L6924D STMicroelectronics, L6924D Datasheet - Page 25

• 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
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
V
voltage rises to the V
When the battery is at the low temperature limit, the TH pin voltage is 900 mV. The correct
resistance ratio to set the low temperature limit at 0°C can be found with the following
equation:
Equation 14
Where R
NTC at 0°C. Since at the low temperature limit V
Equation 15
It follows that:
Equation 16
Similarly, when the battery is at the high temperature limit, the TH pin voltage is 225 mV. The
correct resistance ratio to set the high temperature limit at 50°C can be found with the
following equation:
Equation 17
Where R
that:
Equation 18
Consequently:
Equation 19
MAXTH
= 12.5% of V
UP
NTC50°C
is the pull-up resistor, V
is the value of the NTC at 50°C. Considering V
MAXTH_HYS
REF
(225 mV Typ.), the L6924D stops the charge until the TH pin
V
V
Doc ID 11908 Rev 9
MAXTH
. 0
MINTH
0
= 248 mV (Typ.).
225
9 .
REF
Application information: monitoring and protection
=
=
=
=
R
1
R
V
V
1
NTC
is equal to 1.8 V, and R
8 .
NTC
REF
8 .
REF
×
50
×
° 0
R
°
×
×
C
C
R
UP
R
UP
R
=
=
R
UP
MINTH
UP
R
+
NTC
R
MINTH
+
R
R
R
NTC
R
UP
7
+
UP
+
NTC
R
NTC
0
NTC
R
°
R
50
NTC
C
= 900 mV:
50
NTC
°
0
NTC
0
C
°
= 50% of V
°
°
C
50
C
C
50
°
0
C
°
°
C
C
NTC0°C
MAXTH
REF
MINTH_HYS
is the value of the
= 225 mV it follows
(900 mV typ), the
= 780 mV
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