MAX1203BCAP - 12-Bit 8-Ch SAR ADC, 133kSPS, SSOP-20 | Maxim
MPN: MAX1203BCAP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $21.64 | $21.64 |
| 10 | $19.47 | $194.70 |
| 100 | $17.31 | $1,731.00 |
| 500 | $15.15 | $7,575.00 |
| 1,000 | $12.99 | $12,990.00 |
MAX1203BCAP Overview
A successive-approximation ADC is a type of analog-to-digital converter that uses a binary search algorithm against an internal precision DAC to determine each code, delivering deterministic latency and true 12-bit resolution without pipeline delay. Within the ADC hierarchy, the MAX1203 sits between delta-sigma converters (slower, higher oversampling) and flash/pipeline converters (much faster, lower resolution or higher power). It is ideal for mid-speed multichannel data-acquisition where deterministic conversion time matters.
Key features of the MAX1203BCAP include 8 single-ended/4 differential input channels, 133 kS/s throughput, low 1.5 mA operating supply current, a 2 µA power-down mode, an internal 4.096 V reference (also accepts external reference), and user-adjustable output logic levels between 2.7 V and 5.25 V for mixed 5 V analog / 3 V digital systems. The serial interface reduces pin count relative to parallel ADCs and simplifies board routing.
The architecture pairs a capacitive-DAC successive-approximation core with an input track-and-hold rated to handle full-scale step inputs in less than a conversion clock, with SINAD/SNR measured near 70 dB on the MAX1203B grade and 71 dB on the higher-graded MAX1203A variant per partnumber compare tables.
Typical applications include multi-zone industrial process control loops, rack-mounted data-acquisition cards, portable instrumentation front ends with mixed-voltage rails, medical patient monitoring front ends, and embedded sensor hubs that digitize thermocouples, RTDs, strain gauges, or 4-20 mA loops. The wide analog supply range (single +5 V or dual ±5 V) and the 3 V-friendly logic output let designers bridge legacy 5 V analog front ends to modern 3.3 V microcontrollers without level translators.
When designing, place a 0.1 µF ceramic bypass close to each supply pin and tie the analog and digital grounds together at a single star point near the ADC; the reference decoupling footprint (typically 4.7 µF + 0.1 µF in parallel) is mandatory for 12-bit noise performance.
This page synthesizes distributor pricing, drop-in same-brand replacements, and PCB-layout guidance not aggregated on the manufacturer datasheet, enabling faster part selection and second-source validation.
Drop-in alternatives for MAX1203BCAP — 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 MAX1203BCAP (same form factor and footprint).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1203BCAP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1203BCAP+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1203ACAP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1203BEAP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1202ACAP
✅ Drop-In✓ In Stock
$7.17 / Unit
View Datasheet →MAX1203BCAP Maximum Ratings & Electrical Characteristics
| No specifications available |
MAX1203BCAP Pin Configuration
| Pin 1 | AIN0 — Analog input channel 0 |
| Pin 2 | AIN1 — Analog input channel 1 |
| Pin 3 | AIN2 — Analog input channel 2 |
| Pin 4 | AIN3 — Analog input channel 3 |
| Pin 5 | AIN4 — Analog input channel 4 |
| Pin 6 | AIN5 — Analog input channel 5 |
| Pin 7 | AIN6 — Analog input channel 6 |
| Pin 8 | AIN7 — Analog input channel 7 |
| Pin 9 | AGND — Analog ground |
| Pin 10 | REF — Reference input/output (internal 4.096 V or external) |
| Pin 11 | VDD — +5 V analog supply |
| Pin 12 | DGND — Digital ground |
| Pin 13 | DOUT — Serial data output (SPI/MICROWIRE) |
| Pin 14 | DIN — Serial data input |
| Pin 15 | SCLK — Serial clock input |
| Pin 16 | CS — Chip select (active low) |
| Pin 17 | VDL — Digital logic supply (2.7 V to 5.25 V) |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
MAX1203BCAP is suitable for 6 applications: Industrial Process Control Multi-Channel DAQ, Rack-Mount Data Acquisition Cards, Portable Instrumentation Front Ends, Medical Patient Monitoring Front End, Embedded Sensor Hub / IoT Edge Node, Mixed 5 V Analog / 3.3 V Digital Subsystems.
Industrial Process Control Multi-Channel DAQ
The MAX1203BCAP's 8 single-ended / 4 differential inputs and 133 kS/s throughput suit multi-zone PLC and SCADA modules that must scan thermocouples, 4-20 mA loops, and pressure transducers. Its single +5 V or ±5 V analog supply aligns with legacy industrial backplanes, while the user-adjustable 2.7-5.25 V digital output drives 3.3 V ARM-based controllers without external level-shifters. The 1.5 mA operating current and 2 µA power-down mode fit distributed I/O nodes on loop power. Reference a precision external reference or use the internal 4.096 V source for ratiometric measurement; SNR ~70 dB on the B grade delivers ~11 ENOB at full throughput, adequate for 0.1 % sensor readout.
Recommended
Rack-Mount Data Acquisition Cards
PCI/PCIe-based DAQ cards digitize multiple analog signals synchronously for instrumentation and ATE. The MAX1203BCAP's SPI-compatible serial interface minimizes board routing vs parallel ADCs, freeing FPGA or DSP pins for other tasks. With 133 kS/s and 12-bit resolution, one MAX1203BCAP per slot supports up to eight analog channels, and multiple devices share the bus for higher channel counts. The deterministic SAR conversion time (no pipeline delay) makes the part suitable for event-triggered sampling, and the SSOP-20 footprint keeps each channel card compact. Pair with an FPGA and DDR memory for waveform capture; SNR ~70 dB suffices for many sensor and audio test points.
Recommended
Portable Instrumentation Front Ends
Handheld multimeters, chart recorders, and field-ruggedized instruments benefit from the MAX1203BCAP's 1.5 mA operating current and 2 µA power-down mode, which dominate battery-life calculations. The 8 single-ended channels accept direct connection to op-amp buffers for voltage, current (via shunt), and resistance measurements; 4 differential mode rejects ground noise in long sensor leads. The 3 V-friendly logic interface aligns with modern low-power MCUs; the integrated 4.096 V reference eliminates a precision analog component. At ~$12 at qty-1000 it fits cost-sensitive portable designs without sacrificing 12-bit performance.
Recommended
Medical Patient Monitoring Front End
Patient monitors digitize ECG, SpO2, temperature, and respiration channels at modest rates with high common-mode rejection. The MAX1203BCAP's 4-channel differential mode rejects 50/60 Hz common-mode interference on body-coupled electrodes when paired with right-leg-drive circuits. Its deterministic SAR latency supports paced-event detection; the +5 V analog supply yields wide dynamic range for low-amplitude bioelectric signals. The 3 V digital logic interface bridges to low-power 32-bit MCUs that drive displays and wireless modules. Note: medical designs require IEC 60601 qualification at the system level; the MAX1203BCAP contributes 12-bit data accuracy but is not itself a medical-grade ADC.
Recommended
Embedded Sensor Hub / IoT Edge Node
Industrial IoT edge nodes aggregate multiple analog sensors (temperature, humidity, gas, strain) into a single digital stream. The MAX1203BCAP's 8-channel multiplexer and serial interface let a single SPI bus handle eight sensors without an external MUX, cutting BOM cost. The 2 µA power-down mode lets the MCU duty-cycle the ADC to microamp-average currents when scan rate is low. The SSOP-20 footprint supports reflow soldering on small PCBs, while the +5 V or ±5 V supply accommodates legacy sensor stacks. Provide a stable low-noise reference for absolute readings; rely on internal reference for ratiometric bridges.
Recommended
Mixed 5 V Analog / 3.3 V Digital Subsystems
Mixed-voltage subsystems - legacy 5 V analog with modern 3.3 V digital - often need level translation between ADC output and MCU. The MAX1203BCAP eliminates that need by offering user-adjustable logic levels from 2.7 V to 5.25 V. Place the ADC on a +5 V analog island and route its SPI lines directly into a 3.3 V ARM Cortex-M or RISC-V MCU, with no external level-shifters or buffer ICs. The +5 V analog supply sustains wide input common-mode range on legacy ±5 V op-amp stages, while the digital side stays modern. Robust SSOP-20 packaging simplifies hand-repair and rework on prototype boards.
Recommended
Recommended Products Summary
Engineering reference data for MAX1203BCAP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1203BCAP+ | MAX1203BCAP+T | MAX1203ACAP+ | MAX1203BEAP+ | MAX1202ACAP |
|---|---|---|---|---|---|---|
| Package | SSOP-20 | SSOP-20 | SSOP-20 | SSOP-20 | SSOP-20 | SSOP-20 |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 133 kS/s | 133 kS/s | 133 kS/s | 133 kS/s | 133 kS/s | 40 kS/s |
| Number of Channels | 4 / 8 (diff / SE) | 4 / 8 | 4 / 8 | 4 / 8 | 4 / 8 | 4 / 8 |
| Interface | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE |
Key Differentiators
- 8-channel multiplexer integrated on-chip, with both single-ended and differential modes (vs MAX1202ACAP)
- User-adjustable digital logic levels 2.7 V to 5.25 V eliminate external level shifters (vs MAX1203BCAP+)
- True 12-bit SAR architecture with deterministic conversion latency (vs MAX1162ACUB+T)
Design Notes
Decouple VDD with 1 µF + 0.1 µF ceramic capacitors placed within 5 mm of the supply pin to keep high-frequency digital return currents from corrupting the analog rail. The VDL logic supply, decoupled with 0.1 µF, sets the output level between 2.7 V and 5.25 V; tie it to the MCU VDD rather than VDD when driving a 3.3 V MCU. Tie AGND and DGND together at a single point near the IC rather than running separate returns, and avoid routing digital lines near the reference capacitor.
Place the reference decoupling (typically 4.7 µF + 0.1 µF in parallel) directly at the REF pin; the internal 4.096 V reference settles more slowly without a low-ESR capacitor at REF, and noise here couples straight into the SAR comparator decision levels. Route analog input traces differentially when using 4-channel differential mode and guard them with AGND pours to reject common-mode pickup. Keep the SSOP-20 thermal pad (if any) tied to AGND for stable thermal performance.
Driving analog inputs beyond the +5 V or below AGND violates absolute-maximum ratings and may latch the input ESD diodes, even briefly at power-up. Use a current-limiting resistor or external clamp diodes when connecting to a higher-voltage source. CS must be low for any SPI traffic; a floating CS pin may cause spurious conversion clocks. After power-up allow 10 µs for the internal reference to settle before issuing the first conversion command.
Compliance Information
RoHS-compliant per Maxim datasheet header; the '+' suffix indicates RoHS-compliant tape-and-reel. Reach/halogen-free status not explicitly stated in the verified web data and flagged as unknown.
