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ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - battery management Charge management Li-Ion, NiCd, NiMH TSSOP 8 Surface-mount

SNS

LED

BAT

MOD

bq2000T

www.ti.com

SLUS149D –MAY 1999–REVISED JANUARY 2010

Programmable Multi-Chemistry Fast-Charge Management IC

Check for Samples: bq2000T

FEATURES

GENERAL DESCRIPTION

• Safe Management of Fast Charge for NiCd,

NiMH, or Li-Ion Battery Packs

The bq2000T is a programmable, monolithic IC for

fast-charge management of nickel cadmium (NiCd),

• High-Frequency Switching Controller for

nickel metal-hydride (NiMH), or lithium-ion (Li-Ion)

Efficient and Simple Charger Design

batteries in single- or multi-chemistry applications.

• Pre-Charge Qualification for Detecting

The bq2000T chooses the proper battery chemistry

Shorted, Damaged, or Overheated Cells

(either nickel or lithium) and proceeds with the

• Fast-Charge Termination by ΔT/Δt for Nickel

optimal charging and termination algorithms. This

Chemistries, Minimum Current for Li-Ion

process eliminates undesirable, undercharged, or

overcharged conditions, and allows accurate and safe

Chemistries, Maximum Temperature, and

termination of fast charge.

Maximum Charge Time

• Selectable Top-Off Mode for Achieving

Depending on the chemistry, the bq2000T provides a

Maximum Capacity in NiMH Batteries number of charge termination criteria:

• Rate of temperature rise (ΔT/Δt) (for NiCd and

• Programmable Trickle-Charge Mode for

NiMH)

Reviving Deeply Discharged Batteries and for

• Minimum charge current (for Li-Ion)

Postcharge Maintenance

• Maximum temperature

• Built-in Battery Removal and Insertion

• Maximum charge time

Detection

• Sleep Mode for Low Power Consumption

For safety, the bq2000T inhibits fast charge until the

battery voltage and temperature are within

APPLICATIONS

user-defined limits. If the battery voltage is below the

low-voltage threshold, the bq2000T uses

• Multi-Chemistry Charger

trickle-charge to condition the battery. For NiMH

• Nickel Charger

batteries, the bq2000T provides an optional top-off

• High-Power, Multi-Cell Charger

charge to maximize the battery capacity.

The integrated high-speed comparator allows the

bq2000T to be the basis for a complete,

high-efficiency battery charger circuit for both

nickel-based and lithium-based chemistries.

spacer between para and illustration

8-Pin DIP or Narrow SOIC or TSSOP Pin Names

SNS Current-sense input

System ground

LED Charge-status output

BAT Battery-voltage input

TS Temperature-sense input

RC Timer-program input

Supply-voltage input

MOD Modulation-control output

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.

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.

Summary of content (27 pages)

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bq2000T www.ti.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com 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.
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bq2000T www.ti.com SLUS149D – MAY 1999 – REVISED JANUARY 2010 FUNCTIONAL DESCRIPTION The bq2000T is a versatile, multi-chemistry battery charge control device. See Figure 1 for a functional block diagram and Figure 2 for a state diagram. TS Voltage Reference BAT OSC Voltage Comparators 3x ADC DT/Dt ALU Clock Phase Generator Timer Charge Control LED Voltage Comparators MOD RC Internal OSC SNS VCC VSS Figure 1.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com VCC Reset or Battery Replacement at any time 4.0 V < VCC < 6.0 V Charge Initialization VBAT < VSLP VMCV < VBAT < VSLP Battery Voltage (Voltage at BAT pin checked continuously.) Sleep Mode Charge Qualification State VSLP < VBAT < VCC VBAT < VMCV VTS > VHTF Charge Suspended Battery Temperature (Temperature at TS pin checked continuously. Sampled every 8 seconds for DT/Dt.
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bq2000T www.ti.com SLUS149D – MAY 1999 – REVISED JANUARY 2010 ABSOLUTE MAXIMUM RATINGS (1) VALUE UNIT –0.3 to 7 V –0.3 to VCC V Operating ambient temperature –20 to 70 °C Storage temperature –40 to 125 °C 260 °C VCC VCC relative to VSS VT DC voltage applied on any pin, relative to VSS TOPR TSTG TSOLDER Soldering temperature (10 s max) (1) Permanent device damage may occur if Absolute Maximum Ratings are exceeded.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com Initiation and Charge Qualification The bq2000T initiates a charge cycle when it detects • Application of power to VCC • Battery replacement • Exit from sleep mode • Capacity depletion (Li-Ion only) Immediately following initiation, the IC enters a charge-qualification mode. The bq2000T charge qualification is based on battery voltage and temperature.
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bq2000T www.ti.com SLUS149D – MAY 1999 – REVISED JANUARY 2010 Lithium-Ion Batteries The bq2000T uses a two-phase fast-charge algorithm for Li-Ion batteries (Figure 4). In phase one, the bq2000T regulates constant current until VBAT rises to VMCV. Once VBAT = VMCV, the device identifies the cell as a Li-ion, and changes the termination method from ΔT/Δt to minimum current.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com FAST CHARGE TERMINATION Initial Hold-Off Period The bq2000T incorporates a user programmable hold-off period to avoid premature fast charge termination that can occur with brand new nickel cells at the very beginning of fast charge. The values of the external resistor and capacitor connected to the RC pin set the initial hold-off period.
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bq2000T www.ti.com SLUS149D – MAY 1999 – REVISED JANUARY 2010 Maximum Temperature (NiCd, NiMH, Li-Ion) A negative-coefficient thermistor, referenced to VSS and placed in thermal contact with the battery, may be used as a temperature-sensing device. Figure 6 shows a typical temperature-sensing circuit. VCC 2 VCC 7 VSS RT1 bq2000T TS 5 RT2 N Battery T Pack C Figure 6.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com Once top-off is started, the timer is reset and top-off proceeds until the timer expires, VMCV is reached, or there is a temperature fault. During top-off, current is delivered to the battery in pulses that occur each second. The fixed pulse width allows an average current of 1/16 of the fast charge current to be delivered to the battery every second. The LED is always off during top-off and trickle maintenance charge.
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bq2000T www.ti.com SLUS149D – MAY 1999 – REVISED JANUARY 2010 Table 2.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com Being a hysteretic controller, the switching frequency of the bq2000T is determined by the values of several of the external circuit components. The components that affect the switching frequency are: input voltage, RSNS value, inductor value, hysteresis capacitor value (CHYS), and the value of the filter on the current sense signal (Rf and Cf values).
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bq2000T www.ti.com SLUS149D – MAY 1999 – REVISED JANUARY 2010 BATTERY VOLTAGE INPUT As shown in Figure 3, a resistor voltage-divider between the battery pack's positive terminal and VSS scales the battery voltage measured at the BAT pin. For Li-Ion battery packs, the resistor values RB1 and RB2 are calculated by the following equation: RB1 RB2 æ V = ç N ´ CELL VMCV è ö ÷ -1 ø (5) where N is the number of cells in series and VCELL is the manufacturer-specified charging voltage.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com TEMPERATURE MONITORING The bq2000T measures the temperature by the voltage at the TS pin. This voltage is typically generated by a negative-temperature-coefficient thermistor. The bq2000T compares this voltage against its internal threshold voltages to determine if charging is safe. These thresholds are the following: • High-temperature cutoff voltage: VTCO = 0.225 × VCC .
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bq2000T www.ti.com SLUS149D – MAY 1999 – REVISED JANUARY 2010 Table 5. Summary of Li-Ion Charging Characteristics VALUE (1) PARAMETER Maximum cell voltage (VMCV) 2V Minimum pre-charge qualification voltage (VLBAT) 950 mV High-temperature cutoff voltage (VTCO) 0.225 × VCC High-temperature fault voltage (VHTF) 0.25 × VCC Low-temperature fault voltage (VLTF) 0.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com TYPICAL CHARACTERISTICS CH1 = RC pin, 2V/div CH1 = RC pin, 2V/div 1 CH2 = MOD pin, 5V/div CH2 = MOD pin, 5V/div Voltage - V Voltage - V 2 CH3 = VO, 5V/div 2 CH3 = VI, 5V/div 3 CH4 = LED pin, 5V/div 1 CH4 = LED pin, 5V/div 4 3 4 Time - 0.2s/div Time - 0.2s/div Figure 12. bq2000T Start-up on Battery Insertion Figure 13.
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bq2000T www.ti.com SLUS149D – MAY 1999 – REVISED JANUARY 2010 TYPICAL CHARACTERISTICS (continued) CH1 = VO, 5V/div 1 CH2 = RC pin, 1V/div CH1 = SNS pin, 20mV/div CH3 = MOD pin, 5V/div 2 Voltage - V Voltage - V 1 CH2 = MOD pin, 5V/div 3 2 4 CH4 = LED pin, 1V/div Time - 2ms/div Time - 10ms/div Figure 16. bq2000T in Fast Charge Figure 17.
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bq2000T SLUS149D – MAY 1999 – REVISED JANUARY 2010 www.ti.com REVISION HISTORY Changes from Original (January 1999) to Revision 1 Page • Changed the device status From: Preliminary To: Final ....................................................................................................... 1 • Added state diagram .............................................................................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com (3) 11-Apr-2013 MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Top-Side Marking for that device.
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PACKAGE MATERIALS INFORMATION www.ti.com 11-Jun-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant BQ2000TPWR TSSOP PW 8 2000 330.0 12.4 7.0 3.6 1.6 8.0 12.0 Q1 BQ2000TSN-B5TR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 11-Jun-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) BQ2000TPWR TSSOP PW 8 2000 367.0 367.0 35.0 BQ2000TSN-B5TR SOIC D 8 2500 367.0 367.0 35.
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