LTC2309CUF - 8-Ch 12-Bit SAR ADC I2C | Analog Devices
N.º da peça: LTC2309CUF ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $12.5 | $12,50 |
| 10 | $11.2 | $112,00 |
| 100 | $9.85 | $985,00 |
| 500 | $8.5 | $4.250,00 |
| 1.000 | $7.25 | $7.250,00 |
LTC2309CUF Visão geral
A SAR ADC (successive-approximation-register analog-to-digital converter) is a precision data-conversion architecture that performs a binary search across an internal capacitive DAC to resolve an input voltage in N clock cycles. SAR ADCs are widely used for multi-channel data-acquisition systems in industrial, instrumentation, and sensor-monitoring applications because they offer deterministic latency, no-pipeline-delay sampling, low-power operation, and excellent DC accuracy. The LTC2309CUF belongs to the broader ADC > data converter > mixed-signal IC category, serving as a precision analog front end that digitizes real-world signals for downstream microcontrollers, DSPs, and FPGAs.
Key features include 8 single-ended input channels (or 4 differential pairs via the MUX), 73.4 dB SINAD, guaranteed no missing codes, an I2C-compatible 2-wire serial interface, automatic sleep mode that drops current to 35 uW between conversions, and an external reference option for systems requiring a custom full-scale range. The internal reference maintains low drift, and the input multiplexer supports both unipolar 0-5 V and bipolar ±5 V operating modes by configuring the COM pin as either ground or 2.5 V.
The LTC2309CUF uses a charge-balancing switched-capacitor DAC architecture combined with an internal precision bandgap reference, achieving 12-bit DNL of ±0.5 LSB (typical) and INL of ±0.5 LSB. The differential sample-and-hold rejects common-mode noise from industrial environments, and the device supports both 0 V to 5 V unipolar and ±5 V bipolar input ranges, allowing direct connection to most industrial sensor outputs, strain-gauge bridges, and thermocouple signal-conditioning outputs without external signal conditioning.
Typical applications include multi-sensor industrial monitoring, portable instrumentation, and embedded data-acquisition systems where compact PCB area and low power are essential. Engineers select this part when they need 8 channels of 12-bit precision in a tiny 4x4 mm QFN footprint, with simple I2C wiring to a host microcontroller, while keeping total system current below a few milliamps.
When designing with this device, ensure the I2C address-select pin (ADR) is tied high or low (or left floating for the third address) to set one of three possible 7-bit slave addresses, avoiding conflicts on a shared I2C bus. Decouple VDD with a 10 uF tantalum in parallel with a 0.1 uF ceramic capacitor placed within 5 mm of the supply pin to keep digital switching noise out of the analog domain.
Alternativas drop-in para LTC2309CUF — 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:
LTC2309IUF#PBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC2309CUF#TRPBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC2309IUF#TRPBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC2308CUF#PBF
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
LTC2309CUF
✅ Drop-In✓ Em estoque
$7.25 / unidade
Ver ficha técnica →LTC2309CUF Classificações máximas e características elétricas
| Manufacturer | Analog Devices (formerly Linear Technology) |
| Part Number | LTC2309CUF#PBF |
| Resolução | 12 bits |
| Architecture | SAR (Successive Approximation Register) |
| Number of Input Channels | 8 single-ended / 4 differential |
| Conversion Time | 1.3 us (typical) |
| Throughput Rate | 14 ksps |
| SINAD | 73.4 dB |
| Interface | I2C-compatible 2-wire serial |
| Tensão de alimentação | 5 V single supply |
| Power Consumption | 1.5 mW at 14 ksps |
| Sleep Mode Current | 35 uW |
| Internal Reference | 2.5 V (selectable internal/external) |
| Differential Sample-and-Hold | Yes, fully differential |
| No Missing Codes | Guaranteed (12-bit) |
| Encapsulamento | 24-pin QFN (4x4 mm) |
| Tipo de montagem | Surface Mount |
| Faixa de temperatura de operação | 0 C to +70 C (commercial) |
| Status RoHS | Compliant (PBF suffix) |
| Lead Free | Yes |
Configuração de pinos do LTC2309CUF
| Pino 1 | CH0 — Analog input channel 0 |
| Pino 2 | CH1 — Analog input channel 1 |
| Pino 3 | CH2 — Analog input channel 2 |
| Pino 4 | CH3 — Analog input channel 3 |
| Pino 5 | CH4 — Analog input channel 4 |
| Pino 6 | CH5 — Analog input channel 5 |
| Pino 7 | CH6 — Analog input channel 6 |
| Pino 8 | CH7 — Analog input channel 7 |
| Pino 9 | COM — Common-mode voltage input (GND for unipolar, 2.5 V for bipolar) |
| Pino 10 | GND — Ground |
| Pino 11 | VDD — 5 V supply voltage |
| Pino 12 | REFCOMP — Reference bypass capacitor connection |
| Pino 13 | REF — Reference voltage input/output (2.5 V internal) |
| Pino 14 | GND — Ground |
| Pino 15 | SCL — I2C serial clock input |
| Pino 16 | SDA — I2C serial data input/output |
| Pino 17 | ADR — I2C address select (GND/VDD/NC for 3 addresses) |
| Pino 18 | CONVST — Conversion start input |
| Pino 19 | NC — Not connected (per datasheet) |
| Pino 20 | NC — Not connected (per datasheet) |
| Pino 21 | NC — Not connected (per datasheet) |
| Pino 22 | GND — Ground |
| Pino 23 | GND — Ground |
| Pino 24 | VDD — 5 V supply voltage |
Aplicações típicas
LTC2309CUF é adequado para 7 aplicaçãos: Multi-Sensor Industrial Monitoring, Portable Battery-Powered Instrumentation, Strain-Gauge and Bridge Sensor Digitization, Embedded Data-Acquisition Systems, Automotive Sensor Interface Modules, Medical Patient Monitoring Equipment, IoT Smart-Sensor Edge Nodes.
Multi-Sensor Industrial Monitoring
The LTC2309CUF fits multi-sensor industrial monitoring because its 8 single-ended inputs can digitize up to 8 different sensor signals (temperature, pressure, flow, level) through its internal MUX, with 12-bit resolution providing adequate dynamic range for most industrial process variables. The 14 ksps throughput allows sequential sampling of all 8 channels at 1.5 ksps per channel, suitable for slow-changing process signals. Its 73.4 dB SINAD delivers accurate digital representations of 0-5 V or 0-10 V transducer outputs, while the differential sample-and-hold rejects common-mode noise from long sensor cable runs in factory floors. The 24-pin QFN (4x4 mm) footprint integrates 8 channels of precision ADC into a tiny area, and the I2C interface allows connection to a host MCU with just two wires, reducing wiring complexity in distributed monitoring nodes.
Recomendado
Portable Battery-Powered Instrumentation
The LTC2309CUF fits portable instrumentation because its 1.5 mW power consumption at 14 ksps and 35 uW sleep-mode current extend battery life in handheld multimeters, portable loggers, and field instruments. The 12-bit resolution provides adequate precision for portable measurement devices like digital thermometers, pH meters, and gas analyzers. The single 5 V supply simplifies power-tree design in battery-powered systems that use a boost converter from Li-ion cells. The integrated 2.5 V reference eliminates the need for an external reference IC, saving PCB space and reducing the BOM cost - critical for portable products where every cubic millimeter and dollar matters. The I2C interface allows direct connection to low-power MCUs running at minimal clock rates to preserve battery life.
Recomendado
Strain-Gauge and Bridge Sensor Digitization
The LTC2309CUF fits strain-gauge and bridge-sensor digitization because its fully differential sample-and-hold amplifier can directly digitize differential outputs from Wheatstone bridges, load cells, and pressure transducers without external instrumentation amplifiers. The 12-bit resolution provides adequate dynamic range for weighing scales, force gauges, and pressure transmitters that typically need 0.1% full-scale precision. The bipolar ±5 V input range (with COM pin set to 2.5 V) allows direct connection to bridge outputs that swing both above and below the common-mode voltage. The internal reference maintains low drift, ensuring measurement stability over temperature, while the 73.4 dB SINAD guarantees clean digitization of the small differential signals typical of bridge sensors (often only tens of millivolts full-scale).
Recomendado
Embedded Data-Acquisition Systems
The LTC2309CUF fits embedded data-acquisition systems because its 8-channel MUX, 12-bit resolution, and I2C interface provide a complete analog front end for compact DAQ modules, programmable logic controllers (PLCs), and embedded sensor hubs. The 14 ksps aggregate throughput supports sampling 8 channels at approximately 1.75 ksps each, adequate for vibration, temperature, and process monitoring applications. The differential inputs reject ground noise from industrial power systems, while the small 4x4 mm QFN package enables high-density channel count on small DAQ PCBs. The I2C interface allows up to three LTC2309 devices to share a single I2C bus (three ADR pin settings), expanding a single host MCU's channel count to 24 inputs without additional chip-select GPIOs.
Recomendado
Automotive Sensor Interface Modules
The LTC2309CUF (commercial grade) fits automotive sensor interface prototypes and non-safety-critical modules that operate in cabin-temperature environments (within 0-70 C). For under-hood and exterior automotive applications that need -40 to +85 C or AEC-Q100, choose the LTC2309IUF#PBF industrial variant. The 8-channel MUX can digitize multiple vehicle sensors including cabin temperature, fuel level, oil pressure, and battery monitoring signals through appropriate signal conditioning. The 12-bit resolution suits most body-electronics and chassis-control sensor ranges, and the I2C interface simplifies wiring to automotive body controllers. The differential inputs reject electrical noise from alternator and ignition systems, critical for clean automotive measurements.
Recomendado
Medical Patient Monitoring Equipment
The LTC2309CUF fits medical patient monitoring equipment such as bedside monitors, infusion pumps, and portable diagnostic devices that require 12-bit precision for temperature, pressure, and flow measurements within a controlled indoor environment (0-70 C). The 8-channel input capability allows simultaneous monitoring of multiple physiological parameters, while the I2C interface reduces wiring complexity in compact medical device enclosures. The integrated reference and sample-and-hold minimize external components, helping meet medical device reliability and miniaturization goals. The differential sample-and-hold rejects common-mode noise from medical equipment power supplies and adjacent electronic modules, ensuring clean digitization of low-amplitude physiological signals. For medical applications, verify full regulatory compliance and reliability qualification beyond this datasheet-level overview.
Recomendado
IoT Smart-Sensor Edge Nodes
The LTC2309CUF fits IoT smart-sensor edge nodes that aggregate multiple analog sensors before transmitting data over wireless networks. The 8-channel MUX allows connection of 8 different analog sensors (light, sound, gas, motion, temperature, humidity, pressure, vibration) to a single edge node, while the 12-bit resolution provides adequate dynamic range for most environmental sensing applications. The 1.5 mW operating power and 35 uW sleep current are well-suited for battery-powered IoT nodes that need months-to-years of battery life. The I2C interface shares a bus with other digital sensors on the same node, reducing GPIO usage on the host MCU. The small 4x4 mm QFN footprint allows high-density sensor integration in compact IoT modules for smart-home, smart-building, and industrial-IoT deployments.
Recomendado
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Dados de referência de engenharia para LTC2309CUF — comparação, orientação de projeto e informações de conformidade.
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Comparação com alternativas
| Parâmetro | Este produto | LTC2309IUF#PBF | LTC2309CUF#TRPBF | LTC2309IUF#TRPBF | LTC2308CUF#PBF |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | QFN-24 (UF) 4x4 mm | QFN-24 (UF) 4x4 mm - same | QFN-24 (UF) 4x4 mm - same | QFN-24 (UF) 4x4 mm - same | QFN-24 (UF) 4x4 mm - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Throughput Rate | 14 ksps | 14 ksps | 14 ksps | 14 ksps | 14 ksps |
| Number of Channels | 8 single-ended / 4 differential | 8 / 4 - same | 8 / 4 - same | 8 / 4 - same | 8 single-ended - check datasheet for pin compatibility |
| Supply Voltage | 5 V | 5 V - same | 5 V - same | 5 V - same | 5 V - same |
| Operating Temperature | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) |
| Interface | I2C 2-wire | I2C 2-wire - same | I2C 2-wire - same | I2C 2-wire - same | I2C 2-wire - same |
| Internal Reference | 2.5 V | 2.5 V - same | 2.5 V - same | 2.5 V - same | 2.5 V - same |
| RoHS Compliance | Yes (PBF suffix) | Yes | Yes | Yes | Yes |
Principais diferenciais
- Integrated 2.5 V reference with external override (vs LTC2308CUF#PBF (same family, alternative part))
- True differential sample-and-hold amplifier (vs Single-ended-only ADCs in the same 8-channel class)
- Ultra-low sleep-mode current of 35 uW (vs Typical 8-channel 12-bit SAR ADCs without auto-sleep)
Notas de projeto
Decouple VDD with a 10 uF tantalum capacitor in parallel with a 0.1 uF ceramic capacitor placed within 5 mm of the supply pins (pins 11 and 24). The 10 uF bulk capacitor handles low-frequency supply transients from upstream regulators, while the 0.1 uF ceramic bypasses high-frequency switching noise from the digital I2C interface. Place the REFCOMP pin bypass capacitor (typically 10 uF) close to pins 12-13 to stabilize the internal 2.5 V reference. A noisy VDD will couple directly into conversion accuracy through the internal reference, so use a low-noise LDO such as the Analog Devices ADP150 or LT1761 rather than a switching regulator for the LTC2309 supply rail.
The QFN-24 package has an exposed thermal pad (EPAD) on the underside that must be soldered to a PCB ground plane for both electrical reference and thermal performance. Use an EPAD pad 2.5x2.5 mm with at least 8 thermal vias (0.3 mm diameter) connecting to an internal ground plane. Route analog input traces (CH0-CH7, COM) as differential pairs to the ADC, keeping them short and away from digital traces (SCL, SDA, CONVST) to minimize crosstalk. Use a guard ring around analog input traces connected to the COM pin to absorb stray leakage currents from the PCB substrate.
Keep the I2C SCL and SDA traces short (less than 50 mm on a typical 2-layer PCB) and route them away from the analog input traces and the 5 V VDD trace. Use 4.7 kohm pull-up resistors on SCL and SDA to VDD (5 V) per the I2C standard; smaller values (2.2 kohm) improve noise margin in electrically noisy environments but increase current consumption. Place the pull-up resistors close to the LTC2309CUF rather than near the host MCU to minimize stub length. If the I2C bus must cross long distances (over 100 mm), use an I2C buffer such as the LTC4311 or PCA9600 to maintain signal integrity.
Do not leave the ADR (address select) pin floating - tie it to GND, VDD, or NC per the datasheet to select one of three possible 7-bit I2C addresses (0011x, 0100x, or 0101x). A floating ADR pin can cause bus-address conflicts or unreliable addressing. Do not exceed the absolute maximum ratings of VDD = 6 V or analog input voltages beyond VDD + 0.3 V; over-voltage on CHx inputs can permanently damage the ESD protection diodes. Do not apply CONVST pulses shorter than 20 ns; the internal SAR logic requires minimum pulse width to register a valid conversion start. Do not omit the REFCOMP bypass capacitor - the internal reference will oscillate without proper decoupling, resulting in degraded SINAD performance.
At 1.5 mW typical power consumption and a maximum ambient of 70 C (commercial grade), thermal management is not a primary concern for the LTC2309CUF - junction temperature rise is negligible in normal operation. However, in enclosed industrial environments where ambient temperatures approach 85 C and the LTC2309IUF#PBF industrial variant is used, ensure adequate PCB copper area around the EPAD to keep junction temperature below the 150 C maximum. The QFN-24 package theta_JA is approximately 40 C/W on a standard JEDEC 4-layer test board, but can exceed 80 C/W on a small 2-layer PCB with minimal copper pour, requiring thermal vias to an internal ground plane for adequate heat dissipation.
Informações de conformidade
RoHS compliance indicated by #PBF suffix per Analog Devices part-numbering convention. Lead-free reflow compatible at 260 C peak per JEDEC J-STD-020. Commercial temperature grade (C-suffix); industrial variant (I-suffix) available for -40 to +85 C applications. Not AEC-Q100 qualified; consult Analog Devices for automotive-grade equivalents.
