DAC8742HPBS - HART Modem Interface | Texas Instruments
MPN： DAC8742HPBS ✓ 啟用中DAC8742HPBS 概覽
A HART modem interface is a signal-conditioning IC within the broader industrial communication and data-conversion hierarchy. It encodes and decodes Frequency Shift Keying signals used by HART-compatible fieldbus equipment. This allows an embedded controller to communicate over legacy 4-20 mA instrumentation loops without implementing the analog modulation and filtering as discrete circuitry. In a FOUNDATION Fieldbus or PROFIBUS PA installation, the modem interface supports the physical signaling layer while higher-level protocols and safety mechanisms remain the responsibility of the host system.
The DAC8742HPBS is valued for integrating dedicated modem functionality into a compact 32-TQFP device. Its UART and SPI host interfaces provide selectable connectivity to embedded processors, allowing command and data transfer between the modem and application firmware. The 5x5 mm package also supports space-constrained industrial instrumentation, although exposed-pad layout and thermal verification must follow the manufacturer package drawing. Because the supplied data does not expose individual pin assignments, supply limits, isolation ratings, or accuracy figures, those details must be checked in the official DAC8742H documentation before schematic approval.
Typical uses include HART-compatible sensor transmitters, pressure and flow instrument interfaces, industrial process-control modules, and FOUNDATION Fieldbus or PROFIBUS PA equipment. In these systems, the DAC8742HPBS reduces the discrete component count associated with analog modem circuitry and gives the host MCU a structured digital control path. The principal engineering trade-off is that the modem interface is only one part of the communication chain: the transmitter still requires suitable loop power, filtering, surge protection, grounding, and validated fieldbus wiring.
For new designs, verify the exact device variant, supply rails, UART and SPI logic levels, receive bandwidth, transmit modulation limits, loop-current interface, and exposed-pad requirements in the official Texas Instruments datasheet. Do not derive those values from the distributor snippets. The manufacturer product page describes the DAC8742H as HART, FOUNDATION Fieldbus, and PROFIBUS PA compliant with UART/SPI support, making it the authoritative starting point for design review.
This page combines verified distributor availability, manufacturer positioning, package information, replacement analysis, and practical integration guidance. It also separates confirmed facts from parameters that require datasheet verification, helping engineers avoid treating incomplete distributor metadata as a complete electrical specification.
直接替換替代品，適用於 DAC8742HPBS — 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： DAC8742HPBS （相同外形與佔位） — 差異在於 Host Interface, Product Type.
DAC8742HPBSR
✅ 直接替換聯絡詢價
查看資料表 →DAC8718SPAGR
✅ 直接替換📋 參考替代品（不在目錄中）
DAC8742HPBS 最大額定值與電氣特性
| Product Type | HART modem interface |
| Supported Standards | HART, FOUNDATION Fieldbus, PROFIBUS PA |
| Host Interface | UART/SPI |
| Package Type | 32-TQFP (5x5) |
| Package Pin Count | 32 pins |
| Package Body Size | 5 x 5 mm |
| Manufacturer | Texas Instruments |
| Product Family | DAC874xH |
| Signal Type | HART modem signal |
| 安裝類型 | Surface mount |
| Application Category | Industrial fieldbus communication |
| Distributor Availability | Buy now, ships today |
| Reference Unit Price | $7.9092 |
| Reference Inventory | 6,016 pieces |
| Reference Lead Time | To be confirmed |
| Estimated Delivery Time | Oct 18 - Oct 23 |
DAC8742HPBS 5 x 5 mm 腳位配置指南
DAC8742HPBS（5 x 5 mm 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： DAC8742HPBS.
請參閱 資料表 以查看完整腳位配置。
典型應用
DAC8742HPBS 適用於 6 應用s: HART Sensor Transmitter, Pressure and Flow Instrumentation, FOUNDATION Fieldbus Equipment, PROFIBUS PA Device Interface, Industrial Process-Control Module, Remote Data Acquisition Unit.
HART Sensor Transmitter
The DAC8742HPBS is suited to a HART sensor transmitter because the Texas Instruments DAC8742H family combines a dedicated HART modem interface with selectable UART or SPI host connectivity. A microcontroller can configure and supervise the modem while the interface couples the digital command path to the 4-20 mA instrumentation loop. The 32-TQFP (5x5) package supports compact transmitter boards. Verify supply rails, signal amplitudes, bandwidth, and exposed-pad layout in the official datasheet before schematic release.
推薦
Pressure and Flow Instrumentation
For pressure, level, and flow instruments, the DAC8742HPBS can provide the HART physical-layer interface between a measurement controller and a 4-20 mA loop. UART or SPI support simplifies connection to embedded processing hardware, while the 5x5 mm TQFP package limits board area compared with discrete codec implementations. The interface does not remove the need for sensor excitation, signal conditioning, loop compliance, or surge protection, so those blocks must be designed independently.
推薦
FOUNDATION Fieldbus Equipment
The DAC8742HPBS fits FOUNDATION Fieldbus equipment because the manufacturer identifies the DAC8742H family as HART, FOUNDATION Fieldbus, and PROFIBUS PA compliant. It can provide the dedicated modem interface while a host processor handles higher-layer communication, configuration, diagnostics, and device data. Its UART/SPI host connectivity supports a modular embedded architecture. Detailed bus timing, signal levels, and isolation requirements must be confirmed from the exact device documentation before implementation.
推薦
PROFIBUS PA Device Interface
In a PROFIBUS PA instrument, the DAC8742HPBS can serve as the dedicated HART-compatible modem interface associated with the DAC8742H family, while system firmware manages the application and network layers. UART or SPI host communication allows connection to an embedded processor without implementing analog modulation in discrete logic. The 32-TQFP (5x5) package supports compact field devices, but loop impedance, cable length, EMC behavior, and grounding remain system-level constraints.
推薦
Industrial Process-Control Module
The DAC8742HPBS is applicable to a process-control module that must add HART-compatible communication to an existing embedded control platform. Its UART/SPI host options let the modem interface connect to a microcontroller while diagnostics and configuration data remain software-managed. The 5x5 mm TQFP package is useful for compact multi-channel equipment, but thermal performance and exposed-pad construction must follow the manufacturer land pattern. External loop and surge-protection components should be selected for the installation environment.
推薦
Remote Data Acquisition Unit
A remote data-acquisition unit can use the DAC8742HPBS to add HART modem communication to a controller connected to sensors and actuators. The manufacturer-confirmed HART, FOUNDATION Fieldbus, and PROFIBUS PA positioning supports industrial communication designs, while UART/SPI simplifies firmware integration with embedded processors. The modem interface reduces custom analog-interface complexity, although input filtering, isolated power, cable protection, and precise operating-limit verification remain essential.
推薦
推薦產品摘要
工程參考資料，適用於 DAC8742HPBS — 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 | DAC8742HPBSR | DAC8718SPAGR |
|---|---|---|---|
| Package | 32-TQFP (5x5) | 32-TQFP (5x5) - related variant, exact package drawing requires verification | 32-TQFP (5x5) - same stated package family |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Product Function | HART modem interface | Related DAC8742H-family variant; exact function not verified | Modem-interface comparison candidate; exact function not verified |
| Package Pin Count | 32 pins | 32 pins - exact pinout requires verification | 32 pins - exact pinout requires verification |
| Manufacturer | Texas Instruments | Texas Instruments | Texas Instruments |
| Drop-In Confidence | Reference device | 70% - related suffix variant requiring manufacturer confirmation | 70% - same package family but functional equivalence unverified |
主要差異化特點
- Dedicated industrial modem positioning (對比DAC8718SPAGR)
- Confirmed UART and SPI host connectivity (對比DAC8742HPBSR)
- Documented distributor availability (對比DAC8742HPBSR)
設計說明
Use the exact Texas Instruments DAC8742H package drawing for the 32-TQFP (5x5) footprint rather than relying on a generic TQFP land pattern. Verify pin 1 orientation, pin numbering, exposed-pad dimensions, paste geometry, and via recommendations. The supplied distributor excerpt confirms the package but does not expose the pin table, so schematic-to-footprint cross-checking is mandatory before PCB release.
Confirm the device's permitted supply range, sequencing, digital input thresholds, and analog signal limits from the exact datasheet before assigning power rails. Decouple each required supply according to the manufacturer recommendation and include local high-frequency bypass close to the pins. The supplied records do not state voltage ratings, so do not infer them from the 4-20 mA loop or UART/SPI labels.
Treat the HART connection as an analog communications channel rather than a conventional UART signal path. Follow the manufacturer reference circuit for coupling, filtering, impedance, grounding, and protection. Keep noisy switching and relay paths away from the modem input, and validate signal integrity with the intended cable and termination. The supplied data does not provide cutoff frequencies or drive levels.
Do not substitute DAC8742HPBSR or DAC8718SPAGR based only on a matching 32-pin TQFP description. Confirm that every assigned pin has the same function and that supply, timing, electrical limits, and thermal requirements are compatible. Also verify the HART variant and package suffix against the manufacturer ordering table, because the supplied comparison search does not establish true pin-to-pin interchangeability.
合規資訊
The supplied verified records do not contain explicit compliance declarations for the exact DAC8742HPBS orderable part. Obtain current manufacturer compliance documentation before release.
