CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 A Powerful System-On-Chip for 2.4-GHz IEEE 802.15.4, 6LoWPAN and ZigBee Applications Check for Samples: CC2538 FEATURES 1 • 23 • • • Microcontroller – Powerful ARM Cortex™ M3 With Code Prefetch – Up to 32 MHz Clock Speed – 512-kB, 256-kB or 128-kB In-SystemProgrammable Flash – Supports On-Chip Over-the-Air Upgrade (OTA) – Supports Dual ZigBee Application Profiles – Up to 32-kB RAM (16-kB With Retention in All Power Modes) – cJTAG and JTAG Debugging RF – 2.4-GHz IEEE 802.15.4 Compliant RF Transceiver – Excellent Receiver Sensitivity of –97 dBm – Robustness to Interference With ACR of 44 dB – Programmable Output Power Up to 7 dBm Security Hardware Acceleration – Future Proof AES-128/256, SHA2 Hardware Encryption Engine – Optional – ECC-128/256, RSA Hardware Acceration Engine for Secure Key Exchange – Radio Command Strobe Processor and Packet Handling Processor for Low-Level MAC Functionality Low Power – Active-Mode RX (CPU Idle): 20 mA – Active-Mode TX at 0 dBm (CPU Idle): 24 mA – Power Mode 1 (4-μs Wake-Up, 32 kB RAM retention, full register retention): 0.6 mA – Power Mode 2 (Sleep Timer Running, 16-kB RAM Retention, Configuration Register Retention): 1.3 μA – Power Mode 3 (External Interrupts, 16-kB RAM Retention, Configuration Register Retention): 0.4 μA • • • – Wide Supply-Voltage Range (2 V–3.6 V) Peripherals – µDMA – 4 × General-Purpose Timers (Each 32-Bit or 2 × 16-Bit) – 32-Bit 32-kHz Sleep Timer – 12-Bit ADC With 8 Channels and Configurable Resolution – Battery Monitor and Temperature Sensor – USB 2.0 Full-Speed Device (12 Mbps) – 2 × SPI – 2 × UART – I2C – 32 General-Purpose I/O Pins (28 × 4 mA, 4 × 20 mA) – Watchdog Timer Layout – 8-mm × 8-mm QFN56 Package – Robust Device for Industrial Operation up to 125°C – Few External Components – Only a Single Crystal Needed for Asynchronous Networks Development Tools – CC2538 Development Kit – Reference Design Certified Under FCC and ETSI Regulations – Full Software Support for ZigBee Smart Energy 1.x, ZigBee Smart Energy 2.0, ZigBee Light Link and ZigBee Home Automation With Sample Applications and Reference Designs Available – Code Composer Studio™ – IAR Embedded Workbench® for ARM – SmartRF™ Studio – SmartRF™ Flash Programmer 1 2 3 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. ARM Cortex, Code Composer Studio, SmartRF are trademarks of Texas Instruments. IAR Embedded Workbench is a registered trademark of IAR Systems AB. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2012–2013, Texas Instruments Incorporated CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com APPLICATIONS • • • • • Smart Grid and Home Area Network Home and Building Automation Intelligent Lighting Systems Wireless Sensor Networks Internet of Things DESCRIPTION The CC2538xFnn is the ideal SoC for high-performance ZigBee applications. It combines a powerful ARM Cortex M3-based MCU system with up to 32K on-chip RAM and up to 512 K on-chip flash with a robust IEEE 802.15.4 radio. This enables it to handle complex network stacks with security, demanding applications, and over-the-air download. Thirty-two GPIOs and serial peripherals enable simple connections to the rest of the board. The powerful security accelerators enable quick and efficient authentication and encryption while leaving the CPU free to handle application tasks. The low-power modes with retention enable quick startup from sleep and minimum energy spent to perform periodic tasks. For a smooth development, the CC2538xFnn includes a powerful debugging system and a comprehensive driver library. To reduce the application flash footprint, CC2538xFnn ROM includes a utility function library and a serial boot loader. Combined with the free to use Z-Stack PRO or ZigBee IP stacks from Texas Instruments, the CC2538 provides the most capable and robust ZigBee solution in the market Table 1. CC2538 Family of Devices Available 2 DEVICE FLASH (kB) RAM (kB) SECURITY HW AES/SHA SECURITY HW ECC/RSA CC2538SF53 512 32 Yes Yes CC2538SF23 256 32 Yes Yes CC2538NF53 512 32 Yes No CC2538NF23 256 32 Yes No CC2538NF11 128 16 Yes No Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. JTAG ARM CortexTM± M3 SWO 128 KB/256 KB/512 KB Flash NVIC 32 MHz MPU 16 KB Standard SRAM cJTAG/JTAG 4 KB ROM ICEPick 2 UARTS Systick Timer 2 SSI/SPI Timer/PWM/CCP 4x (32-bit or 2x16-bit) USB Full Speed Watchdog Timer Device I2C SYSTEM SERIAL INTERFACES DEBUG INTERFACE 16 KB Retention SRAM 32 GPIO SECURITY 32ch DMA AES-128/256 SHA-256 32 MHz XTAL and 16 MHz RC Oscillator ECC RSA-2048 32 kHz XTAL and 32 kHz RC Oscillator 32-bit Sleep Timer Command Strobe Processor LDO Regulator Power-on Reset and BrownOut Detection MAC Timer ANALOG IEEE 802.15.4 RADIO Packet Handling Processor Low Power Comparator RF Chain Modulator 12-bit ADC Demod RX Synth TX With Temp Sensor For more details about the modules and their usage, see the corresponding chapters in the CC2538 Technical Reference Manual (SWRU319). Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 3 CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com ABSOLUTE MAXIMUM RATINGS (1) Supply voltage MIN MAX –0.3 3.9 V –0.3 VDD + 0.3, ≤ 3.9 V 10 dBm –40 125 °C All pads, according to human-body model, JEDEC STD 22, method A114 1 kV According to charged-device model, JEDEC STD 22, method C101 500 V All supply pins must have the same voltage Voltage on any digital pin Input RF level Storage temperature range ESD (2) (1) (2) UNIT Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. CAUTION: ESD-sensitive device. Precautions should be used when handling the device in order to prevent permanent damage. RECOMMENDED OPERATING CONDITIONS Operating ambient temperature range, TA Operating supply voltage (1) 4 (1) MIN MAX UNIT –40 125 °C 2 3.6 V The CC2538 contains a power on reset (POR) module and a brown out detector (BOD) that prevent the device from operating under unsafe supply voltage conditions. In the two lowest power modes, PM2 and PM3, the POR is active but the BOD is powered down, which gives a limited voltage supervision. If the supply voltage is lowered to below 1.4 V during PM2/PM3, at temperatures of 70°C or higher, and then brought back up to good operating voltage before active mode is re-entered, registers and RAM contents that are saved in PM2, PM3 may become altered. Hence, care should be taken in the design of the system power supply to ensure that this does not occur. The voltage can be periodically supervised accurately by entering active mode, as a BOD reset is triggered if the supply voltage is below approximately 1.7 V. Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 ELECTRICAL CHARACTERISTICS Measured on Texas Instruments CC2538 EM reference design with TA = 25°C, VDD = 3 V, and 8-MHz system clock, unless otherwise noted. Boldface limits apply over the entire operating range, TA = –40°C to 125°C, VDD = 2 V to 3.6 V, and fc = 2394 MHz to 2507 MHz. PARAMETER Icore Core current consumption TEST CONDITIONS MIN TYP MAX UNIT Digital regulator on. 16-MHz RCOSC running. No radio, crystals, or peripherals active. CPU running at 16-MHz with flash access 7 mA 32-MHz XOSC running. No radio or peripherals active. CPU running at 32-MHz with flash access,. 13 mA 32-MHz XOSC running, radio in RX mode, –50-dBm input power, no peripherals active, CPU idle 20 mA 32-MHz XOSC running, radio in RX mode at –100-dBm input power (waiting for signal), no peripherals active, CPU idle 24 32-MHz XOSC running, radio in TX mode, 0-dBm output power, no peripherals active, CPU idle 24 mA 32-MHz XOSC running, radio in TX mode, 7-dBm output power, no peripherals active, CPU idle 34 mA Power mode 1. Digital regulator on; 16-MHz RCOSC and 32-MHz crystal oscillator off; 32.768-kHz XOSC, POR, BOD and sleep timer active; RAM and register retention 0.6 mA Power mode 2. Digital regulator off; 16-MHz RCOSC and 32-MHz crystal oscillator off; 32.768-kHz XOSC, POR, and sleep timer active; RAM and register retention 1.3 2 μA Power mode 3. Digital regulator off; no clocks; POR active; RAM and register retention 0.4 1 μA 27 mA Peripheral Current Consumption (Adds to core current Icore for each peripheral unit activated) General-purpose timer Iperi Timer running, 32-MHz XOSC used 120 µA SPI 300 µA I2C 0.1 mA UART 0.7 mA Sleep timer Including 32.753-kHz RCOSC 0.9 μA USB 48-MHz clock running, USB enabled 3.8 mA ADC When converting 1.2 mA Erase 12 mA 8 mA Flash Burst-write peak current Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 5 CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com GENERAL CHARACTERISTICS Measured on Texas Instruments CC2538 EM reference design with TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT WAKE-UP AND TIMING Power mode 1 → active Digital regulator on, 16-MHz RCOSC and 32-MHz crystal oscillator off. Start-up of 16-MHz RCOSC 4 μs Power mode 2 or 3 → active Digital regulator off, 16-MHz RCOSC and 32-MHz crystal oscillator off. Start-up of regulator and 16-MHz RCOSC 136 µs Initially running on 16-MHz RCOSC, with 32-MHz XOSC off 0.5 Active → TX or RX With 32-MHz XOSC initially on RX/TX and TX/RX turnaround USB PLL start-up time With 32-MHz XOSC initially on ms 192 μs 192 μs μs 32 RADIO PART RF frequency range Programmable in 1-MHz steps, 5 MHz between channels for compliance with [1] Radio baud rate As defined by [1] 250 Radio chip rate As defined by [1] 2 2394 2507 MHz kbps MChip/s FLASH MEMORY Flash erase cycles 20 Flash page size 6 2 Submit Documentation Feedback k Cycles kB Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 RF RECEIVE SECTION Measured on Texas Instruments CC2538 EM reference design with TA = 25°C, VDD = 3 V, and fc = 2440 MHz, unless otherwise noted. Bold limits apply over the entire operating range, TA = –40°C to 125°C, VDD = 2 V to 3.6 V, and fc = 2394 MHz to 2507 MHz. PARAMETER TEST CONDITIONS MIN PER = 1%, as specified by [1], normal operating conditions (25°C, 3V, 2440 MHz) [1] requires –85 dBm Receiver sensitivity TYP MAX UNIT –97 –92 dBm –88 dBm PER = 1%, as specified by [1], entire operating conditions [1] requires –85 dBm Saturation (maximum input level) PER = 1%, as specified by [1] [1] requires –20 dBm 10 dBm Adjacent-channel rejection, 5-MHz channel spacing Wanted signal –82 dBm, adjacent modulated channel at 5 MHz, PER = 1%, as specified by [1]. [1] requires 0 dB 44 dB Adjacent-channel rejection, –5-MHz channel spacing Wanted signal –82 dBm, adjacent modulated channel at –5 MHz, PER = 1%, as specified by [1]. [1] requires 0 dB 44 dB Alternate-channel rejection, 10-MHz channel spacing Wanted signal –82 dBm, adjacent modulated channel at 10 MHz, PER = 1%, as specified by [1] [1] requires 30 dB 52 dB Alternate-channel rejection, –10-MHz channel spacing Wanted signal –82 dBm, adjacent modulated channel at –10 MHz, PER = 1%, as specified by [1] [1] requires 30 dB 52 dB 51 51 dB Channel rejection Wanted signal at –82 dBm. Undesired signal is an IEEE ≥ 20 MHzXXXXX 802.15.4 modulated channel, stepped through all channels ≤ –20 MHzXXXXX from 2405 to 2480 MHz. Signal level for PER = 1%. Blocking/desensitization 5 MHz from band edgeXXXXX Wanted signal 3 dB above the sensitivity level, CW jammer, 10 MHz from band edgeXXXXX PER = 1%. Measured according to EN 300 440 class 2. 20 MHz from band edgeXXXXX 50 MHz from band edgeXXXXX –5 MHz from band edgeXXXXX –10 MHz from band edgeXXXXX –20 MHz from band edgeXXXXX –50 MHz from band edgeXXXXX –35 –34 –37 –32 –37 –38 –35 –34 Spurious emission. Only largest spurious Conducted measurement with a 50-Ω single-ended load. emission stated within each band. Suitable for systems targeting compliance with EN 300 328, 30 MHz–1000 MHzXXXXX EN 300 440, FCC CFR47 Part 15, and ARIB STD-T-66. 1 GHz–12.75 GHzXXXXX –80 –80 dBm dBm Frequency error tolerance (1) [1] requires minimum 80 ppm ±150 ppm Symbol rate error tolerance (2) [1] requires minimum 80 ppm ±1000 ppm (1) (2) Difference between center frequency of the received RF signal and local oscillator frequency Difference between incoming symbol rate and the internally generated symbol rate Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 7 CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com RF TRANSMIT SECTION Measured on Texas Instruments CC2538 EM reference design with TA = 25°C, VDD = 3 V and fc = 2440 MHz, unless otherwise noted. Boldface limits apply over the entire operating range, TA = –40°C to 125°C, VDD = 2 V to 3.6 V, and fc = 2394 MHz to 2507 MHz. PARAMETER Nominal output power TEST CONDITIONS MIN Delivered to a single-ended 50-Ω load through a balun using maximum-recommended output-power setting [1] requires minimum –3 dBm Programmable output-power range Spurious emissions fc= 2480 MHz (2) Error vector magnitude (EVM) Measured as defined by [1] using maximum-recommended outputpower setting [1] requires maximum 35%. Optimum load impedance Differential impedance on the RF pins (2) 8 MAX UNIT 7 dBm 30 dB –56 –58 –58 –60 –54 –51 –42 dBm Maximum recommended output power setting (1) Measured according to stated regulations. Only largest spurious emission 25 MHz–1000 MHz (outside restricted bands) stated within each band. 25 MHz–1000 MHz (within FCC restricted bands) 25 MHz–1000 MHz (within ETSI restricted bands) 1800–1900 MHz (ETSI restricted band) 5150–5300 MHz (ETSI restricted band) 1 GHz–12.75 GHz (except restricted bands) At 2483.5 MHz and above (FCC restricted band), (1) TYP 3% 66 + j64 Ω Texas Instruments CC2538 EM reference design is suitable for systems targeting compliance with EN 300 328, EN 300 440, FCC CFR47 Part 15, and ARIB STD-T-66. To improve margins for passing FCC requirements at 2483.5 MHz and above when transmitting at 2480 MHz, use a lower output-power setting or less than 100% duty cycle. Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 32-MHz CRYSTAL OSCILLATOR Measured on Texas Instruments CC2538 EM reference design with TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER TEST CONDITIONS MIN Crystal frequency Equivalent series resistance C0 CL –40 40 ppm 60 Ω pF 16 Crystal shunt capacitance 1 1.9 7 Crystal load capacitance 10 13 16 0.3 Power-down guard time The crystal oscillator must be in power down for a guard time before using it again. This requirement is valid for all modes of operation. The need for power-down guard time can vary with crystal type and load. UNIT MHz 6 Start-up time (1) MAX 32 Crystal frequency accuracy requirement (1) ESR TYP pF ms 3 ms Including aging and temperature dependency, as specified by [1] 32.768-kHz CRYSTAL OSCILLATOR Measured on Texas Instruments CC2538 EM reference design with TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER TEST CONDITIONS MIN Crystal frequency TYP MAX 32.768 Crystal frequency accuracy requirement (1) –40 UNIT kHz 40 ppm ESR Equivalent series resistance 40 130 Ω C0 Crystal shunt capacitance 0.9 2 pF CL Crystal load capacitance 12 16 pF Start-up time 0.4 (1) s Including aging and temperature dependency, as specified by [1] 32-kHz RC OSCILLATOR Measured on Texas Instruments CC2538 EM reference design with TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER Calibrated frequency TEST CONDITIONS (1) MAX UNIT kHz ±0.2% Temperature coefficient (2) (3) Calibration time (4) (1) (2) (3) (4) TYP 32.753 Frequency accuracy after calibration Supply-voltage coefficient MIN 0.4 %/°C 3 %/V 2 ms The calibrated 32-kHz RC oscillator frequency is the 32-MHz XTAL frequency divided by 977. Frequency drift when temperature changes after calibration Frequency drift when supply voltage changes after calibration When the 32-kHz RC oscillator is enabled, it is calibrated when a switch from the 16-MHz RC oscillator to the 32-MHz crystal oscillator is performed while SLEEPCMD.OSC32K_CALDIS is 0.*** Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 9 CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com 16-MHz RC OSCILLATOR Measured on Texas Instruments CC2538 EM reference design with TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER Frequency TEST CONDITIONS MIN TYP (1) MAX 16 Uncalibrated frequency accuracy ±18% Calibrated frequency accuracy ±0.6% MHz ±1% Start-up time μs 10 Initial calibration time (1) (2) UNIT (2) μs 50 The calibrated 16-MHz RC oscillator frequency is the 32-MHz XTAL frequency divided by 2. When the 16-MHz RC oscillator is enabled, it is calibrated when a switch from the 16-MHz RC oscillator to the 32-MHz crystal oscillator is performed while SLEEPCMD.OSC_PD is set to 0.*** RSSI/CCA CHARACTERISTICS Measured on Texas Instruments CC2538 EM reference design with TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER TEST CONDITIONS MIN RSSI range TYP MAX UNIT 100 dB Absolute uncalibrated RSSI/CCA accuracy ±4 dB RSSI/CCA offset (1) 73 dB 1 dB Step size (LSB value) (1) Real RSSI = Register value – offset FREQEST CHARACTERISTICS Measured on Texas Instruments CC2538 EM reference design with TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER TEST CONDITIONS MIN FREQEST range TYP MAX UNIT ±250 kHz FREQEST accuracy ±10 kHz FREQEST offset (1) 15 kHz Step size (LSB value) 7.8 kHz (1) Real FREQEST = Register value – offset FREQUENCY SYNTHESIZER CHARACTERISTICS Measured on Texas Instruments CC2538 EM reference design with TA = 25°C, VDD = 3 V and fc = 2440 MHz, unless otherwise noted. PARAMETER Phase noise, unmodulated carrier TEST CONDITIONS MIN TYP At ±1-MHz offset from carrier –111 At ±2-MHz offset from carrier –119 At ±5-MHz offset from carrier –126 MAX UNIT dBc/Hz ANALOG TEMPERATURE SENSOR Measured on Texas Instruments CC2538 EM reference design with TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER TEST CONDITIONS Output at 25°C Initial accuracy without calibration Accuracy using 1-point calibration (entire temperature range) 4.2 Measured using integrated ADC, using internal band-gap voltage reference and maximum resolution Current consumption when enabled (ADC current not included) 10 TYP 1422 Temperature coefficient Voltage coefficient MIN Submit Documentation Feedback 1 MAX UNIT 12-bit ADC /1°C /0.1 V ±10 °C ±5 °C 0.3 mA Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 ADC CHARACTERISTICS TA = 25°C and VDD = 3 V, unless otherwise noted. PARAMETER ENOB (1) 0 VDD V VDD is voltage on AVDD5 pin 0 VDD V External reference voltage differential VDD is voltage on AVDD5 pin 0 VDD Input resistance, signal Using 4-MHz clock speed 197 kΩ Full-scale signal (1) Peak-to-peak, defines 0 dBFS 2.97 V Effective number of bits Single-ended input, 7-bit setting 5.7 Single-ended input, 9-bit setting 7.5 Single-ended input, 10-bit setting 9.3 Single-ended input, 12-bit setting 10.8 Differential input, 7-bit setting V Bits 6.5 Differential input, 9-bit setting 8.3 Differential input, 10-bit setting 10.0 Differential input, 12-bit setting 11.5 7-bit setting, both single and differential 0–20 Single-ended input, 12-bit setting, –6 dBFS –75.2 Differential input, 12-bit setting, –6 dBFS –86.6 kHz dB Single-ended input, 12-bit setting 70.2 Differential input, 12-bit setting 79.3 Single-ended input, 12-bit setting, –6 dBFS 78.8 Differential input, 12-bit setting, –6 dBFS 88.9 Common-mode rejection ratio Differential input, 12-bit setting, 1-kHz sine (0 dBFS), limited by ADC resolution >84 dB Crosstalk Single-ended input, 12-bit setting, 1-kHz sine (0 dBFS), limited by ADC resolution < – 84 dB Offset Midscale –3 mV Gain error DNL (1) Differential nonlinearity INL (1) Integral nonlinearity (1) Signal-to-noise-and-distortion Conversion time dB 0.68% 12-bit setting, mean 12-bit setting, maximum 12-bit setting, mean 0.05 4.6 13.3 Single-ended input, 7-bit setting 35.4 Single-ended input, 9-bit setting 46.8 Single-ended input, 10-bit setting 57.5 Single-ended input, 12-bit setting 66.6 Differential input, 7-bit setting 40.7 Differential input, 9-bit setting 51.6 Differential input, 10-bit setting 61.8 Differential input, 12-bit setting 70.8 7-bit setting 20 9-bit setting 36 10-bit setting 68 12-bit setting 132 Internal reference voltage Internal reference VDD coefficient LSB dB μs 1.2 mA 1.19 V 2 Internal reference temperature coefficient LSB 0.9 12-bit setting, maximum Current consumption (1) UNIT VDD is voltage on AVDD5 pin Signal to nonharmonic ratio (1) SINAD (–THD+N) TYP MAX External reference voltage Total harmonic distortion CMRR MIN Input voltage Useful power bandwidth THD (1) TEST CONDITIONS 0.4 mV/V mV/10°C Measured with 300-Hz sine-wave input and VDD as reference Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 11 CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com CONTROL INPUT AC CHARACTERISTICS TA = –40°C to 125°C, VDD = 2 V to 3.6 V, unless otherwise noted. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 32 MHz System clock, fSYSCLK tSYSCLK = 1/fSYSCLK The undivided system clock is 32 MHz when crystal oscillator is used. The undivided system clock is 16 MHz when calibrated 16-MHz RC oscillator is used. 16 RESET_N low duration See item 1, Figure 1. This is the shortest pulse that is recognized as a complete reset pin request. Note that shorter pulses may be recognized but might not lead to complete reset of all modules within the chip. 1 μs Interrupt pulse duration See item 2, Figure 1.This is the shortest pulse that is recognized as an interrupt request. 20 ns RESET_N 1 2 Px.n T0299-01 Figure 1. Control Input AC Characteristics DC CHARACTERISTICS TA = 25°C, VDD = 3 V, drive strength set to high with CC_TESTCTRL.SC = 1, unless otherwise noted. PARAMETER TEST CONDITIONS MIN TYP Logic-0 input voltage MAX 0.5 Logic-1 input voltage 2.5 Input equals 0 V –300 300 Logic-1 input current Input equals VDD –300 300 20 Logic-0 output voltage, 4-mA pins Output load 4 mA Logic-1 output voltage, 4-mA pins Output load 4 mA Logic-0 output voltage, 20-mA pins Output load 20 mA Logic-1 output voltage, 20-mA pins Output load 20 mA V V Logic-0 input current I/O-pin pullup and pulldown resistors UNIT nA nA kΩ 0.5 2.4 V V 0.5 2.4 V V USB INTERFACE DC CHARACTERISTICS TA = 25°C, VDD = 3 V to 3.6 V, unless otherwise noted. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT USB pad voltage output, high VDD 3.6 V, 4-mA load 3.4 V USB pad voltage output, low VDD 3.6 V, 4-mA load 0.2 V 12 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 DEVICE INFORMATION 43 AVDD_GUARD 44 PD6/XOSC32K_Q1 45 PD7/XOSC32K_Q2 46 JTAG_TMS 47 JTAG_TCK 48 PB7 49 PB6 50 PB5 51 PB4 52 PB3 53 PB2 54 PB1 55 DVDD 56 DCOUPL1 RTQ (Top View) DGND_USB 1 42 R_BIAS USB_P 2 41 AVDD USB_N 3 40 AVDD DVDD_USB 4 39 AVDD PB0 5 38 RF_N PC7 6 37 RF_P PC6 7 36 AVDD PC5 8 35 XOSC32M_Q2 PC4 9 34 XOSC32M_Q1 DVDD 10 33 AVDD RESET_N 28 PD2 27 PD1 26 PD0 25 DVDD 24 PA2 18 PA7 23 29 PD3 PA6 22 PC0 14 PA5 21 30 PD4 PA4 20 PC1 13 PA3 19 31 PD5 PA1 17 PC2 12 PA0 16 32 DCOUPL2 DVDD 15 PC3 11 P0142-01 NOTE: Connect the exposed ground pad to a solid ground plane, as this is the ground connection for the chip. Pin Descriptions PIN NAME AVDD PIN PIN TYPE 33, 36, 39, Power (analog) 40, 41 DESCRIPTION 2-V–3.6-V analog power-supply connection AVDD_GUARD 43 Power (analog) 2-V–3.6-V analog power-supply connection DCOUPL1 56 Power (digital) 1.8-V regulated digital-supply decoupling capacitor DCOUPL2 32 Power (digital) 1.8-V regulated digital-supply decoupling capacitor. Short this pin to pin 56. DGND_USB 1 Ground (USB pads) USB ground DVDD 10, 15, 24, Power (digital) 55 2-V–3.6-V digital power-supply connection DVDD_USB 4 Power (USB pads) 3.3-V USB power-supply connection JTAG_TCK 47 Digital I/O JTAG TCK JTAG_TMS 46 Digital I/O JTAG TMS PA0 16 Digital/analog I/O GPIO port A pin 0. ROM bootloader UART RXD PA1 17 Digital/analog I/O GPIO port A pin 1. ROM bootloader UART TXD PA2 18 Digital/analog I/O GPIO port A pin 2. ROM bootloader SSI CLK PA3 19 Digital/analog I/O GPIO port A pin 3. ROM bootloader SSI SEL Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 13 CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com Pin Descriptions (continued) PIN PIN TYPE DESCRIPTION PA4 PIN NAME 20 Digital/analog I/O GPIO port A pin 4. ROM bootloader SSI RXD PA5 21 Digital/analog I/O GPIO port A pin 5. ROM bootloader SSI TXD PA6 22 Digital/analog I/O GPIO port A pin 6 PA7 23 Digital/analog I/O GPIO port A pin 7 PB0 5 Digital I/O GPIO port B pin 0 PB1 54 Digital I/O GPIO port B pin 1 PB2 53 Digital I/O GPIO port B pin 2 PB3 52 Digital I/O GPIO port B pin 3 PB4 51 Digital I/O GPIO port B pin 4 PB5 50 Digital I/O GPIO port B pin 5 PB6 49 Digital I/O GPIO port B pin 6, TDI (JTAG) PB7 48 Digital I/O GPIO port B pin 7, TDO (JTAG) PC0 14 Digital I/O GPIO port C pin 0, 20 mA output capability, no pull-up or pull-down PC1 13 Digital I/O GPIO port C pin 1, 20 mA output capability, no pull-up or pull-down PC2 12 Digital I/O GPIO port C pin 2, 20 mA output capability, no pull-up or pull-down PC3 11 Digital I/O GPIO port C pin 3, 20 mA output capability, no pull-up or pull-down PC4 9 Digital I/O GPIO port C pin 4 PC5 8 Digital I/O GPIO port C pin 5 PC6 7 Digital I/O GPIO port C pin 6 PC7 6 Digital I/O GPIO port C pin 7 PD0 25 Digital I/O GPIO port D pin 0 PD1 26 Digital I/O GPIO port D pin 1 PD2 27 Digital I/O GPIO port D pin 2 PD3 29 Digital I/O GPIO port D pin 3 PD4 30 Digital I/O GPIO port D pin 4 PD5 31 Digital I/O GPIO port D pin 5 PD6/XOSC32K_Q1 44 Digital/analog I/O GPIO port D pin 6 / 32-kHz crystal oscillator pin 1 PD7/XOSC32K_Q2 45 Digital/analog I/O GPIO port D pin 7 / 32-kHz crystal oscillator pin 1 R_BIAS 42 Analog I/O External precision bias resistor for reference current RESET_N 28 Digital input Reset, active-low RF_N 38 RF I/O Negative RF input signal to LNA during RX Negative RF output signal from PA during TX RF I/O Positive RF input signal to LNA during RX Positive RF output signal from PA during TX 37 RF_P USB_P 2 USB I/O USB differential data plus (D+) USB_N 3 USB I/O USB differential data minus (D–) XOSC32M_Q1 34 Analog I/O 32-MHz crystal oscillator pin 1 or external-clock input XOSC32M_Q2 35 Analog I/O 32-MHz crystal oscillator pin 2 14 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 APPLICATION INFORMATION Few external components are required for the operation of the CC2538xFnn. Figure 2 is a typical application circuit. For a complete USB reference design, see the CC2538xFnn product page on www.ti.com. Table 2 lists typical values and descriptions of external components. The USB_P and USB_N pins require series resistors R21 and R31 for impedance matching, and the D+ line must have a pullup resistor, R32. The series resistors should match the 90-Ω ±15% characteristic impedance of the USB bus. Notice that the pullup resistor and DVDD_USB require connection to a voltage source between 3 V and 3.6 V (typically 3.3 V). To accomplish this, it is recommend to connect the D+ pull-up to a port/pin that does not have an internal pull-up (that is, PC0..3), instead of connecting it directly to a 3.3V supply (that is, software control of D+ pull-up recommended). Optional 32kHz crystal 2.0V-3.6V power supply 3.3V power supply C451 XTAL C561 AVDD_GUARD 43 PD6/XOSC32K_Q1 44 JTAG_TMS 46 R31 PD7/XOSC32K_Q2 45 PB7 48 1 DGND_USB JTAG_TCK 47 PB6 49 PB5 50 PB4 51 PB3 52 PB2 53 PB1 54 DVDD 55 DCOUPL 56 C441 D+ 2 USB_P D- 3 USB_N AVDD 40 4 DVDD_USB AVDD 39 5 PB0 RF_N 38 6 PC7 RF_P 37 R21 R32 C31 C21 AVDD 41 CC2538 7 PC6 Antenna (50 Ohm) R421 R_BIAS 42 C381 C382 L373 C371 C372 2 nH AVDD 36 XOSC32M_Q2 35 8 PC5 9 PC4 L374 3.3 nH L381 C373 1.2 pF L372 XOSC32M_Q1 34 DIE ATTACH PAD: 10 VDD AVDD 33 11 PC3 DCOUPL2 32 12 PC2 PD5 31 13 PC1 PD4 30 14 PC0 PD3 29 C321 PD2 27 RESET_N 28 PD1 26 PD0 25 PA7 23 VDD 24 PA6 22 PA5 21 PA4 20 PA3 19 PA2 18 PA1 17 PA0 16 VDD 15 XTAL C341 C351 C281 Power supply decoupling capacitors are not shown Digital I/O not connected R281 RESET_N Figure 2. CC2538xFnn Application Circuit Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 15 CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com Table 2. Overview of External Components (Excluding Supply Decoupling Capacitors) Component Description Value C21 USB D– decoupling 47 pF C31 USB D+ decoupling 47 pF C341 32-MHz xtal-loading capacitor 12 pF C351 32-MHz xtal-loading capacitor 12 pF C371 Part of the RF matching network 18 pF C381 Part of the RF matching network 18 pF C382 Part of the RF matching network 1 pF C372 Part of the RF matching network 1 pF C441 32-kHz xtal-loading capacitor 22 pF C451 32-kHz xtal-loading capacitor 22 pF C561 Decoupling capacitor for the internal digital regulator 1 μF C321 Decoupling capacitor for the internal digital regulator 1 μF C281 Filter capacitor for reset line 1 nF L372 Part of the RF matching network 2 nH L381 Part of the RF matching network 2 nH R21 USB D– series resistor 33 Ω R31 USB D+ series resistor R32 USB D+ pullup resistor to signal full-speed device presence R281 Filter resistor for reset line 2.2 Ω R421 Resistor used for internal biasing 56 kΩ 33 Ω 1.5 kΩ Input, Output Matching When using an unbalanced antenna such as a monopole, use a balun to optimize performance. One can implement the balun using low-cost discrete inductors and capacitors. The recommended balun shown consists of L372, C372, C382 and L381. If a balanced antenna such as a folded dipole is used, omit the balun. Crystal The 32-MHz crystal oscillator uses an external 32-MHz crystal, XTAL1, with two loading capacitors (C341 and C351). See the 32-MHz Crystal Oscillator section for details. Calculate the load capacitance across the 32-MHz crystal by: 1 CL = + Cparasitic 1 1 + C341 C351 (1) XTAL2 is an optional 32.768-kHz crystal, with two loading capacitors (C441 and C451) used for the 32.768-kHz crystal oscillator. Use the 32.768-kHz crystal oscillator in applications where both low sleep-current consumption and accurate wake-up times are needed. Calculate the load capacitance across the 32.768-kHz crystal by: 1 CL = + Cparasitic 1 1 + C441 C451 (2) Use a series resistor, if necessary, to comply with the ESR requirement. On-Chip 1.8-V Voltage-Regulator Decoupling The 1.8-V on-chip voltage regulator supplies the 1.8-V digital logic. This regulator requires decoupling capacitors (C561, C321) and an external connection between them for stable operation. 16 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 CC2538 www.ti.com SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 Power-Supply Decoupling and Filtering Optimum performance requires proper power-supply decoupling. The placement and size of the decoupling capacitors and the power supply filtering are important to achieve the best performance in an application. TI provides a recommended compact reference design for the user to follow. References 1. IEEE Std. 802.15.4-2006: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Low-Rate Wireless Personal Area Networks (LR-WPANs) http://standards.ieee.org/getieee802/download/802.15.4-2006.pdf 2. CC2538xFnn User's Guide 3. Universal Serial Bus Revision 2.0 Specification http://www.usb.org/developers/docs/usb_20_052709.zip Additional Information Texas Instruments offers a wide selection of cost-effective, low-power RF solutions for proprietary and standardbased wireless applications for use in industrial and consumer applications. The selection includes RF transceivers, RF transmitters, RF front ends, and Systems-on-Chips as well as various software solutions for the sub-1-GHz and 2.4-GHz frequency bands. In addition, Texas Instruments provides a large selection of support collateral such as development tools, technical documentation, reference designs, application expertise, customer support, third-party and university programs. The Low-Power RF E2E Online Community provides technical support forums, videos and blogs, and the chance to interact with engineers from all over the world. With a broad selection of product solutions, end-application possibilities, and a range of technical support, Texas Instruments offers the broadest low-power RF portfolio. Texas Instruments Low-Power RF Web Site Texas Instruments’ Low-Power RF Web site has all the latest products, application and design notes, FAQ section, news and events updates. Go to www.ti.com/lprf. Low-Power RF Online Community • • • Forums, videos, and blogs RF design help E2E interaction Join at: www.ti.com/lprf-forum. Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 17 CC2538 SWRS096A – DECEMBER 2012 – REVISED APRIL 2013 www.ti.com Texas Instruments Low-Power RF Developer Network Texas Instruments has launched an extensive network of low-power RF development partners to help customers speed up their application development. The network consists of recommended companies, RF consultants, and independent design houses that provide a series of hardware module products and design services, including: • RF circuit, low-power RF, and ZigBee design services • Low-power RF and ZigBee module solutions and development tools • RF certification services and RF circuit manufacturing For help with modules, engineering services or development tools: Search the Low-Power RF Developer Network to find a suitable partner. www.ti.com/lprfnetwork Low-Power RF eNewsletter The Low-Power RF eNewsletter is up-to-date on new products, news releases, developers’ news, and other news and events associated with low-power RF products from TI. The Low-Power RF eNewsletter articles include links to get more online information. Sign up at: www.ti.com/lprfnewsletter REVISION HISTORY Changes from Original (December 2012) to Revision A • 18 Page Changed the Product Preview device ................................................................................................................................... 1 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: CC2538 PACKAGE OPTION ADDENDUM www.ti.com 23-Apr-2013 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish (2) MSL Peak Temp Op Temp (°C) Top-Side Markings (3) (4) CC2538SF53RTQR ACTIVE QFN RTQ 56 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-3-260C-168 HR CC2538SF53 CC2538SF53RTQT ACTIVE QFN RTQ 56 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-3-260C-168 HR CC2538SF53 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Top-Side Marking for that device. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 Samples PACKAGE MATERIALS INFORMATION www.ti.com 24-Apr-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant CC2538SF53RTQR QFN RTQ 56 2000 330.0 16.4 8.3 8.3 2.25 12.0 16.0 Q2 CC2538SF53RTQT QFN RTQ 56 250 330.0 16.4 8.3 8.3 2.25 12.0 16.0 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 24-Apr-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) CC2538SF53RTQR QFN RTQ 56 2000 336.6 336.6 28.6 CC2538SF53RTQT QFN RTQ 56 250 336.6 336.6 28.6 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily performed. TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use of any TI components in safety-critical applications. In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and requirements. Nonetheless, such components are subject to these terms. No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties have executed a special agreement specifically governing such use. Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of non-designated products, TI will not be responsible for any failure to meet ISO/TS16949. Products Applications Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive Amplifiers amplifier.ti.com Communications and Telecom www.ti.com/communications Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers DLP® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps DSP dsp.ti.com Energy and Lighting www.ti.com/energy Clocks and Timers www.ti.com/clocks Industrial www.ti.com/industrial Interface interface.ti.com Medical www.ti.com/medical Logic logic.ti.com Security www.ti.com/security Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rfid.com OMAP Applications Processors www.ti.com/omap TI E2E Community e2e.ti.com Wireless Connectivity www.ti.com/wirelessconnectivity Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2013, Texas Instruments Incorporated