STEVAL-ISA076V1 STMicroelectronics, STEVAL-ISA076V1 Datasheet

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Features ■ Fully integrated solution, with a power MOSFET, reverse blocking diode, sense resistor, and thermal protection ■ Ideal for coke and graphite anode single-cell L I packs ON ■ Both linear and quasi-pulse operation ■ Closed loop thermal control ...

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Contents Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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L6924D 8.4 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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Description 1 Description The L6924D is a fully monolithic battery charger dedicated to single-cell Li-Ion/Polymer battery packs the ideal solution for space-limited applications, like PDAs, handheld equipment, cellular phones, and digital cameras. It integrates all of the power ...

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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 ...

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Pins description and connection diagrams Table 2. Pin functions External reference voltage pin.(reference voltage is 1.8 V±2%) REF Charge termination pin. A resistor connected from this pin to GND fixes the charge termination current threshold 13 I/O ...

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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 ...

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Electrical specifications 4 Electrical specifications 4.1 Electrical characteristics ° unless otherwise specified Table 5. Electrical characteristics Symbol Parameter Operating input voltage ( Start up threshold (1) I Supply current ...

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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 ...

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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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L6924D 6 Operation description The L6924D is a fully integrated battery charger that allows a very compact battery management system for space limited applications. It integrates in a small package, all the power elements: power MOSFET, reverse blocking diode and ...

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Operation description When the V pin is not used to program the Pre-Charge voltage threshold, it has two PRE different functions: ● If the voltage across V notified by the status pin, but the charging process is not disabled. The ...

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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 ...

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Operation description 6.2 Quasi-pulse mode 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, ...

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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 ...

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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 ...

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Applications information: charging process Equation 8 Figure 12. V PRE Where R is the resistor between V VPRE the charge current (see threshold. A safety timer is also present. If the battery voltage doesn't rise over V time is expired, ...

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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 ...

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Applications information: charging process 7.6 Recharge flow chart Figure 15. Recharge flow chart FROM CHARGING PROCESS FLOW CHART FAULT IND FAULT V BAT > V RCH NO Detect High Fault V BAT < V ABS NO Detect Low Fault YES ...

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L6924D Figure 16. T PRG Where 1.8V, REF 279 1.23V, and the charging time given in seconds. MAXCH If the battery does not reach the end-of-charge ...

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Applications information: charging process 7.9 Termination modes Figure 17. Charge termination flow chart As shown in Figure resistor between the I after a de-glitch time, the status pins notify that the charge process is complete. This de- glitch time is ...

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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. ...

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Application information: monitoring and protection When the voltage (and thus, the temperature), returns to the window range, the device re- starts the charging process. Moreover, there is a hysteresis for both the upper and lower thresholds, as shown in Figure ...

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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 ...

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Application information: monitoring and protection Based on Equation 16: Equation 20 The temperature hysteresis can be estimated by the equation: Equation 21 Where V is the pin voltage threshold on the rising edge threshold on the falling edge, ...

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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 ...

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Application information: monitoring and protection Figure 23. ST1 and ST2 connection with LEDs or microcontroller Table 6. Status LEDs indications Charge condition Charge in progress Charge done Stand by mode Bad battery temperature Battery absent Over time 8.4 Shutdown The ...

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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 ...

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Additional applications information 9 Additional applications information 9.1 Selecting the input capacitor In most applications µF ceramic capacitor, placed close to the V be used to filter the high frequency noise. 9.2 Selecting the output capacitor Typically, 1 ...

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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 ...

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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 ...

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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 ...

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Application ideas 10 Application ideas 10.1 USB battery charger With a voltage range between 4.75 V and 5.25 V, and a maximum current up to 500 mA, the USB power bus is an ideal source for charging a single-cell Li-Ion ...

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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. ...

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Package mechanical data Table 8. VFQFPN16 ( mm.) mechanical data Dim 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 ...

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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 ...

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