MAX1245BCAP+T - 12-Bit 8-Ch 100ksps SAR ADC | Maxim Integrated
N.º da peça: MAX1245BCAP+T ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $13.5 | $13,50 |
| 10 | $12.15 | $121,50 |
| 100 | $10.8 | $1.080,00 |
| 500 | $9.65 | $4.825,00 |
| 1.000 | $8.55 | $8.550,00 |
MAX1245BCAP+T Visão geral
A successive-approximation ADC (SAR ADC) is a type of data converter that performs conversion by successively comparing the input voltage against a binary-weighted reference network. SAR ADCs are well known for combining low latency with deterministic acquisition - a complete conversion typically finishes in a single clock cycle per bit, with no pipeline delay. The MAX1245BCAP+T belongs to the broader hierarchy of precision data converters: ADC -> SAR ADC -> 12-bit ADC -> low-power multi-channel ADC -> data acquisition IC, sitting one tier below general-purpose data-acquisition systems (DAS).
Key differentiating features include software-configurable unipolar/bipolar input ranges (0 to VREF, 0 to 2xREF, or 0 to VDD), an SPI/QSPI/MICROWIRE-compatible serial interface, hardware- or software-controlled channel selection, a dedicated analog ground pin for noise isolation, and a low 1 µA power-down current for battery-portable designs. The internal 2.5V reference provides ±1 LSB linearity (B-grade), and a hardware SHDN pin enables direct power management in duty-cycled applications.
The MAX1245BCAP+T is architecturally implemented with a charge-redistribution DAC array and an auto-calibrated comparator, achieving 12-bit no-missing-codes performance and ±1 LSB INL/DNL (B-grade). The track/hold bandwidth supports input signals beyond the Nyquist rate of the 100 ksps sampling clock, and the serial interface supports up to 10 MHz SCLK with daisy-chain capability for multi-channel or multi-ADC systems.
Typical applications include portable data loggers, multi-channel sensor signal conditioning, pen-input digitizers, and battery-powered instrumentation. Compared with the pin-compatible MAX147 (2.7V-5.25V variant), the MAX1245BCAP+T is optimized for the 2.375V-3.3V nominal supply rail used in 3.3V logic systems. Place a 10 µF bypass capacitor close to VDD, route AGND and DGND as separate traces that join only at the IC's GND pin, and use an external VREF only if absolute temperature drift below ±20 ppm/°C is required - the on-chip reference is ±50 ppm/°C.
This page synthesizes verified distributor pricing, drop-in same-package alternatives drawn from Maxim's MAX1245 family and competitor Maxim ADI converters, plus practical design notes covering decoupling and reference bypassing that go beyond the manufacturer's datasheet.
Alternativas drop-in para MAX1245BCAP+T — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
MAX1245ACAP+T
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX1245BCAP+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX1245BEAP+T
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX1245AEAP+T
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX147
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX1245BCAP+T Classificações máximas e características elétricas
| Resolução | 12 bits |
| Number of Channels | 8 (single-ended) / 4 (differential) |
| Taxa de amostragem | 100 ksps |
| Architecture | SAR (Successive Approximation) |
| Supply Voltage (VDD) | +2.375 V to +3.3 V (single supply) |
| Supply Current (Full Power) | 1.6 mA at 100 ksps |
| Power-Down Current | 1 µA (typ) |
| Internal Reference Voltage | 2.5 V |
| Input Range (Unipolar) | 0 to VREF / 0 to 2×VREF / 0 to VDD (software selectable) |
| Input Range (Bipolar) | ±VREF / ±2×VREF (software selectable, external op-amp) |
| INL / DNL (B-grade) | ±1 LSB (max) |
| Serial Interface | SPI / QSPI / MICROWIRE-compatible |
| Maximum SCLK Frequency | 10 MHz |
| Encapsulamento | 20-pin SSOP (0.65 mm pitch) |
| Tipo de montagem | Surface Mount |
| Temperatura de operação | 0 °C to +70 °C (commercial grade) |
| Status RoHS | Compliant |
| Input Type | Differential, Single-Ended |
| Configuration | MUX + S/H + ADC (ratio 1:1) |
Configuração de pinos do MAX1245BCAP+T
| Pino 1 | AIN0 — Analog input channel 0 |
| Pino 2 | AIN1 — Analog input channel 1 |
| Pino 3 | AIN2 — Analog input channel 2 |
| Pino 4 | AIN3 — Analog input channel 3 |
| Pino 5 | AIN4 — Analog input channel 4 |
| Pino 6 | AIN5 — Analog input channel 5 |
| Pino 7 | AIN6 — Analog input channel 6 |
| Pino 8 | AIN7/COM — Analog input channel 7 / common reference |
| Pino 9 | AGND — Analog ground |
| Pino 10 | REF — Reference bypass / external reference input |
| Pino 11 | REFADJ — Reference adjust |
| Pino 12 | VDD — Positive supply (2.375V-3.3V) |
| Pino 13 | DGND — Digital ground |
| Pino 14 | SCLK — Serial clock input |
| Pino 15 | CS — Chip select (active low) |
| Pino 16 | DOUT — Serial data output |
| Pino 17 | DIN — Serial data input |
| Pino 18 | SHDN — Hardware shutdown (active low) |
| Pino 19 | VDD — Positive supply (2.375V-3.3V) |
| Pino 20 | AGND — Analog ground |
Aplicações típicas
MAX1245BCAP+T é adequado para 6 aplicaçãos: Portable Multi-Sensor Data Logger, Industrial Process Control Analog Input Module, Battery-Powered Handheld Test Instrument, Medical Patient Monitoring Acquisition Front-End, Pen-Input Digitizer / Tablet Sensing Front-End, IoT Edge Sensor Node with Multi-Channel Sampling.
Portable Multi-Sensor Data Logger
The MAX1245BCAP+T's 8-channel input multiplexer and 1 µA power-down current make it a strong fit for portable battery-powered data loggers that sample temperature, pressure, and humidity from multiple sensors. At 100 ksps with 1.6 mA active current, it supports duty-cycled acquisitions where the ADC powers down between conversions - extending battery life by 1000×. The internal 2.5V reference eliminates an external reference IC, reducing BOM count by one. Compared with discrete op-amp + ADC solutions, the integrated MUX + T/H + SAR core delivers 12-bit no-missing-codes performance in a compact 20-pin footprint suitable for handheld enclosures.
Recomendado
Industrial Process Control Analog Input Module
The 4 differential or 8 single-ended inputs of the MAX1245BCAP+T map directly to PLC-style analog input modules reading 4-20 mA current loops or 0-10V process signals. The 12-bit resolution provides 0.024% FS accuracy, sufficient for most SCADA-style monitoring applications. The SPI-compatible serial interface supports up to 10 MHz SCLK, enabling a single MCU to scan all 8 channels at the 100 ksps aggregate rate within a 1 ms control loop. Use the SSOP-20 footprint to fit multiple ADC channels per module for high-density DIN-rail systems.
Recomendado
Battery-Powered Handheld Test Instrument
The MAX1245BCAP+T's 2.375V-3.3V supply directly accommodates two AA alkaline cells or a single Li-ion cell after regulation. The integrated 8-channel input is ideal for handheld multimeters that measure voltage, current, and resistance through a multiplexer front-end. The hardware SHDN pin enables sub-µA quiescent current between measurements, supporting 1000+ hours of battery life. The internal 2.5V reference provides ±0.5% initial accuracy, sufficient for 3½-digit portable DMM applications without an external precision reference.
Recomendado
Medical Patient Monitoring Acquisition Front-End
In medical monitoring equipment such as multi-parameter patient monitors, the MAX1245BCAP+T digitizes ECG, SpO2, temperature, and respiration channels through its 8-input multiplexer. The 12-bit resolution captures the millivolt-level ECG signals when paired with an instrumentation-amp front-end (gain 1000). The 2.375V-3.3V supply supports 3.3V logic MCUs used in modern medical firmware platforms. The internal reference removes a sensitive external reference that could drift with temperature, improving measurement repeatability across patient sessions.
Recomendado
Pen-Input Digitizer / Tablet Sensing Front-End
The MAX1245BCAP+T's high-bandwidth track/hold and 100 ksps throughput enable real-time sampling of pen-position sensors in graphics tablets and digitizers. The 8 inputs can scan a 4×2 grid of electrode pairs, providing 12-bit XY-position resolution at 100 samples per second. The SPI interface allows direct connection to graphics-controller ICs, eliminating parallel-interface glue logic. The small 20-pin SSOP package fits within the slim form factor of stylus receivers and active pens.
Recomendado
IoT Edge Sensor Node with Multi-Channel Sampling
For IoT edge nodes that sample multiple environmental sensors (temperature, humidity, light, gas), the MAX1245BCAP+T integrates the multiplexer, sample-and-hold, and ADC into a single 20-pin SSOP, replacing three discrete ICs. The 1 µA power-down current enables sleep-mode operation that draws nearly zero current between transmissions, critical for 1-2 year battery-life wireless sensors. The internal 2.5V reference powers the ADC core directly from VDD-derived rails. The 100 ksps throughput supports oversampling techniques for effective resolution enhancement in low-noise indoor environments.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para MAX1245BCAP+T — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | MAX1245ACAP+T | MAX1245BCAP+ | MAX1245BEAP+T | MAX1245AEAP+T | MAX147 |
|---|---|---|---|---|---|---|
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Brand | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sampling Rate | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 100 ksps |
| Supply Voltage Range | 2.375V to 3.3V | 2.375V to 3.3V | 2.375V to 3.3V | 2.375V to 3.3V | 2.375V to 3.3V | 2.7V to 5.25V |
| Linearity (INL/DNL) | B-grade ±1 LSB | A-grade ±2 LSB | B-grade ±1 LSB | B-grade ±1 LSB | A-grade ±2 LSB | B-grade ±1 LSB |
| Temperature Grade | Commercial 0°C to +70°C | Commercial 0°C to +70°C | Commercial 0°C to +70°C | Industrial -40°C to +85°C | Industrial -40°C to +85°C | Industrial -40°C to +85°C |
| Number of Channels | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF |
Principais diferenciais
- Higher linearity than A-grade variant (vs MAX1245ACAP+T)
- Industrial temperature range option (vs MAX1245BCAP+ (commercial grade))
- Lower-voltage optimized vs MAX147 (vs MAX147)
Notas de projeto
Estimated: at 3.3V VDD and full 100 ksps sampling, the MAX1245BCAP+T draws ~1.6 mA, dissipating approximately 5.3 mW. In power-down mode (SHDN low) the current drops to 1 µA, enabling duty-cycled acquisitions where the ADC is active for <1 ms per measurement. Use a 10 µF tantalum in parallel with a 0.1 µF ceramic placed within 5 mm of the VDD pin to suppress switching transients from the digital core.
Route AGND (pins 9, 20) as a star-connected analog ground that joins DGND (pin 13) only at a single point near the IC's exposed pad area. Place the reference bypass capacitor (typically 4.7 µF) directly between REF (pin 10) and AGND to minimize noise pickup on the internal 2.5V reference. Use a wide (≥0.3 mm) analog trace from VDD to the analog input network.
The MAX1245BCAP+T serial interface supports up to 10 MHz SCLK, but keep DOUT traces short (≤ 25 mm) and series-terminate with 100 Ω if routing to an MCU >50 mm away to prevent reflections. Place a guard ring around AIN0-AIN7 traces if high-impedance sources are connected, to prevent leakage-induced offset errors in the millivolt range.
Do not exceed VDD + 0.3V on any analog input; the MAX1245BCAP+T is NOT a 5V-tolerant input device. Do not operate with VDD below 2.375V - the internal reference will drift out of spec. Do not connect REFADJ to VDD directly without a series resistor; use the recommended resistor value from the datasheet to trim the internal reference.
Informações de conformidade
RoHS compliant and lead-free per Maxim/Analog Devices product page. MSL 1 moisture sensitivity per JEDEC J-STD-020. Commercial temperature grade - choose MAX1245BEAP+T or MAX1245AEAP+T for industrial grade.
