19-4817; Rev 1; 9/10
TION KIT
EVALUA
LE
AVAILAB
High-Frequency,
Low-Cost SMBus Chargers
Features
S
S
S
S
Low-Cost SMBus Charger
High Switching Frequency (0.85MHz/0.5MHz)
Internal Boost Switches
SMBus-Programmable Charge Voltage, Input
Current Limit, Charge Current, Relearn Voltage,
and Digital IINP Readback
Single-Point Compensation
Automatic Selection of System Power Source
Adapter n-Channel MOSFETs Driven by an
Internal Dedicated Charge Pump
Adapter Soft-Start
±0.4% Accurate Charge Voltage
±2.5% Accurate Input Current Limiting
±3% Accurate Charge Current
Monitor Outputs for
AC Adapter Current (±2% Accuracy)
Battery Discharge Current (±2% Accuracy)
AC Adapter Presence
AC Adapter Overvoltage Protection
11-Bit Battery Voltage Setting
6-Bit, Charge-Current Setting/Input Current Setting
Improved IINP Accuracy at Low Input Current
General Description
The MAX17435/MAX17535 integrated multichemistry
battery-charger ICs simplify construction of accurate
and efficient chargers. The MAX17435/MAX17535
provide SMBusK-programmable charge current, charge
voltage, input current limit, relearn voltage, and digital
readback of the IINP voltage. The MAX17435/MAX17535
utilize a charge pump to control the adapter selection
n-channel MOSFETs when the adapter is present. When
the adapter is absent, the charge pump is shut down and
a p-channel MOSFET selects the battery.
The MAX17435/MAX17535 provide up to 7A of charge
current to 2, 3, or 4 lithium-ion (Li+) cells in series. The
charge current, and input current-limit sense amplifiers have
low offset errors and can use 10mI sense resistors. The
MAX17435/MAX17535 fixed-inductor ripple architecture
significantly reduces component size and circuit cost.
The MAX17435/MAX17535 provide a digital output that
indicates the presence of the adapter, an analog output
that indicates the adapter or battery current, depending
upon the presence or absence of the adapter, and a
digital output that indicates when the adapter current
exceeds a user-defined threshold.
The MAX17435 switches at an 850kHz frequency and the
MAX17535 switches at 500kHz.
The MAX17435/MAX17535 are available in a small, 4mm
x 4mm x 0.75mm, 24-pin, lead-free TQFN package. An
evaluation kit is available.
MAX17435/MAX17535
S
S
S
S
S
S
S
S
S
S
Ordering Information
PART
MAX17435ETG+
MAX17535ETG+
TEMP RANGE
-40
N
C
to
+85
N
C
-40
N
C to +85
N
C
PIN-PACKAGE
24 TQFN-EP*
24 TQFN-EP*
Applications
Notebook Computers
PDAs and Mobile Communicators
2- to 4- Li+ Cell Battery-Powered Devices
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
Pin Configuration
CSSP
CSSN
TOP VIEW
IINP
CC
PDSL
14
18
ACIN 19
ITHR 20
V
AA
21
V
CC
22
GND 23
EN 24
1
SCL
17
16
15
13
12 CSIP
11 CSIN
10 ACOK
MAX17435
MAX17535
BATT
9
8
7
DHI
LX
BST
2
SDA
3
DCIN
4
LDO
5
DLO
6
ADAPTLIM
SMBus is a trademark of Intel Corp.
_______________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
High-Frequency,
Low-Cost SMBus Chargers
MAX17435/MAX17535
DCIN, CSSP, BATT, CSIP to GND ......................... -0.3V to +28V
CSIP to CSIN, CSSP to CSSN .............................. -0.3V to +0.3V
V
CC
, SCL, SDA, V
AA
, EN, ACIN, ITHR,
ADAPTLIM,
ACOK
to GND .................................. -0.3V to +6V
PDSL to GND......................................................... -0.3V to +37V
GND to PGND ...................................................... -0.3V to +0.3V
DHI to LX. .................................................-0.3V to (V
BST
+ 0.3V)
BST to LX ................................................................. -0.3V to +6V
BST to GND ........................................................... -0.3V to +34V
DLO to PGND .......................................... -0.3V to (V
LDO
+ 0.3V)
LX to GND ................................................................ -6V to +28V
ABSOLUTE MAXIMUM RATINGS
CC, IINP to GND...................................... -0.3V to (V
LDO
+ 0.3V)
LDO Short Circuit to GND ......................................... Momentary
Continuous Power Dissipation (T
A
= +70NC)
24-Pin TQFN (derate 20.8mW/NC above +70NC) .......1666mW
Operating Temperature Range .......................... -40NC to +85NC
Junction Temperature .....................................................+150NC
Storage Temperature Range ............................ -65NC to +150NC
Lead Temperature (soldering, 10s).................................+300NC
Soldering Temperature....................................................+260NC
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, no load on LDO, V
DCIN
= V
CSSP
= V
CSSN
= 19V, V
LX
= 0V, V
BST
- V
LX
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 16.8V,
T
A
= 0
°
C to +85
°
C,
unless otherwise noted. Typical values are at T
A
= +25
°
C.)
PARAMETER
INPUT SUPPLIES
Adapter Present Quiescent
Current (Note 1)
I
DCIN
+ I
CSSP
+
I
CSSN
Charging enabled,
V
ADAPTER
= 19V,
V
BATTERY
= 16.8V
Charging disabled
BATT + CSIP + CSIN +
LX Input Current
DCIN Input Current
V
CC
Supply Current
DCIN Input Voltage Range
for Charger
DCIN Undervoltage-Lockout
Trip Point for Charger
DCIN Input Voltage Range
CHARGE-VOLTAGE REGULATION
ChargingVoltage() = 0x41A0
ChargingVoltage() = 0x3130
ChargingVoltage() = 0x20D0
ChargingVoltage() = 0x1060
Battery Undervoltage-Lockout
Trip Point for Trickle Charge
16.733
-0.4
12.516
-0.6
8.333
-0.8
4.15
-1.0
3
3.5
4.192
8.4
12.592
16.8
16.867
+0.4
12.668
+0.6
8.467
+0.8
4.234
+1.0
4
V
%
V
%
V
%
V
%
V
V
DCIN
falling
V
DCIN
rising
8
I
DCIN
I
CC
V
BATT
= 16.8V
Adapter absent or charger
shut down (Note 1)
200
0.7
1.5
8
7
7.2
7.7
7.9
26
3
1.5
6
2.2
2.0
650
1.0
2.5
26
mA
mA
V
V
V
mA
mA
FA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
BATT
= 2V to 19V, adapter present (Note 1)
Charger disabled
Charger added
Battery Full-Charge Voltage
and Accuracy
2
______________________________________________________________________________________
High-Frequency,
Low-Cost SMBus Chargers
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, no load on LDO, V
DCIN
= V
CSSP
= V
CSSN
= 19V, V
LX
= 0V, V
BST
- V
LX
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 16.8V,
T
A
= 0
°
C to +85
°
C,
unless otherwise noted. Typical values are at T
A
= +25
°
C.)
PARAMETER
CSIP-to-CSIN Full-Scale
Current-Sense Voltage
RS2 = 10mI, Figure 1,
ChargingCurrent() = 0x1f80
Charge Current and Accuracy
RS2 = 10mI, Figure 1,
ChargingCurrent() = 0x0f80
RS2 = 10mI, Figure 1,
ChargingCurrent() = 0x0080
Charge-Current Gain Error
INPUT CURRENT REGULATION
RS1 = 10mI, Figure 1,
InputCurrent() = full scale
Input Current-Limit Threshold
RS1 = 10mI, Figure 1,
InputCurrent() = 0C80
RS1 = 10mI, Figure 1,
InputCurrent() = 0780
CSSP/CSSN Input Voltage Range
IINP Voltage Gain
IINP Output Voltage Range
V
CSSP
- V
CSSN
= 110mV
IINP Accuracy
V
CSSP
- V
CSSN
= 55mV
V
CSSP
- V
CSSN
= 5mV
IINP Gain Error
IINP Offset Error
REFERENCE
REF Output Voltage
REF Undervoltage-Lockout
Threshold
LINEAR REGULATOR
LDO Output Voltage
LDO Load Regulation
LDO Undervoltage-Lockout
Threshold
LDO
I
REF
= 50FA
0 < I
LDO
< 40mA
LDO falling, 500mV (typ) hysteresis
3.2
5.2
5.4
127
4.1
5.6
250
5.0
V
mV
V
REF
I
REF
= 50FA
REF falling
4.082
4.096
3.1
4.115
3.9
V
V
Based on V
CSSP
- V
CSSN
= 110mV and
V
CSSP
- V
CSSN
= 55mV
Based on V
CSSP
- V
CSSN
= 110mV and
V
CSSP
- V
CSSN
= 55mV
107.25
-2.5
62.08
-3
36.86
-4
8
19.7
0
-5
-4
-10
-1.5
-350
20
38.4
64
110
112.75
+2.5
65.92
+3
39.94
+4
26
20.3
4.2
+5
+4
+10
+1.5
+350
%
FV
%
%
V
V/V
V
mV
Based on ChargeCurrent() = 128mA and
8.064A
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CHARGE-CURRENT REGULATION
78.22
7.822
-3
3.829
-3.5
64
-50
-2
128
3.968
80.64
8.064
83.06
8.306
+3
4.107
+3.5
192
+50
+2
mV
A
%
A
%
mA
%
%
MAX17435/MAX17535
_______________________________________________________________________________________
3
High-Frequency,
Low-Cost SMBus Chargers
MAX17435/MAX17535
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, no load on LDO, V
DCIN
= V
CSSP
= V
CSSN
= 19V, V
LX
= 0V, V
BST
- V
LX
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 16.8V,
T
A
= 0
°
C to +85
°
C,
unless otherwise noted. Typical values are at T
A
= +25
°
C.)
PARAMETER
ACOK
ACOK
Sink Current
ACOK
Leakage Current
ACIN
ACIN Threshold
ACIN Input Bias Current
ITHR/ADAPTLIM
ITHR Leakage Current
ADAPTLIM Sink Current
ADAPTLIM Leakage Current
ITHR Threshold
LOGIC LEVELS
SDA/SCL Input Low Voltage
SDA/SCL Input High Voltage
SDA/SCL Input Bias Current
SWITCHING REGULATOR
DHI Off-Time K Factor
Sense Voltage for Minimum
Discontinuous Mode
Ripple Current
Zero-Crossing Comparator
Threshold
Cycle-by-Cycle Current-Limit
Sense Voltage
DHI Resistance High
DHI Resistance Low
DLO Resistance High
DLO Resistance Low
ADAPTER DETECTION
Adapter Absence Detect
Threshold
Adapter Detect Threshold
CHARGE-PUMP MOSFET DRIVER
PDSL Gate-Driver Source Current
PDSL Gate-Driver Output Voltage
HIGH
V
PDSL
- V
DCIN
= 3V, V
DCIN
= 19V
V
DCIN
= 19V, open load
40
V
DCIN
+ 5.3
64
V
DCIN
+8
FA
V
V
DCIN
- V
BATT
, V
DCIN
falling
V
DCIN
- V
BATT
, V
DCIN
rising
50
340
120
430
200
600
mV
mV
V
DCIN
= 19V, V
BATT
= 10V, MAX17435
V
DCIN
= 19V, V
BATT
= 10V, MAX17535
V
CSIP
- V
CSIN
55
93
61
100
5
67
107
ns/V
T
A
= +25NC
2.1
-1
+1
0.8
V
V
FA
V
ITHR
= 0V to LDO, T
A
= +25NC
V
ITHR
> V
IINP
V
ITHR
< V
IINP
, T
A
= +25NC
Calculated = V
ITHR
- V
IINP
-12
-1
1
1
+12
+1
FA
mA
FA
mV
SYMBOL
CONDITIONS
V
ACOK
= 0.4V, V
ACIN
= 2.5V
V
ACOK
= 5.5V, V
ACIN
= 0.5V, T
A
= +25NC
Rising, 20mV (typ) hysteresis
T
A
= +25NC
1.465
-1
1.485
MIN
1
1
1.53
+1
TYP
MAX
UNITS
mA
FA
V
FA
mV
V
CSIP
- V
CSIN
V
CSIP
- V
CSIN
I
DHI
= 10mA
I
DHI
= -10mA
I
DLO
= 10mA
I
DLO
= -10mA
120
5
125
1.5
0.8
3
3
130
3
1.6
6
6
mV
mV
I
I
I
I
4
______________________________________________________________________________________
High-Frequency,
Low-Cost SMBus Chargers
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, no load on LDO, V
DCIN
= V
CSSP
= V
CSSN
= 19V, V
LX
= 0V, V
BST
- V
LX
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 16.8V,
T
A
= 0
°
C to +85
°
C,
unless otherwise noted. Typical values are at T
A
= +25
°
C.)
PARAMETER
ACOVP Threshold
ACOVP Threshold Hysteresis
ADAPTER OVERCURRENT PROTECTION
ACOCP Threshold
ACOCP Blanking Time
ACOCP Waiting Time
PDSL SWITCH CONTROL
PDSL Turn-Off Resistance
SMBus TIMING SPECIFICATIONS
SMBus Frequency
Bus Free Time
START Condition Hold Time
from SCL
START Condition Setup Time
from SCL
STOP Condition Setup Time
from SCL
Holdup Time from SCL
Setup Time from SCL
SCL Low Period
SCL High Period
Maximum Charging Period
Without a Charge_Voltage() or
ChargeCurrent() Command
f
SMB
t
BUF
t
HD:STA
t
SU:STA
t
SU:STO
t
HD:DAT
t
SU:DAT
t
LOW
t
HIGH
10
4.7
4
4.7
4
300
250
4.7
4
140
175
210
100
kHz
Fs
Fs
Fs
Fs
ns
ns
Fs
Fs
s
2.5
4
kI
When ACOCP comparator is high and at the
time the blanking time expires
With respect to V
CSSP
- V
CSSN
144
16
0.6
mV
ms
s
SYMBOL
Rising
CONDITIONS
MIN
2.04
TYP
2
30
MAX
2.1
UNITS
V
mV
ADAPTER OVERVOLTAGE PROTECTION
MAX17435/MAX17535
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, no load on LDO, V
DCIN
= V
CSSP
= V
CSSN
= 19V, V
LX
= 0V, V
BST
- V
LX
= 5V, V
BATT
= V
CSIP
= V
CSIN
= 16.8V,
T
A
= -40
°
C to +85
°
C,
unless otherwise noted.) (Note 2)
PARAMETER
INPUT SUPPLIES
Adapter Present Quiescent
Current
I
DCIN
+ I
CSSP
+
I
CSSN
(Note 1)
Charging enabled,
V
ADAPTER
= 19V,
V
BATTERY
= 16.8V
Charging disabled
6
2.2
mA
mA
SYMBOL
CONDITIONS
MIN
MAX
UNITS
_______________________________________________________________________________________
5