bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 OVERVOLTAGE AND OVERCURRENT PROTECTION IC AND Li+ CHARGER FRONT-END PROTECTION IC • FEATURES 1 • Provides Protection for Three Variables: – Input Overvoltage, with Rapid Response in < 1 μs – User-Programmable Overcurrent with Current Limiting – Battery Overvoltage • 30V Maximum Input Voltage • Supports up to 1.5A Input Current • Robust Against False Triggering Due to Current Transients • Thermal Shutdown • Enable Input • Status Indication – Fault Condition 2 Available in Space-Saving Small 8 Lead 2×2 SON and 12 Lead 4x3 SON Packages APPLICATIONS • • • • • Mobile Phones and Smart Phones PDAs MP3 Players Low-Power Handheld Devices Bluetooth Headsets DESCRIPTION The bq24314 and bq24316 are highly integrated circuits designed to provide protection to Li-ion batteries from failures of the charging circuit. The IC continuously monitors the input voltage, the input current, and the battery voltage. In case of an input overvoltage condition, the IC immediately removes power from the charging circuit by turning off an internal switch. In the case of an overcurrent condition, it limits the system current at the threshold value, and if the overcurrent persists, switches the pass element OFF after a blanking period. Additionally, the IC also monitors its own die temperature and switches off if it becomes too hot. The input overcurrent threshold is user-programmable. The IC can be controlled by a processor and also provides status information about fault conditions to the host. APPLICATION SCHEMATIC AC Adapter 1 IN VDC OUT 8 1 mF 1 mF GND bq24080 Charger IC bq24316DSG SYSTEM VBAT 6 VSS ILIM FAULT 4 2 7 CE 5 1 2 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. PowerPAD is a trademark of Texas Instruments. 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 © 2007, Texas Instruments Incorporated bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. ORDERING INFORMATION (1) DEVICE (2) OVP THRESHOLD PACKAGE MARKING bq24314DSG 5.85 V 2mm x 2mm SON CBV bq24314DSJ 5.85 V 4mm x 3mm SON CBX bq24316DSG 6.80 V 2mm x 2mm SON CBW bq24316DSJ 6.80 V 4mm x 3mm SON BZC (1) (2) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com. To order a 3000 pcs reel add R to the part number, or to order a 250 pcs reel add T to the part number. PACKAGE DISSIPATION RATINGS PART NO. PACKAGE RθJC RθJA BQ24314DSG BQ24316DSG 2×2 SON 5°C/W 75°C/W BQ24314DSJ BQ24316DSJ 4×3 SON 5°C/W 40°C/W ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) PARAMETER Input voltage PIN VALUE UNIT IN (with respect to VSS) –0.3 to 30 OUT (with respect to VSS) –0.3 to 12 ILIM, FAULT, CE, VBAT (with respect to VSS) –0.3 to 7 V Input current IN 2.0 Output current OUT 2.0 A Output sink current FAULT 15 mA Junction temperature, TJ –40 to 150 °C Storage temperature, TSTG –65 to 150 °C 300 °C Lead temperature (soldering, 10 seconds) (1) A 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. All voltage values are with respect to the network ground terminal unless otherwise noted. RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) MIN MAX 3.3 26 V Input current, IN pin 1.5 A Output current, OUT pin 1.5 A 15.0 90.0 kΩ 0 125 °C VIN Input voltage range IIN IOUT RILIM OCP Programming resistor TJ Junction temperature 2 Submit Documentation Feedback UNIT Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 ELECTRICAL CHARACTERISTICS over junction temperature range 0°C ≤ TJ ≤ 125°C and recommended supply voltage (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT IN VUVLO Under-voltage lock-out, input power detected threshold CE = Low, VIN increasing from 0V to 3V 2.6 2.7 2.8 V VHYS-UVLO Hysteresis on UVLO CE = Low, VIN decreasing from 3V to 0V 200 260 300 mV TDGL(PGOOD) Deglitch time, input power detected status CE = Low. Time measured from VIN 0V → 5V 1μs rise-time, to output turning ON IDD Operating current CE = Low, No load on OUT pin, VIN = 5V, RILIM = 25kΩ ISTDBY Standby current CE = High, VIN = 5.0V 8 ms 400 600 μA 65 95 μA 170 280 mV 5.71 5.85 6.00 V 6.60 6.80 7.00 V 1 μs 110 mV INPUT TO OUTPUT CHARACTERISTICS VDO Drop-out voltage IN to OUT CE = Low, VIN = 5V, IOUT = 1A INPUT OVERVOLTAGE PROTECTION VOVP Input overvoltage protection threshold bq24314 tPD(OVP) Input OV propagation delay (1) CE = Low VHYS-OVP Hysteresis on OVP CE = Low, VIN decreasing from 7.5V to 5V tON(OVP) Recovery time from input overvoltage condition CE = Low, Time measured from VIN 7.5V → 5V, 1μs fall-time bq24316 CE = Low, VIN increasing from 5V to 7.5V 25 60 8 ms INPUT OVERCURRENT PROTECTION IOCP Input overcurrent protection threshold range IOCP Input overcurrent protection threshold tBLANK(OCP) Blanking time, input overcurrent detected tREC(OCP) Recovery time from input overcurrent condition 300 CE = Low, RILIM = 25kΩ 1500 mA 930 1000 1070 mA 176 μs 64 ms BATTERY OVERVOLTAGE PROTECTION BVOVP Battery overvoltage protection threshold CE = Low, VIN > 4.4V 4.30 4.35 4.4 V VHYS-BOVP Hysteresis on BVOVP CE = Low, VIN > 4.4V 200 275 320 mV IVBAT TDGL(BOVP) Input bias current on VBAT pin DSG Package VBAT = 4.4V, TJ = 25°C 10 DSJ Package VBAT = 4.4V, TJ = 85°C 10 nA Deglitch time, battery overvoltage CE = Low, VIN > 4.4V. Time measured from VVBAT rising from detected 4.1V to 4.4V to FAULT going low. μs 176 THERMAL PROTECTION TJ(OFF) Thermal shutdown temperature TJ(OFF-HYS) Thermal shutdown hysteresis 140 150 °C °C 20 LOGIC LEVELS ON CE VIL Low-level input voltage 0 VIH High-level input voltage 1.4 0.4 V IIL Low-level input current VCE = 0V 1 μA IIH High-level input current VCE = 1.8V 15 μA V LOGIC LEVELS ON FAULT VOL Output low voltage ISINK = 5mA 0.2 V IHI-Z Leakage current, FAULT pin HI-Z VFAULT = 5V 10 μA (1) Not tested in production. Specified by design. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 3 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 Q1 IN Charge Pump, Bandgap, Bias Gen OUT VBG ISNS ILIM ILIMREF Current limiting loop OFF OCP comparator ILIMREF - Δ t BLANK(OCP) ISNS FAULT VIN VBG COUNTERS, CONTROL, AND STATUS OVP VIN CE VBG t DGL(PGOOD) UVLO VBAT THERMAL SHUTDOW VBG t DGL(BOVP) VSS Figure 1. Simplified Block Diagram 4 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 TERMINAL FUNCTIONS TERMINAL NAME I/O DESCRIPTION DSJ DSG 1, 2 1 I Input power, connect to external DC supply. Connect external 1μF ceramic capacitor (minimum) to VSS. For the 12 pin (DSJ-suffix) device, ensure that pins 1 and 2 are connected together on the PCB at the device. OUT 10, 11 8 O Output terminal to the charging system. Connect external 1μF ceramic capacitor (minimum) to VSS. VBAT 8 6 I Battery voltage sense input. Connect to pack positive terminal through a resistor. 9 7 I/O Input overcurrent threshold programming. Connect a resistor to VSS to set the overcurrent threshold. CE 7 5 I Chip enable input. Active low. When CE = High, the input FET is off. Internally pulled down. FAULT 4 4 O Open-drain output, device status. FAULT = Low indicates that the input FET Q1 has been turned off due to input overvoltage, input overcurrent, battery overvoltage, or thermal shutdown. VSS 3 2 – Ground terminal NC 5, 6, 12 3 IN ILIM Thermal PAD These pins may have internal circuits used for test purposes. Do not make any external connections at these pins for normal operation. – There is an internal electrical connection between the exposed thermal pad and the VSS pin of the device. The thermal pad must be connected to the same potential as the VSS pin on the printed circuit board. Do not use the thermal pad as the primary ground input for the device. The VSS pin must be connected to ground at all times. IN 1 8 7 VSS 2 NC 3 IN 1 12 NC IN 2 11 OUT 10 OUT OUT ILIM VSS 3 bq24314DSG bq24316DSG 6 bq24314DSJ bq24316DSJ VBAT FAULT 4 FAULT 4 5 CE 9 ILIM NC 5 8 VBAT NC 6 7 CE Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 5 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 TYPICAL OPERATING PERFORMANCE Test conditions (unless otherwise noted) for typical operating performance: VIN = 5 V, CIN = 1 μF, COUT = 1 μF, RILIM = 25 kΩ, RBAT = 100 kΩ, TA = 25°C, VPU = 3.3V (see Figure 23 for the Typical Application Circuit) VIN VIN VOUT VOUT IOUT FAULT Figure 2. Normal Power-On Showing Soft-Start, ROUT = 6.6Ω Figure 3. OVP at Power-On, VIN = 0V to 9V, tr = 50μs VIN VIN Max VOUT = 6.84 V Max VOUT = 6.76 V VOUT VOUT FAULT FAULT Figure 4. bq24316 OVP Response for Input Step, VIN = 5V to 12V, tr = 1μs Figure 5. bq24316 OVP Response for Input Step, VIN = 5V to 12V, tr = 20μs VIN VIN Max VOUT = 6.84 V Max VOUT = 6.76 V VOUT VOUT FAULT FAULT Figure 6. bq24314 OVP Response for Input Step, VIN = 5V to 12V, tr = 1μs 6 Figure 7. bq24314 OVP Response for Input Step, VIN = 5V to 12V, tr = 20μs Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 TYPICAL OPERATING PERFORMANCE (continued) VIN VIN VOUT IOUT IOUT VOUT FAULT FAULT Figure 8. Recovery from OVP, VIN = 7.5V to 5V, tf = 400μs Figure 9. OCP, Powering Up into a Short Circuit on OUT Pin, OCP Counter Counts to 15 Before Switching OFF the Device VIN VIN VOUT IOUT IOUT VOUT FAULT FAULT Figure 10. OCP, Zoom-in on the First Cycle of Figure 9 Figure 11. OCP, ROUT Switches from 6.6Ω to 3.3Ω, Shows Current Limiting and Soft-Stop VOUT VVBAT Begin soft-stop VOUT VVBAT tDGL(BAT-OVP) = 220 ms FAULT FAULT Figure 12. BAT-OVP, VVBAT Steps from 4.2V to 4.4V, Shows tDGL(BAT-OVP) and Soft-Stop Figure 13. BAT-OVP, VVBAT Cycles Between 4.1V and 4.4V, Shows BAT-OVP Counter Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 7 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 TYPICAL OPERATING PERFORMANCE (continued) UNDERVOLTAGE LOCKOUT vs FREE-AIR TEMPERATURE DROPOUT VOLTAGE (IN to OUT) vs FREE-AIR TEMPERATURE 280 2.75 260 2.7 VIN Increasing 240 VIN = 4 V 220 VDO @ 1A - mV VUVLO, VHYS-UVLO - V 2.65 2.6 2.55 200 VIN = 5 V 180 160 2.5 140 VIN Decreasing 2.45 2.4 -50 120 100 -30 -10 10 30 50 70 Temperature - °C 90 110 0 130 50 100 150 Temperature - °C Figure 14. Figure 15. OVERVOLTAGE THRESHOLD PROTECTION (bq24316) vs FREE-AIR TEMPERATURE OVERVOLTAGE THRESHOLD PROTECTION (bq24314) vs FREE-AIR TEMPERATURE 5.88 6.82 6.8 5.86 6.78 VOVP, VHYS-OVP - V VOVP, VHYS-OVP - V VIN Increasing 6.76 6.74 5.84 VIN Increasing 5.82 VIN Decreasing 5.8 6.72 6.7 -50 VIN Decreasing -30 -10 10 30 50 70 Temperature - °C 90 110 5.78 -50 130 -30 -10 10 30 50 70 90 110 130 Temperature - °C Figure 16. Figure 17. INPUT OVERCURRENT PROTECTION vs ILIM RESISTANCE INPUT OVERCURRENT PROTECTION vs FREE-AIR TEMPERATURE 985 1600 984 1400 983 1200 982 IOCP - mA IOCP - mA 1000 800 981 980 979 600 978 400 977 200 0 0 976 10 20 30 40 50 60 RILIM - kW 70 80 90 100 975 -50 -30 Figure 18. 8 -10 10 30 50 70 Temperature - °C 90 110 130 Figure 19. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 TYPICAL OPERATING PERFORMANCE (continued) BATTERY OVERVOLTAGE PROTECTION vs FREE-AIR TEMPERATURE LEAKAGE CURRENT (VBAT Pin) vs FREE-AIR TEMPERATURE 4.4 2.5 4.35 BVOVP (VVBAT Increasing) 2 1.5 4.25 IVBAT - nA BVOVP - V 4.3 4.2 1 4.15 0.5 4.1 4.05 -50 Bat-OVP Recovery (VVBAT Decreasing) -30 -10 10 30 50 70 Temperature - °C 90 110 0 -50 130 -30 -10 10 Figure 20. 30 50 70 Temperature - °C 90 110 130 Figure 21. SUPPLY CURRENT (bq24314) vs INPUT VOLTAGE 900 800 IDD (CE = Low) IDD, ISTDBY - mA 700 600 500 400 300 200 ISTDBY (CE = High) 100 0 0 5 10 15 20 25 30 35 VIN - V Figure 22. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 9 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 TYPICAL APPLICATION CIRCUIT VOVP = 6.8V, IOCP = 1000mA, BVOVP = 4.35V (Terminal numbers shown are for the 2×2 DSG package) AC Adapter VDC 1 IN OUT 8 CIN GND COUT 1 mF 1 mF bq24080 Charger IC bq24316DSG RBAT SYSTEM VBAT 6 100 kW VPU RPU 47 kW 47 kW FAULT 4 RFAULT ILIM VSS 47 kW 7 2 CE 5 Host Controller RCE RILM 25 kW Figure 23. DETAILED FUNCTIONAL DESCRIPTION The bq24314 and bq24316 are highly integrated circuits designed to provide protection to Li-ion batteries from failures of the charging circuit. The IC continuously monitors the input voltage, the input current and the battery voltage. In case of an input overvoltage condition, the IC immediately removes power from the charging circuit by turning off an internal switch. In the case of an overcurrent condition, it limits the system current at the threshold value, and if the overcurrent persists, switches the pass element OFF after a blanking period. If the battery voltage rises to an unsafe level, the IC disconnects power from the charging circuit until the battery voltage returns to an acceptable value. Additionally, the IC also monitors its own die temperature and switches off if it becomes too hot. The input overcurrent threshold is user-programmable. The IC can be controlled by a processor, and also provides status information about fault conditions to the host. POWER DOWN The device remains in power down mode when the input voltage at the IN pin is below the undervoltage threshold VUVLO. The FET Q1 connected between IN and OUT pins is off, and the status output, FAULT, is set to Hi-Z. POWER-ON RESET The device resets when the input voltage at the IN pin exceeds the UVLO threshold. All internal counters and other circuit blocks are reset. The IC then waits for duration tDGL(PGOOD) for the input voltage to stabilize. If, after tDGL(PGOOD), the input voltage and battery voltage are safe, FET Q1 is turned ON. The IC has a soft-start feature to control the inrush current. The soft-start minimizes the ringing at the input (the ringing occurs because the parasitic inductance of the adapter cable and the input bypass capacitor form a resonant circuit). Figure 2 shows the power-up behavior of the device. Because of the deglitch time at power-on, if the input voltage rises rapidly to beyond the OVP threshold, the device will not switch on at all, instead it will go into protection mode and indicate a fault on the FAULT pin, as shown in Figure 3. 10 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 OPERATION The device continuously monitors the input voltage, the input current, and the battery voltage as described in detail in the following sections. Input Overvoltage Protection If the input voltage rises above VOVP, the internal FET Q1 is turned off, removing power from the circuit. As shown in Figure 4 to Figure 7, the response is very rapid, with the FET turning off in less than a microsecond. The FAULT pin is driven low. When the input voltage returns below VOVP – VHYS-OVP (but is still above VUVLO), the FET Q1 is turned on again after a deglitch time of tON(OVP) to ensure that the input supply has stabilized. Figure 8 shows the recovery from input OVP. Input Overcurrent Protection The overcurrent threshold is programmed by a resistor RILIM connected from the ILIM pin to VSS. Figure 18 shows the OCP threshold as a function of RILIM, and may be approximated by the following equation: IOCP = 25 ÷ RILIM (current in A, resistance in kΩ) If the load current tries to exceed the IOCP threshold, the device limits the current for a blanking duration of tBLANK(OCP). If the load current returns to less than IOCP before tBLANK(OCP) times out, the device continues to operate. However, if the overcurrent situation persists for tBLANK(OCP), the FET Q1 is turned off for a duration of tREC(OCP), and the FAULT pin is driven low. The FET is then turned on again after tREC(OCP) and the current is monitored all over again. Each time an OCP fault occurs, an internal counter is incremented. If 15 OCP faults occur in one charge cycle, the FET is turned off permanently. The counter is cleared either by removing and re-applying input power, or by disabling and re-enabling the device with the CE pin. Figure 9 to Figure 11 show what happens in an overcurrent fault. To prevent the input voltage from spiking up due to the inductance of the input cable, Q1 is turned off slowly, resulting in a “soft-stop”, as shown in Figure 11. Battery Overvoltage Protection The battery overvoltage threshold BVOVP is internally set to 4.35V. If the battery voltage exceeds the BVOVP threshold, the FET Q1 is turned off, and the FAULT pin is driven low. The FET is turned back on once the battery voltage drops to BVOVP – VHYS-BOVP (see Figure 12 and Figure 13). Each time a battery overvoltage fault occurs, an internal counter is incremented. If 15 such faults occur in one charge cycle, the FET is turned off permanently. The counter is cleared either by removing and re-applying input power, or by disabling and re-enabling the device with the CE pin. In the case of a battery overvoltage fault, Q1 is switched OFF gradually (see Figure 12). Thermal Protection If the junction temperature of the device exceeds TJ(OFF), the FET Q1 is turned off, and the FAULT pin is driven low. The FET is turned back on when the junction temperature falls below TJ(OFF) – TJ(OFF-HYS). Enable Function The IC has an enable pin which can be used to enable or disable the device. When the CE pin is driven high, the internal FET is turned off. When the CE pin is low, the FET is turned on if other conditions are safe. The OCP counter and the Bat-OVP counter are both reset when the device is disabled and re-enabled. The CE pin has an internal pulldown resistor and can be left floating. Note that the FAULT pin functionality is also disabled when the CE pin is high. Fault Indication The FAULT pin is an active-low open-drain output. It is in a high-impedance state when operating conditions are safe, or when the device is disabled by setting CE high. With CE low, the FAULT pin goes low whenever any of these events occurs: • Input overvoltage • Input overcurrent • Battery overvoltage • IC Overtemperature Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 11 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 Power Down All IC functions OFF FAULT = HiZ V(IN) > V(UVLO) ? Any State if V(IN) < V (UVLO), go to Power Down No Any State if CE = Hi, go to Reset Yes Reset Timers reset Counters reset FAULT = HiZ FET off No CE = Low ? V(IN) < V(OVP) ? No Turn off FET FAULT = Low No CE = Hi ? Yes Go to Reset Yes No I < IOCP ? No Turn off FET FAULT = Low Incr OCP counter Wait tREC(OCP) count <15 ? Yes No CE = Hi ? Yes Go to Reset No Turn off FET FAULT = Low VBAT < BATOVP ? No Incr BAT counter count <15 ? Yes TJ < TJ(OFF) ? No Turn off FET FAULT = Low Yes Turn on FET FAULT = HiZ Figure 24. Flow Diagram 12 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 APPLICATION INFORMATION (WITH REFERENCE TO FIGURE 23) Selection of RBAT It is strongly recommended that the battery not be tied directly to the VBAT pin of the device, as under some failure modes of the IC, the voltage at the IN pin may appear on the VBAT pin. This voltage can be as high as 30V, and applying 30V to the battery in case of the failure of the bq2431x can be hazardous. Connecting the VBAT pin through RBAT prevents a large current from flowing into the battery in case of a failure of the IC. In the interests of safety, RBAT should have a very high value. The problem with a large RBAT is that the voltage drop across this resistor because of the VBAT bias current IVBAT causes an error in the BVOVP threshold. This error is over and above the tolerance on the nominal 4.35V BVOVP threshold. Choosing RBAT in the range 100kΩ to 470kΩ is a good compromise. In the case of an IC failure, with RBAT equal to 100kΩ, the maximum current flowing into the battery would be (30V – 3V) ÷ 100kΩ = 246μA, which is low enough to be absorbed by the bias currents of the system components. RBAT equal to 100kΩ would result in a worst-case voltage drop of RBAT × IVBAT = 1mV. This is negligible to compared to the internal tolerance of 50mV on BVOVP threshold. If the Bat-OVP function is not required, the VBAT pin should be connected to VSS. Selection of RCE, RFAULT, and RPU The CE pin can be used to enable and disable the IC. If host control is not required, the CE pin can be tied to ground or left un-connected, permanently enabling the device. In applications where external control is required, the CE pin can be controlled by a host processor. As in the case of the VBAT pin (see above), the CE pin should be connected to the host GPIO pin through as large a resistor as possible. The limitation on the resistor value is that the minimum VOH of the host GPIO pin less the drop across the resistor should be greater than VIH of the bq2431× CE pin. The drop across the resistor is given by RCE × IIH. The FAULT pin is an open-drain output that goes low during OV, OC, battery-OV, and OT events. If the application does not require monitoring of the FAULT pin, it can be left unconnected. But if the FAULT pin has to be monitored, it should be pulled high externally through RPU, and connected to the host through RFAULT. RFAULT prevents damage to the host controller if the bq2431x fails (see above). The resistors should be of high value, in practice values between 22kΩ and 100kΩ should be sufficient. Selection of Input and Output Bypass Capacitors The input capacitor CIN in Figure 23 is for decoupling, and serves an important purpose. Whenever there is a step change downwards in the system load current, the inductance of the input cable causes the input voltage to spike up. CIN prevents the input voltage from overshooting to dangerous levels. It is strongly recommended that a ceramic capacitor of at least 1μF be used at the input of the device. It should be located in close proximity to the IN pin. COUT in Figure 23 is also important: If a very fast (< 1μs rise time) overvoltage transient occurs at the input, the current that charges COUT causes the device’s current-limiting loop to kick in, reducing the gate-drive to FET Q1. This results in improved performance for input overvoltage protection. COUT should also be a ceramic capacitor of at least 1μF, located close to the OUT pin. COUT also serves as the input decoupling capacitor for the charging circuit downstream of the protection IC. Powering Accessories In some applications, the equipment that the protection IC resides in may be required to provide power to an accessory (e.g. a cellphone may power a headset or an external memory card) through the same connector pins that are used by the adapter for charging. Figure 25 and Figure 26 illustrate typical charging and accessory-powering scenarios: Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 13 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 Accessory power supply IN AC Adapter OUT Charger bq24316 e.g. cellphone DIS EN Battery pack to rest of system Figure 25. Charging - The Red Arrows Show the Direction of Current Flow IN OUT Charger bq24316 e.g. cellphone EN Accessory power supply DIS Battery pack to rest of system Figure 26. Powering an Accessory - The Red Arrows Show the Direction of Current Flow In the second case, when power is being delivered to an accessory, the bq24314/bq24316 device is required to support current flow from the OUT pin to the IN pin. If VOUT > VUVLO + 0.7V, FET Q1 is turned on, and the reverse current does not flow through the diode but through Q1. Q1 will then remain ON as long as VOUT > VUVLO – VHYS-UVLO + RDSON*IACCESSORY. Within this voltage range, the reverse current capability is the same as the forward capability, 1.5A. It should be noted that there is no overcurrent protection in this direction. IN Q1 OUT VOUT Charge Pump, Bandgap, Bias Gen Figure 27. 14 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 PCB Layout Guidelines: • • • This device is a protection device, and is meant to protect down-stream circuitry from hazardous voltages. Potentially, high voltages may be applied to this IC. It has to be ensured that the edge-to-edge clearances of PCB traces satisfy the design rules for high voltages. The device uses SON packages with a PowerPAD™. For good thermal performance, the PowerPAD should be thermally coupled with the PCB ground plane. In most applications, this will require a copper pad directly under the IC. This copper pad should be connected to the ground plane with an array of thermal vias. CIN and COUT should be located close to the IC. Other components like RILIM and RBAT should also be located close to the IC. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 15 bq24314 bq24316 www.ti.com SLUS763C – JULY 2007 – REVISED OCTOBER 2007 Revision History Changes from Revision B (September 2007) to Revision C .......................................................................................... Page • • 16 Changed bq24314DSJ marking from preview to CBX .......................................................................................................... 2 Changed bq24316DSJ marking from preview to BZC........................................................................................................... 2 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): bq24314 bq24316 PACKAGE OPTION ADDENDUM www.ti.com 7-Nov-2007 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty BQ24314DSGR ACTIVE SON DSG 8 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24314DSGT ACTIVE SON DSG 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24314DSJR ACTIVE SON DSJ 12 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24314DSJT ACTIVE SON DSJ 12 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24316DSGR ACTIVE SON DSG 8 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24316DSGRG4 ACTIVE SON DSG 8 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24316DSGT ACTIVE SON DSG 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR BQ24316DSGTG4 ACTIVE SON DSG 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR Lead/Ball Finish MSL Peak Temp (3) (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. 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 PACKAGE MATERIALS INFORMATION www.ti.com 3-Nov-2007 TAPE AND REEL BOX INFORMATION Device Package Pins Site Reel Diameter (mm) Reel Width (mm) A0 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant BQ24314DSGR DSG 8 SITE 48 179 8 2.2 2.2 1.2 4 8 Q2 BQ24314DSJR DSJ 12 SITE 41 330 12 3.3 4.3 1.1 8 12 Q1 BQ24314DSJT DSJ 12 SITE 41 180 12 3.3 4.3 1.1 8 12 Q1 BQ24316DSGR DSG 8 SITE 48 179 8 2.2 2.2 1.2 4 8 Q2 BQ24316DSGT DSG 8 SITE 48 179 8 2.2 2.2 1.2 4 8 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 3-Nov-2007 Device Package Pins Site Length (mm) Width (mm) Height (mm) BQ24314DSGR BQ24314DSJR DSG 8 SITE 48 195.0 200.0 45.0 DSJ 12 SITE 41 346.0 346.0 29.0 BQ24314DSJT DSJ 12 SITE 41 190.0 212.7 31.75 BQ24316DSGR DSG 8 SITE 48 195.0 200.0 45.0 BQ24316DSGT DSG 8 SITE 48 195.0 200.0 45.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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