LTC4006EGN-2 Linear Technology, LTC4006EGN-2 Datasheet - Page 15

• Manufacturer Part Number: LTC4006EGN-2
• Description: IC CHARGER BATTERY 4A 16-SSOP
• Manufacturer: Linear Technology

Specifications of LTC4006EGN-2

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 6 V ~ 28 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Output Current: 4A
• Output Voltage: 12.6V
• Operating Supply Voltage (min): 6V
• Operating Supply Voltage (max): 28V
• Operating Temp Range: -40C to 85C
• Package Type: SSOP N
• Mounting: Surface Mount
• Pin Count: 16
• Operating Temperature Classification: Industrial
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIO S I FOR ATIO
Example:
Adapter Limiting
An important feature of the LTC4006 is the ability to
automatically adjust charging current to a level which
avoids overloading the wall adapter. This allows the prod-
uct to operate at the same time that batteries are being
charged without complex load management algorithms.
Additionally, batteries will automatically be charged at the
maximum possible rate of which the adapter is capable.
This feature is created by sensing total adapter output
current and adjusting charging current downward if a
preset adapter current limit is exceeded. True analog
control is used, with closed-loop feedback ensuring that
adapter load current remains within limits. Amplifier CL1
in Figure 9 senses the voltage across R
V
PD = 292mW
I
DCIN
DCIN
*R
LTC4006
= 5mA
CL
= 19V, f
=
ADAPTER CURRENT LIMIT
Figure 9. Adapter Current Limiting
CL1
100mV
–
+
OSC
Table 5. Common R
* Rounded to nearest 5% standard step value. Many non-standard values are popular.
100mV
U
RATING (A)
ADAPTER
= 345kHz, Q
+
1.5
1.8
2.0
2.3
2.5
2.7
3.0
3.3
3.6
4.0
11
12
U
CLP
CLN
+
–7% ADAPTER
C
15nF
RATING (A)
G1
IN
W
CL
1.40
1.67
1.86
2.14
2.33
2.51
2.79
3.07
3.35
3.72
= Q
Resistor Values
R
5k
CL
G2
*
TO SYSTEM
LOAD
CL
= 15nC.
AC ADAPTER
INPUT
, connected
R CL VALUE*
U
4006 F09
V
(Ω) 1%
IN
0.068
0.062
0.051
0.047
0.043
0.039
0.036
0.033
0.030
0.027
LIMIT (A)
between the CLP and DCIN pins. When this voltage ex-
ceeds 100mV, the amplifier will override programmed
charging current to limit adapter current to 100mV/R
lowpass filter formed by 5kΩ and 15nF is required to
eliminate switching noise. If the current limit is not used,
CLP should be connected to CLN.
Setting Input Current Limit
To set the input current limit, you need to know the
minimum wall adapter current rating. Subtract 7% for the
input current limit tolerance and use that current to deter-
mine the resistor value.
As is often the case, the wall adapter will usually have at
least a +10% current limit margin and many times one can
simply set the adapter current limit value to the actual
adapter rating (see Figure 9).
Designing the Thermistor Network
There are several networks that will yield the desired
function of voltage vs temperature needed for proper
operation of the thermistor. The simplest of these is the
voltage divider shown in Figure 10. Unfortunately, since
the HIGH/LOW comparator thresholds are fixed internally,
there is only one thermistor type that can be used in this
network; the thermistor must have a HIGH/LOW resis-
tance ratio of 1:7. If this happy circumstance is true for
1.47
1.61
1.96
2.13
2.33
2.56
2.79
3.07
3.35
3.72
R CL
R
I
LIM
CL
= 100mV/I
= Adapter Min Current –
(Adapter Min Current • 7%)
DISSIPATION (W)
R CL POWER
0.15
0.16
0.20
0.21
0.23
0.26
0.28
0.31
0.33
0.37
LIM
R CL POWER
RATING (W)
0.25
0.25
0.25
0.25
0.50
0.50
0.50
0.50
0.50
0.50
LTC4006
15
CL
4006fa
. A