BQ2057WTS



 
 SLUS025F − MAY 2001 − REVISED JULY 2002                FEATURES D Ideal for Single (4.1 V or 4.2 V) and Dual-Cell D D D D D D D D D D D D D DESCRIPTION (8.2 V or 8.4 V) Li-Ion or Li-Pol Packs Requires Small Number of External Components 0.3 V Dropout Voltage for Minimizing Heat Dissipation Better Than ±1% Voltage Regulation Accuracy With Preset Voltages AutoCompt Dynamic Compensation of Battery Pack’s Internal Impedance to Reduce Charge Time Optional Cell-Temperature Monitoring Before and During Charge Integrated Voltage and Current Regulation With Programmable Charge-Current and Highor Low-Side Current Sensing Integrated Cell Conditioning for Reviving Deeply Discharged Cells and Minimizing Heat Dissipation During Initial Stage Of Charge Charge Status Output for Single or Dual Led or Host Processor Interface Automatic Battery-Recharge Feature Charge Termination by Minimum Current Automatic Low-Power Sleep Mode When VCC Is Removed EVMs Available for Quick Evaluation Packaging: 8-Pin SOIC, 8-Pin TSSOP, 8-Pin MSOP The BENCHMARQ bq2057 series advanced Lithium-Ion (Li-Ion) and Lithium-Polymer (Li-Pol) linear charge-management ICs are designed for costsensitive and compact portable electronics. They combine high-accuracy current and voltage regulation, battery conditioning, temperature monitoring, charge termination, charge-status indication, and AutoComp charge-rate compensation in a single 8-pin IC. MSOP, TSSOP, and SOIC package options are offered to fit a wide range of end applications. The bq2057 continuously measures battery temperature using an external thermistor. For safety, the bq2057 inhibits charge until the battery temperature is within user-defined thresholds. The bq2057 then charges the battery in three phases: conditioning, constant current, and constant voltage. If the battery voltage is below the low-voltage threshold, V(min), the bq2057 precharges using a low current to condition the battery. The conditioning charge rate is approximately 10% of the regulation current. The conditioning current also minimizes heat dissipation in the external passelement during the initial stage of the charge. After conditioning, the bq2057 applies a constant current to the battery. An external sense-resistor sets the current. The sense-resistor can be on either the high or low side of the battery without additional components. The constant-current phase continues until the battery reaches the charge-regulation voltage. bq2057xSN or bq2057xTS SOIC (SN) or TSSOP (TS) PACKAGE (TOP VIEW) SNS BAT VCC TS 1 8 2 7 3 6 4 5 COMP CC VSS STAT bq2057xDGK MSOP (DGK) PACKAGE (TOP VIEW) VCC TS STAT VSS 1 8 2 7 3 6 4 5 BAT SNS COMP CC 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. AutoComp is a trademark of Texas Instruments.     !"#$%! & '("")% $& ! *(
+'$%! ,$%)"!,('%& '!!"# %! &*)''$%!& *)" %.) %)"#& ! )/$& &%"(#)%& &%$,$", 0$""$%1- "!,('%! *"!')&&2 ,!)& !% )')&&$"+1 '+(,) %)&%2 ! $++ *$"$#)%)"&- Copyright  2002, Texas Instruments Incorporated www.ti.com 1 


 
 SLUS025F − MAY 2001 − REVISED JULY 2002 DESCRIPTION (continued) The bq2057 then begins the constant-voltage phase. The accuracy of the voltage regulation is better than ±1% over the operating-temperature and supply-voltage ranges. For single and dual cells, the bq2057 is offered in four fixed-voltage versions: 4.1 V, 4.2 V, 8.2 V, and 8.4 V. Charge stops when the current tapers to the charge termination threshold, I(TERM). The bq2057 automatically restarts the charge if the battery voltage falls below the V(RCH) threshold. The designer also may use the AutoComp feature to reduce charging time. This proprietary technique allows safe and dynamic compensation for the internal impedance of the battery pack during charge. AVAILABLE OPTIONS PACKAGE TA −20°C to 70°C CHARGE REGULATION VOLTAGE SOIC (SN) MSOP† (DGK) 4.1 V Not available bq2057TS bq2057DGK 4.2 V bq2057CSN bq2057CTS bq2057CDGK 8.2 V Not available bq2057TTS 8.4 V bq2057WSN bq2057WTS † Note the difference in pinout for this package. 2 TSSOP (TS) www.ti.com Not available 


 
 SLUS025F − MAY 2001 − REVISED JULY 2002 function block diagram VCC Internal Reference VCC _ DONE + Sleep Mode _ BAT V-Control + G(comp) + _ CC I-Control Voltage Regulation COMP Battery Recharge VCC + _ VCC Battery Conditioning Control Block STAT _ + TS TS2 Trip _ + TS1 Trip I-Control 0.5 VCC _ High/Low SNS Set + SNS VCC−V(SNS) + _ Current Regulation VSS−V(SNS) + _ Charge Termination VSS www.ti.com 3 


 
 SLUS025F − MAY 2001 − REVISED JULY 2002 Terminal Functions TERMINAL NO. NAME I/O DESCRIPTION SOIC (SN) and TSSOP (TS) MSOP (DGK) BAT 2 8 I Voltage sense input CC 7 5 O Charge control output COMP 8 6 I Charge-rate compensation input (AutoComp) SNS 1 7 I Current sense input STAT 5 3 O Charge status output TS 4 2 I Temperature sense input VCC 3 1 I Supply voltage VSS 6 4 Ground detailed description current-sense input Battery current is sensed via the voltage developed on this pin by an external sense resistor. The external resistor can be placed on either the high or low side of the battery. (See schematics for details.) battery-voltage input Voltage sense-input tied directly to the positive side of the battery. temperature sense input Input for an external battery-temperature monitoring circuit. Connecting this input to VCC/2 disables this feature. charge-status output 3-state indication of charge in progress, charge complete, and temperature fault or sleep mode. charge-control output Source-follower output that drives an external pass-transistor (PNP or P-channel MOSFET) for current and voltage regulation. charge-rate compensation input Sets the charge-rate compensation level. The voltage-regulation output may be programmed to vary as a function of the charge current delivered to the battery. supply voltage input Power supply input and current reference for high-side sensing configuration. 4 www.ti.com 


 
 SLUS025F − MAY 2001 − REVISED JULY 2002 absolute maximum ratings over operating free-air temperature (unless otherwise noted)† Supply voltage (VCC with respect to GND) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 to +18 V Input voltage, SNS, BAT, TS, COMP (all with respect to GND) . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to VCC+0.3 V Sink current (STAT pin) not to exceed PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA Source current (STAT pin) not to exceed PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mA Output current (CC pin) not to exceed PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 mA Total power dissipation, PD (at 25°C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300mW Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −20°C to 70°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40°C to 125°C Lead temperature (soldering, 10 s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300°C † 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. DISSIPATION RATING TABLE PACKAGE DGK DERATING FACTOR ABOVE TA = 25°C TA ≤ 25°C POWER RATING 3.4 mW/°C 424 mW TA = 70°C POWER RATING 271 mW recommended operating conditions MIN MAX Supply voltage, VCC 4.5 15 UNIT V Operating free-air temperature range, TA −20 70 °C electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) PARAMETER I(VCC) VCC Current I(VCCS) VCC Sleep current IIB(BAT) IIB(SNS) Input bias current on BAT pin IIB(TS) IIB(COMP) Input bias current on TS pin Input bias current on SNS pin Input bias current on COMP pin TEST CONDITIONS MIN VCC > VCC(min), Excluding external loads For bq2057 and bq2957C, V(BAT) ≥ V(min), V(BAT) – VCC ≥ 0.8 V TYP MAX 2 4 3 6 UNIT mA µA A For bq2057T and bq2957W, V(BAT) ≥ V(min), V(BAT) – VCC ≥ 0.8 V 10 V(BAT) = V(REG) V(SNS)= 5 V 1 µA 5 µA V(TS) = 5 V V(COMP) = 5 V 5 µA 5 µA BATTERY VOLTAGE REGULATION VO(REG) Output voltage bq2057, See Notes 1, 2, 3 4.059 4.10 4.141 bq2057C, See Notes 1, 2, 3 4.158 4.20 4.242 bq2057T, See Notes 1, 2, 3 8.119 8.20 8.282 bq2057W, See Notes 1, 2, 3 8.317 8.40 8.484 V NOTES: 1. For high-side current sensing configuration 2. For low-side current sensing configuration, the tolerance is ±1% for TA = 25°C and ±1.2% for −20°C ≥ TA ≥ 70°C 3. V(BAT)+0.3 V ≤ VCC ≤ VCC(max) www.ti.com 5 


 
 SLUS025F − MAY 2001 − REVISED JULY 2002 electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) (continued) PARAMETER TEST CONDITIONS MIN TYP MAX bq2057 and bq2057C, High-side current sensing configuration 95.4 105 115.5 bq2057T and bq2057W, High-side current sensing configuration 113.6 125 137.5 bq2057 and bq2057C, Low-side current sensing configuration 100 110 121 bq2057T and bq2057W, Low-side current sensing configuration 118.1 130 143 −24 −14 −4 29.1 30 30.9 58.3 60 61.8 bq2057 2.94 3 3.06 bq2057C 3.04 3.1 3.16 bq2057T 5.98 6.1 6.22 bq2057W 6.18 6.3 6.43 UNIT CURRENT REGULATION V(SNS) Current regulation threshold mV CHARGE TERMINATION DETECTION I(TERM) Charge termination current detect threshold Voltage at pin SNS, relative to VCC for high-side sensing, and to Vss for low-side sensing, 0°C ≤ TA ≤ 50°C mV TEMPERATURE COMPARATOR V(TS1) V(TS2) Lower temperature threshold Upper temperature threshold TS pin voltage %VCC PRECHARGE COMPARATOR V(min) Precharge threshold V PRECHARGE CURRENT REGULATION I(PRECHG) Precharge current regulation Voltage at pin SNS, relative to VCC for high-side sensing, and to VSS for low-side sensing, 0°C ≤ TA ≤ 50°C Voltage at pin SNS, relative to VCC for high-side sensing, 0°C ≤ TA ≤ 50°C, VCC = 5 V 13 mV 3 13 22 bq2057 and bq2057C VO(REG)− 98 mV VO(REG)− 100 mV VO(REG)− 102 mV bq2057T and bq2057W VO(REG)− 196 mV VO(REG)− 200 mV VO(REG)− 204 mV V(BAT)+0.3 V ≤ VCC ≤ VCC(max), bq2057, bq2057C, bq2057T, bq2057W 1.87 2.2 2.53 V(BAT)+0.3 V ≤ VCC ≤ VCC(max), bq2057T and bq2057W in low-side sensing configuration 2.09 2.4 2.76 mV VRCH COMPARATOR (Battery Recharge Threshold) V(RCH) Recharge threshold V CHARGE-RATE COMPENSATION (AutoComp) G(COMP) AutoComp gain V/V STAT PIN VOL(STAT) Output (low) voltage IOL = 10 mA VOH(STAT) Output (high) voltage IOH = 5 mA 0.7 V VCC-0.5 CC PIN VOL(CC) IO(CC) 6 Output low voltage Sink current IO(CC) = 5 mA (sink) Not to exceed power rating specification (PD) www.ti.com 5 1.5 V 40 mA 


 
 SLUS025F − MAY 2001 − REVISED JULY 2002 APPLICATION INFORMATION RSNS 0.2 Ω Q1 FZT788B PACK+ DC+ C1 0.1 µF VCC R1 1 kΩ PACK− NTC VCC bq2057 CC C2 0.1 µF COMP SNS BAT VCC TS VSS STAT RT1 TEMP D1 GND RT2 Battery Pack R2 2 kΩ Figure 1. Low Dropout Single- or Two-Cell Li-Ion/Li-Pol Charger functional description The bq2057 is an advanced linear charge controller for single or two-cell Li-Ion or Li-Pol applications. Figure 1 shows the schematic of charger using a PNP pass transistor. Figure 2 is an operational state diagram, and Figure 3 is a typical charge profile. Figure 4 shows the schematic of a charger using P-channel MOSFET. www.ti.com 7 


 
 SLUS025F − MAY 2001 − REVISED JULY 2002 APPLICATION INFORMATION POR Sleep Mode VCC > V(BAT) Checked at All Times Indicate SLEEP MODE (STAT = Hi-Z) No Yes Suspend Charge TS Pin in TS1 to TS2 Range Indicate CHARGE SUSPEND (STAT = Hi-Z) No Yes Regulate I(PRECHG) V(BAT)