L6924D STMicroelectronics, L6924D Datasheet - Page 17

• 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
7.2
7.3
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 and GND, the current is higher than the default value. The R
Equation 6
Figure 10. I
When R
external reference equal to 1.8 V, V
constant equal to 950. See
The relationship is shown in the equation 7:
Equation 7
Figure 11. I
Pre-charge voltage
If the V
Otherwise, the device offers the possibility to program this value, with a resistor connected
between the V
equation 8:
PRE
PRE
PRE
pin to GND or V
pin is floating, a default value of V
is connected to V
PRE
PRE
PRE
pin connection
pin connection
pin and GND (see
REF
Figure
(see
REF
Doc ID 11908 Rev 9
, the current is lower than the default value. V
Figure
R
PRETH
R
11.
BG
PRE
PRE
L6924D
L6924D
L6924D
L6924D
Figure
is the internal reference equal to 1.23 V and K
=
=
). The Pre-charge current has a default value equal
10). When the resistor is connected between I
I
R
V
K
PRECH
V
PRG
BG
Applications information: charging process
12). In this case, the R
PRE
PRETH
REF
V
−
I
I
I
I
PRE
PRE
PRE
PRE
BG
−
−
I
V
K
PRECH
R
is set, equal to 2.8 V (V
V
BG
PRE
PRG
BG
V
V
REF
REF
PRE
VPRE
value is given by:
is given by the
PRETHDefault
REF
is the
PRE
17/38
PRE
).
is a