LTC4099 I2C Controlled USB Power Manager/Charger with Overvoltage Protection Description Features n n n n n n n n n n n The LTC®4099 is an I2C controlled high efficiency USB PowerPath™ controller and full-featured Li-Ion/Polymer battery charger. It seamlessly manages power distribution from multiple sources including USB, a wall adapter and a Li-Ion/Polymer battery.
LTC4099 pIN CONFIGURATION VBUS, WALL (Transient) t < 1ms, Duty Cycle < 1%....................................... –0.3V to 7V VBUS, WALL (Static), BAT, BATSENS, IRQ, NTC, DVCC................................................ –0.3V to 6V SDA, SCL........... –0.3V to Max (VBUS, VOUT, BAT) + 0.3V IOVSENS.................................................................±10mA ICLPROG.....................................................................3mA IPROG, INTCBIAS.............................................
LTC4099 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VBUS = 5V, BAT = 3.8V, DVCC = 3.3V, RPROG = 1.02k, RCLPROG = 3.01k, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN hCLPROG (Note 4) Ratio of Measured VBUS Current to CLPROG Program Current 100mA Mode 500mA Mode 620mA Mode 790mA Mode 1A Mode 1.
LTC4099 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VBUS = 5V, BAT = 3.8V, DVCC = 3.3V, RPROG = 1.02k, RCLPROG = 3.01k, unless otherwise noted. SYMBOL PARAMETER CONDITIONS VPROG,TRKL PROG Pin Servo Voltage in Trickle Charge BAT < VTRKL hPROG Ratio of IBAT to PROG Pin Current VTRKL Trickle Charge Threshold Voltage MIN TYP MAX UNITS 0.100 V 1030 mA/mA BAT Rising 2.7 2.
LTC4099 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VBUS = 5V, BAT = 3.8V, DVCC = 3.3V, RPROG = 1.02k, RCLPROG = 3.01k, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS NTC VTOO_COLD Cold Temperature Fault Threshold Voltage Rising Threshold Hysteresis 72.3 73.8 3.6 75.
LTC4099 Electrical Characteristics Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTC4099 is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls.
LTC4099 Typical Performance Characteristics RCLPROG = 3.01k, unless otherwise noted. USB Compliant Output Current Available Before Discharging Battery USB Compliant Output Current Available Before Discharging Battery 175 700 150 600 125 500 500 400 300 200 100 75 50 25 VBUS INPUT LIMIT SET FOR USB 500mA 2.7 3.0 3.3 3.6 3.9 BATTERY VOLTAGE (V) 0 4.2 400 VFLOAT VOLTAGE SET FOR 4.2V VBUS INPUT LIMIT SET FOR USB 500mA BATTERY CHARGER SET FOR 1200mA 300 200 100 2.7 3.0 0 4.2 3.3 3.6 3.
LTC4099 Typical Performance Characteristics RCLPROG = 3.01k, unless otherwise noted. Oscillator Frequency vs Temperature Battery Charge Current vs Temperature CHARGE CURRENT (mA) 500 FREQUENCY (MHz) 105°C SETTING THERMAL REGULATION 300 200 85°C SETTING 100 0 –40 –20 0 20 40 60 80 2.35 50 2.30 40 VBUS CURRENT (µA) 600 400 2.25 2.20 2.15 2.10 –40 100 120 –15 35 10 TEMPERATURE (°C) 60 4099 G16 20 36 33 30 SUSPEND HIGH 500mA USB MODE 11 8 100mA USB MODE 4.0 3.
LTC4099 Typical Performance Characteristics TA = 25°C, VBUS = 5V, BAT = 3.8V, RPROG = 1.02k, RCLPROG = 3.01k, unless otherwise noted. OVSENS Quiescent Current vs Temperature 6.280 37 6.275 35 6.270 6.265 6.260 6.255 –40 –15 35 10 TEMPERATURE (°C) 60 OVSENS CONNECTED TO INPUT THROUGH 10 6.
LTC4099 Typical Performance Characteristics TA = 25°C, VBUS = 5V, BAT = 3.8V, RPROG = 1.02k, RCLPROG = 3.01k, unless otherwise noted. Battery Charge Current and Voltage vs Time Output Voltage vs Battery Voltage; Battery Charger Overprogrammed 5 1.0 0.6 500mA 2 0.4 CHARGER TERMINATION 4-HOUR SETTING 1 0 5 6 3 4 TIME (HOURS) VBUS INPUT LIMIT SET FOR 790mA BATTERY CHARGER SET FOR 500mA FLOAT VOLTAGE SET FOR 4.2V 0 1 2 7 0.2 8 4099 G34 0 OUTPUT VOLTAGE (V) 0.
LTC4099 Pin Functions IRQ (Pin 8): Open-Drain Interrupt Output. The IRQ pin can be used to generate an interrupt due to a multitude of maskable status change events within the LTC4099. See Table 1. DVCC (Pin 15): Logic Reference for the I2C Serial Port. A 0.01µF bypass capacitor is required. GND (Pin 9, Exposed Pad Pin 21): Ground. The Exposed Pad and pin must be soldered to the PCB to provide a low electrical and thermal impedance connection to ground.
LTC4099 Block Diagram TO AUTOMOTIVE, FIREWIRE, ETC. VIN SW LT3480 VC 4 TO USB OR WALL ADPAPTER 13 6V + – 1 OVGATE s2 5 VC VOUT 3.6V BAT + 0.3V + + – 20 OVERVOLTAGE PROTECTION OVSENS FB WALL 4.3V ACPR 18 Bat-Track HV CONTROL +– VBUS SW TO SYSTEM LOAD 14 NONOVERLAP AND DRIVE LOGIC ISWITCH/N ILDO/M 19 100mV + – VOUT CLPROG 4.
LTC4099 TIMING Diagram SDA tSU, DAT tLOW tSU, STA tHD, DAT tBUF tSU, STO tHD, STA 4099 TD03 SCL tHIGH tHD, STA START CONDITION tSP REPEATED START CONDITION tf tr STOP CONDITION START CONDITION I2C Write Protocol WRITE ADDRESS SUB ADDRESS R/ W A7 0 0 0 1 0 0 1 0 SDA 0 0 0 1 0 0 1 0 ACK SCL 1 2 3 4 5 6 7 8 9 A6 A5 A4 A3 INPUT DATA BYTE A2 A1 A0 B7 B6 B5 B4 B3 B2 B1 B0 START STOP ACK 1 2 3 4 5 6 7 8 ACK 9 1 2 3 4 5 6 7 8 9 4099 TD0
LTC4099 Operation Introduction The LTC4099 is an I2C controlled power manager and Li‑Ion charger designed to make optimal use of the power available from a variety of sources while minimizing power dissipation and easing thermal budgeting constraints. The innovative PowerPath architecture ensures that the application is powered immediately after external voltage is applied, even with a completely dead battery, by prioritizing power to the application.
LTC4099 Operation TO AUTOMOTIVE, FIREWIRE, ETC. HVIN HIGH VOLTAGE STEP-DOWN SWITCHING VC REGULATOR 4 OVGATE s2 5 VC OVERVOLTAGE PROTECTION + – 1 OVSENS 6V +– VOUT 3.6V BAT + 0.3V 4.3V – + VBUS ACPR SW ISWITCH/N VOUT PWM AND GATE DRIVE IDEAL DIODE CONSTANT-CURRENT CONSTANT-VOLTAGE BATTERY CHARGER OmV 15mV CLPROG 1.18V – + AVERAGE INPUT CURRENT LIMIT CONTROLLER + + – 19 WALL 18 Bat-Track HV CONTROL FROM USB OR WALL ADAPTER 13 FB + + – 20 SW – + + – IDGATE 0.3V 3.
LTC4099 Operation the battery to charge. If the input-referred load current exceeds the input current limit at VBUS, VOUT will range between the no-load voltage and slightly below the battery voltage as indicated by the shaded region of Figure 2. If there is no battery present when this happens, VOUT may collapse to ground. In such cases the input-referred load current should be maintained below the programmed input current level in order to keep the VOUT and BAT voltages within specified limits.
LTC4099 Operation If the load current increases beyond the power allowed from the switching regulator, additional power will be pulled from the battery via the ideal diodes. Furthermore, if power to VBUS (USB or wall adapter) is removed, then all of the application power will be provided by the battery via the ideal diodes. The ideal diodes will be fast enough to keep VOUT from drooping with only the storage capacitance required for the switching regulator.
LTC4099 Operation Recall, however, that in many cases the actual battery charge current, IBAT, will be lower than the programmed current, ICHG, due to limited input power available and prioritization of the system load drawn from VOUT. Constant-Voltage Once the battery terminal voltage reaches the preset float voltage, the battery charger will hold the voltage steady and the charge current will decrease naturally toward zero. Two voltage settings, 4.100V and 4.
LTC4099 Operation occurs, it may be desirable to have application software enforce an emergency reduction of power in the portable product. It is possible to enable the battery conditioner circuit at this temperature to reduce stress caused by simultaneous high temperature and high voltage via the I2C port. See the Overtemperature Battery Conditioner section. The thermistor detection circuit samples the thermistor’s value continuously whenever charging is enabled and periodically when it is not.
LTC4099 Operation Overtemperature Battery Conditioner Overvoltage Protection Since Li-Ion batteries deteriorate with full voltage and high temperature, the LTC4099 contains an automatic battery conditioner circuit that reduces the battery voltage if both high temperature and high voltage are present simultaneously. The LTC4099 can protect itself from the inadvertent application of excessive voltage to VBUS or WALL with just two external components: an N-channel MOSFET and a 6.2k resistor.
LTC4099 Operation through ILIM0 in the I2C port determine whether the suspend LDO will limit input current to the low power setting of 500µA or the high power setting of 2.5mA. Interrupt Generation The IRQ pin on the LTC4099 is an open-drain output that can be used to generate an interrupt based on one or more of a multitude of maskable PowerPath/battery charger change events. The interrupt mask register column in Table 1 indicates the categories of events that can generate an interrupt.
LTC4099 Operation down the SDA line during the write acknowledge clock pulse so that it is a stable LOW during the HIGH period of this clock pulse. When the LTC4099 is read from, it releases the SDA line so that the master may acknowledge receipt of the data. Since the LTC4099 only transmits one byte of data, a master not acknowledging the data sent by the LTC4099 has no specific consequence on the operation of the I2C port.
LTC4099 Operation The battery charger current settings are decoded in Table 3. The battery charger current settings are adjusted by selecting one of the eight servo voltages for the PROG pin. Recall that the programmed charge current is given by the expression: V ICHG = PROG • 1030 RPROG The default state for the battery charger current settings is 000, giving the lowest available servo voltage of 500mV. The COVERX1 and COVERX0 bits are decoded in Table 4.
LTC4099 Operation Table 5 lists the possible safety timer settings from 1 to 8 hours, and how to decode them. The default state for the LTC4099 safety timer is 4 hours. Table 5. Safety Timer Decode TIMER2 0 0 0 0 1 1 1 1 *Default Setting SAFETY TIMER SETTINGS TIMER1 TIMER0 0 0 0 1 1 0 1 1 0 0 0 1 1 0 1 1 TIMEOUT 4 Hours* 5 Hours 6 Hours 7 Hours 8 Hours 1 Hour 2 Hours 3 Hours The DISABLE_CHARGER bit can be used to prevent battery charging if needed.
LTC4099 Operation via I2C (a disable followed by an enable). If the bad cell indication returns, then the cell is definitively bad. Bit 4 indicates that the battery charger is in thermal regulation due to excessive LTC4099 junction temperature. Recall that there are two I2C programmable junction temperature settings available at which to regulate, 85°C and 105°C. Bit 4 indicates thermal regulation at whichever setting is chosen.
LTC4099 Applications Information CLPROG Resistor and Capacitor VBUS and VOUT Bypass Capacitors As described in the Bat-Track Input Current Limited StepDown Switching Regulator section, the resistor on the CLPROG pin determines the average input current limit in each of the current limit modes. The input current will be comprised of two components, the current that is used to deliver power to VOUT, and the quiescent current of the switching regulator.
LTC4099 Applications Information nonlinear characteristic of capacitance versus voltage. The actual in-circuit capacitance of a ceramic capacitor should be measured with a small AC signal and DC bias, as is expected in-circuit. Many vendors specify the capacitance versus voltage with a 1VRMS AC test signal and, as a result, overstate the capacitance that the capacitor will present in the application.
LTC4099 Applications Information Reverse-Voltage Protection The LTC4099 can also be easily protected against the application of reverse voltage, as shown in Figure 6. D1 and R1 are necessary to limit the maximum VGS seen by MP1 during positive overvoltage events. D1’s breakdown voltage must be safely below MP1’s BVGS. The circuit shown in Figure 6 offers forward voltage protection up to MN1’s BVDSS and reverse-voltage protection up to MP1’s BVDSS.
LTC4099 Applications Information By using a bias resistor, RNOM, different in value from R25, the hot and cold trip points can be moved in either direction. The temperature span will change somewhat due to the nonlinear behavior of the thermistor. The following equations can be used to easily calculate a new value for the bias resistor: a RNOM = HOT • R25 0.4839 RNOM = a COLD • R25 2.816 From the Vishay curve 2 R-T characteristics, aHOT is 0.4086 at 50°C. Using the prior equation, RNOM should be set to 8.
LTC4099 Applications Information USB Inrush Limiting Voltage overshoot on VBUS may sometimes be observed when connecting the LTC4099 to a lab power supply. This overshoot is caused by long leads from the power supply to VBUS. Twisting the wires together from the supply to VBUS can greatly reduce the parasitic inductance of these long leads, and keep the voltage at VBUS to safe levels. USB cables are generally manufactured with the power leads in close proximity, and thus fairly low parasitic inductance.
LTC4099 Applications Information capacitance on this pin must be kept to a minimum. With no additional capacitance on the PROG pin, the charger is stable for program resistor values as high as 25k. However, additional capacitance on this node reduces the maximum allowed program resistor. The pole frequency at the PROG pin should be kept above 100kHz.
LTC4099 Typical Applications USB/Wall Adapter Battery Charger with Dual Overvoltage Protection, Reverse-Voltage Protection and Low Battery Start-Up M1 5V WALL ADAPTER M3 C1 2.2µF 0603 D3 R1 M5 R2 L1 3.3µH D4 1 13 USB M2 C2 22µF 0805 M4 D2 D1 R3 6.
LTC4099 Typical Applications USB/Automotive Switching Battery Charger with 2A Support From Automotive Input 4 AUTOMOTIVE, FIREWIRE, ETC. C1 4.7µF C2 50V 68nF R1 150k 5 R2 40.2k 10 C3 0.47µF 50V L1 10µH 2 VIN BOOST 3 SW RT PG VC 7 11 8 FB SYNC BD GND 9 R3 R4 499k 100k D1 LT3480 RUN/SS 1 C4 22µF 6 M2 L2 3.3µH M1 USB WALL ADAPTER 13 C5 22µF 0805 1 R5 6.
UDC Package 20-Lead Plastic QFN (3mm × 4mm) LTC4099 (Reference LTC DWG # 05-08-1742 Rev Ø) Package Description UDC Package 20-Lead Plastic QFN (3mm × 4mm) (Reference LTC DWG # 05-08-1742 Rev Ø) 0.70 ±0.05 3.50 ± 0.05 2.10 ± 0.05 1.50 REF 2.65 ± 0.05 1.65 ± 0.05 PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC 2.50 REF 3.10 ± 0.05 4.50 ± 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 3.00 ± 0.10 0.75 ± 0.05 1.50 REF 19 R = 0.05 TYP PIN 1 NOTCH R = 0.20 OR 0.
LTC4099 Revision History (Revision history begins at Rev C) REV DATE DESCRIPTION C 10/09 Text Change to Features 1 Text Changes to Description 1 UDC Package Information Added to Pin Configuration 2 Addition to Order Information 2 Text Changes to Operation Section 16 UDC Package Drawing Added 36 D 03/10 PAGE NUMBER Changes to Features and Description Removal of PDC Package from Pin Configuration and Package Description LTC4099EPDC Designated Obsolete in Order Information Section Changes
LTC4099 Typical Application High Efficiency USB/Automotive Battery Charger with Overvoltage Protection and Low Battery Start-Up 1 AUTOMOTIVE, FIREWIRE, ETC. C1 4.7µF 50V 13 C3 22µF 0805 1 R2 6.2k TO µC 20 3 15-17 8 TO µC 3 R3 100k M1: NTLJS4114N M2: Si2333DS LT3653 ILIM GND VC T L1 4.7µH 9 3 2 VBUS VOUT 2 5 VC WALL 18 14 SYSTEM LOAD ACPR SW VOUT OVSENS IDGATE I 5 L2 3.3µH OVGATE 2C 6 ISENSE HVOK 4 M1 8 BOOST SW VIN C2 0.1µF 10V D2 4 R1 27.
