BQ24901PWG4

 SLUS527 – DECEMBER 2002                FEATURES D Designed for Off-Line Charger Design for D D D D D D D D D DESCRIPTION Single-Cell Li-Ion Packs Provides Control Feedback to a Primary-Side Controller Robust Battery Insertion and Removal Detection Charge Current and Voltage Regulation Feedback to Primary-Side for High-Accuracy Charging Charge Termination by Minimum Current and Time Pre-Charge Conditioning Regulator with Safety Timer Charge Status Outputs for LED or Host Processor Interface Indicates Chargein-Progress, Charge Completion, and Fault Conditions Temperature Monitoring Before and During Charge Short-Circuit Protection Small, 14-Pin TSSOP Package APPLICATIONS D Cradle Chargers for Digital Cameras D Desktop Chargers D Handheld Devices The bq24901 Li-Ion charge management devices are designed specifically for off-line charger applications. The bq24901 resides on the secondary-side of the transformer and provides the control feedback to a variety of primary side controllers. The bq24901 offers current or voltage regulation feedback, temperature monitoring, charge status, and adjustable charge termination, in a single monolithic device. During battery-absent or charge-complete conditions, the bq24901 continuously regulates the secondary-side voltage, used as VCC supply to the device. The bq24901 features a time-limited precon– ditioning phase to condition deeply discharged cells. The pre-conditioning phase is achieved by linear regulation in the secondary side. Following preconditioning, the bq24901 regulates the charge current to the value set by the external current sense resistor. Once the battery reaches the charge voltage, the voltage regulation loop takes over and completes the charge cycle. The accuracy of the voltage regulation is better than ±30mV. Charge is terminated based on minimum current. The minimum current level is set through TADJ pin. An internal five-hour charge timer provides a backup for charge termination. The bq24901 is designed to reliably detect battery insertion and removal conditions, including packs with open protectors. Other standard features include a recharge feature activated when the battery voltage falls below the VRCH threshold. Copyright  2002, Texas Instruments Incorporated     !" # $%&" !#  '%
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 SLUS527 – DECEMBER 2002 DESCRIPTION (continued) In addition to the standard features, the bq24901 offers battery temperature monitoring and status display. The temperature-sense circuit continuously measures battery temperature using an external thermistor and suspends charge until the battery temperature is within the user–defined thresholds. The STAT pins indicate conditions of operation of the charger. These outputs can be used to drive an LED or interface to a host microcontroller. 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 TA CHARGE REGULATION VOLTAGE PACKAGE DEVICES(1) TOP SIDE MARKINGS –20°C to 85°C 4.2 V bq24901PW bq24901 (1) The PW package is also available taped and reeled. Add an R suffix to the device type (i.e., bq24901PWR) for quantities of 2,500 devices per reel. PACKAGE DISSIPATION RATING TABLE PACKAGE θJA TA ≤ 25°C POWER RATING DERATING FACTOR ABOVE TA = 25°C PW 110°C/ W 907 mW 9.07 mW/°C/ ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range unless otherwise noted(1) Supply voltage, VCC I Input t voltage lt range, VI bq24901 UNIT with respect to VSS 11.5 V SNS, BAT, STAT1, STAT2, VCOMP, ICOMP, SCOMP, OPTD, CC (all with respect to Vss) 11.5 TADJ, VREF (all with respect to Vss) TS (with respect to Vss) Output sink/source current, IO O tp t sink current Output c rrent V 7 –0.3 to VCC + 0.3 V STAT1, STAT2, OPTD 20 CC 80 VREF 1 mA Operating free-air temperature range, TA –40 to 100 Junction temperature range, TJ –40 to 125 Storage temperature, Tstg –65 to 150 °C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 300 (1) 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. RECOMMENDED OPERATING CONDITIONS MIN Supply voltage, VCC Operating free-air temperature, TA 2 www.ti.com MAX UNIT 3 10 V –20 85 °C 
 SLUS527 – DECEMBER 2002 ELECTRICAL CHARACTERISTICS Over recommended operating free-air temperature and supply voltage (unless otherwise noted) TEST CONDITIONS PARAMETER MIN TYP MAX UNIT SUPPLY CURRENT ICC(VCC) IIB(BAT) Input current IIB(TS) IIB(SNS) Input bias current on TS pin Input bias current on BAT pin Input bias current on SNS pin IIB(TADJ) Input bias current on TADJ pin BATTERY VOLTAGE and VCC REGULATION VO(REG) VCC Output voltage VCC > VCC(min) VI(BAT) > VO(REG), when not in charge 2 VI(TS) = 2.5 V VCC = 6 V, VI(SNS) = 6 V when not in charge VI(TADJ) = VREF 1 0°C ≤ TA ≤ 70°C Supply voltage mA 1 1 µA A 1 4.17 4.20 4.23 5.8 6.0 6.3 184 200 216 mV VCC V V CURRENT REGULATION Current regulation threshold voltage V(SNS) Voltage at pin SNS relative to BAT, 0°C ≤ TA ≤ 70°C, V(LOWV)≤ V(SNS)≤ VO(REG) Input common mode range on SNS pin V(UVT) PRE-CHARGE AND SHORT-CIRCUIT CURRENT REGULATION Pre-charge voltage threshold ISC Short-circuit current CHARGE TERMINATION DETECTION Charge termination current detect threshold V(ITERM) Voltage at pin SNS relative to BAT pin, 0°C ≤ TA ≤ 70°C V(UVT) ≤ VI(BAT) ≤ V(LOWV) 0°C ≤ TA ≤ 70°C, 0 ≤ VI(BAT) ≤ V(UVT) Voltage at pin SNS relative to BAT pin, 0°C ≤ TA ≤ 70°C TADJ pin tied to VREF pin, VI(SNS) = VO(REG)VI(BAT) > V(RCH) Voltage at pin SNS relative to BAT pin, 0°C ≤ TA ≤ 70°C TADJ pin tied to VSS pin, VI(SNS) = VO(REG)VI(BAT) > V(RCH) 10 20 5.4 16 20 30 mV 30.0 mA 24 mV 7.5 10.0 12.5 VO(REG) –210 VO(REG) – 160 VO(REG) – 110 V(EN-TERM) Enable termination voltage (VI(SNS) – VI(BAT)) < V(ITERM) , VBAT increasing above threshold t(TRMDET2) Falling-edge delay for termination detection (VSNS – VBAT) increasing above threshold, VI(BAT) > V(EN–TERM), 100 ns fall time 2 mV overdrive 100 µs t(TRMDET1) Rising-edge delay for termination detection (VSNS – VBAT) increasing above threshold, VI(BAT) > V(EN–TERM), 100 ns fall time 2 mV overdrive 20 ms V TEMPERATURE COMPARATOR V(LTF) V(HTF) Cold temperature threshold voltage V(TCO) Cutoff temperature threshold voltage Hot temperature threshold voltage LTF hysteresis VTS, VTS, VCC ≥ 3.5 V VCC ≥ 3.5 V VTS, VCC ≥ 3.5 V Hysteresis for LTF threshold voltage 72.6 73.5 74.1 33.7 34.4 35.1 28.7 29.3 29.9 0.1 0.6 1.1 3.00 3.05 3.15 %VCC LOW BATTERY VOLTAGE (LOWV) THRESHOLD COMPARATOR V(LOWV) (1) V Ensured by design. Not production tested. www.ti.com 3 
 SLUS527 – DECEMBER 2002 ELECTRICAL CHARACTERISTICS (continued) Over recommended operating free-air temperature and supply voltage (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT BATTERY RECHARGE THRESHOLD (VRCH) COMPARATOR V(RCH) VO(REG) – 0.24 Recharge threshold voltage VO(REG) – 0.12 V V POWER-ON RESET (POR) V(POR) TIMERS POR threshold voltage t(PRECHG) Precharge time t(CHG) Charge time VI(BAT) < V(LOWV) V(LOWV) < VI(BAT) < VO(REG), (VI(SNS) – VI(BAT)) < V(ITERM) 2.60 2.70 2.85 1,350 1,800 2,250 13,500 18,000 22,500 s OPTO-DRIVER PIN (OPTD) VSAT(OPTD) Output saturation voltage I(OPTDLKG) Opto-driver leakage current gM Transconductance Gain-bandwidth product IO(OPTD) = 10 mA V(OPTD) = 5 V, VI(BAT) < VO(REG) VCC = 5.8 V, (VI(SNS) – VI(BAT)) < 184 mV IO(OPTD) = 5 mA IO(OPTD) = 5 mA, RLOAD = 100 Ω 5 100 mV 100 µA 500 S 1 MHz DISCHARGE CURRENT, DISCHARGE VOLTAGE, CONDITION CURRENT AND WAKE CURRENT 1 V≤ VI(BAT) ≤ 4.2 V I(DISCHG) t(DISCHG1) Discharge current 60 300 800 Discharge time 1 250 310 370 t(DISCHG2) V(DISCHG) Discharge time 2 20 25 30 1.5 2.0 2.5 Discharge voltage(1) 0.8 Batter detection current Battery c rrent I(DETECT_min) at VCC = 5.8 V,VI(BAT) = 4.2 V I(DETECT_max) at VCC = 6 V, VI(BAT) = 0 V 0.8 I(WK_SRC) current source 1 Wake current, I(WK_SRC_min) at VCC = 5.8 V,VI(BAT) = 4.2 V I(WK_SRC_max) at VCC = 6 V, VI(BAT) = 0 V Wake current, c rrent source so rce 2 I(WK_SINK_min) at VCC = 5.8 V, VI(BAT) = 4.2 V I(WK_SINK_max) at VCC = 6 V,VI(BAT) = 0 V 0 I(WK_SINK) I(DETECT) t(WK) Wake time CHARGE STATUS OUTPUT (STAT1/STAT2) VOL(STATx) Low-level output saturation voltage VOLTAGE REFERENCE OUTPUT (VREF) VREF voltage threshold V mA 30 1000 IO(STATx) = 10 mA, VCC ≥ 3.5 V 0°C ≤ TA ≤ 70°C ms 30 100 0 V < IO(VREF) < 500 µA, µA 1.18 125 µA A 150 ms 0.5 V 1.22 V CHARGE CONTROL OUTPUT (CC) VOL COUT Low-level output voltage (FstChg) Output capacitance IO(CC) = 40 mA (sink) LDO to BAT, LDO to VSS 0.45 V 0.1 10.0 µF 2.00 2.15 V UNDERVOLTAGE THRESHOLD SHORT-CIRCUIT PROTECTION V(UVT) (1) 4 Undervoltage threshold voltage Ensured by design. Not production tested. www.ti.com 
 SLUS527 – DECEMBER 2002 PW PACKAGE† (TOP VIEW) OPTD VCC SCOMP ICOMP VCOMP STAT1 STAT2 1 2 3 4 5 6 7 14 13 12 11 10 9 8 VSS CC SNS BAT TS VREF TADJ TERMINAL FUNCTIONS TERMINAL NAME NO. I/O DESCRIPTION BAT 11 I Battery voltage sense input. This input is tied directly to the positive side of the battery pack. CC 13 O Charge control output. CC is an open-drain pulldown output that is used to drive an external pass transistor for charge current and voltage control ICOMP 4 I Current loop compensation. This is the compensation for the fast charge current regulation loop. OPTD 1 O Optocoupler driver output. This open-collector output is used to provide feedback to the primary side by driving an external optocoupler. SCOMP 3 I Supply loop compensation. This is the compensation for the VCC supply regulation loop. SNS 12 I Current sense input. Battery current is sensed via the voltage developed on this pin by an external sense resistor. STAT1 6 O Charge status output 1 (open drain) STAT2 7 O Charge status output 2 (open drain) TADJ 8 I Termination adjust. This input is used to set the minimum current termination level during voltage regulation phase. TS 10 I Temperature sense Input. Input for an external battery temperature monitoring. VCC 2 I VCOMP 5 I VCC supply input. Voltage loop compensation. This is the compensation for the battery regulation loop VREF 9 O Voltage reference output. This buffered output provides the internal bandgap voltage. VSS 14 – Ground input. www.ti.com 5 
 SLUS527 – DECEMBER 2002 FUNCTIONAL BLOCK DIAGRAM VCC CC SNS 2 13 12 11 BAT + + SHUTDOWN POR FILTER SHUTDOWN ITERM FILTER DECODE LOGIC AND RAMP CONTROL PRECHARGE Term_det_EN (to SM) VUVT TERMINATION ILIM BYPASS SUSPEND TS 10 BAT_PRS_wake (to SM) BAT LTF FILTER VHEG – 100 mV SHUT DOWN WAKE_SRC WAKE HTF BAT VCC TCO VREF TADJ 9 8 + CHARGE DISCHARGE CHARGE CONTROL, TIMER, AND DISPLAY LOGIC VBANDGAP ICHARGE_SINK IDSCHRG TERMINATION PRECHARGE SUSPEND FASTCHARGE ITERM START–UP LOGIC VIBAT Term_det_EN BAT_PRS_wake 6 STAT1 7 STAT2 4 ICOMP 5 VCOMP DISC_RES VCC + SHUTDOWN SCOMP 3 OPTD 1 FILTER RAMP CONTROL VICHG FASTCHARGE + + VBANDGAP VBANDGAP SHUTDOWN VSS SUSPEND 14 DISC_RES TERMINATION UDG–02182 6 www.ti.com 
 SLUS527 – DECEMBER 2002 APPLICATION INFORMATION The bq24901 supports a precision current and voltage regulated li-ion charging system suitable for single-cells. Figure 1 shows the typical application diagram, Figure 2 shows a typical charge profile, and Figure 3 shows an operational flow chart. XMFR D2 OPTO1 L1 D1 N1 Q1 COUT N2 C1 bq24901 C3 N3 PRIMARY SIDE CONTROLLER RS 1 OPTD 2 VCC 3 VSS 14 OPTO1 CC 13 SCOMP SNS 12 4 ICOMP BAT 11 5 VCOMP 6 STAT1 VREF 9 7 STAT2 TADJ 8 VCC + TS 10 BATTERY PACK VCC VCC UDG–02180 Figure 1. Typical Application Diagram Current Regulation Phase Voltage Regulation Phase Regulation Voltage Regulation Current Charge Voltage Minimum Charge Voltage Charge Current Pre-Conditioning and Taper Detect Fast Charge Timer Pre-Charge Timer Figure 2. Typical Charge Profile www.ti.com 7 
 SLUS527 – DECEMBER 2002 APPLICATION INFORMATION POR Check for battery Presence Battery Present? No Indicate BATTERY ABSENT Yes Suspend charge TS pin in LTF to HTF range? No Indicate CHARGE SUSPEND Yes VBAT