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Analog Devices Inc. AD7940BRJZ-REEL7
- Part No.:
- AD7940BRJZ-REEL7
- Manufacturer:
- Analog Devices Inc.
- Category:
- Analog to Digital Converters (ADC)
- Package:
- SOT-23-6
- Datasheet:
-
AD7940BRJZ-REEL7.pdf
- Description:
- IC ADC 14BIT SAR SOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:6,015
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Product details
Overview
AD7940BRJZ-REEL7 from Analog Devices is a 14-bit, single-supply successive approximation ADC in a 6-lead SOT-23 package, operating from 2.5 V to 5.5 V with 100 kSPS throughput, 81 dB SINAD at 10 kHz, and internal VDD-referenced input range (0 V to VDD). It serves as a compact, low-power analog-to-digital converter for space-constrained battery-powered signal acquisition.
For engineers reviewing the AD7940BRJZ-REEL7 datasheet, AD7940BRJZ-REEL7 pinout, AD7940BRJZ-REEL7 application, or AD7940BRJZ-REEL7 equivalent, key selection considerations include its SOT-23 footprint, CS-initiated conversion timing, no-pipeline-delay operation, 0.5 µA shutdown current, and SPI/QSPI/MICROWIRE-compatible serial interface.
Technical Context
The AD7940BRJZ-REEL7 implements a capacitive DAC-based successive approximation architecture with a track-and-hold amplifier supporting >7 MHz full-power bandwidth. Conversion is triggered on the falling edge of CS and synchronized to SCLK, requiring exactly 16 clock cycles with no pipeline latency.
It uses an internal reference derived directly from VDD, eliminating external reference components and enabling a 0 V to VDD unipolar input range. Power management includes normal mode (1.9 mA at 3.6 V/100 kSPS) and full power-down mode (0.3 µA at 3.6 V), controlled exclusively via CS timing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 14-bit minimum; guarantees monotonic transfer function and ≥16,384 distinct output codes over full temperature range. |
| Throughput Rate | 100 kSPS maximum; achieved with 2.5 MHz SCLK and CS-controlled conversion initiation-no overhead or latency between samples. |
| SINAD | 81 dB minimum at 10 kHz input; ensures high-fidelity digitization for medium-bandwidth sensor and instrumentation signals. |
| Supply Range | 2.50 V to 5.5 V; supports direct connection to common Li-ion, 3.3 V, and 5 V system rails without LDO regulation. |
| Shutdown Current | 0.3 µA maximum at 3.6 V; enables microamp-level system sleep states in portable devices between acquisitions. |
| Input Range | 0 V to VDD; eliminates need for level-shifting circuitry when interfacing with rail-to-rail sensors or op-amps. |
| Serial Interface | SPI/QSPI/MICROWIRE/DSP compatible; outputs 16-bit frame (2 leading zeros + 14-bit MSB-first data) on SDATA with SCLK falling-edge timing. |
Pinout & Package
AD7940BRJZ-REEL7 is housed in a RoHS-compliant, lead-free 6-lead SOT-23 package (JEDEC MO-178AA), measuring 2.9 mm × 1.6 mm × 1.1 mm, optimized for high-density PCB layouts in portable electronics.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD (Pin 1) | Power supply input | Single 2.5 V–5.5 V supply powering both analog and digital sections; also serves as internal reference source. |
| GND (Pin 2) | Analog ground reference | Common return path for all analog circuitry; must be connected to low-impedance system ground plane to maintain DC accuracy and noise immunity. |
| VIN (Pin 3) | Analog input channel | Single-ended input accepting 0 V to VDD signals; features 30 pF input capacitance and ±0.3 µA leakage-requires low-impedance drive for optimal THD. |
| SCLK (Pin 4) | Serial clock input | Asynchronous logic input controlling conversion timing and data clocking; accepts up to 2.5 MHz; not limited by VDD + 0.3 V. |
| SDATA (Pin 5) | Serial data output | Three-state CMOS output delivering 16-bit frame (MSB first); transitions occur on SCLK falling edge; voltage swing = 0 V to VDD. |
| CS (Pin 6) | Chip select / conversion trigger | Active-low signal initiating sampling on falling edge; determines normal vs. power-down mode based on deassertion timing relative to SCLK edges. |
Key Features
| Feature | Design Value |
|---|---|
| First 14-bit ADC in SOT-23 | Enables ultra-compact signal chain integration-replaces larger MSOP or SOIC ADCs without sacrificing resolution or speed. |
| No pipeline delay | Delivers deterministic, sample-accurate timing: conversion completes in fixed 8 µs (16 × SCLK), critical for real-time control loops. |
| VDD-referenced architecture | Removes external reference IC and associated decoupling, reducing BOM count and layout area while maintaining 0 V to VDD dynamic range. |
| Flexible power management | CS-driven power-down allows dynamic current scaling: 1.9 mA during conversion → 0.3 µA idle, optimizing energy per sample in burst-mode systems. |
| SPI-compatible serial interface | Interoperates with standard microcontroller peripherals (e.g., STM32 SPI, MSP430 USCI) without protocol translation or glue logic. |
Applications
| Battery-Powered Data Loggers | Portable Medical Sensors |
|---|---|
|
Use Scenario: Continuous 10 kHz ECG waveform capture in handheld vital sign monitors with 72-hour battery life. IC Role / Device Role / Timing Role: Primary analog front-end digitizer acquiring single-ended biopotential signals with minimal power overhead between samples. Use Value: 0.3 µA shutdown current extends battery life; 81 dB SINAD preserves diagnostic fidelity; SOT-23 footprint saves >40% board area versus MSOP alternatives. |
Use Scenario: Blood glucose meter using amperometric sensor with ratiometric measurement against internal VDD reference. IC Role / Device Role / Timing Role: Unipolar ADC converting current-to-voltage output with inherent VDD tracking to reject supply ripple. Use Value: VDD-referenced input eliminates separate precision reference, reducing cost and calibration complexity while maintaining ±1 LSB INL. |
| Remote Industrial Sensor Nodes | Low-Power IoT Edge Devices |
|
Use Scenario: Wireless temperature/humidity node transmitting every 5 minutes using LoRaWAN, powered by coin-cell battery. IC Role / Device Role / Timing Role: Intermittent acquisition engine activated by MCU GPIO, converting thermistor and humidity IC analog outputs. Use Value: CS-controlled power-down reduces average current to <1 µA; 100 kSPS headroom supports oversampling for noise reduction in noisy factory environments. |
Use Scenario: Wearable activity tracker sampling accelerometer and ambient light sensor at 100 Hz with motion-triggered wake-up. IC Role / Device Role / Timing Role: Shared ADC resource for multiple analog sensors, managed via time-multiplexed CS assertion. Use Value: Single 6-pin SOT-23 replaces discrete mux + ADC solution; SPI compatibility simplifies firmware integration with Nordic nRF52 series MCUs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 14-bit SAR ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AD7942BRMZ-REEL | 8-lead MSOP package; pseudo-differential input; 250 kSPS max; requires external reference or VDD reference configuration. | Supports differential sensor interfaces (e.g., bridge transducers); higher throughput but larger footprint and added reference design complexity. | Select AD7942BRMZ-REEL only when differential input or >100 kSPS is required-AD7940BRJZ-REEL7 offers superior size/power trade-off for single-ended use cases. |
| ADS7822U | 8-lead SOIC; 12-bit resolution; 200 kSPS; external reference required; 3.3 V only supply. | Limited to lower-resolution applications where 12-bit quantization suffices; lacks VDD-referencing and SOT-23 miniaturization. | Choose ADS7822U only if legacy 12-bit performance is acceptable and SOIC packaging aligns with existing assembly processes-AD7940BRJZ-REEL7 delivers 4× more codes in half the area. |
Compared with AD7942BRMZ-REEL and ADS7822U, AD7940BRJZ-REEL7 uniquely combines 14-bit resolution, SOT-23 size, VDD referencing, and sub-µA shutdown-making it the only option that satisfies simultaneous constraints of miniaturization, precision, and ultra-low quiescent power in portable designs.
Availability
AD7940BRJZ-REEL7 is available at Aetrix Electronics and suitable for battery-powered systems, portable medical instruments, and remote data acquisition systems requiring stable component supply across long production lifecycles.
Supply support for AD7940BRJZ-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 AD7940 belongs to Analog Devices' precision SAR ADC product line, engineered specifically for space- and power-constrained applications demanding high resolution without external references or complex support circuitry.
FAQ
What is the absolute maximum analog input voltage for AD7940BRJZ-REEL7?
The absolute maximum analog input voltage for AD7940BRJZ-REEL7 is VDD + 0.3 V, as specified in the Absolute Maximum Ratings table. Exceeding this limit risks forward-biasing internal ESD diodes and causing irreversible damage. For safe operation, the analog input must remain within 0 V to VDD under normal conditions, with transient excursions strictly bounded by the ±0.3 V margin relative to supply rails.
Does AD7940BRJZ-REEL7 require an external reference voltage?
No, AD7940BRJZ-REEL7 does not require an external reference voltage. Its reference is derived internally from VDD, establishing a 0 V to VDD unipolar input range. This eliminates the need for external reference ICs, decoupling capacitors, and associated layout area-simplifying design and reducing BOM cost while maintaining guaranteed 14-bit linearity across temperature.
How is power-down mode entered and exited on AD7940BRJZ-REEL7?
Power-down mode on AD7940BRJZ-REEL7 is entered by pulling CS high between the 2nd and 10th falling edges of SCLK after conversion initiation. Exit requires a dummy conversion: assert CS low, apply ≥16 SCLK cycles, then read SDATA (which returns undefined data), after which the device resumes normal operation with full functionality. Total wake-up time is ≤1 µs.
What is the guaranteed integral nonlinearity (INL) specification for AD7940BRJZ-REEL7?
The guaranteed integral nonlinearity for AD7940BRJZ-REEL7 is ±1 LSB maximum when VDD is between 2.5 V and 4.096 V, and ±2 LSB maximum when VDD exceeds 4.096 V. This specification applies across the full operating temperature range (−40°C to +85°C) and ensures monotonic behavior and accurate end-point linearity for precision measurement applications.
Can AD7940BRJZ-REEL7 interface directly with 5 V logic microcontrollers?
Yes, AD7940BRJZ-REEL7 can interface directly with 5 V logic microcontrollers. Its digital inputs (CS, SCLK) tolerate voltages up to 7 V regardless of VDD, allowing 5 V logic levels even when VDD = 3 V. However, SDATA output remains rail-to-rail with respect to VDD-so a 3 V-powered AD7940BRJZ-REEL7 outputs 0 V–3 V logic, requiring level-shifting only if the MCU input threshold exceeds 2.0 V.
AD7940BRJZ-REEL7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- SOT-23-6
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Number of Bits:
- 14
- Sampling Rate (Per Second):
- 100k
- Number of Inputs:
- 1
- Input Type:
- Single Ended
- Data Interface:
- SPI, DSP
- Configuration:
- S/H-ADC
- Ratio - S/H:ADC:
- 1:1
- Number of A/D Converters:
- 1
- Architecture:
- SAR
- Reference Type:
- Supply
- Voltage - Supply, Analog:
- 2.5V ~ 5.5V
- Voltage - Supply, Digital:
- 2.5V ~ 5.5V
- Features:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- SOT-23-6
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
AD7940BRJZ-REEL7 FAQ
1.How can I place an order for AD7940BRJZ-REEL7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AD7940BRJZ-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 AD7940BRJZ-REEL7 reliable?
The price and inventory of AD7940BRJZ-REEL7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AD7940BRJZ-REEL7 is usually 5 days.
3.What payment methods are accepted for AD7940BRJZ-REEL7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AD7940BRJZ-REEL7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AD7940BRJZ-REEL7?
AD7940BRJZ-REEL7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AD7940BRJZ-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 AD7940BRJZ-REEL7?
For technical support, including AD7940BRJZ-REEL7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AD7940BRJZ-REEL7 requirements.
6.How does Aetrix verify that AD7940BRJZ-REEL7 is sourced from the original manufacturer or authorized distributors?
All AD7940BRJZ-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 AD7940BRJZ-REEL7 meets industry standards.
7.What is the process for return or replacement of AD7940BRJZ-REEL7?
All AD7940BRJZ-REEL7 units undergo pre-shipment inspection (PSI). If there is an issue with AD7940BRJZ-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 AD7940BRJZ-REEL7 part is unused and in its original packaging.
Return procedure for AD7940BRJZ-REEL7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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