MAX8600AETD+ MAXIM [Maxim Integrated Products], MAX8600AETD+ Datasheet - Page 8

• Manufacturer Part Number: MAX8600AETD+
• Description: Single-Input 1-Cell Li+ Charger with OVP Protection and Programmable Charge Timer
• Manufacturer: MAXIM [Maxim Integrated Products]

Single-Input 1-Cell Li+ Charger with
OVP Protection and Programmable Charge Timer
Figure 2 shows the typical operating circuit for the
MAX8600A. The following section describes component
changes for different charging current and timer durations.
The maximum charging current is programmed by an
external resistor (R
Calculate the R
where I
SETI can also be used to monitor the actual charge-
current level. The output voltage at SETI is proportional
to the charging current as follows:
Note that the prequal charge current (when V
operation is 10% of the fast-charge current set by R
Figure 2 External Components List
Table 1. Fault Temperatures for Different Thermistors
8
Resistance at +25°C
Resistance at +50°C
Resistance at 0°C
Nominal Hot Trip Temperature
Nominal Cold Trip Temperature
_______________________________________________________________________________________
COMPONENT
CHARGE(MAX)
R
C
C1
C2
D1
R1
R2
R3
SETI
T1
CT
V
THERMISTOR BETA
SETI
R
SETI
SETI
Applications Information
= (I
SETI
value as follows:
= 1500/I
CHARGE
is in amps and R
Charge-Current Selection
) connected from SETI to GND.
Filter capacitor
Filter capacitor
Timing capacitor
DC charge-current program resistor
Pullup resistor
Pullup resistor
LED current program resistor
Negative TC thermistor
Charge indicator LED
CHARGE(MAX)
x R
SETI
)/1000
SETI
FUNCTION
BAT
is in ohms.
25,140.55Ω
4587.78Ω
+55.14°C
10,000Ω
< 2.5V)
-3.24°C
3000
SETI
.
Also, the top-off charge-current threshold is set to 6% of
the fast-charge current set by R
The MAX8600A contains timers for prequal, fast-
charge, and top-off operation. These time periods are
determined by the capacitance from CT to GND. To set
the charge times, calculate C
Note that when THM halts charging, the timers stop and
hold their value.
27,148.09Ω
4299.35Ω
+52.60°C
T
T
T
10,000Ω
-1.26°C
FASTCHARGE
PREQUAL
TOPOFF
3250
1µF ceramic capacitor
2.2µF ceramic capacitor
0.068µF low TC ceramic capacitor
2kΩ 1% (for 750mA charge)
470kΩ
100kΩ
330Ω
Phillips NTC thermistor,
P/N 2322-640-63103,
10kΩ 5% at +25°C
LED
= 69.6min x (C
I
I
= 34.8min x (C
PREQUAL
TOP-OFF
= 334min x (C
Timer Capacitor Selection
29,315.94Ω
4029.06Ω
+50.46°C
10,000Ω
+0.46°C
DESCRIPTION
= 90/R
3500
= 150/R
CT
CT
SETI
CT
SETI
as follows:
/0.068µF)
.
/0.068µF)
SETI
CT
/0.068µF)
31,656.90Ω
3775.75Ω
+48.63°C
10,000Ω
+1.97°C
3750