LM8850UREV/NOPB

User's Guide SNVA472A – March 2011 – Revised May 2013 AN-2119 LM8850 Evaluation Board Application Note 1 General Description The LM8850 evaluation board is a working demonstration of a step-up DC-DC converter that has been optimized for use with a super-capacitor. The super-capacitor protects a battery from power surges and enables new high-power applications in mobile device architectures. The LM8850 creates an ideal rail from 3.6V to 5.7V from an input voltage range of 2.3V to 5.5V, VIN must be 10% lower than expected VOUT. An I2C interface controlling multiple output voltage settings, input current limits, and load currents up to 1A provides superior user flexibility. The LM8850 operates in Auto mode, where the converter is in PFM mode at light loads and switches to PWM mode at heavy loads or in forced PWM mode. Hysteretic PFM extends the battery life by reducing the quiescent current to 7µA (typ.) during light load and standby conditions. Synchronous operation provides true shutdown isolation and improves the efficiency at medium to full load conditions. High switching frequency enables smaller passive components. Internal compensation is used for a broader range of inductor and output capacitor values to meet system demand and achieve small system solution size. 2 Typical Application Circuit with Super-Capacitor 3.6V 4.7 PF VIN 1 PH 5V VOUT SW LM8850 4.7 PF PG BAL 0.05F to 1.0F SDA SCLK EN GND Figure 1. Typical Application All trademarks are the property of their respective owners. SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated 1 Connection Diagram and Package Mark Information 3 www.ti.com Connection Diagram and Package Mark Information (Bottom View) (Top View) A3 A2 A1 A1 A2 A3 B3 B2 B1 B1 B2 B3 C3 C2 C1 C1 C2 C3 Figure 2. 9-Bump DSBGA Package 4 Block Diagram SW VOUT VIN Amp BAL SCL PFM Generator SDA Control Logic Error Amp PG VREF EN + - 2.5 MHz Oscillator Ramp Generator GND Figure 3. Block Diagram 2 AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback Pin Descriptions www.ti.com 5 Pin Descriptions Table 1. Pin Descriptions 6 Pin # Name Description A1 VIN Power Supply Input. Connect to input filter capacitor (see Typical Application Circuit). A2 SW Switching node. Connection to the internal NFET switch and PFET synchronous rectifier. A3 GND Ground Pin B1 SDA I2C data (Use a 2kΩ pullup resistor.) B2 PG B3 VOUT Power Good indicator Output pin. C1 SCLK I2C Clock (Use a 2KΩ pull up resistor.) C2 EN Enable pin. The device is in shutdown when voltage to this pin is < 0.4V and enabled when > 1.2V. Do not leave this pin floating. C3 BAL Balancing pin for active voltage balancing of super-capacitor. Board Operation To operate the LM8850, connections to VIN, Ground and the jumper on the enable pin must be in the H position. To start out, supply 3.6V to VIN. With a valid supply, Vout should power up to 5V within 5 seconds. Once enabled, the LM8850 charges the supercapacitor utilizing all of the default settings in the registers. The I2C must be used to change the default settings and this can only be done with the LM8850 enabled. Once a register is written to, the changes will transition immediately. Every time the EN pin transitions from VIL to VIH, registers 0 and 1 are reset to their defaults settings and any settings needed bust rewritten into the appropriate registers. 7 I2C-Compatible Chip Address The device address for LM8850 is 60 (HEX). Register Name Location Type CONTROL 00 R/W Control Register 0 (Figure 4) CONTROL 01 R/W Control Register 1 (Figure 5) SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback Register AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated 3 I2C-Compatible Chip Address www.ti.com MSB 7 LSB 6 5 4 3 2 1 0 Register location = 00 Output Voltage Change 0 0 0 = 3.6V 0 0 1 = 3.9V 0 1 0 = 4.2V 0 1 1 = 4.5V 1 0 0 = 4.7V 1 0 1 = 5.0V (default) 1 1 0 = 5.3V 1 1 1 = 5.7V ` FromRegister Location 01, bit 5 From Register Location 00, bits 0 and 1 PFM Voltage Ripple 0 0 = 50 mV 0 1 = 100 mV (default) 1 0 = 200 mV 1 1 = 250 mV Balance Circuit 0 = OFF 1 = ON (default) Effective when part is enabled Mode 0 = AUTO (PFM/PWM ± default) 1 = FORCED PWM Ton Time 0 0 = 5s (default) 0 1 = 7.5s 1 0 = 10s 1 1 = 12.5s 30150504 Figure 4. CONTROL Register 0 Register Location = 00 4 AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback I2C-Compatible Chip Address www.ti.com MS B 7 LS B 6 5 4 3 2 1 0 Register location = 01 Switch Current Limit ± (Max values) 111 = 1500 mA (default) 101 = 1025 mA 001 = 740 mA 000 = 530 mA Balmode 0 = OFF (default) 1 = ON Effective when part is disabled Enable 0 = OFF 1 = ON (default) Bit 5 used to determine output voltage 0 0 0 = 3.6V 0 0 1 = 3.9V 0 1 0 = 4.2V 0 1 1 = 4.5V 1 0 0 = 4.7V 1 0 1 = 5.0V (default) 1 1 0 = 5.3V 1 1 1 = 5.7V From Register Location 01, bit 5 From Register Location 00, bits 0 and 1 PGOOD (Read only) Figure 5. CONTROL Register 1 Register Location = 01 SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated 5 LM8850 Evaluation Board Schematic www.ti.com 8 LM8850 Evaluation Board Schematic 9 LM8850 Evaluation Board Bill of Materials Table 2. Bill of Materials Item 6 Qty Value C1 (CIN) 1 10 µF C1608X5R0J106M 0603, 6.3V, TDK C2 (COUT) 1 4.7 µF CL10A475KP8NNNB 0603, 10V, SAMSUNG C3 = C4 (FILTER CAP) 2 100 µF TPSC107M006R0075 0805, 10V, AVX C5 (AC FILTER CAP) 1 100 nF CL05F104Z05NNB 0402, 10V, SAMSUNG L1 1 1µF KSLI-252012AG-1R0 2520, 1.5A, HITACHI VDD CONNECTOR 1 - 93K4533 NEWARK GND CONNECTOR 1 - 80P3616 NEWARK SuperCapacitor 1 500Mf EDLC272020-501-2F-50 Super Capacitor LM8850 Boost Regulator U1 1 Total 10 Part Number AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated Description SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback LM8850 Evaluation Board Layers www.ti.com 10 LM8850 Evaluation Board Layers There are a few solder mask openings for various supercapacitor packages. If you plan on changing to a different supercapacitor than what is initially assembled, be sure assemble using the best solder pad openings for your supercapacitor footprint. Below, in the circled areas, are the initial pads used for the TDK supercap initially assembled. If the given pads aren’t acceptable, the solder mask can be removed to expose the copper for any footprint needed. Figure 6. Top Layer SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated 7 LM8850 Evaluation Board Layers www.ti.com Figure 7. Mid- Layer 1 Figure 8. Mid- Layer 2 8 AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback LM8850 Evaluation Board Layers www.ti.com Figure 9. Bottom Layer SNVA472A – March 2011 – Revised May 2013 Submit Documentation Feedback AN-2119 LM8850 Evaluation Board Application Note Copyright © 2011–2013, Texas Instruments Incorporated 9 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