MAX191BC/D - 12-Bit 100ksps SAR ADC w/ Internal Ref | Maxim
N.º da peça: MAX191BC/D ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $19.75 | $19,75 |
| 10 | $18.5 | $185,00 |
| 100 | $16.85 | $1.685,00 |
| 500 | $14.95 | $7.475,00 |
| 1.000 | $12.4 | $12.400,00 |
MAX191BC/D Visão geral
An SAR (Successive Approximation Register) ADC is a type of data converter that resolves one bit per clock cycle by comparing the sampled input against a precision DAC driven by a binary-weighted register. SAR ADCs combine high accuracy (typically 12-18 bits), zero pipeline latency, and excellent DC input behavior, making them the architecture of choice for multiplexed data acquisition systems, precision instrumentation, and process-control front-ends. Within the broader taxonomy, the SAR sits between flash converters (faster, lower resolution) and delta-sigma converters (slower, higher resolution).
Key features of the MAX191BC/D include 12-bit resolution with 1/2 LSB linearity at +/-5V operation, a built-in track/hold, an adjustable internal reference, low power consumption of 3mA in operating mode and 20uA in power-down, and a logic-level PWRDN input. It accepts single +5V or dual +/-5V supplies, allowing ground-referenced bipolar inputs of up to +/-5V. The part uses a SAR core with internal calibration logic for excellent linearity without external trimming.
The MAX191 is most commonly used in high-accuracy data-acquisition boards, industrial process control, battery-powered portable instrumentation, and pen-digitizer/sensor signal chains. The wide bipolar input range simplifies signal conditioning when measuring ground-referenced signals. The low 20uA power-down current extends battery life in duty-cycled portable systems, and the die form factor minimizes PCB area.
When designing with the MAX191BC/D, observe proper die-handling and ESD procedures because the bare die is exposed. Use a low-impedance analog ground plane and decouple AVDD/DVDD with separate 0.1uF/10uF capacitors placed within 5mm of the bond pads. The internal reference may be overdriven with an external 4.096V source if higher accuracy or lower drift is required.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, helping engineers accelerate their selection and PCB-layout decisions for new designs and MAX191BC/D replacements.
Alternativas drop-in para MAX191BC/D — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com MAX191BC/D (mesmo formato e footprint) — diferindo em Analog Supply Voltage, Digital Supply Voltage, Internal Reference, Number of Channels, Package.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
MAX191BCNG+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX191BEPP+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX191BENG+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX191ACNG+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX190BCWG+T
✅ Drop-In✓ Em estoque
$6.15 / unidade
Ver ficha técnica →MAX191BC/D Classificações máximas e características elétricas
| Resolução | 12 bits |
| Architecture | SAR (Successive Approximation) |
| Number of Channels | 1 input |
| Sample Rate | 100 ksps |
| Conversion Time | 7.5 us |
| Acquisition Time | 2 us |
| Input Type | Differential, bipolar |
| Analog Supply Voltage | +5 V or +/-5 V |
| Digital Supply Voltage | 4.75 V to 5.25 V |
| Linearity | 1/2 LSB at +/-5 V |
| Internal Reference | 4.096 V (adjustable) |
| Track/Hold | Built-in |
| Operating Supply Current | 3 mA typical |
| Power-Down Supply Current | 20 uA typical |
| Interface | Parallel or serial uP |
| Encapsulamento | Bare Die (DIE) |
| Number of Terminals | 24 (bond pads) |
| Temperature Grade | Commercial (C suffix) |
Configuração de pinos do MAX191BC/D
| Pino 1 | AGND — Analog ground |
| Pino 2 | AVDD — Analog +5V supply |
| Pino 3 | REF — 4.096V reference output / external reference input |
| Pino 4 | REFADJ — Reference adjust |
| Pino 5 | IN+ — Positive differential analog input |
| Pino 6 | IN- — Negative differential analog input |
| Pino 7 | PWRDN — Power-down control input (active low) |
| Pino 8 | CLK — External clock input / internal clock select |
| Pino 9 | CONVST — Conversion start input |
| Pino 10 | RD — Read input (parallel mode) |
| Pino 11 | CS — Chip select input |
| Pino 12 | HBEN — High-byte enable (parallel mode) |
| Pino 13 | DOUT — Serial data output |
| Pino 14 | SSTRB — Serial strobe output |
| Pino 15 | D11 — Parallel data bit 11 (MSB) |
| Pino 16 | D10 — Parallel data bit 10 |
| Pino 17 | D9 — Parallel data bit 9 |
| Pino 18 | D8 — Parallel data bit 8 |
| Pino 19 | D7 — Parallel data bit 7 |
| Pino 20 | D6 — Parallel data bit 6 |
| Pino 21 | D5 — Parallel data bit 5 |
| Pino 22 | D4 — Parallel data bit 4 |
| Pino 23 | DGND — Digital ground |
| Pino 24 | DVDD — Digital +5V supply |
Aplicações típicas
MAX191BC/D é adequado para 6 aplicaçãos: Industrial Process Control & Data Acquisition, Battery-Powered Portable Instrumentation, Pen-Digitizer & Sensor Signal Chains, Precision Weigh Scale & Strain-Gauge Readout, Medical Patient Monitoring Front-End, Test & Measurement Instrumentation.
Industrial Process Control & Data Acquisition
The MAX191BC/D's 100 ksps throughput, 12-bit resolution, and true bipolar +/-5V differential inputs make it ideal for industrial process control front-ends that digitize 4-20mA loop signals, RTD outputs, and thermocouple-amplified voltages. The internal 4.096V reference and built-in track/hold simplify BOM, while the 3 mA operating current suits multi-channel multiplexed data-acquisition boards. Placed at the analog front-end with separate AVDD/DVDD decoupling and an instrumentation-amp front-end (e.g., MAX147AEPP+), it delivers ±5V ground-referenced bipolar measurement without external signal shifting. Unlike delta-sigma ADCs it provides zero pipeline latency, enabling deterministic sampling for closed-loop control loops.
Recomendado
Battery-Powered Portable Instrumentation
The MAX191BC/D's 20 uA power-down current and 3 mA operating current make it well-suited for duty-cycled portable instrumentation such as handheld multimeters, digital scopes, and field data loggers. Asserting the PWRDN pin drops supply current to 20 uA between conversions while preserving the internal reference state, dramatically extending battery life. Its 100 ksps sample rate is more than adequate for slowly-varying physical signals (temperature, pressure, strain) and its bare-die form factor fits inside ultra-compact probe housings. Used with a low-quiescent LDO (e.g., MAX150ACWP) and a low-power MCU, it forms a complete portable measurement system that can run for months on a single battery.
Recomendado
Pen-Digitizer & Sensor Signal Chains
The MAX191BC/D's 2 us acquisition time and 7.5 us conversion time make it a good fit for pen-digitizer tablets, position sensors, and other high-speed analog front-ends that digitize position-dependent waveforms. The differential bipolar input accepts both polarities of sensor signals without level shifting, simplifying the analog signal chain. Its 12-bit resolution provides 4096 quantization steps which yields ~0.024% of full-scale precision at +/-5V, sufficient for sub-millimeter position resolution when paired with a stable mechanical sensor. The MAX191BC/D's small die footprint is well-suited to hybrid modules that mount directly on the sensor flex PCB.
Recomendado
Precision Weigh Scale & Strain-Gauge Readout
Strain-gauge load cells produce millivolt-level differential signals that require low-noise amplification and high-resolution digitization. The MAX191BC/D's 12-bit SAR core with built-in track/hold and differential input pairs naturally with a low-noise analog front-end (e.g., MAX147AEPP+) to form a precision weigh-scale readout. Its internal 4.096V reference provides stable full-scale reference for ratio-metric measurements. The 100 ksps throughput enables oversampling-and-averaging to exceed 12-bit effective resolution. The bare-die format allows the ADC to be co-located with the analog front-end inside the scale's load-cell housing for optimum EMI immunity.
Recomendado
Medical Patient Monitoring Front-End
Medical patient monitors require high-resolution, low-latency digitization of biopotential waveforms including ECG, EEG, EMG, and pulse oximetry signals. The MAX191BC/D's zero pipeline latency (SAR architecture) makes it suitable for capturing transient cardiac events without the fixed delay of a delta-sigma converter. Its bipolar +/-5V input range allows direct connection to instrumentation-amplifier outputs biased around ground, simplifying signal conditioning. The 12-bit resolution and 100 ksps throughput easily capture ECG bandwidth (0.05-150 Hz) at high oversample ratios. Its bare-die form enables miniaturization of wearable or implantable patient monitors where PCB area is at a premium.
Recomendado
Test & Measurement Instrumentation
Bench-top digital multimeters, source-measure units, and data-acquisition plug-in boards benefit from the MAX191BC/D's combination of 100 ksps sample rate, 12-bit resolution, and bipolar differential inputs. In digitizer applications the ADC captures the post-attenuator signal with no need for level shifting. The internal reference may be overdriven with an external precision reference (e.g., MAX6126) for laboratory-grade absolute DC accuracy. Its 7.5 us conversion time suits GPIB-controlled instruments that require deterministic acquisition. Multiple MAX191BC/D dies can be paralleled inside a single instrument to build multi-channel digitizers for production test.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para MAX191BC/D — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | MAX191BCNG+ | MAX191BEPP+ | MAX191BENG+ | MAX191ACNG+ | MAX190BCWG+T |
|---|---|---|---|---|---|---|
| Package | Bare Die (DIE) | PDIP-24 - same die | PDIP-24 - same die | PDIP-24 - same die | PDIP-24 - same family | SOIC-24 - same family |
| Brand | Maxim Integrated | Maxim Integrated - same brand | Maxim Integrated - same brand | Maxim Integrated - same brand | Maxim Integrated - same brand | Maxim Integrated - same brand |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sample Rate | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 76 ksps (-24%) |
| Linearity | 1/2 LSB (B-grade) | 1/2 LSB | 1/2 LSB | 1/2 LSB | 1 LSB (A-grade) | 1/2 LSB |
| Input Range | +/-5V bipolar differential | +/-5V bipolar | +/-5V bipolar | +/-5V bipolar | +/-5V bipolar | +/-5V bipolar |
| Internal Reference | 4.096V (adjustable) | 4.096V | 4.096V | 4.096V | 4.096V | 4.096V |
Principais diferenciais
- Bare-die format for hybrid module assembly (vs MAX191BCNG+ (PDIP-24))
- Higher sample rate than MAX190 family (vs MAX190BCWG+T (SOIC-24, 76 ksps))
- B-grade linearity in die form (vs MAX191ACNG+ (A-grade, 1 LSB))
Notas de projeto
Decouple AVDD and DVDD with separate 0.1uF and 10uF ceramic capacitors placed within 5mm of the bond pads. Use a low-impedance ground plane and keep analog (AGND) and digital (DGND) ground returns separate, joining them at a single point near the die. Estimated: total dynamic current peaks during conversion are typically 3 mA from AVDD and 1 mA from DVDD; insufficient decoupling will couple digital switching noise into the analog front-end and degrade SNR by 6-10 dB.
Bare-die assemblies require careful handling: store dies in dry nitrogen, bond with gold or aluminum wire, and use a low-stress die-attach epoxy to avoid thermal-mechanical failures. When using the internal 4.096V reference, place the REFADJ capacitor (typically 0.01uF) directly at the REFADJ bond pad with short traces. Avoid routing digital outputs D0-D11 near the analog input bond pads (IN+/IN-) to prevent digital-to-analog crosstalk into the input track-and-hold.
Do not over-drive REF with an external reference exceeding 4.5V, which can damage the reference cell. When powering the MAX191BC/D from a single +5V supply, tie the negative analog input (IN-) to AGND for single-ended unipolar operation; for bipolar +/-5V inputs, use the dual-supply configuration. Do not exceed the maximum analog input voltage of +/-VREF (4.096V) plus 0.3V protection diode headroom - overvoltage on the analog inputs will degrade linearity and may damage the device.
Place a small RC anti-aliasing filter (R+C time constant << 1/2 of the 100 ksps sampling period, i.e. < 5 us) at the analog input bond pads to bandlimit input noise and prevent aliasing of out-of-band signals. A 1kohm/1nF RC yields 1.6 us time constant and 100 kHz -3 dB. For high-impedance sources, add a low-leakage buffer (e.g., MAX147AEPP+ instrumentation amp) between the source and the IN+/IN- bond pads to avoid ADC input-current-induced gain errors.
Informações de conformidade
Bare-die form factor has no lead-finish (lead-free by construction). RoHS compliance status not explicitly stated in available distributor listings - confirm with distributor if RoHS is required for end product. AEC-Q100 not applicable for commercial-grade ADC; industrial-grade variants are not offered in the MAX191 family.
