NXP Semiconductors LPC2420FET208,551

Overview

LPC2420FET208 from NXP Semiconductors is a flashless 32-bit ARM7TDMI-S microcontroller operating at up to 72 MHz, featuring 64 kB local SRAM, 2 kB RTC-powered SRAM, and 82 kB total on-chip RAM. It integrates four UARTs, USB 2.0 full-speed device/host/OTG with 4 kB endpoint RAM, three I²C interfaces, two SSPs, SPI, I²S, 10-bit ADC (8-channel), 10-bit DAC, dual PWM units, and 160 GPIO pins - deployed in industrial protocol converters and medical communication gateways.

For engineers reviewing the LPC2420FET208 datasheet, LPC2420FET208 pinout, LPC2420FET208 application, or LPC2420FET208 equivalent, key selection criteria include its TFBGA208 package, absence of on-chip flash, Ethernet MAC exclusion (vs. LPC2460), CAN channel omission, and dual AHB bus architecture supporting concurrent USB and DMA transfers without contention.

Technical Context

The LPC2420FET208 implements an ARM7TDMI-S core with Thumb/ARM instruction set support, enabling sub-routine-level optimization for code density or performance. Its memory subsystem includes 64 kB SRAM on the ARM local bus, 16 kB general-purpose DMA SRAM accessible by USB, and 2 kB battery-backed SRAM powered from the RTC domain.

Peripheral connectivity centers on serial protocols: four UARTs with fractional baud rate generation and FIFO, USB 2.0 dual-port OTG with integrated PHY, three I²C-bus interfaces (one open-drain), two SSP controllers with multi-protocol capability, and I²S for digital audio - all coordinated via a 32-interrupt Advanced Vectored Interrupt Controller (VIC) and General Purpose DMA controller.

Key Specifications

Pinout & Package

Package: TFBGA208 (plastic thin fine-pitch ball grid array; 208 balls; body 15 × 15 × 0.7 mm; SOT950-1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LPC2460FET208, the LPC2420FET208 removes Ethernet and CAN to reduce cost and power while retaining identical TFBGA208 footprint and software compatibility; versus LPC1769FBD208, it offers legacy ARM7 toolchain continuity and flashless flexibility but lacks Cortex-M3 performance and integrated flash.

Availability

LPC2420FET208 is available at Aetrix Electronics and suitable for industrial protocol converters, medical data gateways, and embedded control hubs requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant TFBGA packaging.

Supply support for LPC2420FET208 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 headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The LPC2400 series was designed as a flashless, high-peripheral-count ARM7 platform targeting communication gateways, protocol translators, and real-time industrial controllers where external memory flexibility and deterministic interrupt latency are critical.

FAQ

Does the LPC2420FET208 include on-chip flash memory?

No, the LPC2420FET208 is a flashless microcontroller. It relies entirely on external memory (e.g., NOR/NAND flash or SDRAM via EMC) or serial bootloaders for program storage. This architecture reduces die cost and simplifies secure firmware updates, making it suitable for applications where code resides off-chip or is loaded dynamically. The LPC2420FET208 itself contains 82 kB of SRAM but zero flash memory.

What is the maximum operating frequency of the LPC2420FET208?

The LPC2420FET208 operates at a maximum CPU clock frequency of 72 MHz. This is achieved using the on-chip PLL, which can be driven by the main crystal oscillator (1–25 MHz), the internal 4 MHz RC oscillator (1% accuracy), or the RTC oscillator. The 72 MHz speed applies to both ARM and Thumb instruction execution modes, with Thumb mode offering >30% code size reduction at minimal performance cost.

Is the LPC2420FET208 pin-compatible with the LPC2460FET208?

Yes, the LPC2420FET208 and LPC2460FET208 share identical TFBGA208 packaging (SOT950-1), pinout, and ball assignment. However, certain pins - such as ENET_TXD0, ENET_RXD0, and CAN-related signals - are no-connect (NC) or unused in the LPC2420FET208 due to omitted Ethernet and CAN peripherals. PCBs designed for LPC2460FET208 can accommodate LPC2420FET208 with no layout changes, though firmware must exclude Ethernet/CAN drivers.

What USB capabilities does the LPC2420FET208 support?

The LPC2420FET208 integrates a USB 2.0 full-speed dual-port device/host/OTG controller with on-chip PHY and 4 kB of dedicated endpoint RAM. It supports simultaneous device and host roles, enumeration as HID, CDC, or mass storage class, and hardware-accelerated DMA transfers. The USB interface is fully functional in LPC2420FET208 - unlike Ethernet or CAN, USB is retained across both LPC2420 and LPC2460 variants.

How is the 2 kB RTC-powered SRAM used in the LPC2420FET208?

The 2 kB SRAM in the LPC2420FET208 is powered from the RTC domain (VBAT or RTC power pin), allowing data retention during main power removal or deep power-down mode. It is commonly used to store calibration constants, security keys, or session logs that must persist across resets or power cycles. Access is controlled via APB bus registers, and the memory remains active as long as RTC power is supplied - independent of the main 3.3 V rail.