ADS8508IBDWRG4 - 12-Bit 250kSPS Serial CMOS ADC | Texas Instruments
MPN: ADS8508IBDWRG4 ✓ פעילADS8508IBDWRG4 סקירה
An SAR ADC is a type of data converter that uses a binary-search successive approximation algorithm to digitize an analog input one bit at a time per clock cycle. SAR converters sit in the broader hierarchy: ADC -> data converter -> signal-chain IC -> mixed-signal semiconductor. They are valued for low latency, deterministic behavior, and excellent DC accuracy, making them a popular alternative to delta-sigma and pipeline architectures in multiplexed data-acquisition systems.
Key features include 250 kHz throughput, hardware- or software-controlled conversion start, an external/internal clock select for the serial data frame, and TAG-input capability for multi-channel systems. The internal reference is trimmed for low drift, and the bipolar input range eliminates external signal-conditioning in industrial ±10V or ±5V transducer interfaces. The serial interface (SPI-/QSPI-/Microwire-compatible) reduces board-routing complexity versus parallel ADCs.
Typical applications include industrial process control (4-20 mA loop digitization), multi-channel data-acquisition front ends, portable instrumentation, and test/measurement equipment. The wide input range supports direct connection to transducers, sensors, and bipolar signal sources without external op-amp scaling.
When designing with this device, ensure the analog and digital grounds are tied at the package via a low-impedance star connection, and place 10 µF + 0.1 µF decoupling on AVDD+ and DVDD. The BW pad is the bipolar common-mode return; keep its trace short. Do not exceed 7 V absolute on analog inputs without external clamping.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
חלופות תחליף ישיר עבור ADS8508IBDWRG4 — אותו מארז, תואם פין-לפין. חלקים במארז שונה הדורשים עיבוד מחדש של ה-PCB אינם נכללים.
וריאנטים בסדרה זו
דגמים מאותה סדרה התואמים Drop-in עם ADS8508IBDWRG4 (אותו גורם צורה וטביעת רגל) — שונים ב Package, Sampling Rate, Resolution, Operating Temperature, Analog Supply Voltage.
ADS8508IBDW
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
ADS8509IDW
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
ADS8509IDWG4
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
ADS8505IDBRG4
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←ADS8507IBDWR
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
ADS7813PGU
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
ADS8508IBDWRG4 דירוגים מרביים ומאפיינים חשמליים
| רזולוציה | 12 bit |
| Number of Inputs | 1 |
| קצב דגימה | 250 kSPS |
| Architecture | SAR (Successive Approximation Register) |
| Input Voltage Ranges | ±3.33 V, ±5 V, ±10 V |
| Input Channel Type | Single-ended, bipolar |
| SINAD | 73 dB |
| Linearity Error (Max) | 0.011% |
| ממשק | Serial (SPI/QSPI/Microwire compatible) |
| Analog Supply Voltage | 5 V nominal |
| Digital Supply Voltage | 5 V nominal |
| Internal Reference | 2.5 V |
| טמפרטורת פעולה | -40 °C to +85 °C (Industrial) |
| מארז | 20-SOIC (DW), wide-body, green (RoHS) |
| סוג הרכבה | Surface Mount |
| סטטוס RoHS | Compliant (Pb-Free) |
תצורת פינים של ADS8508IBDWRG4
| פין 1 | R1 — Range select input 1 (sets ±10 V / ±5 V / ±3.33 V input range) |
| פין 2 | R2 — Range select input 2 (sets ±10 V / ±5 V / ±3.33 V input range) |
| פין 3 | BW — Bipolar input common-mode return / signal return |
| פין 4 | GND — Analog ground |
| פין 5 | REF — Reference decoupling / external reference input (2.5 V internal) |
| פין 6 | AGND — Analog ground (second pin) |
| פין 7 | IN+ — Analog input positive |
| פין 8 | IN- — Analog input negative |
| פין 9 | CAP — Reference bypass capacitor |
| פין 10 | CAP2 — Reference bypass capacitor 2 |
| פין 11 | AGND2 — Analog ground (third pin) |
| פין 12 | AVDD — Analog +5 V supply |
| פין 13 | TAG — Tag input for multi-channel systems (tie low for normal operation) |
| פין 14 | EXT/INT — Clock select: external or internal data clock (tie high for external) |
| פין 15 | RVS — Reverse data output select |
| פין 16 | SDO — Serial data output |
| פין 17 | DVDD — Digital +5 V supply |
| פין 18 | DGND — Digital ground |
| פין 19 | SCLK — Serial clock input |
| פין 20 | CS — Chip select (active low) / CONVST (start of conversion) |
יישומים טיפוסיים
ADS8508IBDWRG4 מתאים עבור 6 יישוםs: Industrial Process Control / 4-20 mA Loop Digitization, Multi-Channel Data Acquisition Front Ends, Portable Instrumentation and Test Equipment, Medical Patient Monitoring Equipment, Power Metering and Energy Monitoring, Automotive Sensor Interface Modules.
Industrial Process Control / 4-20 mA Loop Digitization
The ADS8508IBDWRG4's on-chip input divider accepts ±10 V directly from a 4-20 mA sense resistor, eliminating external signal-conditioning op-amps in industrial PLCs and DCS modules. With 73 dB SINAD (roughly 11.8 ENOB) and 250 kSPS throughput, the SAR architecture delivers deterministic single-shot latency under 5 µs - critical for closed-loop control where delta-sigma group delay would degrade loop stability. The internal 2.5 V reference saves a board component, while the wide SOIC-20 package tolerates factory-floor thermal and ESD stress common in process-control racks. Pair the part with a small SPI-compatible microcontroller and digital isolator for a complete isolated multi-channel acquisition front end.
מומלץ
Multi-Channel Data Acquisition Front Ends
In multiplexed 8- or 16-channel DAQ boards, the ADS8508IBDWRG4 pairs with an external analog multiplexer to digitize multiple sensor lines at a combined throughput up to 250 kSPS. The SAR architecture settles to 12 bits within one acquisition cycle, which is essential when scanning between channels - delta-sigma converters require additional filter settling time and limit channel-switching speed. The SPI-compatible serial output minimizes digital routing on high-channel-count boards, and the SOIC-20 wide-body footprint is footprint-compatible with the 16-bit ADS8505IDBRG4 upgrade, enabling a single PCB design to scale from 12-bit to 16-bit resolution without layout changes. Industrial temperature grade ensures operation in -40 °C to +85 °C enclosure environments.
מומלץ
Portable Instrumentation and Test Equipment
Battery-powered digital multimeters, portable oscilloscope front ends, and handheld calibrators benefit from the ADS8508IBDWRG4's single 5 V supply operation and modest 10 mW power consumption, extending runtime in field instruments. The serial interface reduces controller pin count, allowing small QFN microcontrollers to manage acquisition, display, and user I/O simultaneously. With 73 dB SINAD, the part delivers laboratory-class dynamic range for transducer calibration and sensor verification. The wide -40 °C to +85 °C industrial temperature range supports both indoor lab and outdoor field operation, while the SOIC-20 wide-body package allows hand-rework and field serviceability. Combined with low BOM cost from the integrated reference, this ADC enables handheld tools at a competitive price point.
מומלץ
Medical Patient Monitoring Equipment
Patient monitoring systems such as bedside multi-parameter monitors and ambulatory ECG recorders require 12-bit accuracy for waveform digitization at low sampling rates. The ADS8508IBDWRG4's 250 kSPS throughput easily handles multi-lead ECG at 500 Hz per channel, and its SAR architecture produces no digital-filter group delay that would distort transient waveform features like QRS complexes. The ±10 V input range accommodates direct connection to instrumentation-amp outputs without further scaling. Industrial temperature grade and SOIC-20 wide-body packaging support medical device enclosures with adequate thermal margin. The internal reference reduces BOM and is adequate for the calibration intervals typical of patient monitoring. Note that for diagnostic-grade ECG, the 16-bit ADS8505IDBRG4 upgrade offers higher resolution in the same footprint.
מומלץ
Power Metering and Energy Monitoring
Smart electricity meters and power-quality analyzers use the ADS8508IBDWRG4 to digitize current- and voltage-sense signals with ±10 V range, capturing peak transients and harmonic content. The SAR architecture's 250 kSPS throughput supports sampling fundamental 50/60 Hz waveforms at thousands of samples per cycle, sufficient for FFT-based harmonic analysis up to the 50th harmonic. The 73 dB SINAD ensures accurate true-RMS power computation across dynamic load ranges. Industrial temperature grade handles meter enclosure environments up to +85 °C, and the SOIC-20 wide-body package eases automated assembly and field serviceability. The integrated 2.5 V reference keeps BOM lean for cost-driven residential meter designs, while the serial interface minimizes pin count when interfacing with low-cost metrology microcontrollers.
מומלץ
Automotive Sensor Interface Modules
Although not AEC-Q100 qualified itself, the ADS8508IBDWRG4 is widely used in non-safety automotive test and diagnostic equipment, dealer service tools, and aftermarket sensor-interface modules where industrial -40 °C to +85 °C operation meets underhood and inside-cabin thermal envelopes. The ±10 V input range handles 0-5 V and 0-10 V automotive sensor outputs including pressure transducers and position sensors, while 73 dB SINAD supports 12-bit precision required for engine-control calibration. The SAR architecture's deterministic conversion time simplifies ISO 26262 timing analysis for diagnostic tools that interact with vehicle networks. The SOIC-20 wide-body package provides mechanical robustness against vibration, and the integrated reference reduces calibration drift in mobile service environments.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור ADS8508IBDWRG4 — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה | ADS8508IBDW | ADS8509IDW | ADS8509IDWG4 | ADS8505IDBRG4 | ADS8507IBDWR | ADS7813PGU |
|---|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 20-SOIC (DW), wide-body | 20-SOIC (DW), wide-body - same | 20-SOIC (DW), wide-body - same | 20-SOIC (DW), wide-body - same | 20-SOIC (DB), wide-body - same footprint | 20-SOIC (DW), wide-body - same | 20-SOIC (PGU) - same wide-body footprint |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 16 bit | 14 bit | 12 bit |
| Sampling Rate | 250 kSPS | 250 kSPS | 250 kSPS | 250 kSPS | 500 kSPS | 40 kSPS | 40 kSPS |
| Input Range | ±3.33 V / ±5 V / ±10 V | ±3.33 V / ±5 V / ±10 V | ±3.33 V / ±5 V / ±10 V | ±3.33 V / ±5 V / ±10 V | 0 V to 4 V or ±5 V / ±10 V | ±5 V / ±10 V | ±5 V / ±10 V |
| Reference | Internal 2.5 V | Internal 2.5 V | External required | External required | Internal 2.5 V | Internal 2.5 V | External required |
| Interface | Serial (SPI/QSPI/Microwire) | Serial (SPI/QSPI/Microwire) | Serial (SPI/QSPI/Microwire) | Serial (SPI/QSPI/Microwire) | Serial (SPI/QSPI/Microwire) | Serial (SPI/QSPI/Microwire) | Parallel 12-bit |
| SINAD | 73 dB | 73 dB | 73 dB | 73 dB | 84 dB | 76 dB | 70 dB |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Lifecycle Status | Active | Active | Active | Active | Active | NRND | Active |
מבדילים עיקריים
- On-chip bipolar input divider for ±10 V direct digitization (לעומתADS8509IDW)
- Integrated 2.5 V reference eliminates external reference IC (לעומתADS7813PGU)
- Twice the sampling rate at the same package (לעומתADS8507IBDWR)
- 4x higher throughput than parallel-interface legacy alternatives (לעומתADS7805PG4)
הערות תכנון
The ADS8508IBDWRG4 requires a clean +5 V analog supply on AVDD (pin 12) and DVDD (pin 17). Place a 10 µF tantalum or ceramic bulk capacitor plus a 0.1 µF ceramic decoupling capacitor within 5 mm of each supply pin. According to TI, sharing AVDD and DVDD from the same supply without LC filtering degrades SINAD by 3-5 dB. Use a ferrite bead + 10 µF + 0.1 µF network to isolate the digital supply from the analog supply if both are sourced from the same rail.
Implement a star-ground connection at the package: tie AGND (pins 4, 6, 11) and DGND (pin 18) to a single low-impedance ground plane under the SOIC-20 wide-body package. According to the TI datasheet, separate analog and digital ground returns must converge at the device to avoid digital switching currents coupling into the analog input. Place the CAP and CAP2 reference bypass capacitors (pins 9, 10) directly between their respective pins and AGND with traces under 5 mm to minimize reference noise pickup.
Keep the analog input traces (IN+/IN-, pins 7/8) short and shielded with a guard trace tied to BW (pin 3) to reduce common-mode coupling. According to TI layout guidelines, the bipolar input divider is high-impedance (~10 kΩ effective) and is sensitive to leakage currents - clean the PCB after assembly and conformal coat if used in humid environments. Route the serial interface (CS, SCLK, SDO, EXT/INT) away from analog inputs to avoid digital-noise coupling into the analog path. Estimated: 5 mm trace length, 10 kΩ impedance, 50 mV max coupled noise.
Do not exceed ±15 V on the analog input pins without external clamping - the on-chip input divider survives ±25 V transient but fails at continuous ±30 V overvoltage. According to TI, driving the analog inputs with source impedances above 5 kΩ degrades AC performance; buffer the input with a low-offset op-amp (e.g., OPA227) if source impedance is high. Also, ensure CS transitions low for at least 30 ns before the rising edge of SCLK - shorter CS-to-SCLK timing breaks the first bit read.
For 250 kSPS continuous sampling, ensure SCLK runs at 10 MHz or higher to complete the 16-bit frame within the conversion window. According to TI timing specifications, SCLK period minimum is 100 ns (10 MHz) when using the internal data clock. Drive SCLK from a low-impedance microcontroller pin or external clock buffer; ringing on SCLK directly couples into SDO and produces bit errors. Estimated: at 10 MHz SCLK with 30 pF bus capacitance, keep driver source impedance below 50 Ω to maintain < 5 % overshoot.
מידע על תאימות
RoHS-compliant (Pb-free, green) per TI datasheet. Industrial temperature grade -40 °C to +85 °C. Not AEC-Q100 qualified; not suitable for automotive safety applications without additional qualification.
