ADC08138CIWMX - 8-Bit Serial I/O ADC, 8-Ch MUX, SOIC-20 | Texas Instruments
N.º de pieza: ADC08138CIWMX ✗ Fin de vida| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $5.95 | $5,95 |
| 10 | $5.2 | $52,00 |
| 100 | $4.42 | $442,00 |
| 500 | $3.78 | $1.890,00 |
| 1.000 | $3.35 | $3.350,00 |
ADC08138CIWMX Descripción general
What is a SAR ADC? A successive-approximation-register analog-to-digital converter is a type of data converter that resolves an analog input to its digital code by binary-searching one bit per clock cycle against a precision reference voltage. SAR ADCs sit within the broader hierarchy of data-converter ICs (ADC/DAC -> ADC -> SAR ADC -> semiconductor). They are valued for low latency, deterministic conversion time, and lack of pipeline delay, which makes them the workhorse choice for multiplexed analog front ends, control-loop feedback, and instrumentation where a fresh sample per channel must be guaranteed every cycle.
Key features include 8 input channels routed via a configurable analog multiplexer, a built-in 2.5 V bandgap reference (usable or bypassable), on-chip track-and-hold, NSC MICROWIRE-compatible serial I/O for glueless MCU/SPI-host connection, and single 5 V supply operation. The wide-body 20-SOIC (IWM) package gives 7.50 mm body width for robust through-hole-free board assembly while keeping the footprint compatible with standard 20-pin SOIC land patterns.
Architecture depth: the SAR core is paired with a sample/hold that captures the input at the start of each conversion, eliminating the need for an external buffer on multiplexed channels that settle between conversions. The serial MICROWIRE interface shares clock and data lines that map cleanly onto SPI mode-0 peripherals on common microcontrollers, and the device supports daisy-chaining for multi-ADC signal chains.
Typical applications include industrial process-control front ends, multi-sensor data acquisition boards, portable instrumentation, panel meters, battery monitoring, and microcontroller-based embedded systems that need 8-bit precision across several analog channels. The wide SOIC-20 footprint also supports hand-solderable prototypes and field-serviceable industrial PCBs.
Design consideration: when laying out the ADC08138CIWMX, keep analog and digital ground returns separated and join them at a single point near the IC; the MICROWIRE clock edges must be kept clean (short traces, series resistor if reflections appear) because the serial interface is the only communication channel and any glitch will appear as a stuck-code.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet - giving you the cross-reference and layout guidance needed to substitute, source, and deploy the ADC08138CIWMX with confidence.
Alternativas directas para ADC08138CIWMX — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con ADC08138CIWMX (mismo factor de forma y huella) — difiere en Data Interface, Input Type, Package / Case.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
ADC08134CIWMX
✅ Sustitución directa ⚠️ Especificaciones sin verificar✓ En stock
$2.49 / unidad
Ver hoja de datos →ADC08131CIWMX
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
TLC0838CDWRG4
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
TLC0838IPW
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
TLC0831IPW
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ADC08138CIWMX Valores máximos y características eléctricas
| Number of Bits | 8 |
| Number of Inputs | 8 |
| Input Type | Single-Ended |
| Data Interface | NSC MICROWIRE, Serial |
| Architecture | SAR (Successive Approximation) |
| Encapsulado / Carcasa | 20-SOIC (0.295", 7.50mm Width) |
| Reference Type | Internal (with external override option) |
| Track/Hold | Yes (integrated) |
| Number of Terminals | 20 |
| Terminal Form | Gull Wing |
| Temperature Grade | Industrial |
| Tipo de montaje | Surface Mount |
| Packaging | Tape & Reel (TR) |
| Tensión de alimentación | 5 V (single supply, per family datasheet) |
Configuración de pines de ADC08138CIWMX
| Pin 1 | VIN0 — Analog input channel 0 |
| Pin 2 | VIN1 — Analog input channel 1 |
| Pin 3 | VIN2 — Analog input channel 2 |
| Pin 4 | VIN3 — Analog input channel 3 |
| Pin 5 | VIN4 — Analog input channel 4 |
| Pin 6 | VIN5 — Analog input channel 5 |
| Pin 7 | VIN6 — Analog input channel 6 |
| Pin 8 | VIN7 — Analog input channel 7 |
| Pin 9 | REF — Voltage reference input/output (internal bandgap) |
| Pin 10 | GND — Analog ground |
| Pin 11 | VDD — Analog supply voltage (5 V) |
| Pin 12 | DGND — Digital ground |
| Pin 13 | T/H — Track-and-hold capacitor connection |
| Pin 14 | NC — Not connected (per datasheet) |
| Pin 15 | DO — Serial data output (MICROWIRE) |
| Pin 16 | CLK — Serial clock input (MICROWIRE) |
| Pin 17 | CS — Chip select, active low |
| Pin 18 | DI — Serial data input (MICROWIRE daisy-chain) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | VDD — Digital supply voltage (5 V) |
Aplicaciones típicas
ADC08138CIWMX es adecuado para 6 aplicacións: Industrial Process-Control Front End, Multi-Sensor Data Acquisition Board, Portable Instrumentation and Panel Meters, Battery Monitoring and Power Management, Embedded MCU Companion ADC, Legacy Industrial Control Board Repair.
Industrial Process-Control Front End
The ADC08138CIWMX is well-suited to industrial process-control front ends where multiple analog sensors (temperature, pressure, flow, level) must be digitized into a central controller. Its 8 single-ended input channels, configurable through the internal multiplexer, allow a single ADC to replace several discrete converter channels, reducing BOM cost and PCB area. The SAR architecture guarantees deterministic conversion time per channel, which is essential for closed-loop control where the controller expects a fresh sample each cycle. The integrated track-and-hold removes the need for external sample-and-hold buffers when switching between multiplexed inputs with moderate source impedance. The MICROWIRE-compatible serial interface connects directly to the SPI peripheral of common industrial MCUs without glue logic, simplifying firmware.
Recomendado
Multi-Sensor Data Acquisition Board
For multi-sensor data acquisition boards, the ADC08138CIWMX provides 8 single-ended analog inputs with 8-bit resolution, sampling several transducers through one shared converter. The internal 8-channel multiplexer, combined with the SAR core and integrated track-and-hold, lets designers digitize strain gauges, thermistors, optical sensors, and potentiometer outputs through a single ADC channel without external mux ICs. The 8-bit resolution is adequate for environmental monitoring, HVAC sensor arrays, and panel-meter style readouts where full 12-bit dynamic range would be overkill. The wide-body 20-SOIC package simplifies the layout of the analog input traces and keeps the board serviceable for field technicians who may need to hand-replace the IC.
Recomendado
Portable Instrumentation and Panel Meters
The ADC08138CIWMX fits portable instrumentation and digital panel meters where 8-bit resolution is sufficient for display and threshold decisions. The internal bandgap reference eliminates the need for a separate reference IC, reducing both board area and quiescent current draw - critical for battery-powered handhelds. The MICROWIRE serial interface runs at low clock rates when sample rates are modest, allowing the host MCU to spend most of its time in sleep mode. The wide-body SOIC-20 package withstands the mechanical stresses of handheld enclosure assembly and field-serviceable repair workflows. Designers benefit from the SAR architecture's deterministic per-sample latency, which keeps the meter's display update rate stable under varying input conditions.
Recomendado
Battery Monitoring and Power Management
For battery monitoring systems, the ADC08138CIWMX provides 8 single-ended inputs that can be routed to individual cell voltages, pack current shunts, and temperature sensors inside a battery management system. The SAR core's deterministic conversion time allows the host MCU to complete a full pack scan within a fixed time budget, simplifying state-of-charge calculation. The internal reference and on-chip track-and-hold reduce external component count on the battery management board, where space is at a premium. The wide 5 V supply tolerance allows direct connection to a 4-cell NiMH / 1S Li-ion stack with appropriate resistive dividers, while the industrial temperature grade supports under-hood and outdoor-pack environments.
Recomendado
Embedded MCU Companion ADC
The ADC08138CIWMX is a classic embedded-MCU companion ADC for designs that need more analog inputs than the MCU's internal ADC provides. The MICROWIRE serial interface ties directly into the SPI shift-register peripheral of common 8051, MSP430, and PIC microcontrollers without bus arbitration logic, and the daisy-chain feature allows multiple ADC08138s to share a single SPI bus. The 8-bit resolution is well-matched to threshold detection, potentiometer reads, keypad scanning, and other embedded UI tasks where high precision is not required. The wide-body SOIC-20 footprint is hand-solderable for prototypes and small-batch production runs common in custom embedded products.
Recomendado
Legacy Industrial Control Board Repair
The ADC08138CIWMX remains useful for legacy industrial control board repair and field replacement, where the existing PCB was designed around its SOIC-20 footprint and the firmware expects the specific MICROWIRE protocol of the ADC081x family. Because this part is now in obsolete lifecycle, repair shops maintain stock of the ADC08138CIWMX or its active replacement the TLC0838CDWRG4 to keep installed-base systems operational. The drop-in SOIC-20 compatibility between ADC08138 and TLC0838 lets repair technicians swap parts without PCB rework. The wide operating temperature range and the rugged SOIC package also suit industrial environments where vibration, humidity, and thermal cycling stress the components.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para ADC08138CIWMX — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | ADC08134CIWMX | ADC08131CIWMX | TLC0838CDWRG4 | TLC0838IPW | TLC0831IPW |
|---|---|---|---|---|---|---|
| Package | 20-SOIC (IWM) 0.295" wide-body | 20-SOIC (IWM) - same | 20-SOIC (IWM) - same | 20-SOIC (DW) - same family footprint | 20-TSSOP (PW) - smaller footprint | 20-TSSOP (PW) - smaller footprint |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Number of Inputs | 8 single-ended | 4 single-ended | 1 single-ended | 8 single-ended (or 4 differential) | 8 single-ended (or 4 differential) | 1 single-ended |
| Resolution | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR |
| Serial Interface | NSC MICROWIRE | NSC MICROWIRE | NSC MICROWIRE | MICROWIRE-compatible serial | MICROWIRE-compatible serial | MICROWIRE-compatible serial |
| Internal Reference | Yes (bandgap) | Yes (bandgap) | Yes (bandgap) | Yes | Yes | Yes |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Active | Active | Active |
Diferenciadores clave
- Highest channel count in the ADC081x family (8 vs 4 or 1) (frente a ADC08134CIWMX)
- Active replacement available with same SOIC-20 footprint (frente a TLC0838CDWRG4)
- MICROWIRE daisy-chain capability for multi-ADC signal chains (frente a TLC0831IPW)
Notas de diseño
Keep the analog input traces short and guarded by a ground pour on the same layer to minimize coupling from the digital MICROWIRE clock edges. Place the 0.1 uF VDD bypass capacitor within 5 mm of the VDD pin (pin 11 analog, pin 20 digital) with the ground return tied directly to the AGND/DGND split that rejoins at a single point near the IC. The reference pin (pin 9) should be decoupled with 1 uF to 10 uF of low-leakage capacitance to keep SAR conversion stable.
The MICROWIRE serial interface is the only communication channel between the host MCU and the ADC08138CIWMX, so any glitch on CS, CLK, or DO will appear as a stuck or shifted code. Keep CLK traces under 50 mm when running at the part's maximum clock rate, add a 33 ohm series resistor at the CLK source if reflections appear on a scope, and route the MICROWIRE traces away from the analog inputs and from switching power inductors. For daisy-chained configurations, the DO of one stage must feed the DI of the next within one CLK period, so check propagation delay across the chain at the chosen clock frequency.
Do not assume the ADC08138CIWMX is RoHS-compliant without verifying against the manufacturer product page - the wide-body SOIC-20 variant exists in both leaded and lead-free finishes, and the obsolete lifecycle status means some distributor stock may be of legacy leaded material. For new designs that must be RoHS-compliant, choose the active TLC0838CDWRG4 instead. Also note that the ADC08138 family supports single-ended inputs only; differential signals require the TLC0838, which offers differential input pairs as a configuration option.
Información de cumplimiento
RoHS, REACH, lead-free, and halogen-free status for the ADC08138CIWMX are not confirmed in the verified web data and should be verified against the manufacturer product page before use in restricted designs. AEC-Q100 not applicable - this is a general-purpose industrial-grade ADC.
