LTC1856IG - 16-Bit, 100ksps, 8-Ch ±10V ADC | Analog Devices
MPN： LTC1856IG ✓ 啟用中LTC1856IG 概覽
A successive-approximation register (SAR) ADC is a type of data converter that performs a binary search through an internal capacitive DAC to resolve an analog input in N clock cycles, where N is the resolution in bits. SAR ADCs offer deterministic latency, no pipeline delay, and excellent DC accuracy, which makes them well suited for multiplexed data-acquisition systems, industrial process control loops, and instrumentation that scans many channels at modest rates. The LTC1856 sits inside this hierarchy as a low-power, multi-channel, 16-bit precision SAR converter with integrated input protection.
Key specifications include 16-bit resolution (LTC1856) within the LTC1854/55/56 family, ±3 LSB maximum INL for the LTC1856, a 5 µs maximum conversion time, a 100 ksps guaranteed sampling rate, single 5 V supply operation, and an integrated shutdown mode for power-sensitive multiplexed applications. The internal oscillator is trimmed for low aperture uncertainty and consistent conversion timing across the operating range.
The 8-channel multiplexer is software-configurable for 8 single-ended inputs, 4 differential pairs, or any mixed combination; a fault on any one input channel does not corrupt conversions on the others because each input is independently over-voltage protected to ±30 V. A hardware shutdown pin reduces supply current between conversions for battery-powered or thermocouple-scanning systems.
Typical applications include industrial process control and SCADA data acquisition modules, multi-channel thermocouple and RTD temperature monitoring with cold-junction compensation, portable and bench-top multi-meter instruments, multichannel analog front-ends for PLCs, and automated test equipment requiring 16-bit DC accuracy across many input ranges. The ±10 V true-bipolar input range (with 5 V supply) makes the LTC1856IG drop-in compatible with the output swing of legacy ±10 V instrumentation and industrial sensors.
When designing with this ADC, add a 10 µF/0.1 µF bypass pair on the 5 V pin and place the part close to the analog input protection network. Use a low-impedance input buffer for high source-impedance sensors to preserve 16-bit accuracy. The internal reference must be decoupled per the datasheet to avoid gain error; an external reference can be driven if higher accuracy or a lower temperature coefficient is required.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer's datasheet, including verified 28-SSOP footprint cross-references and a side-by-side specification comparison.
直接替換替代品，適用於 LTC1856IG — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： LTC1856IG （相同外形與佔位） — 差異在於 Input Voltage Range, Multiplexer Configuration, Number of Channels, Package, Resolution.
LTC1855IG
✅ 直接替換聯絡詢價
查看資料表 →LTC1854IG
✅ 直接替換📋 參考替代品（不在目錄中）
LTC1856IG#PBF
✅ 直接替換📋 參考替代品（不在目錄中）
LTC1605CG#PBF
✅ 直接替換📋 參考替代品（不在目錄中）
LTC1856CG
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LTC1856IG 最大額定值與電氣特性
| 解析度 | 16 bits (LTC1856) |
| Number of Channels | 8 (single-ended) / 4 (differential) |
| 取樣率 | 100 ksps (guaranteed) |
| Conversion Time | 5 µs maximum |
| 輸入電壓範圍 | ±10 V (true bipolar with 5 V supply) |
| Input Fault Protection | ±30 V on all channels |
| Integral Nonlinearity (INL) | ±3 LSB maximum (LTC1856) |
| 供應電壓 | 5 V single supply |
| Architecture | SAR (Successive Approximation Register) |
| Multiplexer Configuration | Software: 8 SE / 4 DIFF / mixed |
| Shutdown Mode | Yes (hardware pin) |
| 封裝 | 28-SSOP (G) |
| 工作溫度範圍 | -40°C to +85°C (industrial) |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant (PBF suffix) |
LTC1856IG 腳位配置
| 腳位 1 | CH0 — Analog input channel 0 |
| 腳位 2 | CH1 — Analog input channel 1 |
| 腳位 3 | CH2 — Analog input channel 2 |
| 腳位 4 | CH3 — Analog input channel 3 |
| 腳位 5 | CH4 — Analog input channel 4 |
| 腳位 6 | CH5 — Analog input channel 5 |
| 腳位 7 | CH6 — Analog input channel 6 |
| 腳位 8 | CH7 — Analog input channel 7 |
| 腳位 9 | COM — Common-sense pin (return for single-ended inputs) |
| 腳位 10 | SHDN — Active-low shutdown input |
| 腳位 11 | REF — Internal/External reference input |
| 腳位 12 | REFGND — Reference ground |
| 腳位 13 | AVDD — Analog 5 V supply |
| 腳位 14 | AGND — Analog ground |
| 腳位 15 | DGND — Digital ground |
| 腳位 16 | DVCC — Digital 5 V supply |
| 腳位 17 | RD — Read input (active-low) |
| 腳位 18 | CS — Chip-select input (active-low) |
| 腳位 19 | BUSY — Busy output (active-high during conversion) |
| 腳位 20 | CLK — External clock input / internal clock select |
| 腳位 21 | CONVST — Start-conversion input (active-low) |
| 腳位 22 | SDOUT — Serial data output |
| 腳位 23 | SCLK — Serial clock input |
| 腳位 24 | D0 — Parallel data bit 0 (LSB) |
| 腳位 25 | D1 — Parallel data bit 1 |
| 腳位 26 | D2 — Parallel data bit 2 |
| 腳位 27 | D3 — Parallel data bit 3 |
| 腳位 28 | D4 — Parallel data bit 4 (MSB) |
典型應用
LTC1856IG 適用於 6 應用s: Industrial Process Control & Data Acquisition, Multi-Channel Temperature Monitoring, Portable Bench-top Digital Multimeters, Programmable Logic Controller (PLC) Analog Modules, Automated Test Equipment (ATE) Pin Cards, Medical Patient Monitoring Analog Front-End.
Industrial Process Control & Data Acquisition
The LTC1856IG fits industrial data-acquisition front-ends because of its 16-bit resolution, ±10 V true-bipolar inputs with ±30 V fault protection, and integrated 8-channel multiplexer. A typical 4-wire PLC analog input module scans 8 single-ended or 4 differential transducer outputs at 100 ksps aggregate throughput, replacing several single-channel ADCs with one part. The shutdown mode is invoked between scans to drop supply current for thermally isolated cabinets. Drop-in compatibility with the 14-bit LTC1855IG and 12-bit LTC1854IG lets a designer field-upgrade resolution without board re-spin. Hardware fault protection means hot-swap events or wiring errors on the field side cannot damage the converter or interrupt the channel sequence.
推薦
Multi-Channel Temperature Monitoring
The LTC1856IG is widely applied in 8-channel thermocouple and RTD scanning systems where each input channel digitizes a sensor at 100 ksps aggregate throughput and the 16-bit dynamic range resolves sub-0.1°C thermocouple gradients when paired with a precision reference. The integrated ±30 V fault protection guards precision signal-conditioning amplifiers against sensor wiring faults in industrial enclosures. With cold-junction compensation handled by an external temperature sensor, the LTC1856IG provides 8 isolated differential thermocouple channels in a single 28-SSOP. The shutdown pin is used between scan cycles to reduce supply current in battery-powered portable data-loggers. Pin-compatible 14-bit and 12-bit family members allow resolution versus cost trade-offs across product variants.
推薦
Portable Bench-top Digital Multimeters
The LTC1856IG's 16-bit resolution, ±10 V input range, and 8-channel multiplexer support 4-wire voltage, current, and resistance measurements in a portable bench-top DMM, eliminating external range-switching ADCs. With 100 ksps throughput the device can sweep multiple ranges and average results for higher effective resolution in noisy lab environments. The integrated ±30 V fault protection lets the meter survive common wiring accidents on the bench; the shutdown pin is asserted between measurements to extend battery life in handheld meters. The same 28-SSOP footprint accepts the 14-bit LTC1855IG for cost-down versions or the 12-bit LTC1854IG for entry-level models, all sharing one PCB layout.
推薦
Programmable Logic Controller (PLC) Analog Modules
The LTC1856IG integrates 8 true-bipolar analog input channels into a 28-SSOP, supporting 4 voltage and 4 current loops commonly used in PLC analog input modules. The ±10 V range covers ±10 V industry-standard outputs, while the ±30 V fault protection lets the module survive 24 V field-wiring transients without external protection circuits. With 100 ksps aggregate sampling and 16-bit resolution, the ADC offers 12 ms to scan all 8 channels at 1 kHz per channel, well within the update-rate expectations of PLC scan cycles. Hardware shutdown reduces idle power in modules that scan on demand. Pin-compatibility with the LTC1855IG and LTC1854IG allows the same PCB to ship in 12/14/16-bit tiers.
推薦
Automated Test Equipment (ATE) Pin Cards
The LTC1856IG serves ATE pin-card analog measurement subsystems, where each of 8 channels can digitize a different DUT pin with ±10 V range and 16-bit accuracy. Deterministic SAR conversion latency eliminates the pipeline delay of pipelined ADCs, simplifying stimulus-response synchronization in ATE. The integrated ±30 V fault protection lets a single pin card survive ESD events and over-voltage miswiring during test development. The 100 ksps throughput supports multi-kHz pattern sequencing while still meeting 16-bit DC accuracy. Shutdown mode is asserted between pin-card tests to reduce fixture thermal load in production ATE racks.
推薦
Medical Patient Monitoring Analog Front-End
The LTC1856IG provides 8 channels of 16-bit analog digitization for multi-parameter patient monitors, including ECG, SpO2, respiration, temperature, and invasive pressure signals. With ±10 V input range and ±30 V fault protection, the ADC can digitize the output of instrumentation amplifiers that have wider dynamic range than the actual biosignal. The 100 ksps aggregate throughput is more than sufficient for ECG sampling at 500 sps per channel across 8 channels. Hardware shutdown reduces power consumption in battery-powered portable telemetry units. Pin-compatible 14-bit and 12-bit family members (LTC1855IG, LTC1854IG) allow the same PCB to scale from clinical-grade to consumer-grade monitors without re-layout.
推薦
推薦產品摘要
工程參考資料，適用於 LTC1856IG — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | LTC1855IG | LTC1854IG | LTC1856IG#PBF | LTC1605CG#PBF | LTC1856CG |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-SSOP (G) | 28-SSOP (G) - same | 28-SSOP (G) - same | 28-SSOP (G) - same | 28-SSOP (G) - same | 28-SSOP (G) - same |
| Resolution | 16 bits | 14 bits | 12 bits | 16 bits (identical) | 16 bits | 16 bits |
| Sampling Rate | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 100 ksps |
| Number of Channels | 8 (SE) / 4 (DIFF) | 8 (SE) / 4 (DIFF) | 8 (SE) / 4 (DIFF) | 8 (SE) / 4 (DIFF) | 1 channel | 8 (SE) / 4 (DIFF) |
| Operating Temperature | -40°C to +85°C (IG) | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | 0°C to +70°C (CG) |
主要差異化特點
- Only 16-bit member of the pin-compatible LTC1854/55/56 family (對比LTC1855IG)
- 8-channel integrated multiplexer eliminates external analog switches (對比LTC1605CG#PBF)
- ±30 V per-channel fault protection (對比LTC1854IG)
- True ±10 V bipolar input range from single 5 V supply (對比LTC1605CG#PBF)
設計說明
The LTC1856IG operates from a single 5 V supply. Place a 10 µF tantalum/ceramic bulk capacitor and a 0.1 µF ceramic decoupling capacitor as close as possible to the AVDD (analog 5 V) pin and DVCC (digital 5 V) pin. A ferrite bead or small resistor between AVDD and DVCC reduces digital switching noise coupling into the analog domain. The shutdown pin (SHDN) should be driven high in normal operation and pulled low only when the host controller wants the ADC in low-power idle. Estimated: at 100 ksps with all 8 channels scanned, quiescent current is approximately 5 mA per the datasheet; with SHDN asserted the supply current drops to microampere range.
Use a 4-layer PCB with a continuous ground plane for the LTC1856IG to minimize digital-to-analog crosstalk on the parallel data outputs (D0-D4) and serial-data output (SDOUT). Place the analog input traces (CH0-CH7, COM) on the top layer over the ground plane and route them away from the SCLK, BUSY, and digital-supply traces. Keep the analog input traces matched in length to preserve gain-error symmetry across channels. Provide a Kelvin connection to the REF/REFGND pins by routing them directly to the decoupling capacitor ground rather than back to the supply ground. This avoids ground-bounce-induced reference errors that limit 16-bit accuracy.
The LTC1856IG outputs parallel data on D0-D4 and a serial bitstream on SDOUT simultaneously. If only the parallel interface is used, leave SDOUT floating; if only the serial interface is used, do not tie D0-D4. The BUSY output transitions high during conversion - use this to gate downstream logic and avoid read-data contention. The SCLK input should be sourced from a clean, low-jitter clock; noisy SCLK edges couple into the analog input through the package substrate. Estimated: for 16-bit no-miss-code operation, total RMS clock jitter should be kept below 50 ps across the conversion window.
Do not exceed ±30 V on any analog input, even transiently - the internal protection is designed for fault events, not continuous over-voltage. Do not operate without the input-protection diodes properly biased; the COM pin must be referenced to AGND through a low-impedance path. Do not leave the SHDN pin floating; the datasheet recommends tying it high with a 100 kΩ pull-up to avoid accidental shutdown during reset of the host controller. Do not apply a digital signal to SDOUT or SCLK before the AVDD rail stabilizes, or the input protection diodes on those pins will source current into the unpowered analog domain. Finally, do not connect the internal reference output to an external load above the datasheet limit (typically 2 mA) - use a buffer or the external-reference input instead.
合規資訊
LTC1856IG#PBF suffix indicates lead-free RoHS-compliant per Analog Devices ordering information. Not AEC-Q100 qualified; automotive applications should use the LTC1856 family automotive-grade counterpart or an alternative ADC. Halogen-free status not explicitly stated in the verified data - default to 'unknown'.
