SLUSA44A March   2010  – July 2015 BQ24640

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Output Voltage Regulation
      2. 7.3.2  Output Current Regulation
      3. 7.3.3  Power Up
      4. 7.3.4  Enable and Disable Charging
      5. 7.3.5  Automatic Internal Soft-Start Charger Current
      6. 7.3.6  Converter Operation
      7. 7.3.7  Synchronous and Nonsynchronous Operation
      8. 7.3.8  Input Overvoltage Protection (ACOV)
      9. 7.3.9  Output Overvoltage Protection
      10. 7.3.10 Cycle-by-Cycle Charge Overcurrent Protection
      11. 7.3.11 Thermal Shutdown Protection
      12. 7.3.12 Temperature Qualification
      13. 7.3.13 CE (Charge Enable)
      14. 7.3.14 PG Output
      15. 7.3.15 Charge Status Outputs
    4. 7.4 Device Functional Modes
      1. 7.4.1 Constant Current Mode
      2. 7.4.2 Constant Voltage Mode
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Inductor Selection
        2. 8.2.2.2 Input Capacitor
        3. 8.2.2.3 Output Capacitor
        4. 8.2.2.4 Power MOSFETs Selection
        5. 8.2.2.5 Input Filter Design
        6. 8.2.2.6 Inductor, Capacitor, and Sense Resistor Selection Guidelines
      3. 8.2.3 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
Voltage (2) VCC, SRP, SRN, STAT, PG, CE –0.3 33 V
PH –2 33
VFB(3) –0.3 16
REGN, LODRV, TS –0.3 7
BTST, HIDRV with respect to GND –0.3 39
VREF, ISET –0.3 3.6
Maximum difference voltage SRP–SRN –0.5 0.5 V
Temperature Junction, TJ –40 155 °C
Storage, Tstg –55 155
(1) 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
(2) All voltages are with respect to GND if not specified. Currents are positive into, negative out of the specified terminal. Consult the Package Option Addendum at the end of the data sheet for thermal limitations and considerations.
(3) Must have a series resistor between output to VFB if output voltage is expected to be greater than 16 V. Usually the resistor-divider top resistor will take care of this.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
Charged device model (CDM), per JEDEC specification JESD22-C101(2) ±500
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
Voltage
(with respect to GND)
VCC, SRP, SRN, STAT, PG, CE –0.3 28 V
PH –2 30
VFB –0.3 14
REGN, LODRV, TS –0.3 6.5
BTST, HIDRV with respect to GND –0.3 34
ISET –0.3 3.3
VREF 3.3
Maximum difference voltage SRP–SRN –0.2 0.2 V
Junction temperature, TJ 0 125 °C

6.4 Thermal Information

THERMAL METRIC(1) bq24640 UNIT
RVA (VQFN)
16 PINS
RθJA Junction-to-ambient thermal resistance 43.8 °C/W
RθJC(top) Junction-to-case(top) thermal resistance 81 °C/W
RθJB Junction-to-board thermal resistance 16 °C/W
ψJT Junction-to-top characterization parameter 0.6 °C/W
ψJB Junction-to-board characterization parameter 15.77 °C/W
RθJC(bot) Junction-to-case(bottom) thermal resistance 4 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

6.5 Electrical Characteristics

5 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 UNIT
OPERATING CONDITIONS
VVCC_OP VCC input voltage operating range 5 28 V
QUIESCENT CURRENTS
IOUT Total output discharge current (sum of currents into VCC, BTST, PH, SRP, SRN, VFB), VFB ≤ 2.1V VUVLO < VVCC < VSRN (sleep mode) 15 µA
IAC Adapter supply current into VCC pin VVCC > VSRN, VVCC > VUVLO,
CE = LOW
1 1.5 mA
VVCC > VSRN, VVCC > VVCCLOWV,
CE = HIGH, charge done
2 5
VVCC > VSRN, VVCC > VVCCLOWV,
CE = HIGH, Charging, Qg_total = 20 nC, VVCC = 20 V
25
CHARGE VOLTAGE REGULATION
VFB Feedback regulation voltage 2.1 V
Charge voltage regulation accuracy TJ = 0°C to 85°C –0.5% 0.5%
TJ = –40°C to 125°C –0.7% 0.7%
IVFB Leakage current into VFB pin VFB = 2.1 V 100 nA
CURRENT REGULATION
VISET1 ISET voltage range 2 V
VIREG_CHG SRP-SRN current sense voltage range VIREG_CHG = VSRP – VSRN 100 mV
KISET1 Charge current set factor (amps of charge current per volt on ISET pin) RSENSE = 10 mΩ 5 A/V
Charge current regulation accuracy VIREG_CHG = 40 mV –3% 3%
VIREG_CHG = 20 mV –5% 5%
VIREG_CHG = 5 mV –25% 25%
VIREG_CHG = 1.5 mV –50% 50%
IISET Leakage current into ISET pin VISET1 = 2 V 100 nA
INPUT UNDERVOLTAGE LOCKOUT COMPARATOR (UVLO)
VUVLO AC undervoltage rising threshold Measure on VCC 3.65 3.85 4 V
VUVLO_HYS AC undervoltage hysteresis, falling 350 mV
VCC LOWV COMPARATOR
VLOWV_FALL Falling threshold, disable charge Measure on VCC 4.1 V
VLOWV_RISE Rising threshold, resume charge 4.35 4.5 V
SLEEP COMPARATOR (REVERSE DISCHARGING PROTECTION)
VSLEEP _FALL Sleep falling threshold VVCC – VSRN to enter sleep mdoe 40 100 150 mV
VSLEEP_HYS Sleep hysteresis 500 mV
Sleep rising delay VCC falling below SRN, Delay to pull up PG 1 µs
Sleep falling delay VCC rising above SRN, Delay to pull down PG 30 ms
Sleep rising shutdown deglitch VCC falling below SRN, Delay to enter sleep mode 100 ms
Sleep falling powerup deglitch VCC rising above SRN, Delay to exit sleep mode 30 ms
OUT OVERVOLTAGE COMPARATOR
VOV_RISE Overvoltage rising threshold As percentage of VVFB 104%
VOV_FALL Overvoltage falling threshold As percentage of VVFB 102%
INPUT OVERVOLTAGE COMPARATOR (ACOV)
VACOV AC overvoltage rising threshold Measured on VCC 31 32 33 V
VACOV_HYS AC overvoltage falling hysteresis 1 V
AC overvoltage rising deglitch Delay to disable charge 1 ms
AC overvoltage falling deglitch Delay to resume charge 1 ms
THERMAL SHUTDOWN COMPARATOR
TSHUT Thermal shutdown rising temperature Temperature Increasing 145 °C
TSHUT_HYS Thermal shutdown hysteresis 15 °C
Thermal shutdown rising deglitch Temperature Increasing 100 µs
Thermal shutdown falling deglitch Temperature Decreasing 10 ms
THERMISTOR COMPARATOR
VLTF Cold temperature rising threshold As percentage to VVREF 72.5% 73.5% 74.5%
VLTF_HYS Rising hysteresis As percentage to VVREF 0.2% 0.4% 0.6%
VHTF Hot temperature rising threshold As percentage to VVREF 36.4% 37% 37.6%
VTCO Cutoff temperature rising threshold As percentage to VVREF 33.7% 34.4% 35.1%
Deglitch time for temperature out-of-range detection VTS < VLTF, or VTS < VTCO, or VTS < VHTF 400 ms
Deglitch time for temperature in-valid-range detection VTS > VLTF – VLTF_HYS or VTS >VTCO, or VTS > VHTF 20 ms
CHARGE OVERCURRENT COMPARATOR (CYCLE-BY-CYCLE)
VOC Charge overcurrent rising threshold Current rising, in nonsynchronous mode, measure on V(SRP-SRN), VSRP < 2 V 45.5 mV
Current rising, as percentage of V(IREG_CHG), in synchronous mode, VSRP > 2.2 V 160%
Charge overcurrent threshold floor Minimum OCP threshold in synchronous mode, measure on V(SRP-SRN), VSRP > 2.2 V 50 mV
Charge overcurrent threshold ceiling Maximum OCP threshold in synchronous mode, measure on V(SRP-SRN), VSRP > 2.2 V 180 mV
CHARGE UNDERCURRENT COMPARATOR (CYCLE-BY-CYCLE)
VISYNSET Charge undercurrent falling threshold Switch from CCM to DCM, VSRP > 2.2 V 1 5 9 mV
LOW CHARGE CURRENT COMPARATOR
VLC Low charge current (average) falling threshold to force into nonsynchronous mode Measure V(SRP-SRN) 1.25 mV
VLC_HYS Low charge current rising hysteresis 1.25 mV
VLC_DEG Deglitch on both edges 1 µs
VREF REGULATOR
VVREF_REG VREF regulator voltage VVCC > VUVLO (0–35 mA load) 3.267 3.3 3.333 V
IVREF_LIM VREF current limit VVREF = 0 V, VVCC > VUVLO 35 mA
REGN REGULATOR
VREGN_REG REGN regulator voltage VVCC > 10 V, CE = HIGH (0–40 mA load) 5.7 6 6.3 V
IREGN_LIM REGN current limit VREGN = 0 V, VVCC > VUVLO, CE = HIGH 40 mA
PWM HIGH-SIDE DRIVER (HIDRV)
RDS_HI_ON High-side driver (HSD) turnon resistance VBTST – VPH = 5.5 V 3.3 6 Ω
RDS_HI_OFF High-side driver turnoff resistance VBTST – VPH = 5.5 V 1 1.3 Ω
VBTST_REFRESH Bootstrap refresh comparator threshold voltage VBTST – VPH when low side refresh pulse is requested 4 4.2 V
PWM LOW-SIDE DRIVER (LODRV)
RDS_LO_ON Low-side driver (LSD) turnon resistance 4.1 7 Ω
RDS_LO_OFF Low-side driver turnoff resistance 1 1.4 Ω
PWM DRIVERS TIMING
Driver Dead-Time Dead time when switching between LSD and HSD, no load at LSD and HSD 30 ns
PWM OSCILLATOR
VRAMP_HEIGHT PWM ramp height As percentage of VCC 7%
PWM switching frequency 510 600 690 kHz
INTERNAL SOFT START (8 STEPS TO REGULATION CURRENT ICHG)
Soft start steps 8 step
Soft start step time 1.6 ms
LOGIC IO PIN CHARACTERISTICS (CE, STAT, PG)
VIN_LO CE input low threshold voltage 0.8 V
VIN_HI CE input high threshold voltage 2.1 V
VBIAS_CE CE input bias current VCE = 3.3 nV (CE has internal 1-MΩ pulldown resistor) 6 μA
VOUT_LO STAT, PG output low saturation voltage Sink current = 5 mA 0.5 V
IOUT_HI Leakage current V = 32 V 1.2 μA

6.6 Typical Characteristics

Table 1. Table of Graphs

FIGURES
Power Up (VREF, REGN, PG) Figure 1
Charge Enable and Disable Figure 2
Current Soft Start (CE = HIGH) Figure 3
Continuous Conduction Mode Switching Waveform Figure 5
Discontinuous Conduction Mode Switching Waveform Figure 6
Charge Profile Figure 7
bq24640 pwr_up-lusa44.gif
Figure 1. Power Up
bq24640 soft_st_lusa44.gif
Figure 3. Current Soft Start (CE = HIGH)
bq24640 cc_mode_lusa44.gif
Figure 5. Continuous Conduction Mode
bq24640 chg_profile_lusa44.gif
Figure 7. Charge Profile

bq24640 chg_ena_dis_lusa44.gif
Figure 2. Charge Enable and Disable
bq24640 chg_celow_lusa44.gif
Figure 4. Charge Stops on CE LOW
bq24640 dis_cond_mode_lusa44.gif
Figure 6. Discontinuous Conduction Mode