LTC4100EG Linear Technology, LTC4100EG Datasheet - Page 19

• Manufacturer Part Number: LTC4100EG
• Description: IC SMART BATTERY CHARGER 24-SSOP
• Manufacturer: Linear Technology

Specifications of LTC4100EG

• Function: Charge Management
• Battery Type: Smart Batteries
• Voltage - Supply: 6 V ~ 28 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SSOP (0.200", 5.30mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

OPERATION
The I
The value of an external resistor connected from this pin
to GND determines one of four current limits that are used
for maximum charging current value. These limits provide
a measure of safety with a hardware restriction on charging
current which cannot be overridden by software.
Table 6. I
EXTERNAL
RESISTOR
(R
Short to GND
10k ±1%
33k ±1%
Open (>250k,
or Short to V
The V
The value of an external resistor connected from this pin
to GND determines one of fi ve voltage limits that are ap-
plied to the charger output value. These limits provide a
measure of safety with a hardware restriction on charging
voltage which cannot be overridden by software.
Table 7. V
EXTERNAL
RESISTOR
(R
Short to
GND
10k ±1%
33k ±1%
100k ±1%
Open or
Tied to V
ILIM
VLIM
)
)
LIM
LIM
DD
LIM
LIM
Decoder Block
Decoder Block
DD
V
0.42V
Trip Points and Ranges
0.17V
0.66V
0.91V
)
Trip Points and Ranges (See Figure 5)
VLIM
V
LIM
V
< 0.34V
< 0.59V
< 0.84V
V
ILIM
I
V
ILIM
LIM
VCCP
< 0.09V
VDD
VDD
VDD
0.17V
0.42V
0.66V
ILIM
VOLTAGE
< 0.34V
V
VOLTAGE
< 0.09V
< V
< V
< V
ILIM
< 0.59V
< V
VDD
VDD
VDD
VDD
VDD
VDD
VLIM
VLIM
VLIM
VCCP
VLIM
<
<
<
VDD
DD
CHARGING VOLTAGE
CURRENT RANGE
2900mV < V
2900mV < V
2900mV < V
2900mV < V
2900mV < V
(V
0 < I < 1023mA
0 < I < 2046mA
0 < I < 3068mA
0 < I < 4092mA
CONTROLLED
CONTROLLED
< 13104mV
< 17408mV
< 21712mV
< 28000mV
< 8800mV
CHARGING
OUT
) RANGE
OUT
OUT
OUT
OUT
OUT
GRANULARITY
GRANULARITY
16mV
16mV
16mV
16mV
16mV
1mA
2mA
4mA
4mA
The Voltage DAC Block
Note that the charger output voltage is offset by V
Therefore, the value of V
ChargingVoltage() value in order for the output voltage to
be programmed properly (without offset). If the Charging-
Voltage() value is below the nominal reference voltage of
the charger, nominally 1.184V, the charger output voltage
is programmed to zero. In addition, if the ChargingVolt-
age() value is above the limit set by the V
charger output voltage is set to the value determined by
the V
limits are demonstrated in Figure 6.
NOTE: THE LTC4100 CAN BE PROGRAMMED WITH ChargingVoltage() FUNCTION VALUES
BETWEEN 1.184V AND 2.9V, HOWEVER, THE BATTERY CHARGER CONTROLLER OUTPUT
VOLTAGE MAY BE ZERO WITH PROGRAMMED VALUES BELOW 2.9V.
LIM
resistor and the VOLTAGE_OR bit is set. These
25
20
15
10
Figure 6. Transfer Function of Charger
5
0
0
R
VLIM
5
= 33k
PROGRAMMED VALUE (V)
10
REF
15
is subtracted from the SMBus
20
25
30
LTC4100
LIM
4100 F06
35
pin, then the
19
4100fb
REF
.