L6924D STMicroelectronics, L6924D Datasheet
L6924D
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L6924D Summary of contents
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... Digital cameras ■ Standalone chargers ■ USB-powered chargers Table 1. Device summary Order code L6924D L6924D013TR September 2010 Battery charger system with integrated power switch for Li-Ion/Li-Polymer - I Package VFQFPN16 Doc ID 11908 Rev 9 L6924D VFQFPN16 Packaging Tube Tape and reel 1/38 www.st.com 38 ...
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... Fast charge current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 7.5 End-of-charge current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 7.6 Recharge flow chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.7 Recharge threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.8 Maximum charging time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.9 Termination modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 8 Application information: monitoring and protection . . . . . . . . . . . . . . 23 8.1 NTC thermistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 8.2 Battery absence detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 8.3 Status pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2/38 Doc ID 11908 Rev 9 L6924D ...
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... L6924D 8.4 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 9 Additional applications information . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 9.1 Selecting the input capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 9.2 Selecting the output capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 9.3 Layout guidelines and demonstration board description . . . . . . . . . . . . . 30 10 Application ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 10.1 USB battery charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 11 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 12 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Doc ID 11908 Rev 9 ...
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... Regardless of the charging approach, a closed loop thermal control avoids device overheating. The device has an operating input voltage ranging from 2 The L6924D allows the user to program many parameters, such as pre-charge current, fast-charge current, pre-charge voltage threshold, end-of-charge current threshold, and charge timer ...
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... L6924D 2 Pins description and connection diagrams Figure 3. Pins connection (top view) V 2.1 Pin description Table 2. Pin functions Pin I/O Name Input pin of the power stage. IN Supply voltage pin of the signal circuitry INSNS The operating input voltage ranges from 2 and the start-up threshold ...
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... V (edge sensitive), the maximum charging time is PRE is equal to 10 PRETH CHG 17. Doc ID 11908 Rev 9 status (see Chapter 7.5: PRE pin is lower than 0 PRE . ENDTH ), with an CHG . If I has to be programmed at a PRETH , through a resistor see REF L6924D = PRETH ...
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... L6924D 3 Maximum ratings Stressing the device above the rating listed in the “absolute maximum ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied ...
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... PRG ) 4.06 4.1 4.14 4.16 4.2 4.24 450 490 905 975 1045 REF 29.5 35 40.1 = Floating 2.7 2.8 = 12kΩ 2.87 3.03 3.19 2.7 2 10% 0.4 10 280 L6924D Unit 12 V 4 µA 500 nA 500 525 2 2 hours 380 mΩ ...
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... L6924D Table 5. Electrical characteristics (continued) Symbol Parameter NTC pin hot threshold voltage TH NTC pin cold threshold voltage 1. T from –40°C to 125° Guaranteed by design. Test condition Doc ID 11908 Rev 9 Electrical specifications Min Typ Max Unit 10.625 12.5 14.375 %V REF 45 50 ...
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... Block diagram 5 Block diagram Figure 4. Block diagram 10/38 Doc ID 11908 Rev 9 L6924D ...
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... MOSFET, reverse blocking diode and the sense resistor. It normally works as a linear charger when powered from an external voltage regulated adapter. However, thanks to its very low minimum input voltage (down to 2.5 V) the L6924D can also work as a Quasi-Pulse charger when powered from a current limited adapter. To work in this condition, is enough to set the device’ ...
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... V is the output voltage of the upstream AC-DC adapter that is, in turn, the input voltage ADP of the L6924D. If the battery voltage is lower than a set pre-charge voltage (V pre-charge phase takes place. The battery is pre-charged with a low current I (Chapter 7.2 on page When the battery voltage goes higher than V ...
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... L6924D charging process is usually terminated when the charging current reaches a set value or when a charging timer expires Figure 6 shows the different phases. Figure 6. Typical charge curves in linear mode Pre-Charge Phase V ADP V OPRGTH V PRETH I CHG I PRETH The worst case in power dissipation occurs when the device starts the fast-charge phase. In fact, the battery voltage is at its minimum value ...
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... The quasi-pulse mode can be used when the system can rely on the current limit of the upstream adapter to charge the battery. In this case, I current limit of the adapter. In this mode, the L6924D charges the battery with the same three phases as in linear mode, but the power dissipation is greatly reduced as shown in Figure 7 ...
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... L6924D Where current limit of the wall adapter, and R LIM The difference between the set charge current and the adapter limit should be high enough to minimize the R completely unbalanced and the power element is fully turned on. Figure 8 shows the R adapter current limit of 500 mA. ...
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... Applications information: charging process 7 Applications information: charging process 7.1 Charging process flow chart Figure 9. Charging process flow chart 16/38 Doc ID 11908 Rev 9 L6924D ...
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... L6924D 7.2 Pre-charge current The L6924D allows pre-charging the battery with a low current when the battery voltage is lower than a specified threshold (V to 10% of the fast-charge current. However it can be adjusted by connecting a resistor from the I pin to GND or V PRE pin and GND, the current is higher than the default value. The R Equation 6 Figure 10 ...
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... R R PRE PRE is the resistor used to set PRG current), and V is the selected PRETH , before this PRETH time the beginning , the Pre-Charge phase PRETH ), the L6924D PRETH as follows: PRG ⎛ ⎞ K PRG ⎜ ⎜ ⎟ ⎟ I ⎝ ⎠ CHG (Section 7.8: ...
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... L6924D 7.5 End-of-charge current When the charge voltage approaches the selected value (4 4.2 V), the voltage regulation phase takes place. The charge current starts to decrease until it goes lower than a programmable end value, I the I pin and GND (see END Equation 10 Figure 14. I END Where K is 1050 ...
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... OPRG 7.8 Maximum charging time To avoid the charging of a dead battery for a long time, the L6924D has the possibility to set a maximum charging time starting from the beginning of the fast-charge phase. This timer can be set with a capacitor, connected between the T external capacitor (in nF) and is given by the following equation: ...
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... Also during the pre-charge phase there is a safety timer, given by: Equation 12 If this timer expires and the battery voltage is still lower than V generated, and the charge process is terminated. Applications information: charging process pin connection T PRG L6924D 1 = × T MAXPRECH 8 Doc ID 11908 Rev 9 ...
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... PRE ENDTH pin is lower than 0.8 V during the Pre-charge Phase, the device PRE automatically. pin goes lower than 0.5 V (edge sensitive), the timer is reset, PRE Doc ID 11908 Rev 9 connecting a ENDTH PRE . ENDTH . The status pins notify the end-of- L6924D pin: is MAXCH ...
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... L6924D 8 Application information: monitoring and protection The L6924D uses a VFQFPN 16-pin package with an exposed pad that allows the user to have a compact application and good thermal behavior at the same time. The L6924D has a low thermal resistance because of the exposed pad (approximately 75°C/W, depending on the board characteristics). Moreover, a built-in thermal protection feature prevents the L6924D from having thermal issues typically present in a linear charger ...
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... OK when the battery temperature between 0°C and 50°C BAT Figure 20. Voltage window with hysteresis MINTH_HYS V MAXTH_HYS Figure 21. Pin connection 24/38 Figure 20. V 900mV MINTH 780mV Voltage Variation on TH pin 248mV V MAXTH 225mV TH L6924D Doc ID 11908 Rev 9 Charge disable Charge enable V REF NTC L6924D ...
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... L6924D When the TH pin voltage rises and exceeds the V L6924D stops the charge, and indicates a fault by the status pins. The device re-starts to charge the battery, only when the voltage at the TH pin goes under V (typ). For what concerns the high temperature limit, when the TH pin voltage falls under the ...
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... NTC , the hysteresis is: 0°C 50°C − 900 mV 780 ° HYS 0 C × 900 051 − 225 mV 248 ° HYS 50 C × 225 039 Doc ID 11908 Rev 9 L6924D T is the pin voltage TH_HYS values, see T mV ° ° ≅ ≅ − ...
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... L6924D 8.2 Battery absence detection This feature provides a battery absent detection scheme to detect the removal or the insertion of the battery. If the battery is removed, the charge current falls below the I At the end of the de-glitch time, a detection current I output for a time current equal to I ...
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... Over time 8.4 Shutdown The L6924D has a shutdown pin (SD) that allows enabling or disabling the device. If the SD pin voltage is below 0.4 V (e.g. pin connected to GND), the device is enabled, whereas if the SD pin voltage exceeds 2 V (e.g. the shutdown pin is left floating) the device is disabled. When the device enters the shutdown mode, the current consumption is reduced to 60 μ ...
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... L6924D Figure 24. Shutdown SD SD pin voltage pin voltage 2V 2V 0.4V 0.4V Application information: monitoring and protection device disabled device disabled device enabled device enabled Doc ID 11908 Rev TH,high TH,high SD SD TH,low TH,low 29/38 ...
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... However, in order to maximize the current capability important to CHG = × − J THJ A of the device mounted on board is 75 °C/W, the power dissipated × Doc ID 11908 Rev 9 and V IN INSN and V pin is enough to OUT OUTSN Figure 25 shows the thermal + P T DISS AMB = o 100 C L6924D pins can ...
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... L6924D Figure 25. Thermal image of the demonstration board The V pin can be used as a remote sense; it should be therefore connected as closely OSNS as possible to the battery. The demonstration board layout and schematic are shown in Figure 26, Figure 27 Figure 26. Demonstration board layout, top side Figure 27. Demonstration board layout, bottom side ...
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... Additional applications information Figure 28. Demonstration board schematic C4 CHARGER R1 R2 LD1 LD2 μC 32/ REF OUT V C1 OSNS V I INSNS END T I PRG L6924D PRG C2 J2 ST2 V PRE ST1 J1 SHDN GND V I OPRG PRE Vref R7 Doc ID 11908 Rev R10 R8 L6924D NTC BATTERY ...
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... L6924D Table 7. Demonstration board components description Name Value R1 1k Pull up resistor used when the ST1 is connected to a LED Pull up resistor used when the ST1 is connected to a LED Pull up resistor. Connected between V End of charge current resistor. Used to set the termination current and “Gas ...
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... USB charger application schematic. Figure 29. USB charger application V BUS GND SYSTEM AND USB CONTROLLER 34/38 CHG REF OUT V OSNS V INSNS I END T PRG C2 L6924D I PRG V ST1 PRE ST2 SD GND I V PRE OPRG R4 Doc ID 11908 Rev 9 L6924D with a maximum value lower than BATTERY PACK ...
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... L6924D 11 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ® ECOPACK trademark. Doc ID 11908 Rev 9 Package mechanical data ® ...
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... Figure 30. Package dimensions 36/38 mm. Min. Typ. 0.80 0.90 0.02 0.65 0.20 0.18 0.25 2.85 3.00 1.45 1.60 2.85 3.00 1.45 1.60 0.45 0.50 0.30 0.40 Doc ID 11908 Rev 9 L6924D Max. 1.00 0.05 1.00 0.30 3.15 1.75 3.15 1.75 0.55 0.50 7185330_G ...
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... L6924D 12 Revision history Table 9. Document revision history Date Revision 16-Dec-2005 20-Dec-2005 10-Jan-2006 14-Feb-2006 03-Jul-2006 07-Sep-2006 29-Jun-2007 05-Jul-2010 22-Sep-2010 1 First draft 2 Package dimensions updated 3 Few updates 4 Part number updated 5 Updates to equation in page 22, updated block diagram 6 Added Note: on page 20, updated value C 7 Updated capacitor values C2 ...
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... Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America 38/38 Please Read Carefully: © 2010 STMicroelectronics - All rights reserved STMicroelectronics group of companies www.st.com Doc ID 11908 Rev 9 L6924D ...