Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - battery management Charge management Li-Ion VQFN 20 (3.5x3.5) Surface-mount

6 7 8 9 10

20 19 18 17 16

ACN

ACP

CMPOUT

CMPIN

ACOK

ACDET

IOUT

SDA

SCL

ILIM

IFAULT

SRN

SRP

GND

LODRV

REGN

BTST

HIDRV

PHASE

VCC

bq24707

bq24707A

bq24707

bq24707A

www.ti.com

SLUSA78B –JULY 2010– REVISED MARCH 2011

1-4 Cell Li+ Battery SMBus Charge Controller With Independent Comparator and

Advanced Circuit Protection

Check for Samples: bq24707, bq24707A

FEATURES

DESCRIPTION

• SMBus Host-Controlled NMOS-NMOS

The bq24707 and bq24707A are high-efficiency,

Synchronous Buck Converter with

synchronous battery charger, offering low component

Programmable 615kHz, 750kHz, and 885kHz

count for space-constraint, multi-chemistry battery

charging applications.

Switching Frequency

• Real Time System Control on ILIM Pin to Limit

SMBus controlled input current, charge current, and

Charge Current

charge voltage DACs allow for very high regulation

accuracies that can be easily programmed by the

• Enhanced Safety Features for Over Voltage

system power management micro-controller.

Protection, Over Current Protection, Battery,

Inductor, and MOSFET Short Circuit Protection

The IC uses the internal input current register or

external ILIM pin to throttle down PWM modulation to

• Programmable Input Current, Charge Voltage,

reduce the charge current.

Charge Current Limits

– ±0.5% Charge Voltage Accuracy up to 19.2V The IC provides an IFAULT output to alarm if any

MOSFET fault or input over current occurs. This

– ±3% Charge Current Accuracy up to 8.128A

alarm output allows users to turn off input power

– ±3% Input Current Accuracy up to 8.064A

selectors when the fault occurs. Meanwhile, an

– ±2% 20x Adapter Current or Charge Current

independent comparator with internal reference is

available to monitor input current, output current, or

Output Accuracy

output voltage.

• Programmable Adapter Detection and

Indicator

The IC charges one, two, three, or four series Li+

cells, and is available in a 20-pin, 3.5×3.5 mm

QFN

• Independent Comparator with Internal

package.

Reference

• Integrated Soft Start

• Integrated Loop Compensation

• AC Adapter Operating Range 5V-24V

• 15µA Off-State Battery Discharge Current

• 20-pin 3.5 x 3.5 mm

QFN Package

• bq24707: ACOK delay default 1.3s

• bq24707A: ACOK delay default 1.2ms

APPLICATIONS

• Portable Notebook Computers, UMPC,

Ultra-Thin Notebook, and Netbook

• Personal Digital Assistant

• Handheld Terminal

• Industrial and Medical Equipment

• Portable Equipment

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 (37 pages)

PAGE 1
bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com 1-4 Cell Li+ Battery SMBus Charge Controller With Independent Comparator and Advanced Circuit Protection Check for Samples: bq24707, bq24707A FEATURES DESCRIPTION • The bq24707 and bq24707A are high-efficiency, synchronous battery charger, offering low component count for space-constraint, multi-chemistry battery charging applications.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 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. TYPICAL APPLICATION Q1 (RBFET) Si4435DDY Adapter + Ri 2? Ci 2.2µF Adapter - Q2 (ACFET) Si4435DDY RAC 10m? SYSTEM C1 0.1µF Controlled By Host C3 0.1µF D2 RB751V40 +1.
PAGE 3
bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) (2) VALUE –0.3 to 30 SRN, SRP, ACN, ACP, VCC Voltage range Maximum difference voltage UNIT PHASE –2 to 30 ACDET, SDA, SCL, LODRV, REGN, IOUT, ILIM, ACOK, IFAULT, CMPIN, CMPOUT –0.3 to 7 V BTST, HIDRV –0.3 to 36 SRP–SRN, ACP–ACN –0.5 to 0.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com ELECTRICAL CHARACTERISTICS 4.5 V ≤ V(VCC) ≤ 24 V, 0°C ≤ TJ ≤ 125°C, typical values are at TA = 25°C, with respect to GND (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT OPERATING CONDITIONS VVCC_OP VCC Input voltage operating range 4.5 24 V 19.2 V 16.884 V CHARGE VOLTAGE REGULATION VBAT_REG_RNG BAT voltage regulation range 1.024 16.716 ChargeVoltage() = 0x41A0H –0.5% 12.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com ELECTRICAL CHARACTERISTICS (continued) 4.5 V ≤ V(VCC) ≤ 24 V, 0°C ≤ TJ ≤ 125°C, typical values are at TA = 25°C, with respect to GND (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX 3.5 3.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com ELECTRICAL CHARACTERISTICS (continued) 4.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com ELECTRICAL CHARACTERISTICS (continued) 4.5 V ≤ V(VCC) ≤ 24 V, 0°C ≤ TJ ≤ 125°C, typical values are at TA = 25°C, with respect to GND (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT SMBus TIMING CHARACTERISTICS 1 μs tR SCLK/SDATA rise time tF SCLK/SDATA fall time tW(H) SCLK pulse width high tW(L) SCLK pulse width low 4.7 μs tSU(STA) Setup time for START condition 4.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com TYPICAL CHARACTERISTICS Table 1. Table of Graphs FIGURE NO.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com CH1: HIDRV, 10V/div, CH2: LODRV, 5V/div, CH3: PHASE, 10V/div, CH4: inductor current, 2A/div, 400ns/div Figure 7. Continuous Conduction Mode Switching Waveforms CH1: HIDRV, 10V/div, CH2: LODRV, 5V/div, CH3: PHASE, 10V/div, CH4: inductor current, 1A/div, 400ns/div Figure 8. Cycle-by-Cycle Synchronous to Non-synchronous CH1: PHASE, 10V/div, CH2: LODRV, 5V/div, CH4: inductor current, 2A/div, 4us/div Figure 9.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com 98 4-cell 16.8 V 97 96 Efficiency - % 95 3-cell 12.6 V 94 93 2-cell 8.4 V 92 91 VI = 20 V, f = 750 kHz, L = 4.7 mH 90 89 88 CH1: PHASE, 20V/div, CH2: LODRV, 10V/div, CH3: battery voltage, 5V/div, CH4: inductor current, 2A/div, 4us/div Figure 13. Battery to Ground Short Transition 0 0.5 1 1.5 2 2.5 Charge Current 3 3.5 4 4.5 Figure 14. Efficiency vs Output Current PIN FUNCTIONS – 20-PIN QFN PIN NO.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com PIN FUNCTIONS – 20-PIN QFN (continued) PIN NO. DESCRIPTION NAME 13 SRP Charge current sense resistor positive input. Connect SRP pin to a 10 Ω resistor first then from resistor another terminal connect to current sensing resistor. Connect a 0.1µF ceramic capacitor between current sensing resistor to provide differential mode filtering.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com FUNCTIONAL BLOCK DIAGRAM 3.75V bq24707 and bq24707A Block Diagram UVLO ** Threshold or deglitch time is adjustable by ChargeOption() VCC 20 EN_REGN WAKEUP ACDET 6 0.6V ACGOOD WATCHDOG TIMER 175s ** VCC_SRN 2.4V ACOK 5 ACOK_DRV EN_CHRG WATCHDOG TIMEOUT 1.3s rising deglitch** (bq24707) 1.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com DETAILED DESCRIPTION SMBus Interface The IC operates as a slave, receiving control inputs from the embedded controller host through the SMBus interface. The IC uses a simplified subset of the commands documented in System Management Bus Specification V1.1, which can be downloaded from www.smbus.org. The IC uses the SMBus Read-Word and Write-Word protocols (see Figure 16) to communicate with the smart battery.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com Figure 17.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com Setting Charger Options By writing ChargeOption() command (0x12H or 0b00010010), the IC allows users to change several charger options after POR (Power On Reset) as shown in Table 3. Table 3. Charge Options Register (0x12H) BIT [15] BIT NAME DESCRIPTION ACOK Deglitch Time Adjust ACOK deglitch time. Adjust 0: ACOK deglitch time 1.3s for bq24707, 1.2ms for bq24707A 1: ACOK deglitch time set to minimum (<50µs).
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com can also be used. With a larger sense resistor comes a larger sense voltage, and higher regulation accuracy; but, at the expense of higher conduction loss. If the current sensing resistor value is too high, it may trig over current protection threshold due to the current ripple voltage being too high.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com Table 5. Charge Voltage Register (0x15H) (continued) BIT BIT NAME 4 Charge Voltage, DACV 0 0 = Adds 0mV of charger voltage. 1 = Adds 16mV of charger voltage. DESCRIPTION 5 Charge Voltage, DACV 1 0 = Adds 0mV of charger voltage. 1 = Adds 32mV of charger voltage. 6 Charge Voltage, DACV 2 0 = Adds 0mV of charger voltage. 1 = Adds 64mV of charger voltage. 7 Charge Voltage, DACV 3 0 = Adds 0mV of charger voltage.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com If input current rises above 108% of the input current limit set point, the charger shuts down immediately to let the input current fall fast. After stopping charge, the charger soft restarts to charge the battery if the adapter still has power left to charge the battery. This prevents overloading the adapter to crash when system has a high and fast loading transient.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com Ceramic capacitors show a dc-bias effect. This effect reduces the effective capacitance when a dc-bias voltage is applied across a ceramic capacitor, as on the output capacitor of a charger. The effect may lead to a significant capacitance drop, especially for high output voltages and small capacitor packages. See the manufacturer's data sheet about the performance with a dc bias voltage applied.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com The ACOC function can be disabled or the threshold can be set to 1.33X, 1.66X or 2.22X of input DPM current via SMBus command (ChargeOption() bit [2:1]). Charge Over Current Protection (CHGOCP) The IC has a cycle-by-cycle peak over-current protection. It monitors the voltage across SRP and SRN, and prevents the current from exceeding of the threshold based on the DAC charge current set point.
PAGE 22
bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com Inductor Short, MOSFET Short Protection The IC has a unique short circuit protection feature. Its cycle-by-cycle current monitoring feature is achieved through monitoring the voltage drop across RDS(on) of the MOSFETs after a certain amount of blanking time. In case of MOSFET short or inductor short circuit, the over current condition is sensed by two comparators and two counters will be triggered.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com Table 8. Component List for Typical System Circuit of Figure 1 PART DESIGNATOR QTY DESCRIPTION C1, C2, C3, C13, C14 5 Capacitor, Ceramic, 0.1µF, 25V, 10%, X7R, 0603 C4 1 Capacitor, Ceramic, 100pF, 25V, 10%, X7R, 0603 C5, C6 2 Capacitor, Ceramic, 1µF, 25V, 10%, X7R, 0603 C7 1 Capacitor, Ceramic, 0.047µF, 25V, 10%, X7R, 0603 C8, C9, C10, C11 4 Capacitor, Ceramic, 10µF, 25V, 10%, X7R, 1206 Ci 1 Capacitor, Ceramic, 2.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com The maximum inductor ripple current happens with D = 0.5 or close to 0.5. For example, the battery charging voltage range is from 9V to 12.6V for 3-cell battery pack. For 20V adapter voltage, 10V battery voltage gives the maximum inductor ripple current. Another example is 4-cell battery, the battery voltage range is from 12V to 16.8V, and 12V battery voltage gives the maximum inductor ripple current.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com The lower the FOM value, the lower the total power loss. Usually lower RDS(ON) has higher cost with the same package size. The top-side MOSFET loss includes conduction loss and switching loss.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com D1 Adapter connector R2(1206) 10-20 Ω R1(2010) 2Ω VCC pin C1 2.2μF C2 0.47-1μF Figure 20. Input Filter IC Design Guideline The IC has a unique short circuit protection feature. Its cycle-by-cycle current monitoring feature is achieved through monitoring the voltage drop across Rdson of the MOSFETs after a certain amount of blanking time.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com To prevent unintentional charger shut down in normal operation, MOSFET RDS(on) selection and PCB layout is very important. Figure 22 shows a need improve PCB layout example and its equivalent circuit. In this layout, system current path and charger input current path is not separated, as a result, the system current causes voltage drop in the PCB copper and is sensed by IC.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com PCB Layout The switching node rise and fall times should be minimized for minimum switching loss. Proper layout of the components to minimize high frequency current path loop (see Figure 24) is important to prevent electrical and magnetic field radiation and high frequency resonant problems. Here is a PCB layout priority list for proper layout. Layout PCB according to this specific order is essential. 1.
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bq24707 bq24707A SLUSA78B – JULY 2010 – REVISED MARCH 2011 www.ti.com Charge Current Direction R SNS To Inductor To Capacitor and battery Current Sensing Direction To SRP and SRN pin Figure 25. Sensing Resistor PCB Layout REVISION HISTORY Changes from Original (July 2010) to Revision A Page • Changed the Functional Block Diagram, Figure 1 ................................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 25-Feb-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 BQ24707ARGRR VQFN RGR 20 3000 330.0 12.4 3.75 3.75 1.15 8.0 12.0 Q1 BQ24707ARGRR VQFN RGR 20 3000 330.0 12.4 3.75 3.75 1.15 8.0 12.0 Q1 BQ24707ARGRT VQFN RGR 20 250 180.0 12.4 3.75 3.75 1.15 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 25-Feb-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) BQ24707ARGRR VQFN RGR 20 3000 552.0 367.0 36.0 BQ24707ARGRR VQFN RGR 20 3000 367.0 367.0 35.0 BQ24707ARGRT VQFN RGR 20 250 210.0 185.0 35.0 BQ24707ARGRT VQFN RGR 20 250 552.0 185.0 36.0 BQ24707RGRR VQFN RGR 20 3000 367.0 367.0 35.0 BQ24707RGRR VQFN RGR 20 3000 552.0 367.0 36.
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.