Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - power management - special purpose 1 mA VQFN 16 Exposed Pad (3.5x3.5)

VCC

STAT

BTST

HIDRV

LODRV

REGN

GND

SRP

SRN

VFB

ISET

VREF

bq24640

QFN-16

TOP VIEW

5 6 7 8

1314

1516

OGA

bq24640

www.ti.com

SLUSA44 –MARCH 2010

High-Efficiency Synchronous Switch-Mode Super Capacitor Charger

Check for Samples: bq24640

FEATURES

DESCRIPTION

• Charge Super Capacitor Pack from 2.1V to 26V

• CC–CV Charge Profile from 0V Without

The bq24640 is highly integrated switch-mode super

capacitor charge controller. It offers a constant-

Precharge

frequency synchronous PWM controller with high

• 600kHz NMOS-NMOS Synchronous Buck

accuracy charge current and voltage regulation, and

Controller

charge status monitoring.

• Over 90% Efficiency for up to 10A Charge

The bq24640 charges super capacitor in two phases:

Current

constant current and constant voltage. The charge

• 5V–28V VCC Input Voltage Range

starts from down to 0V with current set on ISET pin.

• Accuracy

The charge current starts tapering down, when the

voltage on VFB reaches an internal reference,

– ±0.5% Charge Voltage Regulation

The bq24640 enters a low-current sleep mode

– ±3% Charge Current Regulation

(<15mA) when the input voltage falls below the output

• High Integration

capacitor voltage.

– Internal Loop Compensation

The bq24640 has an input CE pin to enable and

– Internal Digital Soft Start

disable charge; and, the STAT and PG output pins

• Safety

report charge and adapter status. The TS pin on the

bq24640 monitors the temperature of the capacitor

– Input Over-Voltage Protection

and suspends charge during HOT/COLD conditions.

– Capacitor Temperature Sensing Hot/Cold

Charge Suspend

PACKAGE

– Thermal Shutdown

• Status Outputs

– Adapter Present

– Charger Operation Status

• Charge Enable Pin

• 30ns Driver Dead Time and 99.5% Max

Effective Duty Cycle

• Automatic Sleep Mode for Low Power

Consumption

– <15µA Off-State Super Capacitor Discharge

Current

– <1.5mA Off-State Input Quiescent Current

• Small 3.5 × 3.5 mm

QFN-16 Package

APPLICATIONS

• Memory Backup System

• Industrial UPS system and Power Transient

Buffering

• Bridge Power to Buffer the Battery

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 (29 pages)

PAGE 1
bq24640 www.ti.com SLUSA44 – MARCH 2010 High-Efficiency Synchronous Switch-Mode Super Capacitor Charger Check for Samples: bq24640 FEATURES 1 • • • • APPLICATIONS • • • LODRV PACKAGE 16 15 14 13 VCC 1 12 REGN 11 GND 10 SRP 9 SRN OGA CE 2 bq24640 QFN-16 STAT 3 TOP VIEW TS 4 5 6 7 8 VFB • The bq24640 has an input CE pin to enable and disable charge; and, the STAT and PG output pins report charge and adapter status.
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bq24640 SLUSA44 – MARCH 2010 www.ti.com TYPICAL APPLICATION D2 MBRS540T3 Adapter R6: 10 W R 11 2W C2 2.2 mF Temp S ensing C8 10 m F C 7: 1 mF R7 100 kW R9 9.31 kW C4 1 mF VREF CE VCC REGN ISET BTST R 5: 100 W HIDRV TS R8 22.1 kW R10 10k (SEMITEC 430 kW 103AT - 2) C1 0.1 m F PH C5:1 mF D1 BAT54 Q4 C6 0. 1 mF SRP R1 4:10 kW L: 6.8 µ H SiS412DN STAT R1 3 :10 kW RSR 10m W SiS412DN Q5 LODRV GND Adapter C9 10 m F C10 0.1 m F C1 1: 0.
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bq24640 www.ti.com SLUSA44 – MARCH 2010 PIN FUNCTIONS (continued) PIN NO. NAME TYPE (1) PIN DESCRIPTION 14 PH P Switching node, charge current output inductor connection. Connect the 0.1-mF bootstrap capacitor from PH to BTST. 15 HIDRV O PWM high side driver output. Connect to the gate of the high side N-channel power MOSFET with a short trace. 16 BTST P PWM high side driver positive supply. Connect the 0.1-mF bootstrap capacitor from PH to BTST. PowerPad Exposed pad beneath the IC.
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bq24640 SLUSA44 – MARCH 2010 www.ti.com ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) VALUE VCC, SRP, SRN, STAT, PG, CE PH Voltage range (2) Maximum difference voltage VFB (3) MAX –0.3 33 –2 33 –0.3 16 REGN, LODRV, TS –0.3 7 BTST, HIDRV with respect to GND –0.3 39 VREF, ISET –0.3 3.6 SRP–SRN –0.5 0.5 Electrostatic Discharge (HBM) QSS 009-105 (JESD22-A114A) Electrostatic Discharge (CDM) QSS 009-147 (JESD22-C101B.
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bq24640 www.ti.com SLUSA44 – MARCH 2010 ELECTRICAL CHARACTERISTICS (continued) 5.0 V ≤ V(VCC) ≤28 V, 0°C < T < +125°C, typical values are at TA = 25°C, with respect to GND (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS CHARGE VOLTAGE REGULATION VFB Feedback regulation voltage 2.1 Charge voltage regulation accuracy IVFB Leakage current into VFB pin V TJ = 0°C to 85°C –0.5% 0.5% TJ = –40°C to 125°C –0.7% 0.7% VFB = 2.
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bq24640 SLUSA44 – MARCH 2010 www.ti.com ELECTRICAL CHARACTERISTICS (continued) 5.0 V ≤ V(VCC) ≤28 V, 0°C < T < +125°C, typical values are at TA = 25°C, with respect to GND (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS THERMISTOR COMPARATOR VLTF Cold temperature rising threshold As percentage to VVREF VLTF_HYS Rising hysteresis As percentage to VVREF 72.5% 73.5% 74.5% 0.2% VHTF Hot temperature rising threshold As percentage to VVREF 36.
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bq24640 www.ti.com SLUSA44 – MARCH 2010 ELECTRICAL CHARACTERISTICS (continued) 5.0 V ≤ V(VCC) ≤28 V, 0°C < T < +125°C, typical values are at TA = 25°C, with respect to GND (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS INTERNAL SOFT START (8 steps to regulation current ICHG) Soft start steps Soft start step time 8 step 1.6 ms LOGIC IO PIN CHARACTERISTICS (CE, STAT, PG) VIN_LO CE input low threshold voltage VIN_HI CE input high threshold voltage 0.
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bq24640 SLUSA44 – MARCH 2010 www.ti.com CE REGN PH IOUT Figure 3. Charge Enable and Disable CE REGN PH IOUT Figure 4.
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bq24640 www.ti.com SLUSA44 – MARCH 2010 PH LODRV CE IOUT Figure 5. Charge Stops on CE LOW PH HIDRV LODRV IL Figure 6.
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bq24640 SLUSA44 – MARCH 2010 www.ti.com PH LODRV IL Figure 7. Discontinuous Conduction Mode VCC STAT VOUT IOUT Figure 8.
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bq24640 www.ti.com SLUSA44 – MARCH 2010 BLOCK DIAGRAM VREF bq24640 VOLTAGE REFERENCE VREF 3.
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bq24640 SLUSA44 – MARCH 2010 www.ti.com DETAILED DESCRIPTIONS Constant Current VOREG (PROG) ICHARGE (PROG) Constant Voltage Taper Current Time Figure 10. Typical Charging Profile OUTPUT VOLTAGE REGULATION The bq24640 uses a high accuracy voltage regulator for the charging voltage. The charge voltage is programmed via a resistor divider from the output to ground, with the midpoint tied to the VFB pin. The voltage at the VFB pin is regulated to 2.
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bq24640 www.ti.com • • SLUSA44 – MARCH 2010 Thermal Shut (TSHUT) is not valid TS fault is not detected One of the following conditions will stop on-going charging: • CE is LOW; • Adapter is removed, causing the device to enter VCCLOWV; • The device is in SLEEP mode (i.e., VCC < SRN); • Adapter is over voltage; • The REGN or VREF LDOs voltage are not valid; • TSHUT IC temperature threshold is reached; • TS voltage goes out of range indicating the temperature is too hot or too cold.
PAGE 14
bq24640 SLUSA44 – MARCH 2010 www.ti.com During non-synchronous operation, the body-diode of lower-side MOSFET can conduct the positive inductor current after the high-side n-channel power MOSFET turns off. When the load current decreases and the inductor current drops to zero, the body diode will be naturally turned off and the inductor current will become discontinuous. This mode is called Discontinuous Conduction Mode (DCM).
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bq24640 www.ti.com SLUSA44 – MARCH 2010 VREF VREF CHARGE SUSPENDED CHARGE SUSPENDED VLTF VLTFH VLTF VLTFH TEMPERATURE RANGE TO INITIATE CHARGE TEMPERATURE RANGE DURING A CHARGE CYCLE VHTF VTCO CHARGE SUSPENDED CHARGE SUSPENDED GND GND Figure 11.
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bq24640 SLUSA44 – MARCH 2010 www.ti.com PG OUTPUT The open drain PG (power good) output indicates when the VCC voltage is present. The open drain FET turns on whenever bq24640 is not in UVLO mode and not in SLEEP mode (i.e., V(VCC) > V(SRN) and V(VCC) > V(UVLO)). The PG pin can be used to drive an LED or communicate to the host processor. CHARGE STATUS OUTPUTS The open-drain STAT output indicates various charger operations as shown in Table 2.
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bq24640 www.ti.com SLUSA44 – MARCH 2010 Table 4. Component List for Typical System Circuit of Figure 1 PART DESIGNATOR Qty DESCRIPTION Q4, Q5 2 N-channel MOSFET, 30 V, 12 A, PowerPAK 1212-8, Vishay-Siliconix, Sis412DN D1 1 Diode, Dual Schottky, 30 V, 200 mA, SOT23, Fairchild, BAT54C D2 1 Schottky Diode, 40V, 5A, SMC, ON Semiconductor, MBRS540T3 D3, D4 2 LED Diode, Green, 2.
PAGE 18
bq24640 SLUSA44 – MARCH 2010 www.ti.com APPLICATION INFORMATION INDUCTOR SELECTION The bq24640 has 600kHz switching frequency to allow the use of small inductor and capacitor values.
PAGE 19
bq24640 www.ti.com FOM top = RDS(on) ´ QGD ; SLUSA44 – MARCH 2010 FOM bottom = RDS(on) ´ QG (11) 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.
PAGE 20
bq24640 SLUSA44 – MARCH 2010 www.ti.com A cost effective and small size solution is shown in Figure 13. The R1 and C1 are composed of a damping RC network to damp the hot plug-in oscillation. As a result the over voltage spike is limited to a safe level. D1 is used for reverse voltage protection for VCC pin. C2 is VCC pin decoupling capacitor and it should be place to VCC pin as close as possible. The R2 and C2 form a damping RC network to further protect the IC from high dv/dt and high voltage spike.
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bq24640 www.ti.com SLUSA44 – MARCH 2010 L1 SW R1 V OUT High Frequency V IN Current C1 Path C2 PGND C3 Super Capacitor Figure 14. High Frequency Current Path Charge Current Direction R SNS To Inductor To Capacitor and Output Current Sensing Direction To SRP and SRN pin Figure 15. Sensing Resistor PCB Layout Refer to the EVM design (SLUU410) for the recommended component placement with trace and via locations. For the QFN information, refer to SCBA017 and SLUA271A.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 26-Jan-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 BQ24640RVAR VQFN RVA 16 3000 330.0 12.4 3.75 3.75 1.15 8.0 12.0 Q1 BQ24640RVAR VQFN RVA 16 3000 330.0 12.4 3.75 3.75 1.15 8.0 12.0 Q1 BQ24640RVAT VQFN RVA 16 250 180.0 12.4 3.75 3.75 1.15 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 26-Jan-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) BQ24640RVAR VQFN RVA 16 3000 367.0 367.0 35.0 BQ24640RVAR VQFN RVA 16 3000 367.0 367.0 35.0 BQ24640RVAT VQFN RVA 16 250 210.0 185.0 35.0 BQ24640RVAT VQFN RVA 16 250 210.0 185.0 35.
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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.