1 Copyright © Richtek Technology 2015 Richtek Technology Corporation is one of the world’s leading analog IC companies. The company consistently delivers inventive power management solutions that improve the performance of consumer electronics, computers, and communications equipment. Richtek adds value to end equipment by synthesizing technological innovation, uncompromised quality, and devotion to customer service. Founded in 1998, the Richtek provides a wide range of power management solutions for Li-Ion battery powered applications Company is headquartered in Taiwan with additional offices in Asia, the U.S., and from battery front-end chargers and protection ICs to DC/DC converters and low quiescent LDOs. Europe. For more information about Richtek and its analog IC solutions, please visit the Company’s Web site at www.richtek.com. SG003-01 OCT 2015 2 3 Copyright © Richtek Technology 2015 Designing with Li-ion Batteries Advantages of Li-ion batteries Single Li-Ion cell as power source Advantages of Li-ion batteries: When powering your application from a single Li-Ion cell, the application input range must consider the voltage →→ Light weight fluctuation of the battery, which for most Li-Ion batteries ranges from 4.2V fully charged down to 3.0V fully discharged. →→ No memory effect Most applications will require some form of voltage regulation. Richtek offers a wide range of LDOs, buck, boost →→ Compared to NiMH batteries: →→ Twice energy density typically and buck-boost converters that can operate from the typical Li-Ion battery cell voltage range and provide a stable output voltage. →→ 6~8 times less self-discharge →→ The high cell voltage of 3.6 volts is often sufficient to power General application remarks applications from a single cell Li-Ion batteries are sensitive to over-discharge, which is why many cells have build-in under-voltage protection These properties make Li-Ion batteries very popular in modern portable circuits that switch off the cell when the cell is discharged below 2.5V. It is recommended to re-charge the battery electronic applications. When designing applications with Li-Ion cells, it or disconnect the battery from the system well before this battery internal protection is activated. is important to understand the battery characteristics during charging and Figure 1. Battery Capacities from discharging, to ensure safe application and best battery life time. 200mAh to 2800A When Li-Ion batteries are not used for a prolonged time period, it is better to discharge them to around 40% (~3.7V) to reduce their aging effect. Battery capacity Figure 1 shows several types of Lithium cells, used in different applications, with capacities ranging from 200mAh to 2800Ah. Standard Li-Ion batteries normally use a rigid case, while Li-Polymer batteries often use the flexible foil type or pouch cell case, which reduces size and weight. Figure 2 shows the typical discharge curves of a 2000mAh Li-Ion battery, from fully charged (4.2V) to fully discharged (3.0V) condition. The Figure 2. Typical Discharge Curves discharge rates are expressed as a ratio of battery capacity (C). At high of a 2000mAh Li-Ion Battery discharge currents, the battery capacity cannot be fully utilized and the battery voltage will drop due to battery internal resistance. SG003-01 OCT 2015 4 5 Copyright © Richtek Technology 2015 Boost Converters Switching and Linear Regulators →→ Low EMI →→ Up to 45V VOUT →→ Additional detection features included →→ Enhanced light load efficiency VOUT ISW_MAX Product Up to 5V 2A Synchronous Boost Converter with Bypass mode Product portfolio for Li-ion battery powered applications Most Richtek switching regulators have enhanced light load efficiency, thereby increasing the battery span. Up to 5.5V 2A Boost converters, such as RT9276 can be used to produce a stable USB 5V supply at varying battery voltage and provide Synchronous Boost Converter with current limit control Synchronous Boost Converter with LDO Controller battery monitoring function. Buck-boost regulators like RT6150A or RT6154A can be used when the output voltage lies in between the battery max and min voltage range, Up to 6.5V 1.6A and with four internal switches, they seamlessly switch over from buck to boost mode. Most low voltage buck Synchronous Boost Converter with Voltage Detector converters will operate in 100% duty-cycle mode when battery voltage approaches the output voltage, increasing the useful battery range, such as RT8059. Up to 16V Low quiescent current LDOs like RT9063 can be used to regulate the output voltage for micro power applications 1.6A PWM Asynchronous Boost Converter PSM Asynchronous Boost Converter Up to 24V 3.0A Asynchronous Boost Converter Up to 36V 1.2A Asynchronous Boost Converter Up to 45V 1.0A Asynchronous Boost Converter with minimal battery loading. The 1μA ground current ensures minimal battery drain in low power standby mode. SG003-01 OCT 2015 6 7 Key Features P/N →→ Low BOM solution with small external components →→ Smooth transition between boost mode and bypass mode →→ Less than 1µA quiescent current in shutdown mode →→ I C control to optimise target V →→ WL-CSP-16B 1.67x1.67 (BSC) package →→ CMCOT topology for fast transient response →→ Small output ripple when V is close to V →→ Adjustable 1A/2A, two level current limit threshold →→ PSM for enhanced light load efficiency →→ TSOT-23-8 package →→ For All One-Cell, Two-Cell and Three-Cell Alkaline, NiCd, 2 RT4803A OUT IN OUT RT4812 RT9296 NiMH and Single-Cell Li+ batteries powered applications →→ True load disconnection during shutdown to extend battery power →→ Output voltage is monitored by a PGOOD signal →→ Enhanced light load efficiency at power save mode →→ Low EMI →→ WDFN-10L 3x3 package →→ Component size or efficiency consideration by optional 640kHz/1.2MHz operation frequency RT9276 Sample RT9277B →→ Internal or External programmable Soft-Start →→ Loop responses can be optimized by external compensation →→ MSOP-8, WDFN-8L 3x3 and WDFN-10L 3x3 packages →→ Small package and PCB footprint →→ 550kHz operation frequency →→ Internal power N-MOSFET switch →→ Supports up to 10 WLED strings →→ PWM-Analog dimming (RT4503) →→ 32 step pulse dimming (RT4503A) →→ WDFN-6L 2x2 package →→ Small package and simple external circuit design →→ 1MHz operation frequency →→ Internal power N-MOSFET switch →→ Supports up to 10 WLEDs for backlighting and OLED power application →→ TSOT-23-6 and WDFN-8L 2x2 packages RT9277C RT9297 RT4503/A RT9293 Copyright © Richtek Technology 2015 Support up to 5A peak current Dual Buck Converters →→ Seamlessly switching between Buck and Boost mode →→ Power save mode enable control VOUT IOUT Product Key Features 0.6V ~ VIN 1A + 1A Dual Buck Converter 0.8V ~ VIN 1A + 1.5A Dual Buck Converter →→ 50μA Quiescent Current per channel →→ 1.5MHz Fixed frequency PWM operation →→ WDFN-12L 3x3 package →→ Power Good output voltage monitor →→ 1.2MHz Fixed frequency PWM operation →→ WQFN-16L 4x4 package P/N RT8020 Sample RT8012A Sample →→ Support up to 5A peak current (3A max load capability) Linear Regulators General LDO VOUT ISW_MAX 1.6A Product Current Mode Buck-boost Converter 1.8V ~ 5.5V 5.0A Current Mode Buck-boost Converter Key Features →→ Up to 90% efficiency →→ Fixed frequency at 1MHz →→ WDFN-10L 3x3 and WDFN-10L 2.5x2.5 package →→ Up to 96% efficiency →→ Fixed frequency at 2.4MHz →→ Can be synchronized to external clock 2.2MHz P/N RT6150A/B VIN VOUT IOUT IQ 2.5V ~ 5.5V 1.5V ~ 5.0V 300mA 90μA 2.5V ~ 5.5V RT6154A/B 1.5V ~ 5.0V 300mA 90μA to 2.6MHz for low interference solution →→ Up to 95% Efficiency →→ No Schottky diode required 100% duty-cycle mode VIN VOUT IOUT IQ 2.2V ~ 5.5V 1.2V ~ 3.3V 500mA 25μA 1.5V ~ 5.5V 0.9V ~ 3.5V 300mA + 300mA 29μA + 29μA Product 1.25MHz Buck Converter 0.6V ~ VIN 0.6A 1.5MHz Buck Converter 0.7V ~ VIN 0.6A 1.5MHz Buck Converter 0.6V ~ VIN 1.0A 1.5MHz Buck Converter 0.6V ~ VIN 1.0A 2.25MHz Buck Converter 0.6V ~ VIN 1.0A 1.5MHz Buck Converter 0.6V ~ VIN 1.0A 1.5MHz Buck Converter SG003-01 OCT 2015 RT9193 Key Features →→ PSM enhanced light load efficiency →→ SOT-23-5 / TSOT-23-5 packages →→ PSM enhanced light load efficiency →→ SOT-23-5 / TSOT-23-5 packages →→ PWM mode / low-dropout auto switch and shutdown mode →→ Auto discharge function →→ 0.5mm height low profile, ideal for applications with height limitations →→ UDFN-6L 1.6x1.6 packages →→ PSM enhanced light load efficiency →→ WDFN-6L 2x2 package →→ 2.25MHz high operating frequency for reducing external component size →→ PWM operation →→ TSOT-23-5 / WDFN-6SL 2x2 packages →→ PWM enhanced light load efficiency →→ TSOT-23-5 package →→ PWM mode/ low-dropout auto switch and shutdown mode →→ WDFN-6L 2x2 package Key Features →→ Auto discharge function: 5mA discharge current of VOUT when shutdown →→ SOT-23-5 & SC-70-5 packages →→ Dual LDO regulator →→ In tiny CSP package →→ WL-CSP-6B 0.8x1.2 package Action RT9020 RT9055 Ultra Low Quiescent Current LDO VIN 0.4A →→ Bypass pin for ultra low noise →→ Auto discharge function →→ SC-70-5, SOT-23-5, TSOT-23-5, Special LDO →→ Low profile and small footprint 0.5V ~ VIN RT9198 MSOP-8 & WDFN-6L 2x2 packages Buck Converters IOUT P/N TSOT-23-5, MSOP-8, & WDFN-6L 2x2 packages →→ WDFN-14L 4x3 package VOUT Key Features →→ Auto discharge function →→ SC-70-5, SC-82, SOT-23-3, SOT-23-5, TSOT-23-3, VOUT IOUT IQ P/N 2.0V ~ 6.0V RT8025 1.2V ~ 5.0V 100mA 4μA Sample RT8008 Sample RT8099 Key Features P/N →→ TO-92, SOT-89, SOT-23-3 & SOT-23-5 packages RT9169 →→ With enable pin active high →→ SOT-23-5 package Sample RT9169H 2.5V ~ 6.0V 1.2V ~ 3.3V 200mA 1μA →→ SOT-23-3 & SOT-89-3 packages RT9063 1.2V ~ 5.5V 0.9V ~ 3.3V 250mA 1μA →→ SOT-23-5, SC-70-5 & SC-82 packages →→ With EN pin RT9073 RT8016 Sample RT8057A RT8059 RT8080 Sample 8 9 Copyright © Richtek Technology 2015 Battery Management Products Battery charging Charging Li-Ion cells needs special care, as overcharge can lead to unsafe conditions. Most Li-Ion chargers have During the constant current mode, the battery is charged with a defined current. When the battery voltage comes pre-conditioning - constant current - constant voltage - current cut-off –recharge functionality as shown in Figure 3. close to the regulation voltage (4.2V or 4.35V depending on battery type), the charge current drops gradually and the charger will work in constant voltage mode. This maximum regulation voltage needs to be accurately controlled to avoid over-charging which would damage the battery and result in unsafe conditions. The battery is considered fully charged when the battery voltage is at its regulation voltage and charging current is less than a user defined percentage of rated charge current and charging is terminated. It is not recommended to continuously trickle charge Li-Ion cells, as this will reduce battery life. Most chargers will start a re-charge cycle when the battery voltage drops below a certain level (usually 0.1V ~ 0.2V below the regulation voltage). When Li-Ion batteries are not used for a prolonged time period, it is better to discharge them to around 40% (~3.7V) to reduce their aging effect. Battery temperature during charging needs to be monitored and too high or too low battery temperature should stop the charging process. For most Li-Ion batteries, normal charging conditions can be applied within the 10°C ~ 45°C temperature range. Charging is normally cut-off when battery temperature is below 0°C or above 60°C. Selected battery management components Richtek has a wide range of Li-Ion chargers from linear to switching types. Linear charger topology is often used with batteries up to 1000mAh, while switching chargers are used for larger capacity batteries which can be charged with higher currents (>1A), or when using adapters with higher output voltage. Figure 3. Battery Charger Operation Modes The charger maximum regulation voltage needs to be accurately controlled. In case of deep discharge, the battery charger will first provide a low pre-charge current, to pre-condition the battery for normal charging. This low preconditioning current can also reset the battery internal under-voltage protection. SG003-01 OCT 2015 10 11 Copyright © Richtek Technology 2015 Linear Charger IC Switching Charger The switching charger with I2C control allows flexible selection of charging conditions and system control. →→ Ideal for 1000mAh batteries In some devices the switching MOSFETs can also be set in boost mode where a stable 5V can be supplied from →→ Up to 1.2A current charger ICs battery to the VIN pin for powering USB-on-the-Go (OTG) devices. →→ Auto power path management Li-ion Switching Charger Product AC and USB Dual Input Supplies Charger ICs Product 1.2A Linear Single Cell Li-ion Battery Charger 1.2A Linear Single Cell Li-ion Battery Charger with Input Over Voltage Protection 1.2A Linear Single Cell Li-ion Battery Charger with 4.9V/50mA LDO 2 Key Features 1.5A, I C Switch-Mode Single Cell Li-Ion Battery Charger with USB On-The-Go (OTG) P/N →→ Automatic input supplies selection between AC and USB →→ Integrated selectable 100mA and 500mA USB charge current and 1A AC adapter charge current RT9502 →→ NTC sense for battery temperature monitor →→ AC Power Good and charge status indicators →→ WDFN-10L 3x3 package →→ Cost effective solution →→ 28V(max) input rating for AC adapter →→ Power good and charge status indicators →→ Programmable charging current →→ Adjustable end-of-charge(EOC) current →→ Thermal feedback optimizing charge rate →→ WDFN-8L 2x3 & SOT-23-6 package →→ 28V(max) input rating for AC adapter →→ 4.2V/2.3A factory mode →→ 50mA LDO to support the power of peripheral circuit →→ Programmable charging current →→ Integrated selectable 100mA and 500mA USB charge current →→ Power good and charge status indicators →→ WDFN-10L 3x2 package 1.55A, I2C Switch Mode Single Cell Li-ion Battery Charger with USB-OTG Sample 4.0A, I2C Switch Mode Single Cell Li-ion Battery Charger with USB-OTG RT9526A RT9532 RT9455 provides up to 1.6A current to the USB input →→ Ideal for 2,000mAh ~ 4,000mAh capacity batteries →→ All charge parameters can be executed via the I C interface →→ WQFN-32L 4x4 package RT9451 Generic Switching Charger Product RT9536 battery power when the adapter input current limit is exceeded. These ICs also include many protection features 2A Asynchronous Switch Mode Battery Charger like input overvoltage protection, output short protection and load disconnect function. SG003-01 OCT 2015 RT9450A Sample Auto Power Path feature allows the application to be run from adapter power, but it will gradually move back to 1.2A I2C Linear Single Cell Li-ion Battery Charger with Auto Power Path Management and USB/AV Switch P/N 2 Linear charger with auto power path management 1.2A Linear Single Cell Li-ion Battery Charger with Auto Power Path Management and System Off →→ 4V-6V Input voltage →→ Synchronous 3MHz fixed frequency with up to 99.5% duty cycle →→ Ideal for 2000mAh battery capacity →→ 4.3V-6V Input voltage →→ Synchronous 1.5MHz fixed frequency with up to 95% duty cycle →→ State machine controls via IRQ output →→ Ideal for 2,000mAh battery capacity →→ All charge parameters can be executed via the I C interface →→ WL-CSP-16B 1.7x1.77 package →→ 4.3V-12V Input voltage →→ Synchronous 375kHz fixed frequency with up to 99.0% duty cycle →→ USB OTG mode boosts the battery voltage to 5V and 2 2A Asynchronous Switch Mode Battery Charger Product Key Features Key Features →→ 28V(max) input rating for AC adapter →→ Auto Power Path Management(APPM) with system off →→ Adjustable Power current limit 0.1/0.5/1.5A →→ NTC sense for battery temperature monitor →→ Power good and charge status indicators →→ WQFN-16L 3x3 package →→ 28V(max) input rating for AC adapter →→ Integrated 3.3V LDO for NTC sense circuitry →→ Auto Power Path Management(APPM) →→ USB/Audio/Video switches →→ Termination, timer, charge current and VSYS settings through I C →→ Interrupt status, power good and charge status indicators →→ WQFN-28L 4x4 package P/N Key Features →→ 4.5V-28V input voltage →→ Adjustable battery voltages from 2.5V-22V →→ Internal Power MOSFETs →→ 500kHz switching frequency →→ NTC sense for battery temperature monitor →→ WQFN-16L 4x4 package →→ 4.5V-28V input voltage →→ Adjustable battery voltages from 2.5V-25V →→ External Power MOSFETs →→ Input current limit maximizes charging rate →→ 475kHz switching frequency →→ Flag indicates Charging status →→ WQFN-16L 4x4 package P/N RT9535A RT9538 RT9525 Sample RT9528 2 12 13 Copyright © Richtek Technology 2015 Battery Gauge EZPBS™ Power Bank Solution →→ SOC based on dynamic voltage measurements →→ EZPBS™ highly integrated single chip solution and battery voltaic model →→ Ideal for 3,000mAh battery capacity →→ ±7.5mV highly accurate voltage measurement →→ In many battery applications it is important to know how much charge is left in the battery. Product Conventional Coulomb Counting Method EZPBS™ Integrated Chip with Two Ports Output Checking the state of charge (SOC) of Li-Ion cells is often done by coulomb counting method. These methods are accurate in theory, but suffer from accumulation errors over time. In addition, the circuit is complicated due to the current sense circuit. 4.0A, I2C Switch Mode Single Cell Li-ion Battery Charger with USB OTG Richtek Solution An alternative way to determine the SOC is using a dynamic voltage based battery gauge, which measures the battery voltage over time, and uses the dynamic voltage measurements in combination with a battery model to EZPBS™ Integrated Chip with Switch Charger calculate the relative SOC. This topology does not suffer from error accumulation, and is used in RT9420 and Key Features →→ Easy-to-use Power Bank Solution (EZPBS™) →→ Compact BOM elements with EZPBS™ single chip →→ Support charging and discharging at the same time by smart algorithm →→ 1.2A linear charger, asynchronous Boost with dual output load management and a torch function support included →→ Support dual USB output (Total 2.5A ) →→ Support one sync-boost up to 2.5A →→ Battery state of charge(SoC) indicator by 4LEDs →→ WQFN-24L 4x4 package →→ Provide up to 1.6A USB output current in OTG mode for power bank →→ WQFN-32L 4x4 package →→ Easy-to-use Power Bank Solution (EZPBS™) →→ Built-in USBOUT DCP Controller, Attach/Detach Detection, Light Load Detection →→ Built-in Adapter Detection with BC1.2 →→ Charge Voltage Regulation form 3.65V to 4.6V →→ Charge Current Regulation form 0.7A to 2.7A →→ All charge parameters can be executed via the I C interface →→ 750kHz switching frequency →→ Current Regulation of Load Switch for 3A →→ WQFN-24L 4x4 package P/N RT9480 RT9451 RT9481 2 RT9428 battery gauge ICs. These ICs are simply connected to the battery terminals, and monitor the battery voltage very accurately. They use an internal algorithm to calculate the relative SOC and communicate it back to the host microcontroller via I2C. For best SOC accuracy, the application battery pack needs to be characterized during design stage, and battery specific compensation as well as temperature and charge/discharge effects can be included in the SOC calculation. Product I2C Host-side Single Cell Li-ion Battery gauge I2C Host-side Single Cell Li-ion Battery gauge SG003-01 OCT 2015 Key Features →→ ±3% State-of-Charge (SOC) error under general charging/discharging →→ Precise voltage measurement ±12.5mV accuracy →→ Accurate relative capacity(RSOC) calculated from Voltaic P/N Gauge algorithm with temperature compensation RT9420 Gauge algorithm with temperature compensation RT9428 →→ No accumulation error on capacity calculation →→ No battery relearning necessary and no current sense resistor required →→ WDFN-8L 2x3 package →→ ±3% State-of-Charge (SOC) error under general charging/discharging →→ Precise voltage measurement ±7.5mV accuracy →→ Accurate relative capacity(RSOC) calculated from Voltaic →→ No accumulation error on capacity calculation →→ No battery relearning necessary and no current sense resistor required →→ WL-CSP-8B 1.6x1.52 (BSC) package 14 15 Copyright © Richtek Technology 2015 Wireless Power Receiver Solution Front-end Protection IC Robust and flexible WPC Qi compliant 7.5W wireless power receiver RT9718 is fully integrated circuit designed to provide protection to Li-ion batteries powered applications from up to 28V abnormal high input voltage. RT9718 monitors the input voltage, battery voltage and the charging current. In case of an input over-voltage condition, RT9718 will turn off the power MOSFET within 1μs to remove the power before any damage occurs. Additionally, RT9718 can provide a voltage output without the existence of battery. Product 28V Over Voltage Protection IC Product Key Features Wireless power receiver →→ A high efficiency fully synchronous rectifier stage and a →→ Highly integrated with on-board 32-bit ARM-Cortex-M0 MCU →→ Very flexible with a user configurable MTP memory →→ Compliant with the WPC1.1 for low power up to 5W and Key Features →→ Fully integrated protection function: programmable OCP, input OVP and battery OVP →→ Over voltage turn off time less than 1μs →→ High accuracy protection threshold →→ WDFN-8L 2x2 package P/N RT9718 P/N WPC1.2.0 for medium power up to 7.5W low drop 1.5A linear post regulator stage RT1650 →→ A special headroom control system regulates the LDO headroom for optimal balance between transient response and system efficiency up to 80% →→ Supporting both adapter input and wireless power transfer input →→ CSP 3.0mmx3.4mm 48B (pitch=0.4mm) in 0.55mm low profile Find out more in the application note for the basic principles of Wireless Power Transfer, Wireless Power standards and the Qi WPC1.1 low power standard, and a practical example of the WPC1.1 5W application where a Nokia DT601 wireless power transmitter is paired with the wireless power receiver RT1650 evaluation board. SG003-01 OCT 2015 16 17 Copyright © Richtek Technology 2015 Design Support Li-ion Battery and Gauge Introduction by Vincent Ho SOC (State-Of-Charge) is defined as the status of available energy in the battery and usually expressed as percentages. Because the available energy change depends on different charging/discharging currents, temperatures and aging effects, the SOC could be defined more clearly as ASOC (Absolute State-OfCharge) and RSOC (Relative State-Of-Charge)... DIY - How to Make a Power Bank by Yourself How to make a safe and efficient power bank? The safety and performance of power bank is critical. It's easy to DIY a power bank, but how to select the key control IC for your power bank?... https://www.youtube.com/watch?v=SHYyogri-O4 http://www.richtek.com/Design Support/Technical Document/AN024 Understanding the characteristics of Li-ion batteries and Richtek power management solutions by Gary Zheng, Project Manager Designing Applications with Lithium Ion Batteries by Roland van Roy Li-Ion batteries have several advantages when compared Lithium-ion/polymer rechargeable batteries, which have with other battery types: The energy density of lithiumbeen widely used today, have distinguished properties, ion is typically twice that of the standard nickelbut are very delicate and have to be used with extreme cadmium. Li-Ion batteries have no memory effect, and care. Improper use of Li-ion batteries will bring about the self-discharge is less than half compared to nickelcatastrophic consequences.... http://www.richtek.com/Design Support/Technical Document/AN023 Parametric Search cadmium. The high cell voltage of 3.6 volts is often Filter component by your requirements sufficient to power applications from a single cell... http://www.richtek.com/Parametric Search/Parametric Search?tree_ ID=27 http://www.richtek.com/Design Support/Technical Document/AN025 Wireless Application : How to Make a Wireless LED Light The video introduces wireless charging principle and explains the application of Richtek RT1650, a flexible Qi compliant wireless power receiver for power transfer up to 7.5W. https://www.youtube.com/watch?v=y4gS0xCHOxA SG003-01 OCT 2015 18 19 Copyright © Richtek Technology 2015 SG003-01 OCT 2015 20