LTC1759CG#PBF Linear Technology, LTC1759CG#PBF Datasheet - Page 27
![IC SMART BATTERY CHARGER 36SSOP](/photos/6/59/65995/161-36-ssop_sml.jpg)
LTC1759CG#PBF
Manufacturer Part Number
LTC1759CG#PBF
Description
IC SMART BATTERY CHARGER 36SSOP
Manufacturer
Linear Technology
Type
Battery Chargerr
Datasheet
1.LTC1759CGPBF.pdf
(28 pages)
Specifications of LTC1759CG#PBF
Function
Charge Management
Battery Type
Smart Batteries
Voltage - Supply
11 V ~ 24 V
Operating Temperature
0°C ~ 70°C
Mounting Type
Surface Mount
Package / Case
36-SSOP (0.200", 5.30mm Width)
Output Current
8A
Operating Supply Voltage (min)
3V
Operating Supply Voltage (max)
5.5V
Operating Temp Range
0C to 70C
Package Type
SSOP
Mounting
Surface Mount
Pin Count
36
Operating Temperature Classification
Commercial
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
APPLICATIONS
Charging Indication
When a CHARGECURRENT() command with a value of
zero is sent to the LTC1759, current stops flowing into the
battery. However, the command does not cause the CHGEN
pin to pull low. This prevents use of the CHGEN pin as a
charge termination indication. Figure 16 shows a circuit
that reliably indicates when the battery is receiving a
charge current.
The circuit shown, except for the optional 555 timer IC,
filters out the I
Q1 and R5 partially isolate the capacitance of C1 from
effecting the I
Figure 14. Kelvin Sensing of Charging Current
SET
SET
pin of the LTC1759. Q1 is configured as
DAC 80kHz output into a smooth signal.
DIRECTION OF CHARGING CURRENT
U
TO R
INFORMATION
U
0.1 F
R
R6
3.3V = 330k
5V = 680k
S1
SENSE
C1
AND R
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
S2
V
DD
W
R1
3.3V = 240
5V = 510
R1
R6
R7
330k
CHARGE
Q1
MMBT3904
R4
4.7M
R5
10k
1759 F14
G
Figure 16. Battery Charge Indicator Circuit
D
Q2, 2N7002
S
U
1
2
3
4
GROUND
TRIGGER
OUTPUT
RESET
(OPTIONAL, SEE TEXT)
LMC555
THRESHOLD
DISCHARGE
a crude voltage level detector looking for voltage going
below approximately one volt on the emitter. The RC
circuit consisting of R4 and C1 filters low pulses from the
I
logic level type interface. The circuit is powered from the
logic output driver of the CHGEN pin of the LTC1759. The
circuit does not need any capacitive supply bypassing to
function and draws little current. When the CHGEN pin
goes low, the current consumption of the circuit is elimi-
nated. Note that some resistor values must change de-
pending on the supply voltage connected to the V
the LTC1759. An optional low power 555 timer can be
added to to give a blinking LED charge indication.
CONTROL
SET
VOLTAGE
V
CC
pin. Q2 buffers the RC filter circuit allowing a more
8
7
6
5
V
IN
Figure 15. High Speed Switching Path
R2
4.7k
R3
2.7M
C3
0.1 F
C
IN
CIRCULATING
FREQUENCY
V
C2
0.1 F
DD
SWITCH NODE
HIGH
PATH
16
12
25
24
18
17
28
27
11
20
19
14
15
13
7
4
5
6
UV
V
SYNC
SDB
CHGEN
V
I
DGND
I
PROG
V
COMP1
AGND
RNR
THERM
SDA
SCL
INTB
LIMIT
SET
DD
LIMIT
C
LTC1759
U2
BOOSTC
BOOST
BGATE
SENSE
DCDIV
TGATE
GBIAS
PGND
INFET
DCIN
BAT1
BAT2
SPIN
V
CLP
CLN
1759 F16
V
SW
SET
CC
L1
D1
22
21
8
32
33
9
10
2
3
35
1
34
30
29
31
23
26
36
C
OUT
LTC1759
BAT
1759 F15
DD
V
27
BAT
pin of