto-conversion. |
| SINAD | 69 dB min @ 50 kHz (differential mode) - ensures >11.2 effective bits for clean spectral analysis in motor control feedback loops. |
| INL | ±1 LSB max (differential mode) - guarantees monotonicity and no missing codes up to full 12-bit range. |
| Reference Accuracy | ±0.2% max @ 25°C, 25 ppm/°C max - eliminates need for external precision reference in cost-sensitive DAQ designs. |
| Power Dissipation | 6 mW max @ 3 V / 1.5 MSPS - enables thermally constrained embedded systems with minimal heat sink requirements. |
| Full-Power Bandwidth | 50 MHz @ 3 dB - supports accurate digitization of fast-rising signals like PWM edge detection or ultrasonic echo returns. |
Pinout & Package
AD7938BCP-REEL7 is housed in a 32-lead LFCSP (Lead Frame Chip Scale Package) with exposed pad, optimized for low-inductance grounding and thermal performance in high-density PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| DB0–DB11 | Parallel data bus (12-bit) | Three-state outputs deliver conversion result; DB8/HBEN doubles as high-byte enable in byte mode - enables flexible 8-/16-bit host interfacing. |
| CONVST | Conversion start trigger | Falling-edge initiated sampling and conversion; controls T/H transition - provides deterministic, jitter-free sampling timing. |
| BUSY | Conversion status indicator | Active-high open-drain output signals conversion progress - allows polling or interrupt-driven readout without clock synchronization overhead. |
| VREFIN/VREFOUT | Reference input/output | Supplies or accepts 2.5 V reference; internal buffer supports 10 Ω output impedance - simplifies decoupling (470 nF to AGND) and enables external reference override. |
| VDRIVE | I/O voltage rail | Sets logic threshold for DBx, RD, WR, CS - permits independent 3 V/5 V I/O interfacing while VDD powers analog core at optimal voltage. |
Key Features
| Feature | Design Value |
|---|---|
| 8-channel sequencer with software configuration | Reduces host CPU load by automating round-robin or custom channel scan sequences - ideal for unattended sensor arrays. |
| Single-supply operation with VDRIVE decoupling | Eliminates level-shifter ICs when connecting to mixed-voltage processors - lowers BOM count and layout complexity. |
| No pipeline delay | Delivers first valid sample after one conversion cycle (tCONV = t2 + 13×tCLKIN) - essential for closed-loop control where latency must be bounded and predictable. |
| Configurable input types (SE/pseudo-diff/full-diff) | Enables reuse across diverse sensor topologies (e.g., RTD 2-wire SE, strain gauge full-diff) without hardware change - improves design flexibility and reduces variant SKUs. |
| Autostandby and full shutdown modes | Reduces IDD to 160 µA (autostandby) or 2 µA (shutdown) - extends battery life in portable test equipment between measurement bursts. |
Applications
| Industrial PLC Analog Input Module | Motor Drive Current Sensing |
|---|---|
Use Scenario: Digitizing 8 channels of 4–20 mA current loop signals from field sensors in a programmable logic controller rack. IC Role / Device Role / Timing Role: Primary ADC performing synchronized, sequenced sampling of isolated analog inputs with <100 ns aperture jitter. Use Value: 12-bit resolution and ±1 LSB INL ensure <0.025% reading accuracy across temperature; 1.5 MSPS throughput allows oversampling for noise reduction in noisy factory environments. | Use Scenario: Measuring phase currents in a 3-phase inverter using shunt resistors with differential amplification. IC Role / Device Role / Timing Role: High-speed SAR ADC capturing simultaneous current samples for field-oriented control (FOC) algorithms. Use Value: 50 MHz full-power bandwidth and 69 dB SINAD preserve harmonic content of fast-switching PWM waveforms; no pipeline delay enables tight current-loop timing budgets. |
| Medical Patient Monitor Front-End | Automated Test Equipment (ATE) Channel Card |
Use Scenario: Acquiring ECG, respiration, and temperature signals from multiple patient leads in a multi-parameter bedside monitor. IC Role / Device Role / Timing Role: Multi-channel ADC providing isolated, low-noise digitization with on-chip 2.5 V reference for consistent calibration. Use Value: Integrated 2.5 V reference (±0.2% @ 25°C) eliminates external reference drift errors; low 6 mW power enables fanless enclosure design. | Use Scenario: High-throughput digital I/O card in ATE systems requiring rapid sampling across 8 DUT signal lines. IC Role / Device Role / Timing Role: Parallel-interface ADC delivering burst-mode sampled data to FPGA-based pattern generator/analyzers. Use Value: Word/byte parallel interface with BUSY handshake enables >1 MSPS sustained data transfer; 32-lead LFCSP package supports dense channel packing per board area. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed multi-channel SAR ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AD7939BCP-REEL7 | 10-bit resolution, same 8-channel sequencer, identical package and pinout, lower power (5.5 mW @ 3 V) | Lower resolution suitable for cost-sensitive applications where 10-bit accuracy suffices (e.g., basic temperature logging) | Select when system SNR requirements are ≤61 dB and BOM cost reduction is prioritized over precision. |
| AD7682BCPZ-RL7 | 16-bit, 4-channel, 250 kSPS, SPI interface, no on-chip reference, requires external REF | Higher resolution but lower speed and channel count; serial interface reduces PCB routing density | Select when ultra-high precision (16-bit) is required for static measurements and lower throughput is acceptable. |
Compared with AD7938BCP-REEL7, AD7939BCP-REEL7 trades 2 bits of resolution for lower cost and power, while AD7682BCPZ-RL7 sacrifices speed and channel count for 16-bit accuracy and serial simplicity - making AD7938BCP-REEL7 the optimal balance of speed, channel density, and 12-bit fidelity in parallel-interfaced industrial DAQ.
Availability
AD7938BCP-REEL7 is available at Aetrix Electronics and suitable for industrial PLC analog input modules, motor drive current sensing, medical patient monitor front-ends, and automated test equipment channel cards requiring stable component supply and long-term production continuity.
Supply support for AD7938BCP-REEL7 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, headquartered in Norwood, MA.
The AD7938 is part of Analog Devices' precision SAR ADC product line, designed specifically for high-speed, multi-channel data acquisition in industrial automation, energy metering, and medical instrumentation where accuracy, speed, and integration are critical.
FAQ
What is the maximum sampling rate supported by the AD7938BCP-REEL7?
The AD7938BCP-REEL7 supports a maximum throughput rate of 1.5 MSPS, achieved with a 25.5 MHz master clock (CLKIN). Conversion time is fixed at 13 clock cycles plus setup time (t₂), yielding deterministic latency. This rate applies across all 8 channels when using the internal sequencer, enabling high-fidelity capture of fast transient events in real-time control systems. The AD7938BCP-REEL7 maintains this performance across its full operating temperature range (−40°C to +85°C).
Does the AD7938BCP-REEL7 require an external reference voltage?
No, the AD7938BCP-REEL7 includes an accurate on-chip 2.5 V reference with ±0.2% maximum error at 25°C and 25 ppm/°C maximum temperature coefficient. This internal reference is sufficient for most precision applications and eliminates the need for an external reference IC. However, the VREFIN/VREFOUT pin can be overdriven with an external reference (0.1 V to VDD) if tighter accuracy or custom voltage scaling is required. The AD7938BCP-REEL7 uses this reference for both conversion and internal bias generation.
How does the AD7938BCP-REEL7 handle analog input configurations?
The AD7938BCP-REEL7 supports three analog input modes - single-ended, pseudo-differential, and fully differential - selected via the RANGE and CODING bits in its control register. Single-ended mode accepts 0 to VREF or 0 to 2×VREF inputs; pseudo-differential allows VIN− to swing within −0.3 V to +1.8 V (VDD = 5 V); fully differential uses twos-complement coding with common-mode ranges centered at VREF/2 or VREF. All modes are software-configurable without hardware changes, enabling flexible sensor interface adaptation in the AD7938BCP-REEL7.
What package type is used for the AD7938BCP-REEL7?
The AD7938BCP-REEL7 is packaged in a 32-lead LFCSP (Lead Frame Chip Scale Package) with exposed thermal pad (CP-32-7 footprint), as confirmed in Revision F of the datasheet. This package offers low thermal resistance (θJA = 108.2°C/W), compact size (5 mm × 5 mm), and enhanced high-frequency performance due to minimized lead inductance. The exposed pad must be soldered to the PCB ground plane using multiple vias for optimal thermal dissipation and noise immunity in the AD7938BCP-REEL7.
Can the AD7938BCP-REEL7 interface directly with a 3 V microcontroller?
Yes, the AD7938BCP-REEL7 supports direct interfacing with 3 V microcontrollers via its VDRIVE pin, which independently sets the logic voltage level for the parallel data bus (DB0–DB11), RD, WR, and CS signals. When VDRIVE = 3 V, the AD7938BCP-REEL7 outputs are compatible with 3 V CMOS logic thresholds (VIH ≥ 2.4 V, VIL ≤ 0.8 V), while VDD may be set to 5 V for optimal analog performance. This eliminates level shifters and simplifies interconnect in mixed-voltage systems using the AD7938BCP-REEL7.
AD7938BCP-REEL7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 32-VFQFN Exposed Pad, CSP
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Number of Bits:
- 12
- Sampling Rate (Per Second):
- 1.5M
- Number of Inputs:
- -
- Input Type:
- -
- Data Interface:
- Parallel
- Configuration:
- -
- Ratio - S/H:ADC:
- -
- Number of A/D Converters:
- 1
- Architecture:
- -
- Reference Type:
- -
- Voltage - Supply, Analog:
- -
- Voltage - Supply, Digital:
- -
- Features:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 32-LFCSP-VQ (5x5)
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
AD7938BCP-REEL7 FAQ
1.How can I place an order for AD7938BCP-REEL7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AD7938BCP-REEL7 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 AD7938BCP-REEL7 reliable?
The price and inventory of AD7938BCP-REEL7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AD7938BCP-REEL7 is usually 5 days.
3.What payment methods are accepted for AD7938BCP-REEL7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AD7938BCP-REEL7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AD7938BCP-REEL7?
AD7938BCP-REEL7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AD7938BCP-REEL7 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 AD7938BCP-REEL7?
For technical support, including AD7938BCP-REEL7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AD7938BCP-REEL7 requirements.
6.How does Aetrix verify that AD7938BCP-REEL7 is sourced from the original manufacturer or authorized distributors?
All AD7938BCP-REEL7 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 AD7938BCP-REEL7 meets industry standards.
7.What is the process for return or replacement of AD7938BCP-REEL7?
All AD7938BCP-REEL7 units undergo pre-shipment inspection (PSI). If there is an issue with AD7938BCP-REEL7, 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 AD7938BCP-REEL7 part is unused and in its original packaging.
Return procedure for AD7938BCP-REEL7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AD7938BCP-REEL7 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…
