NXP Semiconductors LPC51U68JBD48K

Overview

LPC51U68JBD48K from NXP Semiconductors is a 32-bit ARM Cortex-M0+ microcontroller designed for low-power embedded control applications. It integrates 256 KB flash, 96 KB SRAM (32 KB SRAMX + 64 KB SRAM0), crystal-less USB 2.0 full-speed device interface, eight Flexcomm serial peripherals (configurable as USART/SPI/I2C), a 12-bit 5.0 Msamples/sec ADC with 12 channels, and an integrated temperature sensor - enabling compact, cost-sensitive USB-connected sensor hubs and industrial I/O controllers.

For engineers reviewing the LPC51U68JBD48K datasheet, LPC51U68JBD48K pinout, LPC51U68JBD48K application, or LPC51U68JBD48K equivalent, key selection criteria include its LQFP48 package with 37 GPIOs, USB device-only operation without external crystal, SCTimer/PWM flexibility for motor control, and support for deep power-down wake-up via RTC alarm or Micro-tick Timer.

Technical Context

The LPC51U68JBD48K implements an ARM Cortex-M0+ core running at up to 150 MHz with single-cycle multiplier and NVIC-based interrupt handling. Its clock system combines a factory-trimmed internal FRO (48/96 MHz), system PLL, 32.768 kHz RTC oscillator, and watchdog oscillator - enabling precise timing across sleep, deep-sleep, and deep power-down modes.

Digital peripheral integration includes an 18-channel DMA controller, four GPIO grouped interrupts (GINT), CRC engine, and eight Flexcomm interfaces - two of which support I2S with FIFO and fractional rate generation. Analog subsystem features dual-trigger ADC sequences and on-die temperature sensing routed to ADC channel 0.

Key Specifications

Pinout & Package

LPC51U68JBD48K uses a plastic LQFP48 package (7 × 7 × 1.4 mm, SOT313-2) with 48 leads and exposed thermal pad. Pin functions are multiplexed across GPIO, Flexcomm interfaces, USB, ADC, clock, and debug resources.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LPC51U68JBD48K, LPC54102JBD48 offers stronger compute but higher power and crystal dependency, while LPC55S06JBD48 adds security and analog precision at the cost of USB simplicity - making LPC51U68JBD48K optimal for cost-sensitive, USB-connected embedded nodes where crystal elimination and ultra-low-power wake-up are critical.

Availability

LPC51U68JBD48K is available at Aetrix Electronics and suitable for USB-connected sensor hubs, industrial I/O modules, smart lighting nodes, and portable medical instruments requiring stable component supply and long-term manufacturability.

Supply support for LPC51U68JBD48K 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 specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in ARM-based microcontrollers and edge processing.

The LPC51U68 product line targets cost-optimized, USB-enabled embedded control - emphasizing crystal-less operation, flexible serial interfaces, and ultra-low-power modes for battery-powered and space-constrained designs.

FAQ

What is the maximum operating frequency of the LPC51U68JBD48K?

The LPC51U68JBD48K features an ARM Cortex-M0+ core rated for operation up to 150 MHz. This frequency is achievable using the internal FRO oscillator (96 MHz output) or system PLL, and is validated across the full industrial temperature range (-40°C to +105°C) and supply voltage range (1.62 V to 3.6 V). The LPC51U68JBD48K maintains timing compliance at this speed with appropriate flash wait states enabled.

Does the LPC51U68JBD48K support crystal-less USB device operation?

Yes, the LPC51U68JBD48K supports crystal-less USB 2.0 full-speed device operation using its factory-trimmed internal FRO oscillator and dedicated USB software library (documented in Technical Note TN00035). This eliminates the need for an external 12 MHz crystal, reducing BOM cost and PCB area. The LPC51U68JBD48K achieves ±0.25% accuracy in device mode without external timing components.

How many GPIO pins does the LPC51U68JBD48K provide in its LQFP48 package?

The LPC51U68JBD48K in LQFP48 package provides 37 GPIO pins. These include PIO0_0 through PIO0_31 and PIO1_0 through PIO1_5 (with PIO1_6–PIO1_11 not bonded in this package variant), all supporting configurable pull-up/pull-down, open-drain mode, and input inversion. GPIO registers reside on AHB for single-cycle access, ensuring deterministic I/O timing in real-time applications.

What ADC capabilities does the LPC51U68JBD48K offer?

The LPC51U68JBD48K integrates a 12-bit successive-approximation ADC with up to 12 input channels (ADC0_0 to ADC0_11), sample rates up to 5.0 Msamples/sec, and support for two independent conversion sequences triggered by software, timers, or peripheral events. An integrated temperature sensor is connected to ADC channel 0, enabling on-die thermal monitoring without external components.

Is the LPC51U68JBD48K pin-compatible with other NXP microcontrollers?

The LPC51U68JBD48K is not pin-compatible with LPC5410x or LPC5411x devices - those families use LQFP64 packages. However, the LPC51U68JBD48K shares functional compatibility (same peripheral set, register map, and toolchain) with LPC51U68JBD64 and is software-compatible with LPC541xx series, enabling scalable design migration. Pin mapping is unique to the LQFP48 footprint.