NXP Semiconductors LPC1857JET256,551

Overview

LPC1857JET256 from NXP Semiconductors is a 32-bit ARM Cortex-M3 microcontroller operating at up to 180 MHz, featuring 1 MB dual-bank flash, 136 kB SRAM, 16 kB EEPROM, Ethernet MAC with IEEE 1588 support, dual High-speed USB (one OTG), LCD controller, and external memory controller - deployed in industrial automation gateways requiring real-time connectivity and deterministic I/O.

For engineers reviewing the LPC1857JET256 datasheet, LPC1857JET256 pinout, LPC1857JET256 application, or LPC1857JET256 equivalent, key selection criteria include its LBGA256 package, -40 °C to +105 °C temperature grade, integrated SCTimer/PWM for motor control, dual ADCs (8-channel total), and support for RMII/MII Ethernet interfaces.

Technical Context

The LPC1857JET256 implements an ARM Cortex-M3 r2p1 core with Harvard architecture, 3-stage pipeline, and integrated MPU/NVIC - enabling deterministic interrupt handling and memory protection for safety-critical firmware. Its clock system includes three PLLs: one for CPU up to 180 MHz, one dedicated to USB high-speed operation, and one configurable as audio PLL.

Digital peripheral integration centers on the State-Configurable Timer/PWM (SCTimer/PWM) subsystem on AHB, coupled with Global Input Multiplexer Array (GIMA) for flexible event routing between timers, ADCs, and communication peripherals - supporting complex timing sequences without CPU intervention.

Key Specifications

Pinout & Package

Package: LBGA256 (Plastic low profile ball grid array; 256 balls; body 17 × 17 × 1 mm; SOT740-2).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microcontroller applications.

Compared with LPC1837JET256, the LPC1857JET256 adds LCD support and doubles flash capacity - critical for HMI-rich industrial devices; versus LPC4357JET256, it trades M4F compute power for deterministic M3 timing and on-chip EEPROM - favoring reliability over raw throughput in metering and gateway use cases.

Availability

LPC1857JET256 is available at Aetrix Electronics and suitable for industrial automation gateways, smart energy metering systems, and RFID reader platforms requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LPC1857JET256 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT markets.

The LPC18xx product line was designed specifically for high-performance, feature-rich embedded applications demanding real-time Ethernet, USB, and display connectivity - targeting industrial control, metering, and human-machine interface platforms.

FAQ

What is the maximum operating frequency of the LPC1857JET256?

The LPC1857JET256 operates at a maximum CPU frequency of 180 MHz, achieved via its ARM Cortex-M3 core and internal PLL configuration. This frequency is sustained across the full -40 °C to +105 °C industrial temperature range, as validated in NXP's characterization testing and documented in the LPC185X_3X_2X_1X datasheet Rev. 5.3. The LPC1857JET256 achieves this using a dedicated CPU PLL independent of USB or audio clock domains.

Does the LPC1857JET256 support IEEE 1588 Precision Time Protocol?

Yes, the LPC1857JET256 includes hardware-accelerated IEEE 1588-2008 v2 timestamping within its Ethernet MAC, supporting both one-step and two-step clock synchronization modes. The LPC1857JET256 implements full PTP message parsing and hardware timestamp insertion on transmit/receive - enabling sub-microsecond accuracy in industrial time-sensitive networking applications without CPU overhead.

What memory resources are integrated into the LPC1857JET256?

The LPC1857JET256 integrates 1 MB of on-chip dual-bank flash memory (512 kB per bank), 136 kB of SRAM distributed across multiple AHB-accessible blocks, 16 kB of EEPROM for non-volatile data storage, 64 kB of ROM containing boot code and USB/SD/MMC drivers, and 64-bit + 256-bit OTP memory. All memory types are accessible without external components, and the dual-bank flash enables safe over-the-air firmware updates on the LPC1857JET256.

How many analog-to-digital converter channels does the LPC1857JET256 provide?

The LPC1857JET256 features two independent 10-bit ADCs (ADC0 and ADC1), sharing eight analog input channels (ADC0_0–ADC0_7 and ADC1_0–ADC1_7). Each channel is electrically tied between both converters, allowing simultaneous sampling or redundancy - delivering up to 400 kSamples/s per ADC. This architecture is confirmed in Table 2 and Section 6.2 of the LPC185X_3X_2X_1X datasheet for the LPC1857JET256.

What package type and pin count does the LPC1857JET256 use?

The LPC1857JET256 uses an LBGA256 package (SOT740-2): a 17 mm × 17 mm × 1 mm plastic low-profile ball grid array with 256 solder balls arranged in a 16 × 16 array. This package is explicitly listed in Table 1 of the NXP datasheet and supports industrial thermal dissipation requirements while enabling high I/O density for complex peripheral interfacing on the LPC1857JET256.