Arm Cortex-M4|Kinetis K21 120 MHz 32-bit USB MCUs

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The Kinetis K21 120 MHz MCU family targets cost-sensitive applications requiring low-power functionality.

Features hardware encryption and tamper detection
Includes a rich suite of analog, communication, timing and control peripherals to accommodate a wide range of requirements
Maximizes board space and enhances performance with minimum-length interconnections
Provides performance efficiency with low power
Delivers significant BOM savings through smart on-chip integration
Shares the comprehensive enablement and scalability of the Kinetis portfolio

Please contact your local NXP representative to download the K21 Security Data sheet and Reference Manual documents (under NDA).

Product Details

10 low-power modes with power and clock gating for optimal peripheral activity and recovery times. Stop currents of <500 nA, run currents of <200 µA/MHz, 4 µs wake-up from Stop mode
Full memory and analog operation down to 1.71 volts for extended battery life
Low-leakage wake-up unit with up to eight internal modules and 16 pins as wake-up sources in low-leakage stop (LLS)/very low-leakage stop (VLLS) modes
Low-power timer for continual system operation in reduced power state

512 KB-1 MB flash. Fast access, high reliability with four-level security protection
128 KB of SRAM
FlexMemory: 32 bytes-16 KB of user-segmentable byte write/erase EEPROM for data tables/system data. EEPROM with over 10M cycles and flash with 70 µsec write time (brownouts without data loss/corruption). No user or system intervention to complete programming and erase functions and full operation down to 1.71 volts. In addition, 128 KB of FlexNVM for extra program code, data or EEPROM backup

Up to two high-speed, 16-bit analog-to-digital converters (ADCs) with configurable resolution. Single or differential output mode operation for improved noise rejection. 500 ns conversion time achievable with programmable delay block triggering
Up to two 12-bit digital-to-analog converters (DACs) for analog waveform generation for audio applications
Up to three high-speed comparators providing fast and accurate motor over-current protection by driving PWMs to a safe state
Analog voltage reference provides an accurate reference to analog blocks, ADC and DAC, and replaces external voltage references to reduce system cost

Arm® Cortex-M4® core + DSP. 120 MHz, single cycle MAC, single instruction multiple data (SIMD) extensions, single precision floating point unit
Up to 16-channel DMA for peripheral and memory servicing with reduced CPU loading and faster system throughput
Cross bar switch enables concurrent multi-leader bus accesses, increasing bus bandwidth
Independent flash banks allow concurrent code execution and firmware updating with no performance degradation or complex coding routines

Up to four FlexTimers with a total of 20 channels. Hardware dead-time insertion and quadrature decoding for motor control
Carrier modulator timer for infrared waveform generation in remote control applications
Four-channel 32-bit periodic interrupt timer provides time base for RTOS task scheduler or trigger source for ADC conversion and programmable delay block

USB 2.0 On-The-Go (full-speed). Device charge detect optimizes charging current/time for portable USB devices enabling longer battery life. Low-voltage regulator supplies up to 120 mA off-chip at 3.3 volts to power external components from 5 volts input
Up to six UARTs with IrDA support including one UART with ISO7816 smart card support. Variety of data size, format and transmission/reception settings supported for multiple industrial communication protocols
Inter-IC Sound (I²S) serial interface for audio system interfacing
CAN module for industrial network bridging
Up to three DSPI and two I²C

Hardware Encryption coprocessor for secure data transfer and storage. Faster than software implementations and with minimal CPU loading. Supports a wide variety of algorithms - DES, 3DES, AES, MD5, SHA-1, SHA-256
System security and tamper detect with secure real-time clock with independent battery supply. Secure key storage with internal/external tamper detect for unsecure flash, temperature, clock, and supply voltage variations and physical attack detection

Memory protection unit provides memory protection for all leaders on the cross bar switch, increasing software reliability
Cyclic redundancy check engine validates memory contents and communication data, increasing system reliability
Independent-clocked COP guards against clock skew or code runaway for fail-safe applications such as the IEC 60730 safety standard for household appliances
External watchdog monitor drives output pin to safe state external components if watchdog event occurs

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Quick reference to our design files types.

3 design files

Receive the full breakdown. See the product footprint and more in the eCad file.