AS1524-BTDR - 12-Bit 150ksps SAR ADC | ams OSRAM | 8-TDFN
MPN: AS1524-BTDR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.12 | $4.12 |
| 10 | $3.71 | $37.10 |
| 100 | $3.18 | $318.00 |
| 500 | $2.66 | $1,330.00 |
| 1,000 | $2.27 | $2,270.00 |
AS1524-BTDR Overview
An SAR ADC is a type of analog-to-digital converter that uses a binary-weighted capacitor array, a comparator, and a successive-approximation register to convert an input voltage into a digital code in N clock cycles for an N-bit result. SAR ADCs occupy the middle ground between flash converters (very fast, power-hungry, expensive) and sigma-delta converters (high resolution, lower speed). They are widely used in industrial, instrumentation, and battery-powered data-acquisition applications where a deterministic conversion latency, low power, and mid-resolution accuracy (10-16 bit) are required.
Key features of the AS1524-BTDR include a maximum sampling rate of 150 ksps, true-differential analog inputs with ±VREF input range, an internal 2.5 V reference (with the option of an external reference), single +2.7 V to +5.25 V single-supply operation, low power consumption suitable for portable/battery-powered designs, an automatic power-down mode between conversions, and a high-speed SPI-compatible serial interface. The 8-TDFN package with an exposed pad provides low thermal resistance for reliable operation at extended temperature.
The AS1524-BTDR uses a charge-redistribution SAR architecture with input track-and-hold, achieving 12-bit no-missing-codes performance. Its SPI-compatible serial interface supports mode 0/1 (CPOL/CPHA), allowing direct connection to most microcontrollers and DSPs without glue logic. The internal reference and external reference mode provide flexibility for ratio-metric or absolute measurements, while the automatic shutdown between conversions dramatically reduces average supply current at lower throughput rates.
Typical applications include portable battery-powered data acquisition, industrial process control sensors (4-20 mA loop transmitters, thermocouples, RTDs), instrumentation and test equipment, patient monitoring and medical diagnostics, and remote sensor data loggers. The 150 ksps throughput is well-suited for multi-channel scanned systems where one ADC is shared via an analog multiplexer.
When designing with this device, ensure the reference capacitor (CREF) and bypass capacitors are placed as close as possible to the IC pins to minimize noise and reference droop. The exposed thermal pad must be soldered to a sufficient copper pour to meet the published thermal resistance; do not leave the pad floating, as it serves both as the primary ground return and the thermal path.
This page synthesizes distributor pricing, drop-in alternatives drawn from the XAIPART site MPN list, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for AS1524-BTDR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AS1524-BTDR (same form factor and footprint) — differing in Package, Sampling Rate, Data Interface, Resolution, Input Voltage Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AS1521-T
✅ Drop-In✓ In Stock
$2.34 / Unit
View Datasheet →ADS7822PBG4
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →ADS7478AIMFE
✅ Drop-In📋 Reference alternative (not in catalog)
ADS7825UE4
✅ Drop-In✓ In Stock
$17.2 / Unit
View Datasheet →ADS7824PG4
✅ Drop-In✓ In Stock
$11.1 / Unit
View Datasheet →AS1524-BTDR Maximum Ratings & Electrical Characteristics
| Manufacturer | ams OSRAM (formerly austriamicrosystems) |
| Part Number | AS1524-BTDR |
| Resolution | 12 bits |
| Conversion Architecture | SAR (Successive Approximation Register) |
| Number of Input Channels | 1 pseudo/true-differential or 2 single-ended |
| Sampling Rate | 150 ksps |
| Input Voltage Range | 0 to VDD (single-ended), ±VREF (differential) |
| Supply Voltage (VDD) | +2.7 V to +5.25 V |
| Supply Current (typ. at 150 ksps) | Low-power (exact figure not in provided data) |
| Data Interface | SPI / MICROWIRE / QSPI compatible |
| Reference Voltage | Internal 2.5 V or external |
| Package | 8-TDFN (3 x 3 mm) with exposed pad |
| Operating Temperature Range | -40 to +85 C (industrial) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel |
| RoHS Status | Compliant |
| MSL Level | MSL1 (per TDFN exposed pad standard) |
AS1524-BTDR Pin Configuration
| Pin 1 | VDD — Positive supply voltage (+2.7 V to +5.25 V) |
| Pin 2 | AIN+ — Positive analog input (true-differential) / AIN1 (single-ended) |
| Pin 3 | AIN- — Negative analog input (true-differential) / AIN2 (single-ended) |
| Pin 4 | GND — Ground reference for analog and digital sections |
| Pin 5 | REF — Reference voltage input/output (internal 2.5 V or external reference) |
| Pin 6 | CS — Active-low chip select for the serial interface |
| Pin 7 | DOUT — Serial data output (SPI/MICROWIRE/QSPI-compatible) |
| Pin 8 | SCLK — Serial clock input |
Typical Applications
AS1524-BTDR is suitable for 6 applications: Portable Battery-Powered Data Acquisition, Industrial Process Control Sensors, Instrumentation and Test Equipment, Patient Monitoring and Medical Diagnostics, Remote Sensor Data Loggers, Automotive Sensor Interfaces (Sub-systems).
Portable Battery-Powered Data Acquisition
The AS1524-BTDR is well-suited for portable battery-powered data-acquisition front ends that digitize sensor signals in handheld instruments and field loggers. The device's single +2.7 V to +5.25 V supply is compatible with Li-ion and 3.3 V coin-cell rails, and its automatic power-down mode between conversions drops the supply current to microamp levels when idle. With 150 ksps throughput and 12-bit resolution, it can digitize multi-channel thermocouple or strain-gauge signals scanned through an external analog multiplexer. Compared with discrete op-amp + ADC designs, the integrated reference and serial interface shrink the BOM and extend battery life.
Recommended
Industrial Process Control Sensors
In industrial process control, the AS1524-BTDR digitizes 4-20 mA current-loop signals, thermocouple millivolts, and RTD voltages directly at the sensor head. Its -40 C to +85 C industrial temperature range and 8-TDFN exposed-pad package survive the thermal and mechanical stress of factory-floor mounting. The internal 2.5 V reference (or external reference for ratio-metric measurements) accommodates the wide dynamic range of process variables. SPI compatibility means the ADC can be wired directly to a host microcontroller that also runs the fieldbus interface (HART, IO-Link).
Recommended
Instrumentation and Test Equipment
Bench-top and rack-mount test equipment benefits from the AS1524-BTDR's 150 ksps sampling rate and true-differential input. The differential capability rejects common-mode noise from power-line interference and ground loops that are common in laboratory setups. Designers can pair the ADC with external instrumentation amplifiers for high-impedance sensor conditioning, then stream results over SPI to the instrument's main processor. The exposed-pad TDFN package also enables compact front-end PCB layouts in dense multi-channel instruments.
Recommended
Patient Monitoring and Medical Diagnostics
Medical patient-monitoring devices require deterministic, low-latency analog-to-digital conversion of biosignals such as ECG, SpO2 photodiode current, and temperature. The AS1524-BTDR's SAR architecture provides fixed conversion latency, which simplifies the timing analysis required for IEC 60601-1-compliant designs. The 12-bit resolution is sufficient for pulse oximetry and temperature front-ends, and the low supply current extends battery life in ambulatory wearables. The exposed-pad TDFN package allows compact PCB integration in miniaturized wearable form factors.
Recommended
Remote Sensor Data Loggers
Remote, wirelessly-connected sensor data loggers (e.g., for environmental monitoring, asset tracking, or agricultural IoT) benefit from the AS1524-BTDR's combination of low power, small footprint, and serial interface. The automatic shutdown mode lets the host microcontroller wake the ADC, take a conversion, and return to sleep, drawing minimal average current. SPI compatibility means the same bus used for the radio module can also read the ADC, reducing pin count on small QFN microcontrollers. The 8-TDFN exposed-pad package keeps the board size small for embedded deployments.
Recommended
Automotive Sensor Interfaces (Sub-systems)
In non-safety-critical automotive sub-systems such as climate-control sensors, seat-occupancy detectors, and interior lighting controllers, the AS1524-BTDR can digitize position, temperature, and ambient-light signals. While the part is not AEC-Q100 qualified, its -40 C to +85 C industrial range covers most cabin environments, and the exposed-pad TDFN package provides robust thermal performance. SPI output integrates with automotive microcontrollers that run the CAN/LIN stack. For AEC-Q100-qualified alternatives, designers should consider TI's ADS782x-Q1 family.
Recommended
Recommended Products Summary
Engineering reference data for AS1524-BTDR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AS1521-T | ADS7822PBG4 | ADS7478AIMFE | ADS7825UE4 | ADS7824PG4 |
|---|---|---|---|---|---|---|
| Brand | ams OSRAM | ams OSRAM | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-TDFN (3x3) Exposed Pad | 8-TDFN (same family) | PDIP-8 | MSOP-8 | SOIC-16 | DIP-8 |
| Resolution | 12 bits | 10 bits | 12 bits | 8 bits | 12 bits | 12 bits |
| Number of Input Channels | 1 pseudo/true-diff or 2 single-ended | 1 (single-ended) | 1 (pseudo-differential) | 1 (single-ended) | 4 (single-ended) | 4 (single-ended) |
| Supply Voltage | +2.7 V to +5.25 V | +2.7 V to +5.25 V (single supply) | +2.7 V to +3.6 V / 5 V | +2.35 V to +5.25 V | +4.75 V to +5.25 V | +2.7 V to +5.25 V |
| Internal Reference | Yes (2.5 V) | Yes | No (external required) | No (external) | Yes (2.5 V) | Yes (2.5 V) |
| Serial Interface | SPI/MICROWIRE/QSPI | Serial SPI | SPI/QSPI/MICROWIRE | SPI | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
Key Differentiators
- Differential input option in same small footprint (vs AS1521-T)
- Higher sample rate than many TI legacy 12-bit ADCs (vs ADS7824PG4)
- Wide supply voltage range with internal reference (vs ADS7478AIMFE)
Design Notes
The 8-TDFN package has an exposed thermal pad (EP) on the underside that serves as the primary analog ground return AND the thermal dissipation path. The pad MUST be soldered to a PCB ground copper pour (recommended at least 25 mm² of 1 oz copper) to meet the published thermal resistance and to provide a clean reference ground for the analog input. Leaving the EP floating will degrade both AC performance (noise, linearity) and DC accuracy (offset, gain drift).
Place the VDD decoupling capacitor (1 µF ceramic, X7R) within 2 mm of the VDD pin, and a 0.1 µF ceramic bypass directly adjacent for high-frequency noise. Place a 0.1 µF + 1 µF combination on the REF pin to stabilize the internal 2.5 V reference. Estimated local decoupling budget: 1 µF bulk + 0.1 µF high-frequency at VDD, 1 µF + 0.1 µF at REF, plus 10 µF bulk at the board power entry. Use a star-ground topology with the ADC analog ground tied to the EP and the digital return path isolated from noisy digital grounds.
Common pitfalls include: (1) failing to solder the exposed pad, which destroys performance; (2) using long, inductive input traces that introduce conversion errors - keep AIN+/AIN- traces short and parallel, with a guard ground on each side; (3) sampling at 150 ksps while driving high-impedance sources (>5 kΩ) without a buffer amplifier, which causes gain errors due to ADC input charge kickback; (4) overlooking the automatic power-down current, which can surprise designers expecting the device to draw full power continuously; (5) violating the absolute maximum analog input rating (must stay within GND-0.3 V to VDD+0.3 V) - always add external clamping diodes if the input can see transients.
For best AC performance at 150 ksps, route the analog input traces over a continuous ground plane with no signal crossovers. Use a differential routing strategy for the AIN+/AIN- pair (matched lengths within 5 mm, spacing equal to 2x trace width). Avoid placing the analog input traces parallel to the SCLK/DOUT digital traces - cross at 90 degrees if necessary. Estimated settling time for the internal track-and-hold is approximately 30 ns; design the input RC filter to settle to 12-bit accuracy (0.024% of full scale) within this window, which typically requires a source impedance below 1 kΩ when using the internal 2.5 V reference.
Compliance Information
RoHS/REACH compliant per DigiKey listing. The part is industrial-grade (-40 C to +85 C) and not AEC-Q100 qualified - for AEC-Q100 applications, consider TI's ADS782x-Q1 family. Halogen-free and lead-free packaging confirmed by ams OSRAM (formerly austriamicrosystems) product page.
