BQ2954PNG4

bq2954 Lithium Ion Charge Management IC with Integrated Switching Controller Features General Description ➤ Safe charge of Li-Ion battery packs The bq2954 Li-Ion Charge-Management IC uses a flexible pulse-width modulation regulator to control voltage and current during charging. The regulator frequency is set by an external capacitor for design flexibility. The switch-mode design minimizes power dissipation. ➤ Pulse-width modulation control for current and voltage regulation ➤ Programmable high-side/low-side current-sense ➤ Fast charge terminated by selectable minimum current; safety backup termination at maximum time ➤ Pre-charge qualification detects shorted or damaged cells and conditions battery ➤ Charging continuously qualified by temperature and voltage limits ➤ Direct LED control outputs to display charge status and fault conditions Pin Connections The bq2954 charges a battery in two phases. First a constant-current phase replenishes approximately 70% of battery capacity. Then a voltage-regulation phase completes the battery charge. The bq2954 provides status indications of all charger states and faults for accurate determination of the battery and charge-system conditions. For safety, the bq2954 inhibits fast charging until the battery voltage and temperature are within configured limits. If the battery voltage is less than the low-voltage threshold, the bq2954 provides low-current conditioning of the battery. For charge qualifiction, the bq2954 uses an external thermistor to measure battery temperature. Charging begins when power is applied or the battery is inserted Pin Names TM Time-out programming input CHG Charge active output TM 1 16 LED2/DSEL CHG 2 15 LED1/CSEL BAT Battery voltage input BAT 3 14 MOD VCOMP Voltage loop comp input VCOMP 4 13 VCC ICOMP Current loop comp input ICOMP 5 12 VSS ITERM ITERM 6 11 LCOM Minimum current termination select input SNS 7 10 BTST SNS Sense resistor input TS 8 9 TPWM TS Temperature sense input 16-Pin Narrow DIP or SOIC PN295401.eps SLUS064–OCTOBER 1998 B 1 TPWM Regulator timebase input BTST Battery test output LCOM Common LED output VSS System ground VCC 5.0V± 10% power MOD Modulation control output LED1/ CSEL Charge status output 1/ Charge sense select input LED2/ DSEL Charge status output 2/ Display select input bq2954 TPWM Pin Descriptions TM Uses an external timing capacitor to ground to set the pulse-width modulation (PWM) frequency. See Equation 7. Time-out programming input Sets the maximum charge time. The resistor and capacitor values are determined using Equation 5. Figure 10 shows the resistor/capacitor connection. CHG BAT VCOMP BTST Charge active output An open-drain output is driven low when the battery is removed, during a temperature pend, when a fault condition is present, or when charge is done. CHG can be used to disable a high-value load capacitor to detect quickly any battery removal. LCOM Battery voltage input VSS Ground Sense input. This potential is generally developed using a high-impedance resistor divider network connected between the positive and the negative terminals of the battery. See Figures 6 and 7 and Equation 1. VCC VCC supply 5.0V, ±10% MOD Current loop compensation input LED1– LED2 Charger display status 1–2 outputs Drivers for the direct drive of the LED display. These outputs are tri-stated during initialization so that DSEL and CSEL can be read. Charge full and minimum current termination select DSEL Charging current sense input Display select input (shared pin with LED2) Three-level input that controls the LED1–2 charge display modes. Battery current is sensed via the voltage developed on this pin by an external sense-resistor. TS Current-switching control output Pulse-width modulated push/pull output used to control the charging current to the battery. MOD switches high to enable current flow and low to inhibit current flow. (The maximum duty cycle is 80%.) Voltage loop compensation input Three-state input is used to set IFULL and IMIN for fast charge termination. See Table 4. SNS Common LED output Common output for LED1-2. This output is in a high-impedance state during initialization to read programming input on DSEL and CSEL. Connects to an external R-C network to stabilize the regulated current. ITERM Battery test output Driven high in the absence of a battery in order to provide a potential at the battery terminal when no battery is present. Connects to an external R-C network to stabilize the regulated voltage. ICOMP Regulation timebase input CSEL Temperature sense input Charge sense-select input (shared pin with LED1) Input that controls whether current is sensed on low side of battery or high side of battery. A current mirror is required for high-side sense. Used to monitor battery temperature. An external resistor-divider network sets the lower and upper temperature thresholds. (See Figures 8 and 9 and Equations 3 and 4.) 2 bq2954 VCC TM Power-On Reset MTO Timer ITERM TPWM Oscillator DSEL CSEL VSS Charge Control State Machine Voltage Reference LED1 LED2 BTST CHG Display Control TS VCOMP LCOM BAT PWM Regulator SNS ICOMP MOD BD2954.eps Figure 1. Functional Block Diagram Functional Description Charge Qualification The bq2954 functional operation is described in terms of the following (Figure 1): The bq2954 starts a charge cycle when power is applied while a battery is present or when a battery is inserted. Figure 2 shows the state diagram for the bq2954. The bq2954 first checks that the battery temperature is within the allowed, user-configurable range. If the temperature is out of range, the bq2954 remains in the QUALIFICATION state (S01) and waits until the battery temperature and voltage are within the allowed range. ■ Charge algorithm ■ Charge qualification ■ Charge status display ■ Configuring the display and termination ■ Voltage and current monitoring ■ Battery insertion and removal ■ Temperature monitoring ■ Maximum time--out ■ Charge regulation ■ Recharge after fast charge If during any state of charge, a temperature excursion occurs HOT, the bq2954 proceeds to the DONE state (S04) and indicates this state on the LED outputs and provides no current. If this occurs, the bq2954 remains in the DONE state unless the following two conditions are met: ■ Temperature falls within valid charge range ■ VBAT falls below the internal threshold,VRCHG If these two conditions are met, a new charge cycle begins. During any state of charge, if a temperature excursion occurs COLD, the bq2954 terminates charge and returns to the QUALIFICATION state (S01). Charge restarts if VBAT and temperature are in valid range. Charge Algorithm The bq2954 uses a two-phase fast-charge algorithm. In phase 1, the bq2954 regulates constant current until the voltage on the BAT pin, VBAT, rises to the internal threshold, VREG. The bq2954 then transitions to phase 2 and regulates constant voltage (VBAT = VREG) until the charging current falls below the programmed I MIN threshold. Fast charge then terminates, and the bq2954 enters the Charge Complete state. (See Figure 2.) When the temperature and voltage are valid, the bq2954 enters the CONDITIONING state (S02) and regulates current to ICOND (=IMAX/10). After an initial holdoff period tHO (which prevents the IC from reacting to transient voltage spikes that may occur when charge current is first applied), the IC begins monitoring VBAT. If VBAT does not rise to at least VMIN before the expiration of 3 bq2954 Volt Fault: When VBAT > VHCO Time Fault: When T = MTO/4 in State S02 or T = MTO in S03a Hold Time: A VHCO Fault or State charge held off for 0.740s to 1.12s VCC "Up" Power-On Reset Mod = 0 No Action Latch DSEL/CSEL Inputs Battery Removal VBAT < 0.8V Reset Faults Latch DSEL/CSEL Inputs Temp Not Valid 0.8V > VBAT > VHCO Hold Time Hold-off Faults CHG = 0 Battst = 1 VBAT< VRCHG QUALIFICATION Fault CHG = 0 S01 Temp Valid VHCO < VBAT >0.8V Reset MTO CONDITIONING Volt or Time Fault VBAT < VMIN: ISNS = IMAX/10 Hold Time CHG = 1 S02 Time Fault Temp Not Valid T = MTO/25 VBAT >VMIN Reset MTO CURRENT REGULATION ISNS = IMAX: VBAT < VREG T < MTO Hold Time CHG = 1 S03a Volt or Time Fault Temp Not Valid VBAT > VHCO or T = MTO VBAT = VREG Full Charge Indication VOLTAGE REGULATION VBAT = VREG: IMAX > ISNS > ITRMN T< MTO CHG = 1 S03b ISNS = IMIN Volt Fault Temp Not Valid VBAT > VHCO T = MTO ISNS = ITRM DONE Temp Hot VBAT > VRCHG Hold-off MOD VRCHG < VBAT < VHCO CHG = 1 S04 Temp Not Hot andVBAT < VRCHG Volt Fault VBAT > VHCO 1s Hold Time after VBAT < VRCHG VBAT Voltages: VRCHG = 1.92V 0.5V VMIN = 1.50V 0.5V VREG = 2.05V VHCO = 2.30V Figure 2. bq2954 Charge Algorithm 4 FGbg295401.eps bq2954 R2 D4 8-24VDC ±10% VDC R1 C10 47uF 25V R4 10K U2 ZMR500 G OUT IN N D C3 1uF 25V L2 4.7K Q1 FMMT3906 B130DI D5 B130DI 1K 5V R5 10K C2 1uF BAT+ 47uH Q5 FZT789A Q2 FMMt3904 L1 10 uH D1 1N4148 Q3 FMMT451 C11 10uF 20V PCS4106 R14 RB1 5V R15 RB2 R6 10K R9 220 BATR10 62K D2 GRREN 5V R7 1K U1 0.1 uF R13 1K C8 1000pF C4 0.1 uF C6 R8 0.25 5% 0.5W 16 15 14 13 12 11 10 9 D3 RED R3 10K C9 LED2/DSEL LED1/CSEL MOD VCC VSS LCOM BTST TPWM 1 2 3 4 5 6 7 8 TM CHG BAT VCOMP ICOMP ITERM SNS TS R11 4.32K 1% R12 8.45K 1% TEM+ C7 bq2954 C5 470pF 0.1uF Q4 FMMT3904 0.01uF C1 0.1uF 2954sch9/23/98 1. IMAX = 1.0A, Vreg = 4.2V ± 1% PER CELL 2. MTO = 3 HRS, IFULL = IMAX/5, ITERM = IMAX/10 3. TEMP = 0-45˚C, 4. Frequency = 200kHz Figure 3. High-Efficiency Li-Ion Charger for 1–4 Cells 5 bq2954 Table 1. Normal Fast Charge Cycle VBAT Battery Absent IBAT Qualification Fast Charge Current Regulate VREG Voltage Regulate Current Taper IFULL Detect Charge Complete IMAX VMIN ICOND IFULL IMIN MTO Time Mode 1 (DSEL = 0) Mode 2 (DSEL = 1) Mode 3 (DSEL = F) Mode 1 and 2 Mode 3 LED1 LED2 LED1 LED2 LED1 LED2 CHG BTST CHG BTST Low Low Low Low Low Low Low High Low High High Low High Low High Low High Low High High High Low High Low High Low High Low High Low High Low High Low High High High Low High Low Low High Low High Low High High Low High Low Low High Low High Low High Low Low Low Low GR295401.eps time-out limit tQT (i.e., the battery has failed short), the bq2954 enters the Fault state. Then tQT is set to 25% of tMTO. If VMIN is achieved before expiration of the time limit, the bq2954 begins fast charging. Configuring the Display Mode, IFULL/IMIN, and ISENSE DSEL/LED2 and CSEL/LED1 are bi-directional pins with two functions: as LED driver pins (output) and as programming pins (input). The selection of pull-up, pull-down, or no-resistor programs the display mode on DSEL as shown in Tables 1 through 3. A pull-down or no-resistor programs the current-sense mode on CSEL. Once in the Fault state, the bq2954 waits until VCC is cycled or a new battery insertion is detected. It then starts a new charge cycle and begins the qualification process again. Charge Status Display The bq2954 latches the programming data sensed on the DSEL and CSEL input when VCC rises to a valid level. The LEDs go blank for approximately 400ms (typical) while new programming data are latched. Charge status is indicated by the LED driver outputs LED1–LED2. Three display modes (Tables 1– 3) are available in the bq2954 and are selected by configuring pin DSEL. Table 1 illustrates a normal fast charge cycle, Table 2 a recharge-after-fast-charge cycle, and Table 3 an abnormal condition. When fast charge reaches a condition where the charging current drops below IFULL, the LED1 and LED2 outputs indicate a full-battery condition. Fast charge terminates when the charging current drops below the 6 bq2954 Table 2. Recharge After Fast Charge Cycle VBAT Charge Complete IBAT Fast Charge Current Regulate VREG IMAX VRECHG Voltage Regulate Current Taper IFULL Detect Charge Complete Discharge VMIN ICOND IFULL IMIN Time Mode 1 (DSEL = 0) Mode 2 (DSEL = 1) Mode 3 (DSEL = F) Mode 1 and 2 Mode 3 LED1 LED2 LED1 LED2 LED1 LED2 CHG BTST CHG BTST Low High Low High Low High Low Low Low Low High Low High Low High Low High Low High Low MTO High Low High Low High High High Low High Low Low High Low High Low High Low Low Low Low Low High Low High Low High High Low High Low Grbq295402.eps 7 bq2954 Table 3. Abnormal Condition VBAT Battery Absent IBAT Qualification Abnormal Battery VREG IMAX VMIN ICOND IMIN Time Mode 1 (DSEL = 0) Mode 2 (DSEL = 1) Mode 3 (DSEL = F) CHG BTST LED1 LED2 LED1 LED2 LED1 LED2 Low Low Low Low Low Low Low High tQT High Low High Low High Low High Low Flash Low Low Low Low Low Low Low GR295403.eps Table 4. IFULL and IMIN Thresholds ITERM IFULL IMIN 0 IMAX/5 IMAX/10 1 IMAX/10 IMAX/15 Z IMAX/15 IMAX/20 8 bq2954 Battery insertion is detected within 500ms. Transition to the fast-charge phase, however, will not occur for time tHO (approximately one second), even if voltage qualification VMIN is reached. This delay prevents a voltage spike at the BAT input from causing premature entry into the fast-charge phase. It also creates a delay in detection of battery removal if the battery is removed during this hold-off period. minimum current threshold, IMIN. The IFULL and IMIN thresholds are programmed using the ITERM input pin (See Table 4.) Figures 4 and 5 show the bq2954 configured for display mode 2 and IFULL = IMAX/5 while IMIN = IMAX/10. Voltage and Current Monitoring Temperature Monitoring In low-side current sensing, the bq2954 monitors the battery pack voltage as a differential voltage between BAT and pins. In high-side current sensing, the bq2954 monitors the battery pack voltage as a differential voltage between BAT and VSS pins. This voltage is derived by scaling the battery voltage with a voltage divider. (See Figures 6 and 7.) The resistance of the voltage divider must be high enough to minimize battery drain but low enough to minimize noise susceptibility. RB1 + RB2 is typically between 150kΩ and 1MΩ. The voltage-divider resistors are calculated from the following: RB1 N ∗ VCELL = −1 RB2 VREG Temperature is measured as a differential voltage between TS and BAT-. This voltage is typically generated by a NTC (negative temperature coefficient) thermistor and thermistor linearization network. The bq2954 compares this voltage to its internal threshold voltages to determine if charging is allowed. These thresholds are the following: ■ (1) ■ where VCELL = Manufacturer-specified charging cell voltage N = Number of cells in series VREG = 2.05V ■ The current sense resistor, RSNS (see Figures 6 and 7), determines the fast-charge current. The value of RSNS is given by the following: R SNS = 0.25V I MAX High-Temperature Cutoff Voltage: VTCO = 0.4 ∗ VCC This voltage corresponds to the maximum temperature (TCO) at which charging is allowed. High-Temperature Fault Voltage: VHTF = 0.44 ∗ VCC This voltage corresponds to the temperature (HTF) at which charging resumes after exceeding TCO. Low-Temperature Fault Voltage: VLTF = 0.6 ∗ VCC This voltage corresponds to the minimum temperature (LTF) at which charging is allowed. Charging is inhibited if the temperature is outside the LTF—TCO window. Once the temperature exceeds TCO, it must drop below HTF before charging resumes. (2) RT1 and RT2 for the thermistor linearization network are determined as follows: where IMAX is the current during the constant-current phase of the charge cycle. (See Table 1.) 0.6 ∗ VCC = V RT1 ∗ (RT2 + R LTF ) 1+ (RT2 ∗ R LTF ) (3) 0.44 = 1 RT1 ∗ (RT2 + R HTF ) (RT2 ∗ R HTF ) (4) Battery Insertion and Removal VBAT is interpreted by the bq2954 to detect the presence or absence of a battery. The bq2954 determines that a battery is present when VBAT is between the High-Voltage Cutoff (V HCO = V REG + 0.25V) and the Low-Voltage Cutoff (VLCO = 0.8V). When VBAT is outside this range, the bq2954 determines that no battery is present and transitions to the battery test state, testing for valid battery voltage. The bq2954 detects battery removal when VBAT falls below VLCO. The BTST pin is driven high during battery test and can activate an external battery contact pull-up. This pull-up may be used to activate an over-discharged Li-Ion battery pack. The VHCO limit implicitly serves as an over-voltage charge fault. The CHG output can be used to disconnect capacitors from the regulation circuitry in order to quickly detect a battery-removed condition. 1+ where RLTF = thermistor resistance at LTF RHTF = thermistor resistance at HTF V = VCC - 0.250 in low-side current sensing V = VCC in high-side current sensing TCO is determined by the values of RT1 and RT2. 1% resistors are recommended. 9 bq2954 VCC LED2/DSEL LED1 VCC 10K 1K 16 LED2/DSEL 15 LED1 10K 1K 16 15 1K 1K VCC VSS 6 LCOM 13 VCC 12 VSS 6 11 LCOM bq2954 13 12 10K 11 bq2954 VSS VSS Low-Side Sense Mode High-Side Sense Mode FGbq295402LS.eps FGbq295402HS.eps Figure 4. Configured Display Mode (Low-Side Sense) VCC Figure 5. Configured Display Mode (High-Side Sense) BAT + VCC RB1 BAT 13 12 Current Mirror MOD BAT 13 12 RB2 VSS bq2954 BAT + 3 VCC SNS RSNS Switching Circuit RB2 VSS SNS RSNS bq2954 VSS 3 VCC BAT - 7 RB1 BAT - 7 RB3 VSS Low-Side Sense Mode High-Side Sense Mode FGbq295403HS.eps FGbq295403LS.eps Figure 6. Configuring the Battery Divider (Low-Side Sense) Figure 7. Configuring the Battery Divider (High-Side Sense) 10 bq2954 VCC VCC RT1 bq2954 LPD1 13 12 bq2954 LPD1 RT2 VSS SNS TS 13 NTC Thermistor RT t VCC 12 BAT - 7 RT1 NTC Thermistor VCC RT2 VSS SNS 7 8 TS 8 RCSEL BAT - RSNS VSS VSS Low-Side Sense Mode High-Side Sense Mode FGbq295404LS.eps FGbq295404HS.eps Figure 8. Low-Side Temperature Sensing Figure 9. High-Side Temperature Sensing Disabling Temperature Sensing VCC Temperature sensing can be disabled by placing a 10kΩ resistor between TS and BAT- and a 10kΩ resistor between TS and VCC. See Figures 8 and 9. R 1 TM Maximum Time-Out C VCC VSS Maximum Time-Out period (tMTO) is programmed from 1 to 24 hours by an R-C network on the TM pin (see Figure 10) per the following equation: 13 12 tMTO = 500 ∗ R ∗ C (5) where R is in ohms, C is in Farads, and tMTO is in hours. The recommended value for C is 0.1µF. The MTO timer is reset at the beginning of fast charge. If the MTO timer expires during the voltage regulation phase, fast charging terminates and the bq2954 enters the Charge Complete state. If the conditioning phase continues for time equal to tQT (MTO/4) and the battery potential does not reach VMIN, the bq2954 enters the fault state and terminates charge. See Table 3. If the MTO timer expires during the current-regulation phase (VBAT never reaches VREG), fast charging is terminated, and the bq2954 enters the fault state. bq2954 VSS FGbq295405.eps Figure 10. R-C Network/Setting MTO 11 bq2954 Where C is in Farads and the frequency is in Hz. A typical switching rate is 100kHz, implying CPWM = 0.001µF. MOD pulse width is modulated between 0 and 80% of the switching period. Charge Regulation The bq2954 controls charging through pulse-width modulation of the MOD output pin, supporting both constant-current and constant-voltage regulation. Charge current is monitored at the SNS pin, and charge voltage is monitored at the BAT pin. These voltages are compared to an internal reference, and the MOD output is modulated to maintain the desired value. The maximum duty cycle is 80% . To prevent oscillation in the voltage and current control loops, frequency compensation networks (C and R-C respectively) are typically required on the VCOMP and ICOMP pins . Recharge After Fast Charge Voltage at the SNS pin is determined by the value of resistor RSNS, so nominal regulated current is set by the following equation: IMAX =VSNS /RSNS Once charge completion occurs, a fast charge is initiated when the battery voltage falls below VRECHG threshold. A delay of approximately one second passes before recharge begins so that adequate time is allowed to detect battery removal. (See Table 1.) (6) The switching frequency of the MOD output is determined by an external capacitor (CPWM) between the pin TPWM and VSS pins, per the following: fPWM = 1 ∗ 10 −4 CPWM (7) 12 bq2954 Absolute Maximum Ratings Symbol Parameter Minimum Maximum Unit Notes VCC VCC relative to VSS -0.3 +7.0 V VT DC voltage applied on any pin excluding VCC relative to VSS -0.3 +7.0 V -20 +70 °C Commercial TOPR Operating ambient temperature -40 +85 °C Industrial “N” -55 +125 °C - +260 °C TSTG Storage temperature TSOLDER Soldering temperature Note: Permanent device damage may occur if Absolute Maximum Ratings are exceeded. Functional operation should be limited to the Recommended DC Operating Conditions detailed in this data sheet. Exposure to conditions beyond the operational limits for extended periods of time may affect device reliability. DC Thresholds Symbol 10s max. (TA = TOPR; VCC = 5V ± 10%) Rating Unit Tolerance Internal reference voltage 2.05 V 1% Temperature coefficient -0.5 mV/°C 10% VLTF TS maximum threshold 0.6 * VCC V ± 0.03V Low-temperature fault VHTF TS hysteresis threshold 0.44 * VCC V ± 0.03V High-temperature fault VTCO TS minimum threshold 0.4 * VCC V ± 0.03V Temperature cutoff VHCO High cutoff voltage VREG + 0.25V V ± 0.03V VMIN Under-voltage threshold at BAT 1.5 V ± 0.05V VRECHG Recharge voltage threshold at BAT 1.92 V ± 0.05V VLCO Low cutoff voltage 0.8 V ± 0.03V 0.250 V 10% IMAX VSNS Current sense at SNS 0.025 V 10% ICOND VREG Parameter 13 Notes TA = 25°C bq2954 Recommended DC Operating Conditions (TA = TOPR) Symbol Parameter VCC Supply voltage VTEMP Minimum Typical Maximum Unit Notes 4.5 5.0 5.5 V TS voltage potential 0 - VCC V VBAT BAT voltage potential 0 - VCC V ICC Supply current - 2 4 mA Outputs unloaded DSEL tri-state open detection -2 - 2 µA Note VTS - VSNS IIZ ITERM tri-state open detection 2 µA VIH Logic input high VCC - 0.3 - - V DSEL, ITERM VIL Logic input low - - VSS + 0.3 V DSEL, CSEL, ITERM LED1, LED2, BTST, output high VCC - 0.8 - - V IOH ≤ 10mA MOD output high VCC - 0.8 - - V IOH ≤ 10mA LED1, LED2, BTST, output low - - VSS +0.8 V IOL ≤ 10mA MOD output low - - VSS + 0.8 V IOL ≤ 10mA CHG output low - - VSS + 0.8 V IOL ≤ 5mA, Note 3 LCOM output low - - VSS + 0.5 V IOL ≤ 30mA LED1, LED2, BTST, source -10 - - mA VOH =VCC - 0.5V MOD source -5.0 - - mA VOH =VCC - 0.5V LED1, LED2, BTST, sink 10 - - mA VOL = VSS + 0.5V MOD sink 5 - - mA VOL = VSS + 0.8V VOH VOL IOH IOL IIL IIH Notes: -2 CHG sink 5 - - mA VOL = VSS + 0.8V, Note 3 LCOM sink 30 - - mA VOL = VSS + 0.5V DSEL logic input low source - - +30 µA V = VSS to VSS + 0.3V, Note 2 ITERM logic input low source - - +70 µA V = VSS to VSS + 0.3V DSEL logic input high source -30 - - µA V = VCC - 0.3V to VCC ITERM logic input high source -70 - - µA V = VCC - 0.3V to VCC 1. All voltages relative to VSS. 2. Conditions during initialization after VCC applied. 3. SNS = 0V. 14 bq2954 Impedance (TA = TOPR; VCC = 5V ± 10%) Symbol Parameter Minimum Typical Maximum Unit Notes RBATZ BAT pin input impedance 50 - - MΩ RSNSZ SNS pin input impedance 50 - - MΩ RTSZ TS pin input impedance 50 - - MΩ RPROG1 Soft-programmed pull-up or pull-down resistor value (for programming) - - 10 kΩ DSEL, CSEL RPROG2 Pull-up or pull-down resistor value - - 3 kΩ ITERM RMTO Charge timer resistor 20 - 480 kΩ Minimum Typical Maximum Unit Timing (TA = TOPR; VCC = 5V ± 10%) Symbol Parameter tMTO Charge time-out range 1 - 24 hours tQT Pre-charge qual test time-out period - 0.25 ∗ tMTO - - tHO Pre-charge qual test hold-off period 300 600 900 ms fPWM PWM regulator frequency range - 100 200 kHz dPWM Duty cycle 0 - 80 % Notes See Figure 10 See Equation 7 Capacitance Symbol Parameter Minimum Typical Maximum Unit CMTO Charge timer capacitor - - 0.1 µF CPWM PWM capacitor - 0.001 - µF 15 bq2954 16-Pin DIP Narrow (PN) 16-Pin PN (0.300" DIP) Inches Millimeters Dimension Min. Max. Min. Max. A 0.160 0.180 4.06 4.57 A1 0.015 0.040 0.38 1.02 B 0.015 0.022 0.38 0.56 B1 0.055 0.065 1.40 1.65 C 0.008 0.013 0.20 0.33 D 0.740 0.770 18.80 19.56 E 0.300 0.325 7.62 8.26 E1 0.230 0.280 5.84 7.11 e 0.300 0.370 7.62 9.40 G 0.090 0.110 2.29 2.79 L 0.115 0.150 2.92 3.81 S 0.020 0.040 0.51 1.02 16-Pin SOIC Narrow (SN) 16-Pin SN (0.150" SOIC) Inches D e B E H A C A1 .004 L 16 Millimeters Dimension Min. Max. Min. Max. A 0.060 0.070 1.52 1.78 A1 0.004 0.010 0.10 0.25 B 0.013 0.020 0.33 0.51 C 0.007 0.010 0.18 0.25 D 0.385 0.400 9.78 10.16 E 0.150 0.160 3.81 4.06 e 0.045 0.055 1.14 1.40 H 0.225 0.245 5.72 6.22 L 0.015 0.035 0.38 0.89 bq2954 Data Sheet Revision History Change No. Page No. 1 All Note: Description of Change “Final” changes from “Preliminary” version Change 1 = Oct. 1998 B changes from Nov. 1997 “Preliminary.” Ordering Information bq2954 Package Option: PN = 16-pin plastic DIP SN = 16-pin narrow SOIC Device: bq2954 Li-Ion Fast-Charge IC 17 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. 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Copyright © 1999, Texas Instruments Incorporated 18 PACKAGE OPTION ADDENDUM www.ti.com 13-Jul-2022 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) Samples (4/5) (6) BQ2954PN ACTIVE PDIP N 16 25 RoHS & Green NIPDAU N / A for Pkg Type 0 to 70 2954PN-A3 Samples BQ2954SN ACTIVE SOIC D 16 40 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 2954 -A3 Samples BQ2954SNTR ACTIVE SOIC D 16 2500 RoHS & Green NIPDAU Level-1-260C-UNLIM 0 to 70 2954 -A3 Samples (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) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of