MAX11905GTP+ - 20-Bit 1.6Msps Low-Power SAR ADC | Analog Devices
MPN: MAX11905GTP+ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $56.1 | $56.10 |
| 10 | $50.49 | $504.90 |
| 100 | $44.88 | $4,488.00 |
| 500 | $42.4 | $21,200.00 |
| 1,000 | $39.74 | $39,740.00 |
MAX11905GTP+ Overview
An SAR ADC (Successive Approximation Register analog-to-digital converter) is a precision data converter that uses a binary-search algorithm and an internal capacitive DAC to resolve an analog input voltage to N bits in N conversion cycles. SAR ADCs sit in the broader hierarchy of data converters (ADC/DAC) within mixed-signal ICs, and are prized for their deterministic latency, zero pipeline delay, and excellent DC accuracy, which makes them the dominant choice for precision instrumentation, industrial process control, and high-accuracy multi-channel data-acquisition systems.
Key features include 1.6 Msps throughput, 20-bit resolution with no missing codes, true-differential inputs with ±VREF range, integrated reference buffers that eliminate external buffer amps, and a serial peripheral interface (SPI/QSPI/MICROWIRE-compatible) for digital communication. The device also offers low drift across temperature and excellent AC performance including high SNR and THD suitable for precision measurement.
The MAX11905 uses a charge-redistribution SAR core with on-chip input sampling switches and a precision internal reference buffer architecture. Power consumption scales linearly with sample rate, allowing the device to draw minimal current at lower throughput, which is ideal for battery-powered or thermally constrained designs. The differential input structure and high common-mode rejection provide robust performance in electrically noisy industrial environments.
Typical applications include industrial process control and instrumentation, precision weigh scales and sensor signal conditioning, medical instrumentation such as patient monitoring and diagnostic equipment, automated test equipment (ATE), seismic and vibration data acquisition, and high-accuracy multi-channel data-acquisition systems. The wide dynamic range and low noise also suit audio-bandwidth precision measurement applications.
When designing with the MAX11905GTP+, keep analog and digital grounds separated with a single-point star connection at the board-level AGND/DGND plane, place the 3.3 V and 1.8 V decoupling capacitors as close as possible to the supply pins, and ensure the input common-mode voltage is biased within the specified range for full-scale accuracy.
This page synthesizes distributor pricing, drop-in package alternatives, and practical design notes not found in the manufacturer datasheet alone, giving engineers a faster path from spec to prototype.
Drop-in alternatives for MAX11905GTP+ — 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 MAX11905GTP+ (same form factor and footprint) — differing in Architecture, Input Type, Package, Resolution, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX11905ETP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX11905GTP+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX11905ETP+T
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX11903ETP+T
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$8.8 / Unit
View Datasheet →MAX11905GTP+ Maximum Ratings & Electrical Characteristics
| Resolution | 20 bit |
| Sample Rate | 1.6 Msps |
| Architecture | SAR (Successive Approximation Register) |
| Number of Channels | 1 |
| Input Type | Fully Differential, unipolar ±VREF range |
| Analog Supply Voltage | 3.3 V |
| Digital Supply Voltage | 1.8 V |
| Reference | Internal reference buffers (external reference required) |
| Interface | SPI/QSPI/MICROWIRE-compatible serial |
| Package | 20-pin TQFN (4x4 mm) |
| Mounting Type | Surface Mount |
| Power Consumption | Scales with throughput; best-in-class low power |
| RoHS Status | ROHS3 Compliant |
| Differential Input Range | ±VREF |
MAX11905GTP+ Pin Configuration
| Pin 1 | AGND — Analog ground |
| Pin 2 | AVDD — 3.3 V analog supply |
| Pin 3 | REF — External reference input (internally buffered) |
| Pin 4 | REFGND — Reference ground return |
| Pin 5 | IN+ — Differential positive analog input |
| Pin 6 | IN- — Differential negative analog input |
| Pin 7 | AGND — Analog ground |
| Pin 8 | AVDD — 3.3 V analog supply |
| Pin 9 | DGND — Digital ground |
| Pin 10 | DVDD — 1.8 V digital supply |
| Pin 11 | CNV — Convert / Start of conversion input |
| Pin 12 | CS — Chip select (active low) |
| Pin 13 | SCK — Serial clock input |
| Pin 14 | SDI — Serial data input (daisy-chain) |
| Pin 15 | SDO — Serial data output |
| Pin 16 | DGND — Digital ground |
| Pin 17 | DVDD — 1.8 V digital supply |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | EP — Exposed thermal pad - tie to AGND |
Typical Applications
MAX11905GTP+ is suitable for 6 applications: Industrial Process Control and Instrumentation, Precision Weigh Scales and Load Cell Signal Conditioning, Medical Instrumentation and Patient Monitoring, Automated Test Equipment (ATE) and Data Acquisition, Seismic and Vibration Data Acquisition, High-Accuracy Multi-Channel Data Acquisition Systems.
Industrial Process Control and Instrumentation
The MAX11905GTP+ is well suited for industrial process-control loops that require high-accuracy digitisation of 4-20 mA-derived or sensor-conditioned signals at multi-kHz bandwidth. Its 20-bit resolution and 1.6 Msps throughput let a single ADC service multiple multiplexed input channels in PLC analog modules while maintaining >100 dB SNR-class dynamic range. The differential ±VREF input rejects common-mode noise from long sensor cables, and the 3.3 V/1.8 V split supply rails integrate cleanly with modern low-voltage FPGA and MCU back-end controllers used in distributed control systems.
Recommended
Precision Weigh Scales and Load Cell Signal Conditioning
Load-cell-based weigh scales need microvolt-level noise performance and excellent DC linearity, both of which the MAX11905GTP+ delivers through its 20-bit SAR architecture and internal reference buffers. The throughput-scaled power consumption keeps thermal dissipation low in compact bench-scale enclosures, and the SPI-compatible serial interface simplifies connection to host microcontrollers for display and calibration management. Placing the MAX11905GTP+ directly behind a low-noise instrumentation amp such as the MAX44241 makes a complete weigh-scale signal chain in a small PCB footprint.
Recommended
Medical Instrumentation and Patient Monitoring
Patient-monitoring front-ends demand high DC accuracy, low noise, and reliable differential measurement across safety-isolated boundaries - all met by the MAX11905GTP+'s 20-bit SAR core. The differential ±VREF input accommodates the bipolar ECG, SpO2, and temperature-sensor signals used in multi-parameter patient monitors, while the 1.6 Msps throughput supports oversampling techniques that improve effective resolution beyond the native 20 bits. The TQFN-20 package's small 4x4 mm footprint suits compact wearable designs and the SPI output simplifies isolation with digital isolators.
Recommended
Automated Test Equipment (ATE) and Data Acquisition
ATE pin-cards and modular data-acquisition systems benefit from the MAX11905GTP+'s combination of 1.6 Msps throughput, 20-bit resolution, and deterministic zero-latency SAR conversion. Multiplexed test points can be sampled back-to-back without the delay of sigma-delta digital filters, which is critical for timing-sensitive production test of semiconductors. The differential input handles the wide dynamic range of stimulus-and-response measurements, and the small TQFN-20 package enables high channel density on space-constrained pin cards.
Recommended
Seismic and Vibration Data Acquisition
Vibration monitoring systems for structural-health monitoring and industrial condition-based maintenance require wide dynamic range at audio and ultrasonic bandwidths. The MAX11905GTP+ provides 1.6 Msps sampling, sufficient to capture vibration spectra up to ~800 kHz with anti-alias filtering, while its 20-bit resolution preserves the low-amplitude harmonics critical for fault diagnosis. Differential IEPE-compatible inputs via a front-end amplifier connect directly to the MAX11905's ±VREF differential input, producing a compact and high-fidelity acquisition chain.
Recommended
High-Accuracy Multi-Channel Data Acquisition Systems
Modular DAQ systems that aggregate dozens of analog inputs benefit from the MAX11905GTP+'s pin-compatible 20-pin TQFN package, allowing layout reuse across channel cards with different speed/resolution variants. The 1.6 Msps throughput lets a single ADC scan multiple channels sequentially with deterministic latency, while the 20-bit resolution supports 4-digit digital multimeter and 16-bit effective-system-grade performance. Internal reference buffers reduce external component count and BOM cost per channel in dense DAQ subsystems.
Recommended
Recommended Products Summary
Engineering reference data for MAX11905GTP+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX11905ETP+ | MAX11905GTP+T | MAX11905ETP+T | MAX11903ETP+T |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 20-pin TQFN (4x4) | 20-pin TQFN (4x4) - same | 20-pin TQFN (4x4) - same | 20-pin TQFN (4x4) - same | 20-pin TQFN (4x4) - same |
| Resolution | 20 bit | 20 bit | 20 bit | 20 bit | 20 bit |
| Sample Rate | 1.6 Msps | 1.6 Msps | 1.6 Msps | 1.6 Msps | ~1 Msps |
| Input Type | Fully Differential ±VREF | Fully Differential ±VREF | Fully Differential ±VREF | Fully Differential ±VREF | Fully Differential |
| Analog Supply | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V |
| Digital Supply | 1.8 V | 1.8 V | 1.8 V | 1.8 V | 1.8 V |
| Temperature Grade | Industrial | Extended commercial | Industrial | Extended commercial | Extended commercial |
| RoHS Compliance | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant |
Key Differentiators
- Fastest and lowest-power 20-bit SAR ADC in its class (vs MAX11903ETP+T)
- Internal reference buffers eliminate external reference amp (vs MAX11905ETP+)
- Industrial temperature grade with full production status (vs MAX11905ETP+)
Design Notes
Place the 3.3 V AVDD and 1.8 V DVDD decoupling capacitors as close as possible to the respective supply pins (AVDD, DVDD) and to the exposed thermal pad (EP), which must be soldered to a dedicated analog-ground copper pour. Use separate AGND and DGND planes joined at a single-point star under the IC, and route the REF input with a wide, ground-guarded trace to keep the buffered reference noise below 1 LSB. Add a 0.1 µF X7R bypass in parallel with a 10 µF tantalum or polymer cap on each supply rail for broadband decoupling.
Drive the differential IN+ and IN- pins from a low-noise, low-distortion driver such as the MAX44241 or ADA4945 to preserve the ADC's 20-bit dynamic range. Keep the input traces matched in length and symmetrically routed to avoid differential-to-common-mode conversion; place a common-mode bias network (resistor divider from REF) right at the IC inputs if the source is AC-coupled. Avoid routing digital SCK, SDO, and CNV signals under or near the analog input traces to minimise digital feed-through.
Do not exceed the absolute maximum ratings on AVDD (typically 4 V) or DVDD (typically 2 V), and ensure DVDD is brought up before or simultaneously with AVDD to avoid latch-up. The MAX11905 requires an external reference - applying 0 V on REF will not work and may damage the buffer; provide a clean low-noise reference such as the MAX6126A21 (2.048 V). When using CNV in high-throughput mode, observe the minimum acquisition time (tACQ) before initiating a new conversion or settled data will be corrupted.
Compliance Information
ROHS3 compliant per full-electronic.com distributor listing. AEC-Q100 not qualified - this is a precision industrial/medical-grade part, not automotive. REACH, halogen-free, and conflict-minerals status not stated in the verified web data.
