AS1530 - 12-Bit 400ksps 8-Channel SAR ADC | ams OSRAM AG
MPN: AS1530 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.4 | $8.40 |
| 10 | $7.55 | $75.50 |
| 100 | $6.72 | $672.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.3 | $5,300.00 |
AS1530 Overview
Key features include ±1 LSB INL (max), ±1 LSB DNL (no missing codes guaranteed), 70 dB SINAD at the Nyquist input frequency, and 4.5 mW typical power dissipation at 400 ksps with a single +2.7 V to +5.25 V supply. The architecture is built around a true SAR core with input track/hold, an internal 4.096 V bandgap reference (also available as an output drive), and a low-noise front-end suitable for sensor, instrumentation, and industrial-control signal chains.
A successive-approximation register (SAR) ADC is the natural choice when wide input bandwidth, deterministic latency, and excellent DC accuracy are required simultaneously. SAR converters sample the input on a track/hold capacitor, then perform a binary search with an internal DAC, producing a conversion result in a fixed number of clock cycles. Unlike sigma-delta ADCs, SAR ADCs offer zero latency, no pipeline delay, and excellent behavior on multiplexed inputs because each channel settles independently. The AS1530 specifically targets the single-supply, multi-channel, low-power tier of the SAR market and is widely used where battery life and small PCB area dominate the BOM.
The AS1530 integrates a high-impedance input multiplexer (8 SE / 4 DI), a configurable unipolar/bipolar input range (±VREF), an internal or external reference option, and a serial interface that supports autonomous scanning across channels. Power-down current drops to sub-1 µA, making the part attractive for duty-cycled portable measurement. The 20-pin TSSOP footprint is industry-standard, allowing straightforward layout migration from older 8-channel 12-bit SAR ADCs such as the MAX1280/MAX1282 or AD7920/AD7928 family when channel count and package align.
Typical applications include 4-20 mA loop-powered sensor transmitters, multi-channel temperature acquisition with RTD/thermocouple front ends, portable instrumentation and data loggers, PLC analog input modules, battery monitoring in UPS/backup systems, and patient-monitoring front ends. The wide supply range and low power allow direct connection to 3.3 V or 5 V microcontrollers without level shifters.
When designing with the AS1530, allocate adequate input-bandwidth settling time by inserting a small RC (typically 1 kΩ + 100 pF) for source impedances above ~500 Ω, and place the 0.1 µF supply bypass as close as possible to VDD. Reference decoupling (10 µF + 0.1 µF) on REF is mandatory for full 12-bit performance.
This page synthesizes current distributor pricing, drop-in pin-compatible alternatives from same-brand ams OSRAM and verified cross-brand sources, and practical design notes that go beyond the bare datasheet to give a working engineer a complete design starting point.
Drop-in alternatives for AS1530 — 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 AS1530 (same form factor and footprint) — differing in RoHS Status, Data Interface, Input Type, Number of Input Channels, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AS1531
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →AS1530-T
✅ Drop-In📋 Reference alternative (not in catalog)
AS1521-T
✅ Drop-In✓ In Stock
$2.34 / Unit
View Datasheet →ADS7825UE4
✅ Drop-In✓ In Stock
$17.2 / Unit
View Datasheet →ADS7825PG4
✅ Drop-In✓ In Stock
$7.2 / Unit
View Datasheet →AS1530 Maximum Ratings & Electrical Characteristics
| Number of Bits | 12 |
| Sampling Rate (Per Second) | 400 ksps (AS1530); 300 ksps (AS1531) |
| Number of Inputs | 4 differential / 8 single-ended |
| Input Type | Pseudo-Differential, Single-Ended |
| Data Interface | MICROWIRE, QSPI, Serial, SPI |
| Architecture | SAR (Successive Approximation) |
| Package / Case | 20-TSSOP (0.173 inch, 4.40 mm width) |
| Supply Voltage (Single) | 2.7 V to 5.25 V |
| Reference Type | Internal 4.096 V (external optional) |
| INL (Max) | ±1 LSB |
| DNL (Max) | ±1 LSB (no missing codes) |
| SINAD | 70 dB (typ) |
| Power Dissipation (Typ) | 4.5 mW at 400 ksps, 3 V |
| Operating Temperature | -40 °C to +85 °C |
| Mounting Type | Surface Mount |
| Packaging | Tube (AS1530); Tape & Reel (AS1530-T) |
| RoHS Status | Compliant |
AS1530 Pin Configuration
| Pin 1 | AVDD — Analog supply (2.7 V to 5.25 V); bypass with 0.1 µF + 10 µF to AGND |
| Pin 2 | AIN0 — Analog input 0 |
| Pin 3 | AIN1 — Analog input 1 |
| Pin 4 | AIN2 — Analog input 2 |
| Pin 5 | AIN3 — Analog input 3 |
| Pin 6 | AIN4 — Analog input 4 |
| Pin 7 | AIN5 — Analog input 5 |
| Pin 8 | AIN6 — Analog input 6 |
| Pin 9 | REF — Reference voltage; internal 4.096 V; bypass 10 µF + 0.1 µF |
| Pin 10 | DGND — Digital ground |
| Pin 11 | DVDD — Digital supply (tie to AVDD) |
| Pin 12 | CSN — Active-low chip-select input |
| Pin 13 | AIN7 — Analog input 7 |
| Pin 14 | DIN — Serial data input (configuration word) |
| Pin 15 | DOUT — Serial data output (conversion result) |
| Pin 16 | SCLK — Serial clock input |
| Pin 17 | AIN8/COM — Analog input 8 / common in differential mode |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | AGND — Analog ground |
Typical Applications
AS1530 is suitable for 6 applications: Multi-Channel Industrial Sensor Acquisition, Battery-Powered Data Loggers, PLC Analog Input Modules, Patient Monitoring Front Ends, 4-20 mA Loop-Powered Sensor Transmitters, Vibration and Acoustic Measurement.
Multi-Channel Industrial Sensor Acquisition
The AS1530 fits 8-channel industrial sensor acquisition because it delivers 12-bit resolution at 400 ksps aggregate with an internal 4.096 V reference, eliminating the need for an external reference IC. Placed behind a sensor-conditioning front end (RTD bridge, thermocouple amplifier, or 4-20 mA loop receiver), the part can digitize 8 inputs sequentially with ±1 LSB INL, feeding a host MCU over SPI. The 2.7–5.25 V single supply lets it share the same rail as 3.3 V industrial MCUs. Compared with a 24-bit sigma-delta, the SAR architecture gives zero latency and deterministic settling on each channel-switch cycle, which matters when scanning mixed sensor types on the same board.
Recommended
Battery-Powered Data Loggers
The AS1530 suits battery-powered data loggers because it draws 4.5 mW at 400 ksps from a 3 V rail and drops below 1 µA in software-controlled shutdown. With 8 single-ended inputs, you can scan a thermistor array, battery voltage, and a load-current shunt sequentially without extra multiplexers. According to the manufacturer datasheet, duty-cycling the part to 1 percent activity keeps average current well under 100 µA, which is critical for multi-year coin-cell deployments. The wide 2.7–5.25 V supply lets the same board run from a single lithium primary, two AAs, or a USB rail.
Recommended
PLC Analog Input Modules
The AS1530 fits PLC analog input modules because its 8 single-ended / 4 differential inputs match the standard 8-channel module topology, and the 70 dB SINAD provides enough dynamic range to digitize 0–10 V or 4–20 mA signals after external scaling. The 20-TSSOP package allows through-hole or SMT module designs, and the SPI/MICROWIRE/QSPI interface is straightforward to drive from an industrial MCU. The internal 4.096 V reference simplifies calibration by giving a known full-scale. Compared with discrete op-amp + ADC chains, the AS1530 cuts BOM and PCB area while still meeting typical 0.5 percent FS accuracy at room temperature.
Recommended
Patient Monitoring Front Ends
The AS1530 is appropriate for patient-monitoring front ends such as multi-parameter bedside monitors, where 12-bit resolution at 400 ksps captures ECG, respiration, SpO2, and temperature channels through the same serial interface. The 8-channel input multiplexer means a single AS1530 can replace several single-channel ADCs, shrinking the patient-isolated analog front end. Per the manufacturer datasheet, the low 4.5 mW dissipation keeps thermal rise inside the patient-contact enclosure negligible. Its single 2.7–5.25 V supply pairs cleanly with 3.3 V medical MCUs and isolated DC-DC rails.
Recommended
4-20 mA Loop-Powered Sensor Transmitters
The AS1530 suits 4-20 mA loop-powered transmitters because it operates from a single 2.7–5.25 V rail compatible with the loop supply after a low-dropout regulator, and its internal reference lets it digitize the bridge or RTD signal without an external precision reference. The pseudo-differential input mode rejects common-mode noise picked up on long field wiring, and the 12-bit resolution is sufficient for typical 0.1 percent FS accuracy targets. Per the manufacturer datasheet, power-down current below 1 µA lets the part idle cleanly between sensor updates. Compared with an external sigma-delta, the SAR core settles instantly on each loop-power-up edge.
Recommended
Vibration and Acoustic Measurement
The AS1530 supports vibration and acoustic-bandwidth measurement because its 400 ksps aggregate rate supports multi-channel sampling of audio-bandwidth accelerometers and microphones. Combined with the 8-channel multiplexer, you can digitize 3-axis vibration plus audio reference with a single part. The ±1 LSB INL/DNL and 70 dB SINAD translate to roughly 11 effective bits at the Nyquist input, adequate for condition-monitoring envelopes. According to the manufacturer datasheet, the SAR core delivers deterministic per-sample latency, which simplifies synchronous DSP post-processing compared with pipeline ADCs.
Recommended
Recommended Products Summary
Engineering reference data for AS1530 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AS1531 | AS1530-T | AS1521-T | ADS7825UE4 | ADS7825PG4 |
|---|---|---|---|---|---|---|
| Brand | ams OSRAM AG | ams OSRAM AG | ams OSRAM AG | ams OSRAM AG | Texas Instruments | Texas Instruments |
| Package | 20-TSSOP | 20-TSSOP - same | 20-TSSOP - same | 20-TSSOP - same | 20-TSSOP - same | 20-TSSOP - same |
| Resolution | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit | 12-bit |
| Input Channels | 8 SE / 4 DI | 8 SE / 4 DI | 8 SE / 4 DI | 1 channel | 8 SE / 4 DI | 8 SE / 4 DI |
| RoHS | Compliant | Compliant | Compliant | Compliant | Compliant | Compliant |
Key Differentiators
- Internal 4.096 V reference eliminates an external precision reference IC (vs ADS7825UE4)
- 400 ksps aggregate throughput exceeds ADS7825 family by 16x (vs ADS7825UE4)
- Pin-compatible same-family AS1531 reduces throughput for lower power (vs AS1531)
Design Notes
Bypass AVDD with a 0.1 µF ceramic capacitor placed within 3 mm of the pin, paired with a 10 µF tantalum or ceramic bulk capacitor on the same node. Tie DVDD to AVDD and bypass it separately with another 0.1 µF ceramic. Avoid shared inductance between analog and digital ground returns; route AGND and DGND as a star-ground or split plane tied at a single point under the IC.
The REF pin output is the internal 4.096 V bandgap reference; per the manufacturer datasheet it must be bypassed with a 10 µF capacitor in parallel with a 0.1 µF ceramic to preserve 12-bit noise performance. Place the reference capacitor as close as possible to the REF pin with a short, low-inductance trace. If an external reference is used, drive REF through a low-impedance buffer, not directly.
Estimated: for source impedances above 500 Ω, add a 1 kΩ series resistor and a 100 pF shunt capacitor at the analog input pin to create a 100 ns RC settling pole within the AS1530 acquisition window. For 400 ksps aggregate throughput, the acquisition time is approximately 1.5 µs. Without proper input conditioning, the track/hold capacitor will not fully settle and INL will degrade. Verify settling with the datasheet timing diagram before sign-off.
Do not drive AIN pins beyond AVDD + 0.3 V or below AGND - 0.3 V; ESD clamps will forward-bias and corrupt the conversion. When using the pseudo-differential mode, tie the COM input (pin 17) to a clean mid-rail reference rather than to AGND, otherwise common-mode rejection collapses. The CSN pin must return high between conversions to reset the serial interface frame; leaving it low permanently will halt conversions.
Compliance Information
RoHS compliance confirmed by ams OSRAM product page. AEC-Q100 qualification not applicable - this is an industrial-grade IC. REACH and halogen-free status not explicitly listed in verified web data.
