LTC1855IG - 14-Bit 8-Channel 100ksps ADC | Analog Devices
MPN： LTC1855IG ✓ 啟用中LTC1855IG 概覽
An ADC is an interface IC that converts continuous analog voltage into a numeric representation for measurement, control, monitoring, or recording systems. The ADC belongs to the data-converter hierarchy, where it sits between sensors or signal-conditioning circuits and a microcontroller, DSP, FPGA, or industrial controller. Its purpose is to provide repeatable digital measurements while preserving the voltage relationships present at its analog inputs.
The LTC1855 family combines 12-bit, 14-bit, and 16-bit resolution options with a common eight-channel multiplexing architecture. The LTC1855 specifically provides ±1.5LSB integral nonlinearity, a trimmed internal clock, a maximum conversion time of 5µs, and a guaranteed sampling rate of 100ksps. Shutdown capability allows the converter to reduce power use when continuous acquisition is unnecessary.
Internally, the converter uses a successive-approximation conversion technique and a serial output architecture. Its eight-input multiplexer reduces the need for separate converter channels when several analog signals must be measured sequentially. The internal clock is trimmed to maintain consistent conversion timing, while the single 5V supply simplifies system power architecture compared with converters requiring separate analog and digital rails.
Typical applications include industrial process monitoring, multichannel sensor acquisition, data logging, laboratory instrumentation, factory automation, and embedded measurement systems. The 28-pin SSOP package can support compact controller boards, although analog routing, reference grounding, input conditioning, and digital interface timing require careful PCB layout.
Designers should verify the complete pin description and electrical limits in the manufacturer datasheet before assigning connector or signal-ground pins. Input protection, source impedance, acquisition time, reference quality, and digital clock timing can materially affect code accuracy even when the converter's nominal resolution and conversion rate meet the application requirement.
This product page combines the confirmed 14-bit resolution, eight-channel multiplexing, 100ksps throughput, ±10V input classification, single 5V operation, shutdown function, and SSOP packaging with practical guidance for selecting a compatible replacement and integrating the converter into a multichannel analog measurement system.
直接替換替代品，適用於 LTC1855IG — 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： LTC1855IG （相同外形與佔位） — 差異在於 Input Voltage Range, Multiplexer Configuration, Number of Channels, Package, Resolution.
LTC1854IG
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LTC1856IG
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →LTC1855CG
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LTC1855IMS
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LTC1855IG#PBF
✅ 直接替換📋 參考替代品（不在目錄中）
LTC1855IG 最大額定值與電氣特性
| ADC Type | Successive-approximation ADC (SAR) |
| 解析度 | 14 bit |
| Number of Channels | 8 channels |
| 取樣率 | 100ksps |
| Maximum Conversion Time | 5 µs |
| 輸入電壓範圍 | ±10 V |
| Integral Nonlinearity | ±1.5 LSB |
| 供應電壓 | 5 V |
| Multiplexer Configuration | Programmable single-ended inputs and differential pairs |
| Shutdown Support | Yes |
| Internal Clock | Trimmed |
| Output Interface | Serial |
| 封裝 | 28-pin SSOP |
| 安裝類型 | Surface mount |
| Manufacturer | Analog Devices |
| Product Family | LTC1854/LTC1855/LTC1856 |
| Power-Supply Architecture | Single 5 V supply |
LTC1855IG 28-pin ssop 腳位配置指南
LTC1855IG（28-pin ssop 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： LTC1855IG.
請參閱 資料表 以查看完整腳位配置。
典型應用
LTC1855IG 適用於 6 應用s: Industrial Process Monitoring, Data Logging and Acquisition, Laboratory Instrumentation, Embedded Sensor Acquisition, Factory Automation Control, Battery-Powered Portable Measurement.
Industrial Process Monitoring
The LTC1855IG fits multichannel process monitoring because it combines eight selectable analog inputs with 14-bit resolution and a guaranteed 100ksps sampling rate. It can scan pressure, temperature, level, or valve-feedback signals through its programmable multiplexer while operating from one 5V supply. The 5µs maximum conversion time supports sequential acquisition, but each sensor path still needs suitable input impedance, filtering, and protection. For noisy factory environments, place protection ahead of the converter and route analog and digital returns carefully. Verify settling time against the source impedance and use the converter's differential-input capability where common-mode rejection is valuable.
推薦
Data Logging and Acquisition
The LTC1855IG is appropriate for a compact data logger that records several slowly changing analog quantities. Eight multiplexed channels reduce the converter count, 14-bit resolution preserves small signal detail, and the 100ksps rate provides margin for faster sampled events. A microcontroller or DSP can issue channel-selection commands, clock the serial conversion, and store the resulting words. Design the firmware around the converter's acquisition and conversion timing, and use the shutdown mode during idle intervals. For long records, verify reference stability and provide buffering when sensor outputs have high source impedance.
推薦
Laboratory Instrumentation
The LTC1855IG can serve as the measurement front end in laboratory instruments that digitize several bipolar input ranges. Its ±10V input classification, eight-channel multiplexing, and 14-bit resolution suit general-purpose monitoring, while differential pairing supports instrumentation-style connections. The single 5V supply simplifies analog and digital power partitioning around a controller. Use shielded analog routing, careful grounding, and stable references to preserve repeatability. Because instrumentation accuracy depends on the complete signal chain, calibrate gain and offset in software and keep wide-band noise and settling effects out of the measurement bandwidth.
推薦
Embedded Sensor Acquisition
The LTC1855IG is suitable for embedded acquisition boards that monitor multiple resistive, voltage-based, or conditioned sensor outputs. Its eight-channel multiplexer limits analog routing compared with separate converter packages, while 14-bit resolution improves representation of low-level sensor changes. The converter's 100ksps maximum sampling rate is substantially higher than many slow industrial sensors, leaving timing margin for filtering and system processing. Use the shutdown function during inactive intervals to conserve power. Ensure each source settles within the acquisition window and consider protection, filtering, and calibration as parts of the measurement accuracy budget.
推薦
Factory Automation Control
The LTC1855IG can digitize analog feedback and operator-panel signals in a factory automation controller. Eight channels permit grouped monitoring of actuator commands, pressure references, supply conditions, or sensor returns, while 100ksps throughput supports deterministic scan schedules. A controller such as a PLC companion MCU can manage channel selection, shutdown state, and serial data transfer. Keep high-energy actuator wiring separate from sensitive analog traces, use front-end protection where cables leave the board, and follow the pin-description table for ground and reference assignments. Thermal drift and reference accuracy should be included in production calibration limits.
推薦
Battery-Powered Portable Measurement
The LTC1855IG supports portable measurement systems that need multiple analog inputs but do not require continuous conversion. Its shutdown capability allows a controller to activate the converter for a measurement burst and disable it afterward, while the single 5V supply simplifies power design around common portable rails. The 28-pin SSOP package helps limit board area, and the eight-channel multiplexer reduces component count. Power-budget the 5V input current over both active and shutdown periods, and verify startup settling before the first sample is accepted. Low-power operation also requires avoiding always-on sensor circuits that would undermine the converter's shutdown savings.
推薦
推薦產品摘要
工程參考資料，適用於 LTC1855IG — 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 | LTC1854IG | LTC1856IG | LTC1855CG | LTC1855IMS | LTC1855IG#PBF |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP |
| Resolution | 14 bit | 12 bit | 16 bit | 14 bit | 14 bit | 14 bit |
| Number of Channels | 8 channels | 8 channels | 8 channels | 8 channels | 8 channels | 8 channels |
| Sampling Rate | 100ksps | 100ksps | 100ksps | 100ksps | 100ksps | 100ksps |
| Maximum Conversion Time | 5 µs | 5 µs | 5 µs | 5 µs | 5 µs | 5 µs |
| Integral Nonlinearity | ±1.5 LSB | ±3 LSB | ±1 LSB | ±1.5 LSB | ±1.5 LSB | ±1.5 LSB |
| Input Voltage Range | ±10 V | ±10 V | ±10 V | ±10 V | ±10 V | ±10 V |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Shutdown Support | Yes | Yes | Yes | Yes | Yes | Yes |
主要差異化特點
- Balanced 14-bit resolution and 100ksps throughput (對比LTC1854IG)
- Lower integral nonlinearity than the 12-bit family member (對比LTC1854IG)
- Eight-channel multiplexing with shutdown (對比LTC1855IG#PBF)
設計說明
Route each analog input as a short, continuous trace from the protection or conditioning network to the converter. Keep digital clock, serial data, and chip-select traces away from high-impedance input nodes. Place input filtering and protection close to the source connector, while placing the converter close to the analog reference and bypass network. This separation reduces capacitive coupling from switching digital edges and helps preserve the usable 14-bit measurement accuracy.
Treat acquisition time as a signal-integrity requirement rather than a nominal sampling-rate calculation. The converter is guaranteed to support 100ksps and has a 5µs maximum conversion time, but the input network must also settle before sampling. Use the manufacturer input-capacitance and acquisition guidance, add a buffer when source impedance is high, and include the settling error in the system accuracy budget. This is particularly important for multiplexed sensors with widely varying impedance.
Do not substitute the 12-bit LTC1854IG or 16-bit LTC1856IG without reviewing software scaling, calibration, and full-scale assumptions. Although they belong to the same converter family, changing resolution changes the code range and potentially the INL behavior. Likewise, verify every physical pin against the manufacturer pin-description table before using a lead-free ordering code or family variant on an existing board.
Provide a stable 5V supply and place the manufacturer's recommended bypass network close to the supply pins. Avoid routing converter current through traces shared with sensitive input references, because acquisition pulses and digital transitions can couple into the analog node. If shutdown is used for duty-cycle control, allow the complete startup and settling sequence before accepting a conversion result.
合規資訊
The lead-free LTC1855IG#PBF ordering code appears in the verified distributor listing, but separate RoHS, REACH, halogen-free, and conflict-minerals declarations are not stated. AEC-Q100 is not applicable to this industrial data-converter family.