AS1531 - 12-Bit 8-Channel 300ksps ADC | ams OSRAM | 20-TSSOP
N.º da peça: AS1531 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $6.42 | $6,42 |
| 10 | $5.78 | $57,80 |
| 100 | $5.12 | $512,00 |
| 500 | $4.61 | $2.305,00 |
| 1.000 | $4.1 | $4.100,00 |
AS1531 Visão geral
An SAR analog-to-digital converter is a type of data converter that uses a binary search algorithm and a precision DAC to digitize an analog input in a single clock cycle per bit, achieving N conversion cycles for N bits of resolution. SAR ADCs sit in the broader data converter family (SAR -> ADC -> data converter -> signal chain IC -> mixed-signal semiconductor) and are favored for applications requiring deterministic latency, low power, and moderate-to-high resolution without the latency of sigma-delta converters or the complexity of pipeline ADCs.
Key features of the AS1531 include true 12-bit linearity with no missing codes, 4 (or 8 with COM pin) software-configurable input channels, a wide analog input range of 0V to VREF (or 2xVREF in pseudo-differential mode), a high-speed SPI/QSPI/MICROWIRE-compatible serial interface, and a hardware power-down input that drops quiescent current to microamp levels. The internal 2.5V reference eliminates the need for an external reference IC, simplifying BOM cost in space-constrained designs.
The AS1531 is built on a CMOS process with a built-in track-and-hold amplifier, enabling accurate conversions of full-scale input signals up to Nyquist without external buffering. The successive-approximation register and on-chip clock generator remove the need for an external high-frequency clock, allowing designers to drive the chip from a low-cost MCU oscillator and re-evaluate the analog front end in software.
Typical applications include portable industrial instrumentation, multi-channel data loggers, battery-powered sensor arrays, patient monitoring front-ends, and process-control analog input modules. The combination of low power, small footprint, and 8-channel input multiplexer makes the AS1531 particularly attractive for handheld multimeters and panel meters.
When designing with this part, ensure the analog input does not exceed VDD + 0.3V or fall below GND - 0.3V to avoid latch-up. Decouple VDD with a 10uF tantalum plus 0.1uF ceramic combination placed within 5 mm of the supply pin, and place the SHDN pin high within 10 ms after VDD settles to guarantee rated first-conversion accuracy.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet alone.
Alternativas drop-in para AS1531 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com AS1531 (mesmo formato e footprint) — diferindo em Package, Data Interface, Sampling Rate, Input Type, Resolution.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
AS1531-T
✅ Drop-In✓ Em estoque
$2.55 / unidade
Ver ficha técnica →AS1521-T
✅ Drop-In✓ Em estoque
$2.34 / unidade
Ver ficha técnica →AS1530
✅ Drop-In✓ Em estoque
$5.3 / unidade
Ver ficha técnica →ADS7822PBG4
✅ Drop-In✓ Em estoque
$2.1 / unidade
Ver ficha técnica →ADS7824PG4
✅ Drop-In✓ Em estoque
$11.1 / unidade
Ver ficha técnica →ADS7825UE4
✅ Drop-In✓ Em estoque
$17.2 / unidade
Ver ficha técnica →AS1531 Classificações máximas e características elétricas
| Resolução | 12 bits |
| Sample Rate | 300 ksps |
| Number of Input Channels | 4 single-ended / 2 pseudo-differential (8 with COM pin) |
| Supply Voltage (VDD) | +2.7 V to +3.6 V |
| Supply Current (300 ksps) | 2.2 mA |
| Internal Reference Voltage | 2.5 V |
| Analog Input Range (Single-Ended) | 0 V to VREF |
| Analog Input Range (Pseudo-Differential) | 0 V to 2xVREF |
| Interface | SPI / QSPI / MICROWIRE-compatible serial |
| Architecture | SAR (Successive Approximation Register) |
| Encapsulamento | 20-pin TSSOP |
| Status RoHS | Compliant (per DigiKey listing) |
Configuração de pinos do AS1531
| Pino 1 | AIN0 — Analog input channel 0 |
| Pino 2 | AIN1 — Analog input channel 1 |
| Pino 3 | AIN2 — Analog input channel 2 |
| Pino 4 | AIN3 — Analog input channel 3 |
| Pino 5 | COM — Common reference / additional input (8-channel mode) |
| Pino 6 | AGND — Analog ground |
| Pino 7 | REF — Reference voltage (internal 2.5V, or external drive) |
| Pino 8 | AVDD — Analog supply (+2.7V to +3.6V) |
| Pino 9 | SHDN — Hardware power-down (active high) |
| Pino 10 | DGND — Digital ground |
| Pino 11 | DOUT — Serial data output |
| Pino 12 | DIN — Serial data input |
| Pino 13 | SCLK — Serial clock |
| Pino 14 | CS — Chip select (active low) |
| Pino 15 | DVDD — Digital supply (+2.7V to +3.6V) |
| Pino 16 | NC — Not connected (per datasheet) |
| Pino 17 | NC — Not connected (per datasheet) |
| Pino 18 | NC — Not connected (per datasheet) |
| Pino 19 | NC — Not connected (per datasheet) |
| Pino 20 | NC — Not connected (per datasheet) |
Aplicações típicas
AS1531 é adequado para 6 aplicaçãos: Portable Industrial Data Logger, Battery-Powered Sensor Array Front End, Patient Monitoring Analog Front End, Process Control Analog Input Module, Handheld Digital Multimeter (DMM), Panel Meter / HMI Display Module.
Portable Industrial Data Logger
The AS1531's 4 (or 8) single-ended input channels and 300 ksps throughput make it well-suited for multi-sensor industrial data loggers. Each channel can be routed to a different transducer - thermocouple amplifier, strain gauge, 4-20 mA loop monitor - while the 2.2 mA supply current preserves battery life in remote or handheld enclosures. The on-chip 2.5V reference eliminates a reference IC, reducing BOM cost; unlike a discrete ADC-plus-FIFO design, the SAR architecture delivers zero pipeline latency so each conversion is deterministic in time, simplifying post-processing of timestamped sensor data.
Recomendado
Battery-Powered Sensor Array Front End
For battery-powered multi-sensor platforms, the AS1531's +2.7V to +3.6V single-supply operation and 2.2 mA active current let the ADC run directly from a Li-ion or 3xAA cell. The hardware power-down input drops quiescent current to microamp levels between scans, enabling duty-cycled sampling that extends battery life by 10x or more versus always-on designs. The internal reference buffer rejects battery voltage variation, so readings remain stable as the cell discharges - critical for accurate long-term environmental monitoring in unattended field deployments.
Recomendado
Patient Monitoring Analog Front End
Medical patient monitors require multi-channel precision signal acquisition at low power, and the AS1531 fits this profile with 4 (or 8) inputs sampled at 300 ksps aggregate. The SAR architecture guarantees no latency between sample and conversion, so vital-sign traces (ECG, SpO2, temperature) appear in real time without pipeline-induced phase shift. The internal 2.5V reference delivers sufficient stability for diagnostic-grade readings, and the 20-TSSOP footprint keeps the analog front end compact enough to fit in a bedside monitor chassis.
Recomendado
Process Control Analog Input Module
In a PLC analog input module, the AS1531 multiplexes up to 8 single-ended transducer signals (4-20 mA loops scaled by shunt, 0-10V valve position, RTD bridges) into a single high-speed SPI stream to the module MCU. The 300 ksps throughput enables oversampling and averaging per channel, suppressing 50/60 Hz line noise without external filtering. Compared to integrating ADCs used in legacy PLCs, the SAR design provides faster scan cycles for closed-loop control loops, and the 20-TSSOP package simplifies CE/UL creepage and clearance layout in industrial enclosures.
Recomendado
Handheld Digital Multimeter (DMM)
The AS1531's 4 single-ended inputs handle voltage, current (via shunt), and temperature (via thermocouple or RTD) measurements in a handheld DMM. The 2.2 mA active current keeps the ADC from dominating the multimeter's battery budget, and the SAR zero-latency conversion produces instantly readable digits when the user probes a node. The internal 2.5V reference provides sufficient accuracy for a 6000-count meter, and the 20-TSSOP package fits the slim form factor of a hand-held instrument housing.
Recomendado
Panel Meter / HMI Display Module
Panel meters and HMI displays use the AS1531 to digitize 4-8 process variables (temperature, pressure, flow, level) and stream them to a host MCU for display on an LCD or TFT. The 300 ksps aggregate throughput allows simultaneous update of all displayed channels at 50+ Hz refresh, eliminating visible lag. The integrated reference and SPI interface reduce external component count, which matters in cost-sensitive panel-meter SKUs where every BOM line erodes margin. The 20-TSSOP package also gives a slim profile behind the panel display.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para AS1531 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | AS1531-T | AS1521-T | AS1530 | ADS7822PBG4 | ADS7824PG4 | ADS7825UE4 |
|---|---|---|---|---|---|---|---|
| Brand | ams OSRAM | ams OSRAM | ams OSRAM | ams OSRAM | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 20-TSSOP | 20-TSSOP - same | 20-TSSOP - same | 20-TSSOP - same | 20-TSSOP - same | 20-TSSOP - same | 20-TSSOP - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Number of Input Channels | 4 single-ended / 2 pseudo-diff (8 with COM) | 4 / 8 | 1 | 8 | 1 | 4 | 4 |
| Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR | SAR |
Principais diferenciais
- Multi-channel input multiplexer on-chip (vs ADS7822PBG4)
- 300 ksps throughput with 2.2 mA supply current (vs ADS7824PG4)
- Single-supply 3.3V operation matches modern MCUs (vs AS1530)
Notas de projeto
Decouple AVDD and DVDD with separate 10 uF tantalum plus 0.1 uF ceramic capacitor pairs, placed within 5 mm of each supply pin. The AS1531's 2.2 mA active supply current is dominated by the switched-capacitor input stage; inadequate decoupling couples digital switching noise into the analog reference, degrading INL/DNL by 0.5-1 LSB. Tie AVDD and DVDD to the same 3.3V rail but isolate them with a ferrite bead for best noise performance.
Do not allow analog inputs (AIN0-AIN3, COM) to exceed AVDD + 0.3V or fall below AGND - 0.3V; the AS1531 is not over-voltage tolerant on its analog pins. For 0-10V or +/-10V industrial signals, add an external resistor-divider or op-amp buffer ahead of the input pin. Also note that the SHDN pin must be held low for at least 100 ns after VDD settles before the first conversion to guarantee reset of the internal state machine.
Route the SPI bus (CS, SCLK, DIN, DOUT) as a controlled-impedance group away from the analog inputs and REF pin. Keep the AGND and DGND planes joined at a single point under the AGND pin to avoid ground-loop noise. Place the REF decoupling capacitor (1 uF ceramic in parallel with 0.01 uF) directly between REF and AGND, and avoid running digital traces under the REF pin or the analog input traces.
Informações de conformidade
RoHS compliance confirmed per DigiKey listing; REACH, halogen-free, and conflict-minerals status not explicitly stated in verified web data.
