RT4813 RICHTEK | Alldatasheet
Document overview
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Technical content
Features
CMCOT Topology and Small Output Ripple when VIN Close VOUT Voltage Operates from a Single Li-ion Cell : 1.8V to 5.5V Adjustable Output Voltage : 1.8V to 5.5V PSM Operation Up to 96% Efficiency Input Over Current Limit Input / Output Over Voltage Protection Programmable Average Output Current Limit Range : 3100mA to 1225mA Internal Compensation Output Discharge Output Short Protection True Load Disconnect
Applications
Single-Cell Li-Ion, LiFePO4 Smart-Phones Portable Equipment Marking Information 3V : Product Code W : Date Code 3VW Simplified Application Circuit GND SW VOUT SCL VIN FB RT4813 VOUT SDAI2C Control VIN EN EN
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4813-00 April 2016 Pin Configurations (TOP VIEW) SCL VINEN VOUT FB SW GND PGND SDA 91 8 UQFN-9L 2x2 (FC) Functional Pin Description Pin No. Pin Name Pin Function 1 EN Enable Input (1 enabled, 0 disabled), Must Not be Left Floating. 2 VOUT Boost Converter Output. 3 SW Switching Node. 4 PGND Power Ground. 5 SDA I2C Interface Data Input. 6 GND Analog Ground. 7 FB Voltage Feedback. 8 VIN Power Input. Input capacitor CIN must be placed as close to IC as possible. 9 SCL I2C Interface Clock Input. Functional Block Diagram Gate DRV AMP VOUT GND PWM CTRL VREF Digital CTRL SW PGND SDA VIN OSC OTP UVLO OCP FB SCL EN
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. specification, it will enter the Fault mode. Figure 1. RT4813 State Chart is turned-off in shutdown mode. The timeout of LIN2 is over the 1024s. current drops below the OCP limit. The converter has an over -temperature protection.
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4813-00 April 2016 Absolute Maximum Ratings (Note 1) Power Dissipation, PD @ TA = 25C Package Thermal Resistance (Note 2) ESD Susceptibility (Note 3) Recommended Operating Conditions (Note 4)
Electrical Characteristics
(VIN = 3.6V, TA = 25C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Under Voltage Lockout Rising Threshold VUVLOR 1.6 1.7 1.8 V Under Voltage Lockout Falling Threshold VUVLOF 1.5 1.6 1.7 V FB Voltage VFB CCM 0.495 0.5 0.505 V VOUT Voltage (I2C) VOUT CCM 1 0 1 % Shutdown Current ISHDN EN = 0V, -- 0.1 2 A Quiescent Current Close loop, no load -- 120 -- A Pre-Charge Current IPre -- 1 -- A Switching Frequency fSW VOUT VIN > 1V, CCM -- 0.5 -- MHz Valley Current Limit IOC -- 6 -- A High Side Switch RON VIN = VINA = 5V -- 43 55 m Low Side Switch RON VIN = VINA = 5V -- 26 35 m FB Pin Input Leakage IFB 1 -- 1 A Leakage of SW ISW -- -- 5 A
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 www.richtek.com Parameter Symbol Test Conditions Min Typ Max Unit Line Regulation VOUT, LINE CCM, VIN = 2.7V to 4.5V, VOUT = 5V, IOUT = 500mA -- 0.5 -- % Load Regulation VOUT, LOAD CCM, IOUT < 3.1A, VIN = 3.6V, Output Over Voltage Protection VOVP -- 6 -- V EN Input Voltage Low-Level VIL -- -- 0.4 V High-Level VIH 1.2 -- -- V EN Sink Current -- 0.1 1 A Thermal Shutdown TSD -- 160 C Thermal Shutdown Hysteresis TSD -- 30 C Note 1. Stresses beyond those listed “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 in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect device reliability. Note 2. JA is measured at T A = 25C on a high effective thermal conductivity four -layer test board per JEDEC 51 -7. JC is measured at the exposed pad of the package. Note 3. Devices are ESD sensitive. Handling precaution recommended. Note 4. The device is not guaranteed to function outside its operating conditions.
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4813-00 April 2016 Typical Application Circuit GND SW VOUT SCL PGND EN VIN FB RT4813 VOUT SDA5 VIN I2C control R4 R5 VIN 22μF x 2 1μF 10k10k 909k 22μF x 2 100k EN
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 www.richtek.com Typical Operating Characteristics Efficiency vs. Output Curent 100 0 500 1000 1500 2000 2500 3000 Output Current (mA) Efficiency (%) VIN = 4.2V VIN = 3.7V VIN = 3.3V VIN = 2.5V VIN = 1.8V VOUT = 5V, L = 1.5μH (TDK SPM6530), COUT = 22μF x 2, Load = 1mA to 3A VIN = 2.5V, VOUT = 5V, IOUT = 0mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 LX (2V/Div) VOUT_ac (50mV/Div) Output Voltage Ripple Time (10s/Div) LX (2V/Div) VOUT_ac (50mV/Div) Output Voltage Ripple Time (10s/Div) VIN = 3.6V, VOUT = 5V, IOUT = 0mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 LX (2V/Div) VOUT_ac (50mV/Div) Output Voltage Ripple Time (10s/Div) VIN = 4.2V, VOUT = 5V, IOUT = 0mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 LX (2V/Div) VOUT_ac (20mV/Div) Time (1s/Div) Output Voltage Ripple L = 1.5H (TDK SPM6530), COUT = 22F x 2 VIN = 2.5V, VOUT = 5V, IOUT = 1000mA LX (2V/Div) VOUT_ac (20mV/Div) VIN = 3.6V, VOUT = 5V, IOUT = 1000mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 Output Voltage Ripple Time (1s/Div)
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4813-00 April 2016 LX (2V/Div) VOUT_ac (20mV/Div) Output Voltage Ripple Time (1s/Div) VIN = 4.2V, VOUT = 5V, IOUT = 1000mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 IOUT (1A/Div) VOUT_ac (500mV/Div) Time (250s/Div) Load Transient Response VIN = 2.5V, VOUT = 5V, IOUT = 1.5A to 3A L = 1.5H (TDK SPM6530), COUT = 22F x 2 Slew rate = 100mA/μs IOUT (1A/Div) VOUT_ac (500mV/Div) Time (250s/Div) Load Transient Response VIN = 3.7V, VOUT = 5V, IOUT = 1.5A to 3A L = 1.5H (TDK SPM6530), COUT = 22F x 2 Slew rate = 100mA/μs IOUT (1A/Div) VOUT_ac (500mV/Diiv) Load Transient Response Time (250s/Div) VIN = 4.2V, VOUT = 5V, IOUT = 1.5A to 3A L = 1.5H (TDK SPM6530), COUT = 22F x 2 Slew rate = 100mA/μs IOUT (1A/Div) VOUT_ac (500mV/Diiv) Time (250s/Div) Load Transient Response VIN = 2.5V, VOUT = 5V, IOUT = 50mA to 150mA L = 1.5H, COUT = 22F x 2 Slew rate = 5mA/μs Time (250s/Div) Load Transient Response IOUT (1A/Div) VOUT_ac (500mV/Diiv) VIN = 3.7V, VOUT = 5V, IOUT = 50mA to 150mA L = 1.5H, COUT = 22F x 2 Slew rate = 5mA/μs
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 www.richtek.com Time (250s/Div) Load Transient Response IOUT (1A/Div) VOUT_ac (500mV/Diiv) VIN = 4.2V, VOUT = 5V, IOUT = 50mA to 150mA L = 1.5H, COUT = 22F x 2 Slew rate = 5mA/μs
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4813-00 April 2016 I2C Interface RT4813 I2C slave address = 0111001 (7 bits). I2C interface supports fast mode (bit rate up to 400kb/s). The write or read bit stream (N ≥ 1) is shown below : S 0 1 A P LSBMSB A Assume Address = m Data for Address = m Data for Address = m + N - 1 A Data for Address = m + 1 S 0 P Assume Address = m Data for Address = m Data for Address = m + N - 1 Data for Address = m + 1 Sr Slave Address Register Address Slave Address Data 1 R/W R/W Data N LSBMSB AA A A A A A A Read N bytes from RT4813 LSBMSB Data 2 Data N LSBMSB LSBSlave Address Register Address Data 1 Data 2MSB MSBLSB Write N bytes to RT4813 Driven by Master, Driven by Slave (RT4813), Start, Repeat StartStop, S SrP I2C Waveform Information SDA SCL tF tLOW tHD,STA tHD,DAT tHIGH tSU,DAT tSU,STA tHD,STA tSP tBUF tSU,STO P S tR SrS tF tR
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 www.richtek.com I2C Register Function Register Address b[7] (MSB) b[6] b[5] b[4] b[3] b[2] b[1] b[0] (LSB) Config 0X01 Meaning Reversed ILIM_OFF IPCHG DRV_SEL<2:0> SSFM Default 0 0 0 1 1 1 1 0 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W ILIM_OFF Boost valley current limit setting 0 : Boost current limit enable (default) 1 : Boost current limit disable IPCHG Pre-charge current setting. 00 : 0.5A 01 : 1A (default) 10 : 1.5A 11 : 2A DRV_SEL<2:0> LG driver driving capability 000 : Slowest 111 : Fastest (default) SSFM Spread spectrum setting. 0 : Spread spectrum disable (default) 1 : Spread spectrum enable Function Register Address b[7] (MSB) b[6] b[5] b[4] b[3] b[2] b[1] b[0] (LSB) Charger Control 3 0X03 Meaning ILIM_SS<7:4> ILIM_AVG<3:0> Default 0 0 0 0 0 0 0 0 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W ILIM_SS<7:4> Soft-start period boost current limit setting. The default current is 1500mA. Code Current Code Current Code Current Code Current 0000 1500mA (default) 0100 1500mA 1000 2500mA 1100 4500mA 0001 1500mA 0101 1500mA 1001 3000mA 1101 5000mA 0010 1500mA 0110 1500mA 1010 3500mA 1110 5500mA 0011 1500mA 0111 2000mA 1011 4000mA 1111 6000mA ILIM_AVG<3:0> Average Output Current limit setting. The default current is 3000mA. Code Current Code Current Code Current Code Current 0000 3100mA (Default) 0100 2420mA 1000 1740mA 1100 1060mA 0001 2930mA 0101 2250mA 1001 1570mA 1101 890mA 0010 2760mA 0110 2080mA 1010 1400mA 1110 720mA 0011 2590mA 0111 1910mA 1011 1230mA 1111 550mA
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4813-00 April 2016 Function Register Address b[7] (MSB) b[6] b[5] b[4] b[3] b[2] b[1] b[0] (LSB) OPTION 0X04 Meaning Reversed Reversed Reversed Reversed FSW EN _IAVGCL EN _Discharge Default 0 0 0 0 1 1 1 1 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W FSW Boost frequency setting. 00 : 2MHz 01 : Do not allowed 10 : 1MHz 11 : 500kHz (default) EN_IAVGCL Enable average output current limit 0 : Disable 1 : Enable (default) EN_Discharge Enable discharge 0 : Disable 1 : Enable (default)
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 www.richtek.com
Application Information
The device can be enabled or disabled by the EN pin. When the EN pin is higher than the threshold of logic-high, the device starts operating with soft-start. Once the EN pin is set at low, the device will be shut down. In shutdown mode, the converter stops switching, internal control circuitry is turned off, and the load is disconnected from the input. This also means that the output voltage can drop below the input voltage during shutdown. Soft-Start State After the successful completion of the LIN state (VOUT ≥ VIN 300mV), the regulator begins switching with boost valley-current limited value 3500mA. During Soft-Start state, VOUT is ramped up by Boost internal loop. If VOUT fails to reach target value during the Soft -Start period for more than 2ms, a fault condition is declared. Output Voltage Setting The output voltage is adjustable by an external resistive divider. The resistive divider must be connected between VOUT, FB and GND. When the output voltage is regulated properly, the typical value of the voltage at the FB pin is 500mV. Output voltage can be calculated by equation as below : OUT FB VR1 R2 1 V Power Save Mode PSM is the way to improve efficiency at light load. When the output voltage is lower than a set threshold voltage, the converter will operate in PSM. It raises the output voltage with several pulses until the loop exits PSM. Under-Voltage Lockout The under-voltage lockout circuit prevents the device from operating incorrectly at low input voltages. It prevents the converter from turning on the power switches under undefined conditions and prevents the battery from deep discharge. VIN voltage must be greater than 1. 65V to enable the converter. During operation, if VIN voltage drops below 1. 55V, the converter is disabled until the supply exceeds the UVLO rising threshold. The RT 4813 automatically restarts if the input voltage recovers to the input voltage UVLO high level. Thermal Shutdown The device has a built -in temperature sensor which monitors the internal junction temperature. If the temperature exceeds the threshold, the device stops operating. As soon as the IC temperature has decreased below the thres hold with a hysteresis, it starts operating again. The built -in hysteresis is designed to avoid unstable operation at IC temperatures near the over temperature threshold. Inductor Selection The recommended nominal inductance value is 1.5H It is recommended to use inductor with dc saturation current ≥ 5000mA Table 1. List of Inductors
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. voltage and maximum output load. proper power up of the system. scheme to sense inductor current during the off -time. current is decreased to valley -current threshold. implemented by the scheme, refer to Figure 2. over the limit, output current will be clamped. Figure 2. Inductor Currents In Current Limit Operation
Copyright © 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS4813-00 April 2016 Outline Dimension Symbol Dimensions In Millimeters Dimensions In Inches Min. Max. Min. Max. A 0.500 0.600 0.020 0.024 A1 0.000 0.050 0.000 0.002 A3 0.100 0.175 0.004 0.007 b 0.130 0.230 0.005 0.009 b1 0.200 0.300 0.008 0.012 D 1.950 2.050 0.077 0.081 E 1.950 2.050 0.077 0.081 e 0.500 0.020 L 0.350 0.450 0.014 0.018 L1 1.250 1.350 0.049 0.053 U-Type 9L QFN 2x2 (FC) Package Richtek Technology Corporation 14F, No. 8, Tai Yuen 1st Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications witho ut notice at any time. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is curre nt and complete. Richtek cannot assume responsibility for use of any circuitry other than circ uitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of pate nts or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its su bsidiaries.