L6924D STMicroelectronics, L6924D Datasheet - Page 23

• Manufacturer Part Number: L6924D
• Description: IC BATTERY CHARGER SYS 16-VFQFPN
• Manufacturer: STMicroelectronics

Specifications of L6924D

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 2.5 V ~ 12 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-VFQFN
• Product: Charge Management
• Output Current: 30 mA
• Operating Supply Voltage: 2.5 V to 12 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• For Use With: 497-8428 - BOARD EVAL CHARGER ST7260/L6924D497-8247 - BOARD EVAL FOR L6924UTR497-5504 - EVAL BOARD FOR L6924D
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L6924D
8
Figure 18. Power dissipation both linear and quasi pulse mode with thermal loop
8.1
Application information: monitoring and protection
The L6924D uses a VFQFPN 3 mm x 3 mm 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.
Thermal control is implemented with a thermal loop that reduces the charge current
automatically when the junction temperature reaches approximately 120 °C. This avoids
further temperature rise and keeps the junction temperature constant. This simplifies the
thermal design of the application as well as protects the device against over-temperature
damage.
The
temperature reaches 120°C.
NTC thermistor
The device allows designers to monitor the battery temperature by measuring the voltage
across an NTC or PTC resistor. Li-Ion batteries have a narrow range of operating
temperature, usually from 0°C to 50 °C. This window is programmable by an external divider
which is comprised of an NTC thermistor connected to GND and a resistor connected to
V
(internal window comparator), the device stops the charge process, and indicates a fault
condition through the status pin.
REF
Figure 18
. When the voltage on the TH pin exceeds the minimum or maximum voltage threshold
shows how the thermal loop acts (with the dotted lines), when the junction
Doc ID 11908 Rev 9
Application information: monitoring and protection
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