ADS7042 - 12-Bit 1-MSPS Ultra-Low-Power SAR ADC | TI
N.º de pieza: ADS7042 ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $1.95 | $1,95 |
| 10 | $1.75 | $17,50 |
| 100 | $1.48 | $148,00 |
| 500 | $1.25 | $625,00 |
| 1.000 | $1.05 | $1.050,00 |
ADS7042 Descripción general
An ADC (analog-to-digital converter) converts continuous analog signals into discrete digital values. The ADS7042 is a SAR (successive-approximation register) ADC, a data-converter architecture that uses a binary search with a capacitor-based DAC to approximate the input voltage, offering an excellent balance of speed, resolution, and power efficiency within the broader mixed-signal IC hierarchy. SAR ADCs with inherent sample-and-hold circuits eliminate the need for an external sample-and-hold amplifier.
Key features include 12-bit resolution at 1 MSPS, ultra-low power consumption (typically 0.3 mW at 1 MSPS), a wide analog input range defined by AVDD (0V to AVDD), and a power-down mode that further reduces current draw during idle periods. The SPI-compatible serial interface is controlled by CS and SCLK signals, with the interface supporting fast serial clocking for high data throughput.
Technically, the ADS7042 uses a charge-redistribution SAR architecture with a capacitor DAC that performs the sampling function internally. Power consumption scales with sampling rate, making the device highly efficient in low-throughput, duty-cycled systems. An external reference can be applied for improved accuracy in precision measurement designs.
Typical applications include battery monitoring, portable instrumentation, industrial process control, sensor interfaces (temperature, pressure), and medical devices. Its miniature form factor and extremely low power consumption make it especially suitable for space-constrained, battery-powered products such as wearables and wireless sensor nodes.
Design consideration: keep the analog input within 0V to AVDD at all times, decouple AVDD and DVDD each with 0.1uF ceramic capacitors placed close to the pins, and use a low-impedance source or buffer amplifier to preserve AC performance.
Alternativas directas para ADS7042 — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
ADS7046
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ADS7044
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
ADS7866
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
ADS7867
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
ADS7868
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
ADS7042 Valores máximos y características eléctricas
| Resolución | 12 bit |
| Frecuencia de muestreo | 1 MSPS |
| Architecture | SAR (capacitor-based, charge redistribution) |
| Number of Input Channels | 1 (pseudo-differential) |
| Analog Input Voltage Range | 0 V to AVDD (1.65 V to 3.6 V) |
| Analog Supply (AVDD) | 1.65 V to 3.6 V |
| Digital Supply (DVDD) | 1.65 V to 3.6 V |
| Power Consumption | 0.3 mW typical at 1 MSPS |
| Interfaz | SPI-compatible (CS, SCLK, SDO) |
| Sample-and-Hold | Inherent (capacitor DAC) |
| Power-Down Mode | Yes |
| Temperatura de funcionamiento | -40C to +125C |
| Encapsulado | 8-VSSOP (DGK) / 8-X2QFN (RUG) |
| Tipo de montaje | Surface Mount |
| Estado RoHS | Compliant |
Configuración de pines de ADS7042
| Pin 1 | AINP — Non-inverting analog input |
| Pin 2 | AINM — Inverting analog input (pseudo-differential return) |
| Pin 3 | AVDD — Analog supply, 1.65 V to 3.6 V; defines input range |
| Pin 4 | GND — Ground reference |
| Pin 5 | CS — Chip select, active low, frames conversion |
| Pin 6 | SCLK — Serial clock for SPI-compatible interface |
| Pin 7 | SDO — Serial data output |
| Pin 8 | DVDD — Digital supply, 1.65 V to 3.6 V |
Aplicaciones típicas
ADS7042 es adecuado para 6 aplicacións: Battery Monitoring, Portable Instrumentation, Industrial Process Control, Sensor Interfaces, Medical and Wearable Devices, Wireless Sensor Nodes and IoT.
Battery Monitoring
The ADS7042 fits battery monitoring in portable products because its 0.3 mW typical consumption at 1 MSPS minimizes load on the measured cell, and the 1.65V to 3.6V AVDD range allows the ADC to be powered directly from the battery rail through a regulator. Its power-down mode eliminates quiescent drain between periodic voltage samples in duty-cycled systems. Used with a resistive divider and buffer, it tracks cell voltage within the 0V-to-AVDD input range with no external sample-and-hold needed thanks to the inherent capacitor-DAC sampling circuit.
Recomendado
Portable Instrumentation
In handheld and portable instruments, board area and battery life dominate design constraints. The ADS7042's 8-VSSOP (DGK) or 8-X2QFN (RUG) package occupies minimal PCB area, while 12-bit resolution at 1 MSPS covers general-purpose measurement needs for temperature, pressure, and user-interface sensing. The SPI-compatible interface (CS, SCLK, SDO) connects directly to portable MCUs, and power scaling with sample rate lets firmware trade throughput for runtime. External reference support allows calibration against a precision reference when measurement accuracy must exceed supply-river tolerances.
Recomendado
Industrial Process Control
The ADS7042 suits distributed industrial sensing nodes where many channels are digitized in remote locations. Its -40C to +125C operating range covers harsh cabinet and field environments, and the low power per channel keeps thermal budgets small in sealed enclosures. At 1 MSPS, it comfortably handles slow process variables such as pressure, level, and temperature with oversampling to improve effective resolution. The SPI interface isolates easily with digital isolators for galvanically isolated loops. Per TI datasheet, a low-impedance source or buffer amplifier is recommended to preserve AC performance.
Recomendado
Sensor Interfaces
For temperature, pressure, and light sensors, the ADS7042 offers a pseudo-differential analog input (AINP/AINM) that rejects low-level ground offsets, improving effective resolution in noisy layouts. The input range defined by AVDD matches common 1.8V, 2.5V, and 3.3V sensor rails without level shifting. At 1 MSPS it oversamples slowly varying sensor signals for noise averaging, and the inherent sample-and-hold removes aperture uncertainty. Its ultra-small X2QFN option lets designers place the ADC directly at the sensor connector, shortening analog traces and reducing pickup.
Recomendado
Medical and Wearable Devices
Battery-powered medical devices such as patches, monitors, and diagnostic wearables benefit from the ADS7042's combination of 0.3 mW consumption, miniature 8-X2QFN package, and 12-bit accuracy for biopotential-adjacent and physiological parameter sensing. The 1.65V to 3.6V supply range matches coin-cell and single-cell lithium rails, and the power-down mode supports intermittent sampling profiles typical of patient monitoring. Because power scales with sample rate, firmware can drop to kilohertz rates for most biosignals, further extending battery life in always-on wearable form factors.
Recomendado
Wireless Sensor Nodes and IoT
In IoT and wireless sensor nodes, the ADS7042 digitizes analog sensors ahead of the radio transceiver while adding negligible average power draw. Duty-cycled operation - wake, sample, convert, power down - pairs well with sub-GHz and BLE radio duty cycles. The SPI bus is shared easily with common RF MCUs, and the ultra-small footprint fits coin-cell-sized PCBs. At 1 MSPS, firmware can also burst-sample vibration or acoustic signatures for edge diagnostics before sleeping. According to TI, the miniature form factor and extremely low power are explicit design goals of this device family.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para ADS7042 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | ADS7046 | ADS7044 | ADS7866 | ADS7867 |
|---|---|---|---|---|---|
| Package | 8-VSSOP (DGK) / 8-X2QFN (RUG) | 8-VSSOP (DGK) - same footprint | 8-VSSOP (DGK) - same footprint | 8-VSSOP (DGK) - same footprint | 8-VSSOP (DGK) - same footprint |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 10 bit |
| Sampling Rate | 1 MSPS | 3 MSPS | 1 MSPS | 1.14 MSPS | 1.28 MSPS |
| Analog Supply Range | 1.65 V to 3.6 V | 1.65 V to 3.6 V | 1.65 V to 3.6 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Pin Compatibility | Reference | Pin-for-pin compatible (TI E2E confirmed) | Family pin-compatible, verify timing | Verify pinout before drop-in | Verify pinout before drop-in |
| Interface | SPI (CS/SCLK/SDO) | SPI, different SCLK count per conversion | SPI (CS/SCLK/SDO) | SPI (CS/SCLK/SDO) | SPI (CS/SCLK/SDO) |
| Temperature Range | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +85C | -40C to +85C |
Diferenciadores clave
- Lowest power in 12-bit 1-MSPS class (~0.3 mW) (frente a ADS7866)
- Extended -40C to +125C temperature range (frente a ADS7866)
- Pin-for-pin faster upgrade path (frente a ADS7046)
Notas de diseño
Decouple AVDD and DVDD each with a 0.1uF ceramic capacitor placed as close to the pins as possible, per the TI ADS7042 datasheet. Keep the analog input traces short and away from SCLK/SDO switching lines; the pseudo-differential AINM input should be tied to a clean local ground or offset source near the ADC rather than a remote ground to gain offset rejection.
Never allow AINP or AINM to exceed 0V to AVDD; the input is not fault tolerant beyond the supply rails. When substituting the pin-compatible ADS7046 for higher throughput, note the serial interface timing requires a different number of SCLK pulses per conversion period (TI E2E forum), so SPI driver firmware must be updated. Verify the DGK vs RUG package pin assignment difference before layout reuse.
Drive the analog input from a low-impedance source or buffer amplifier, as recommended in the datasheet, to fully settle the capacitor-DAC sampling capacitance within the acquisition window. For slow signals, adding a small RC filter (e.g., 100 ohm / 1 nF) ahead of AINP reduces wideband noise and provides charge kickback isolation with minimal settling penalty at 1 MSPS.
Información de cumplimiento
RoHS compliant per TI product page. REACH, halogen-free, and conflict minerals status not stated in provided data.
