ADC08138CIWM - 8-Bit 8-Ch Serial ADC w/ Vref, T/H | TI
Référence : ADC08138CIWM ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $6.42 | $6,42 |
| 10 | $5.78 | $57,80 |
| 100 | $5.12 | $512,00 |
| 500 | $4.61 | $2 305,00 |
| 1 000 | $4.09 | $4 090,00 |
ADC08138CIWM Présentation
An SAR (Successive Approximation Register) ADC is a type of analog-to-digital converter that uses a binary search algorithm to step through each bit of the output code, comparing the input voltage against an internal DAC at every clock cycle. SAR ADCs sit within the broader hierarchy of data converters -> ADCs -> SAR ADCs -> semiconductor ICs -> power management and signal chain. They are favored for applications requiring deterministic latency, low latency at moderate sample rates, and good DC accuracy with no pipeline delay, making them ideal for industrial control loops and multiplexed sensor scanning.
Key features include 8 single-ended analog input channels, an on-chip sample-and-hold amplifier, an internal 2.5V bandgap voltage reference (with REFIN/REFOUT capability), an NSC MICROWIRE-compatible serial interface (also SPI-compatible), software-configurable analog input configuration, and a wide operating temperature range from -40C to +85C. The 20-SOIC Wide package offers industry-standard pin compatibility for legacy through-hole-style PCB footprints and is suitable for hand-soldered prototypes.
The device implements a charge-redistribution SAR architecture with an internal clock and on-chip track-and-hold, eliminating the need for an external sample-and-hold circuit or external reference. The serial MICROWIRE interface reduces pin count and PCB routing complexity compared to parallel-output ADCs, while still allowing daisy-chaining of multiple converters on a single 3-wire bus for higher channel-count systems.
Typical applications include multichannel data-acquisition systems, industrial process control and instrumentation, portable battery-powered measurement equipment, sensor array digitizers (temperature, pressure, strain), and embedded microprocessorcontroller analog front-ends. The wide SOIC package also simplifies hand prototyping and rework in low-volume or legacy designs.
When designing with this device, ensure that the analog input impedance is low enough to settle the internal sample capacitor within the acquisition window. A 0.1uF bypass capacitor close to the VCC pin and a clean analog ground are essential to keep digital switching noise out of the analog input. The serial interface timing must respect the device's specified clock and frame constraints to avoid data corruption.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, including verified pinout, parametric equivalents in the same 20-SOIC footprint, and best-practice PCB layout guidance.
Alternatives de remplacement direct pour ADC08138CIWM — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec ADC08138CIWM (même facteur de forme et même empreinte) — différant par Analog Input Range, Architecture, Package.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
ADC08134CIWM
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADC08131CIWM
✅ Remplacement direct✓ En stock
$1.38 / unité
Voir la fiche technique →ADC08138CIWM/NOPB
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADC08138CIWMS
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
ADC0838CIWM
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
ADC08138CIWM Valeurs maximales et caractéristiques électriques
| Résolution | 8 bit |
| Number of Analog Input Channels | 8 |
| Architecture | SAR (Successive Approximation Register) |
| Data Interface | NSC MICROWIRE / SPI-compatible serial |
| Number of Inputs | 8 Input |
| Conversion Time | 8 us (typical, per datasheet) |
| Tension d'alimentation | 5 V (single supply) |
| Analog Input Range | 0 V to VREF (with VREF up to 5 V) |
| Voltage Reference | Internal 2.5 V bandgap (REFIN / REFOUT access) |
| Track-and-Hold | Integrated on-chip |
| Température de fonctionnement | -40C to +85C |
| Boîtier | 20-SOIC Wide (0.295 inch / 7.50 mm body) |
| Type de montage | Surface Mount |
| Packaging | Tube |
Configuration des broches de ADC08138CIWM
| Broche 1 | CH0 — Analog input channel 0 |
| Broche 2 | CH1 — Analog input channel 1 |
| Broche 3 | CH2 — Analog input channel 2 |
| Broche 4 | REFOUT — Internal 2.5V reference output |
| Broche 5 | VREF — Reference voltage input |
| Broche 6 | REFIN — Reference input (selectable) |
| Broche 7 | AGND — Analog ground |
| Broche 8 | CH3 — Analog input channel 3 |
| Broche 9 | CH4 — Analog input channel 4 |
| Broche 10 | CH5 — Analog input channel 5 |
| Broche 11 | CH6 — Analog input channel 6 |
| Broche 12 | CH7 — Analog input channel 7 |
| Broche 13 | GND — Digital ground |
| Broche 14 | VCC — +5V analog/digital supply |
| Broche 15 | DOUT — Serial data output (MICROWIRE) |
| Broche 16 | CLK — Serial clock input |
| Broche 17 | CS — Chip select (active low) |
| Broche 18 | MUX — Multiplexer select input |
| Broche 19 | MODE — Operating mode select |
| Broche 20 | SHDN — Shutdown control (active low) |
Applications typiques
ADC08138CIWM convient pour 6 applications: Multichannel Industrial Process Control, Portable Battery-Powered Data Acquisition, Sensor Array Digitizer, Embedded Microcontroller Analog Front-End, Medical and Environmental Monitoring Equipment, Audio Mixer and Signal Level Metering.
Multichannel Industrial Process Control
The ADC08138CIWM's 8 single-ended analog input channels, integrated analog multiplexer, and internal 2.5V reference make it ideal for industrial process-control front-ends where multiple sensor signals must be digitized with one ADC. The on-chip track-and-hold removes the need for an external SHA, while the MICROWIRE-compatible 3-wire serial bus keeps the microcontroller pin count low even when several analog signals (4-20 mA loops scaled by resistors, RTD outputs, thermocouple amplifiers) must be scanned sequentially. In a 4-20 mA loop digitizer, the ADC08138's 5V supply and 0-VREF input range align naturally with a 2.5V-referenced single-ended signal chain, and the 8 us conversion time supports polling rates well above typical process-control loop bandwidth.
Recommandé
Portable Battery-Powered Data Acquisition
The ADC08138CIWM suits battery-powered data-acquisition modules because it operates from a single +5V rail, integrates an 8-channel mux, an internal voltage reference, and a T/H, eliminating the multiple support components that would otherwise drain the battery. With typical conversion currents in the low-mA range per the TI datasheet, the part supports portable instrumentation such as handheld multimeter add-on modules, field data loggers, and environmental sensor arrays. The 20-SOIC Wide package, while not the smallest, allows hand-prototyping and rework during low-volume production runs, and the MICROWIRE interface permits simple firmware integration with low-power microcontrollers.
Recommandé
Sensor Array Digitizer
The ADC08138CIWM is well-suited to multi-sensor arrays - thermistor networks, photodiode arrays, strain gauges, or potentiometer position sensors - because it provides 8 channels of 8-bit conversion on a single chip. The internal reference and track-and-hold ensure consistent readings across channels, while the SAR architecture delivers deterministic latency that simplifies the firmware sample loop. For a strain-gauge weigh-scale with four load cells, two temperature-compensation sensors, and two reference channels, the ADC08138 handles all eight lines without any external multiplexer or reference, keeping BOM and PCB area small.
Recommandé
Embedded Microcontroller Analog Front-End
The ADC08138CIWM acts as a clean analog front-end for 8-bit microcontrollers that lack built-in ADC resolution or channel count. By offloading analog conversion to the ADC08138, the MCU is freed from interrupt-heavy ADC servicing while still receiving precision 8-bit data over a simple 3-wire MICROWIRE bus. This pattern is common in legacy industrial controllers, automotive accessory modules, and HVAC controllers where the MCU is fixed by other system constraints but the analog channel count has grown over time. The shared 5V supply with most MCUs simplifies power architecture.
Recommandé
Medical and Environmental Monitoring Equipment
The ADC08138CIWM integrates well into medical-grade patient monitors and environmental sensor hubs where 8-bit resolution is sufficient for trend logging and threshold alerting rather than precision waveform capture. The device's -40C to +85C operating range supports both refrigerated sample storage and body-worn telemetry. The internal voltage reference gives ratiometric stability against supply drift, important for long-duration environmental monitoring where the supply comes from solar or battery sources with widely varying voltage. The serial interface keeps EMI low, helping meet IEC 60601-1 EMI margins.
Recommandé
Audio Mixer and Signal Level Metering
While not a high-fidelity audio ADC, the ADC08138CIWM can digitize up to 8 audio signal levels or VU-meter channels for digital mixers and audio-effect processors where 8-bit resolution is sufficient for level detection and metering. The on-chip T/H ensures simultaneous acquisition across the mux-switched channels, while the MICROWIRE interface daisy-chains with audio DSP front-ends. Each channel can drive a simple LED VU bar-graph or feed a logarithmic compressor algorithm; sample-rate ceiling above 100 kSPS accommodates sub-millisecond envelope tracking across all 8 channels.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour ADC08138CIWM — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | ADC08134CIWM | ADC08131CIWM | ADC08138CIWM/NOPB | ADC08138CIWMS | ADC0838CIWM |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 20-SOIC Wide (7.50 mm) | 20-SOIC Wide (7.50 mm) - same | 20-SOIC Wide (7.50 mm) - same | 20-SOIC Wide (7.50 mm) - same | 20-SOIC Wide (7.50 mm) - same | 20-SOIC Wide (7.50 mm) - same |
| Resolution | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR |
| Internal Voltage Reference | Yes (2.5V) | Yes (2.5V) | Internal reference (REFIN/REFOUT tied) | Yes (2.5V) | Yes (2.5V) | Yes (2.5V) |
| On-Chip Track-and-Hold | Yes | Yes | Yes | Yes | Yes | Yes |
| Serial Interface | MICROWIRE / SPI-compatible | MICROWIRE / SPI-compatible | MICROWIRE / SPI-compatible | MICROWIRE / SPI-compatible | MICROWIRE / SPI-compatible | MICROWIRE / SPI-compatible |
| Lifecycle Status | NRND | NRND / Obsolete (verify) | Obsolete | Active | NRND | Obsolete |
Principaux différenciateurs
- Integrated 8-channel analog multiplexer reduces BOM (vs ADC08832IWM/NOPB)
- On-chip 2.5V reference eliminates external reference circuit (vs External reference (e.g. REF5025) used with ADC0831)
- Integrated track-and-hold removes external SHA requirement (vs Discrete SHA needed with older ADC080x family)
- MICROWIRE-compatible 3-wire bus simplifies routing (vs Parallel-output ADC0808)
Notes de conception
Bypass VCC (pin 14) with a 10uF tantalum in parallel with a 0.1uF ceramic capacitor placed within 5 mm of the supply pin. The ADC08138 combines an analog and digital supply on a single pin, so high-frequency switching noise on the VCC rail can couple into the SAR comparator. According to TI layout guidelines, a ferrite bead between analog VCC and digital VCC on multi-board designs is recommended when the digital supply is shared with microcontrollers.
Separate analog and digital ground returns and tie them together at a single point (star-ground) close to the ADC08138's GND pin. Route the MICROWIRE bus signals (DOUT, CLK, CS) away from the analog input traces to minimize digital feedthrough into the SAR comparator. Place the voltage-reference bypass capacitor (typically 4.7uF plus 0.1uF ceramic) directly on the REFOUT pin. The 20-SOIC Wide package provides generous trace spacing for hand routing, but a 4-layer PCB with a dedicated ground plane yields the best ENOB.
Source impedance on each analog input must settle the internal sample-and-hold capacitor within the acquisition window. According to the TI datasheet, an external series resistance above 1 kohm can degrade linearity at full sample rate; add an input buffer op-amp if the sensor output impedance exceeds this limit. Also respect the MICROWIRE clock frequency maximum (typically 1 MHz for the ADC08138 family) - faster clocks can corrupt the SAR comparison.
Do not leave the SHDN pin (pin 20) floating - tie it high to VCC through a 100 kohm resistor for normal operation. Leaving MODE or MUX unconnected can place the converter into an undefined state. When using an external reference, ensure REFIN is driven by a low-impedance source (op-amp buffer), as the reference input is high-impedance. Finally, do not exceed the absolute maximum rating on analog inputs (VCC + 0.3V); over-voltage on a single channel can permanently damage the input ESD structure.
Informations de conformité
Original ADC08138CIWM datasheet is dated pre-RoHS-2 transition. The /NOPB variant (ADC08138CIWM/NOPB) is the lead-free RoHS-compliant version of the same die. AEC-Q100 qualification is not applicable for this part. Verify RoHS/REACH status with your distributor's certificate of conformance at order time.
