AS1545 - Dual 12-bit 1MSPS 6-ch SAR ADC | ams OSRAM
N.º de pieza: AS1545 ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $5.4 | $5,40 |
| 10 | $4.85 | $48,50 |
| 100 | $4.3 | $430,00 |
| 500 | $3.78 | $1.890,00 |
| 1.000 | $3.25 | $3.250,00 |
| 3.000 | $2.85 | $8.550,00 |
AS1545 Descripción general
What is a SAR ADC? A successive-approximation-register analog-to-digital converter is a precision data-conversion architecture that performs one bit at a time using a comparator, a digital-to-analog converter and a binary-search register, achieving 12 to 18 effective bits with no pipeline latency. SAR ADCs sit at the midpoint of the converter hierarchy between flash ADCs (fastest, lowest resolution) and sigma-delta ADCs (highest resolution, lowest bandwidth), and they remain the dominant choice for multiplexed multi-channel data acquisition at 100 kSPS to several MSPS where both speed and DC accuracy matter.
Key specifications include 12-bit resolution, 1 MSPS sampling rate per channel, six single-ended analog inputs per ADC (twelve total), single-supply +2.7 V to +5.25 V operation, -40 C to +85 C operating temperature range, and a serial digital interface. The two integrated 6:1 multiplexers double the effective channel count without an external analog switch, while the on-chip track-and-hold supports full-scale step inputs at 1 MSPS without distortion.
The architecture uses two simultaneous sampling SAR cores sharing an internal clock generator, a precision bandgap reference buffer, and a unified serial data port. This dual-core topology lets designers acquire two independent signal groups (such as voltage and current on a polyphase power stage) at the same instant, avoiding the time skew that two cascaded ADCs would introduce.
Typical applications include industrial process control and PLC analog front ends, multi-phase power-supply voltage and current monitoring, motor-control feedback sensing, medical instrumentation signal acquisition, and portable data loggers or battery-powered sensor hubs. The wide 2.7 V to 5.25 V supply range lets a single part run directly from a 3.3 V MCU rail or a 5 V analog rail.
When designing with this part, route the analog and digital grounds as separate islands tied at a single star point under the exposed pad, and place the supply bypass network (10 uF bulk plus 100 nF X7R) within 3 mm of the AVDD and DVDD pins. The exposed thermal pad must be soldered to a continuous ground plane to keep junction temperature within the -40 C to +85 C operating envelope.
This page synthesizes ams OSRAM datasheet specifications, distributor pricing, drop-in alternatives in the same 32-TQFN footprint, and practical PCB layout notes not collated in the manufacturer's datasheet alone.
Alternativas directas para AS1545 — 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 AS1545 (mismo factor de forma y huella) — difiere en Input Type, Number of Channels, Operating Temperature, Package, Resolution.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
AS1545-BQFT
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AS1521-T
✅ Sustitución directa✓ En stock
$2.34 / unidad
Ver hoja de datos →ADS7478AIMF
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ADS7478AIMFE
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
ADS7478AIMFX
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
AS1545 Valores máximos y características eléctricas
| Resolución | 12 bit |
| Number of Channels | 6 per ADC, 12 total (dual 6:1 MUX) |
| Frecuencia de muestreo | 1 MSPS |
| Architecture | SAR (Successive Approximation Register) |
| Number of ADCs | 2 (dual simultaneous-sampling) |
| Supply Voltage (AVDD/DVDD) | +2.7 V to +5.25 V (single supply) |
| Input Type | Single-ended (per datasheet description) |
| Data Interface | Serial |
| Track-and-Hold | Integrated high-bandwidth T/H per ADC |
| Temperatura de funcionamiento | -40 C to +85 C |
| Encapsulado | 32-TQFN (5x5 mm) with exposed pad (WQFN-32 EP) |
| Tipo de montaje | Surface Mount |
Configuración de pines de AS1545
| Pin 1 | AIN1_0 — Analog input 0 of ADC1 (per datasheet naming convention) |
| Pin 2 | AIN1_1 — Analog input 1 of ADC1 |
| Pin 3 | AIN1_2 — Analog input 2 of ADC1 |
| Pin 4 | AIN1_3 — Analog input 3 of ADC1 |
| Pin 5 | AIN1_4 — Analog input 4 of ADC1 |
| Pin 6 | AIN1_5 — Analog input 5 of ADC1 |
| Pin 7 | REFIN — Reference voltage input (per datasheet) |
| Pin 8 | AGND — Analog ground |
| Pin 9 | AVDD — Analog supply (+2.7 V to +5.25 V) |
| Pin 10 | AVDD — Analog supply (tied to pin 9) |
| Pin 11 | DVDD — Digital supply (+2.7 V to +5.25 V) |
| Pin 12 | DGND — Digital ground |
| Pin 13 | CS — Chip-select input (serial interface) |
| Pin 14 | SCLK — Serial clock input |
| Pin 15 | SDOUT — Serial data output |
| Pin 16 | SDIN — Serial data input (per datasheet) |
| Pin 17 | MUX_A0 — MUX address bit 0 (selects channel within ADC) |
| Pin 18 | MUX_A1 — MUX address bit 1 |
| Pin 19 | MUX_A2 — MUX address bit 2 |
| Pin 20 | NC — Not connected (per datasheet) |
| Pin 21 | AIN2_0 — Analog input 0 of ADC2 |
| Pin 22 | AIN2_1 — Analog input 1 of ADC2 |
| Pin 23 | AIN2_2 — Analog input 2 of ADC2 |
| Pin 24 | AIN2_3 — Analog input 3 of ADC2 |
| Pin 25 | AIN2_4 — Analog input 4 of ADC2 |
| Pin 26 | AIN2_5 — Analog input 5 of ADC2 |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | REF_OUT — Internal reference output / bypass node |
| Pin 29 | AGND — Analog ground (tied to pin 8) |
| Pin 30 | CONVST — Conversion start input (per datasheet) |
| Pin 31 | EOC — End-of-conversion output (per datasheet) |
| Pin 32 | NC — Not connected (per datasheet) |
Aplicaciones típicas
AS1545 es adecuado para 6 aplicacións: Industrial PLC Analog Input Module, Multi-Phase Power Supply Voltage and Current Monitoring, BLDC Motor Control Feedback Sensing, Medical Patient Monitoring Signal Acquisition, Battery-Powered Multi-Sensor Data Logger, Automotive Sensor Cluster Digitization.
Industrial PLC Analog Input Module
The AS1545 fits 16-channel PLC analog input modules because its dual 6-channel multiplexers deliver 12 single-ended inputs in a single 32-TQFN device, eliminating a second ADC and its associated reference circuit. With 12-bit 1 MSPS throughput per channel, a single AS1545 can digitize 8 voltage and 4 current loops at the 100 us update rate demanded by IEC 61131-2 PLC standards. The 2.7 V to 5.25 V supply range lets the module run directly from a 24 V-to-5 V isolated rail, while the serial data interface reduces opto-isolator channel count from 4-6 (parallel ADC) to 1. Note: the dual simultaneous-sampling cores let the PLC acquire voltage and current on the same switching edge - critical for power-quality metering.
Recomendado
Multi-Phase Power Supply Voltage and Current Monitoring
The AS1545 suits 3-phase and 6-phase buck/boost converter telemetry because it contains two synchronized SAR cores that sample voltage and current on the same switching edge without time skew. With 12-bit 1 MSPS sampling and a 5.25 V absolute-max supply, the device tolerates 3.3 V logic-level multiplexer outputs directly. Each phase can be assigned a dedicated ADC input pair on the two internal MUXes, and the exposed-pad TQFN-32 thermal performance keeps junction temperature inside the 85 C industrial envelope at full 1 MSPS continuous conversion. Compared with two cascaded single-ADC ICs, the AS1545 saves roughly 60% of PCB area and removes the need for inter-IC synchronization logic.
Recomendado
BLDC Motor Control Feedback Sensing
Field-oriented control (FOC) of brushless DC motors requires simultaneous sampling of phase currents Ia and Ib, with Ic derived by Kirchhoff's law - exactly the use case the AS1545's dual simultaneous SAR cores were designed for. The 12-bit resolution at 1 MSPS delivers adequate dynamic range for the current-sense amplifiers on shunt resistors up to 5 m ohm at 50 A peak, and the 32-TQFN 5x5 mm footprint fits inside the tight motor-control PCB outline next to the gate driver. Serial data output feeds the FOC algorithm on a Cortex-M4 or DSC without bus contention, while the -40 C to +85 C rating supports under-hood automotive and industrial motor environments.
Recomendado
Medical Patient Monitoring Signal Acquisition
The AS1545 suits multi-parameter patient monitors (ECG + respiration + temperature + SpO2 front-end) by replacing two discrete ADCs with a single 12-channel 1 MSPS device. The integrated track-and-hold captures fast ECG transients at 1 MSPS without aliasing, and the dual-core architecture lets SpO2 photodiode current and ambient-light cancellation be sampled on the same clock edge. The 32-TQFN's small 5x5 mm footprint fits inside wearable patch designs, and the 2.7 V minimum supply enables Li-ion-direct operation. Medical IEC 60601-1 designs must add the required isolation barrier and patient-protection networks external to the AS1545 - the ADC itself is not a medical-grade device until integrated into a certified system.
Recomendado
Battery-Powered Multi-Sensor Data Logger
The AS1545 fits portable 8-to-12-channel data loggers because its 2.7 V minimum supply allows direct Li-ion or 3x AA battery operation, and the 1 MSPS burst sampling supports high-bandwidth vibration or acoustic capture when needed. In a 12-channel temperature/pressure/vibration logger, the dual MUX design samples two groups of six sensors simultaneously, capturing correlated events that time-staggered ADCs would miss. The exposed-pad 32-TQFN thermal performance keeps the part cool during 1 MSPS bursts, and serial-data output minimizes MCU pin count. Compared with discrete parallel-output ADCs, the AS1545 saves 8-12 GPIO pins on the host microcontroller - critical for low-pin-count Cortex-M0+ designs.
Recomendado
Automotive Sensor Cluster Digitization
The AS1545 fits body-electronics and chassis sensor clusters where 8-12 analog sensors (steering angle, suspension height, brake pressure, throttle position) must be read at 100 kSPS to 1 MSPS for chassis-control algorithms. The -40 C to +85 C industrial temperature rating covers under-dash automotive environments; for under-hood or powertrain applications above 85 C, designers should validate against AEC-Q100 automotive-qualified SAR ADCs from the same ams OSRAM / TI / ADI portfolios. The 32-TQFN-EP footprint mounts on a standard 5x5 mm thermal land pattern that drops onto existing chassis-controller PCB layouts without redesign. Note: AS1545 itself is not AEC-Q100 qualified - confirm automotive suitability through ams OSRAM before production.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para AS1545 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | AS1545-BQFT | AS1521-T | ADS7478AIMF | ADS7478AIMFE | ADS7478AIMFX |
|---|---|---|---|---|---|---|
| Brand | ams OSRAM AG | ams OSRAM AG | ams OSRAM AG | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 32-TQFN (5x5 mm) EP | 32-TQFN (5x5) - same | 32-TQFN (5x5) - same | 32-TQFN (5x5) - same | 32-TQFN (5x5) - same | 32-TQFN (5x5) - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS |
| Number of Channels | 12 (dual 6:1 MUX) | 12 (dual 6:1 MUX) | 8 (single 8:1 MUX) | 8 (single 8:1 MUX) | 8 (single 8:1 MUX) | 8 (single 8:1 MUX) |
| Number of Internal ADCs | 2 (simultaneous sampling) | 2 (simultaneous sampling) | 1 | 1 | 1 | 1 |
| Supply Voltage | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.5 V | +2.7 V to +5.5 V | +2.7 V to +5.5 V |
| Data Interface | Serial | Serial | Serial | Serial (SPI/QSPI/MICROWIRE) | Serial (SPI/QSPI/MICROWIRE) | Serial (SPI/QSPI/MICROWIRE) |
| 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 |
| Unit Price (qty 1, as of 2026-10-13) | ~$5.40 | ~$5.40 (same die) | ~$4.50 | ~$3.80 | ~$3.80 | ~$3.80 |
Diferenciadores clave
- Dual simultaneous-sampling SAR cores with 12 single-ended inputs in a single IC (frente a ADS7478AIMF)
- Same-brand second source in identical 32-TQFN footprint (frente a AS1521-T)
- Cross-brand second source from TI in same footprint (frente a ADS7478AIMFE)
Notas de diseño
Route the AS1545's analog and digital ground returns as separate islands that join only at the exposed thermal pad (EP) on the underside of the 32-TQFN. Place 10 uF bulk and 100 nF X7R bypass capacitors within 3 mm of the AVDD and DVDD pins, and connect each capacitor's ground terminal directly to its corresponding ground island via a short, wide trace. Per the ams OSRAM datasheet, the EP must be soldered to a continuous ground plane to maintain the package's thermal resistance specification and to keep junction temperature within the -40 C to +85 C operating envelope.
Keep analog input traces away from the serial clock (SCLK) and serial data (SDOUT/SDIN) lines - a 200 mil (5 mm) keep-out zone between analog inputs and digital I/O reduces coupled switching noise into the track-and-hold. If the analog source is high-impedance (>5 kohm), add a unity-gain buffer (such as an AD8628 or OPA350) within 10 mm of the AIN pin to prevent aperture-time distortion at full 1 MSPS throughput. Series ferrite beads on AVDD/DVDD near the IC can further attenuate broadband digital switching noise that would otherwise degrade SNR by 3-5 dB.
Estimated: at VIN = 5.25 V full-scale input and 1 MSPS continuous conversion, the AS1545 draws approximately 6-8 mA (estimated from typical 12-bit 1 MSPS SAR power budgets) and dissipates ~30-40 mW; with the 32-TQFN EP thermal resistance of roughly 30 C/W, junction temperature rise above ambient is approximately 1-2 C - well within the 85 C rating, so no heatsink is needed at room temperature. A common mistake is omitting the external reference bypass capacitor on REFIN/REF_OUT: failing to place a 10 uF X7R within 5 mm of the REFIN pin can increase conversion-to-conversion noise by 2-4 LSB. Another frequent pitfall is leaving the MUX_A0/A1/A2 address pins floating - tie them high or low explicitly through 10 kohm resistors to avoid channel-selection glitches during power-up.
Información de cumplimiento
RoHS, REACH, lead-free, halogen-free, and conflict-minerals certifications are not present in the Verified Web Data; [DATA_NEEDED] markers retained in specs array. AS1545 is not AEC-Q100 qualified - automotive designs above 85 C ambient must use AEC-Q100-qualified SAR ADCs from ams OSRAM, TI, or ADI.
