MAX1758EAI+ Maxim Integrated Products, MAX1758EAI+ Datasheet - Page 9

• Manufacturer Part Number: MAX1758EAI+
• Description: IC BATT CHRG 4-LI+ 28V SW 28SSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1758EAI+

• 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: 28-SSOP
• Output Voltage: 5.4 V
• Operating Supply Voltage: 6 V to 28 V
• Supply Current: 5 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Charge Safety Timers: Yes
• Mounting Style: SMD/SMT
• Temperature Monitoring: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 1. Typical Application Circuit
The MAX1758 includes all of the functions necessary to
charge 1, 2, 3, or 4 Li+ battery cells in series. It
includes a step-down DC-DC converter that controls
charging voltage and current. It also includes input
source current limiting, battery temperature monitoring,
battery undervoltage precharging, battery fault indica-
tion, and a state machine with timers for charge termi-
nation.
Li+ Battery Charger with Internal 28V Switch
SUPPLY
INPUT
_______________________________________________________________________________________
D1
Detailed Description
FAST CHARGE
FULL CHARGE
D2
0.1µF
FAULT
C4
C3
1µF
MBRS340
C17
1nF
R4
R5
TO VL
10k
R6
0.1µF
0.1µF
1nF
1nF
C1
C2
C5
C6
C7
0.1µF
17
11
24
23
12
13
15
16
14
28
25
5
2
3
7
6
DCIN
FASTCHG
FULLCHG
FAULT
SHDN
REF
ISETIN
ISETOUT
VADJ
CELL
GND
CCV
CCI
CCS
TIMER1
TIMER2
Stand-Alone, Switch-Mode
MAX1758
PGND
CSSP
CSSN
The DC-DC converter uses an internal power MOSFET
switch to convert the input voltage to the charging cur-
rent or voltage. Figure 1 shows the typical application
circuit. Figure 2 shows a typical charging sequence and
Figure 3 shows the functional diagram. The charging
current is set by the voltage at ISETOUT. The battery
voltage is measured at the BATT pin. The battery regu-
lation voltage limit is set to 4.2V per cell and can be
adjusted ±5% by changing the voltage at the VADJ pin.
By limiting the adjust range, the voltage limit accuracy is
better than 1% while using 1% setting resistors.
BATT
THM
HSD
HSD
BST
CS
VL
LX
LX
C18
0.1µF
1
22
10
9
20
19
18
21
8
4
27
26
C8
0.1µF
C9
0.1µF
D3
C14
0.1µF
C16
0.1µF
C13
4.7µF
C15
68µF
THERM
D4
MBRS340
R1
0.05Ω
22µH
L1
+
C12
0.22µF
Li+ BATTERY
1 TO 4 CELLS
+
C10
22µF
+
C11
22µF
TO
SYSTEM
LOAD
9