LTC1855IG - 14-Bit 8-Channel 100ksps ADC | Analog Devices
N.º de pieza: LTC1855IG ✓ ActivoLTC1855IG Descripción general
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.
Alternativas directas para LTC1855IG — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con LTC1855IG (mismo factor de forma y huella) — difiere en Input Voltage Range, Multiplexer Configuration, Number of Channels, Package, Resolution.
LTC1854IG
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
LTC1856IG
✅ Sustitución directa ⚠️ Especificaciones sin verificarConsulte el precio
Ver hoja de datos →LTC1855CG
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
LTC1855IMS
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
LTC1855IG#PBF
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LTC1855IG Valores máximos y características eléctricas
| ADC Type | Successive-approximation ADC (SAR) |
| Resolución | 14 bit |
| Number of Channels | 8 channels |
| Frecuencia de muestreo | 100ksps |
| Maximum Conversion Time | 5 µs |
| Rango de tensión de entrada | ±10 V |
| Integral Nonlinearity | ±1.5 LSB |
| Tensión de alimentación | 5 V |
| Multiplexer Configuration | Programmable single-ended inputs and differential pairs |
| Shutdown Support | Yes |
| Internal Clock | Trimmed |
| Output Interface | Serial |
| Encapsulado | 28-pin SSOP |
| Tipo de montaje | Surface mount |
| Manufacturer | Analog Devices |
| Product Family | LTC1854/LTC1855/LTC1856 |
| Power-Supply Architecture | Single 5 V supply |
Guía de configuración de pines de LTC1855IG 28-pin ssop
Configuración de pines para LTC1855IG (encapsulado 28-pin ssop). Este componente analógico presenta pines de entrada, salida y alimentación. Consulte la hoja de datos del fabricante para conocer las configuraciones de los pines de ajuste de offset, compensación y habilitación. Ideal para circuitos de acondicionamiento de señal y amplificadores.
No hay datos detallados de patillaje disponibles para LTC1855IG.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
LTC1855IG es adecuado para 6 aplicacións: 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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para LTC1855IG — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | 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 |
Diferenciadores clave
- Balanced 14-bit resolution and 100ksps throughput (frente a LTC1854IG)
- Lower integral nonlinearity than the 12-bit family member (frente a LTC1854IG)
- Eight-channel multiplexing with shutdown (frente a LTC1855IG#PBF)
Notas de diseño
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.
Información de cumplimiento
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.