MAX1648ESE-T [MAXIM]
Power Supply Support Circuit, Fixed, 1 Channel, CMOS, PDSO16, 0.150 INCH, MS-012AC, SOIC-16;
| 型号： | MAX1648ESE-T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Power Supply Support Circuit, Fixed, 1 Channel, CMOS, PDSO16, 0.150 INCH, MS-012AC, SOIC-16 光电二极管 |
| 文件： | 总25页 (文件大小：328K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1158; Rev 1; 12/02
Chemistry-Independent Battery Chargers
_______________General Description
____________________________Features
The MAX1647/MAX1648 provide the power control neces-
sary to charge batteries of any chemistry. In the MAX1647,
all charging functions are controlled through the Intel
System Management Bus (SMBus™) interface. The
SMBus 2-wire serial interface sets the charge voltage and
current, and provides thermal status information. The
MAX1647 functions as a level 2 charger, compliant with
the Duracell/Intel Smart Battery Charger Specification. The
MAX1648 omits the SMBus serial interface, and instead
sets the charge voltage and current proportional to the
voltage applied to external control pins.
ꢀ Charges Any Battery Chemistry:
Li-Ion, NiCd, NiMH, Lead Acid, etc.
ꢀ Intel SMBus 2-Wire Serial Interface (MAX1647)
ꢀ Intel/Duracell Level 2 Smart Battery Compliant
(MAX1647)
ꢀ 4A, 2A, or 1A Maximum Battery-Charge Current
ꢀ 11-Bit Control of Charge Current
ꢀ Up to 18V Battery Voltage
In addition to the feature set required for a level 2 charger,
the MAX1647 generates interrupts to signal the host when
power is applied to the charger or a battery is installed or
removed. Additional status bits allow the host to check
whether the charger has enough input voltage, and
whether the voltage on or current into the battery is being
regulated. This allows the host to determine when lithium-
ion batteries have completed charge without interrogating
the battery.
ꢀ 10-Bit Control of Voltage
ꢀ
0.75% Voltage Accuracy with External 0.1%
Reference
ꢀ Up to 28V Input Voltage
ꢀ Battery Thermistor Fail-Safe Protection
The MAX1647 is available in a 20-pin SSOP with a 2mm
profile height. The MAX1648 is available in a 16-pin SO
package.
______________Ordering Information
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
20 SSOP
________________________Applications
MAX1647EAP
MAX1648ESE
Notebook Computers
Personal Digital Assistants
Charger Base Stations
Phones
16 Narrow SO
__________________________________________________________Pin Configurations
TOP VIEW
IOUT
DCIN
VL
1
2
3
4
5
6
7
8
9
20 BST
19 LX
DCIN
VL
1
2
3
4
5
6
7
8
16 BST
LX
15
18 DHI
14 DHI
13 DLO
CCV
CCI
CCV
CCI
17
DLO
16 PGND
MAX1648
MAX1647
CS
PGND
12
SEL
CS
15
14
13
DACV
SDA
11 SETV
BATT
REF
SETI
THM
10
9
SCL
BATT
REF
AGND
12 THM
11 INT
AGND 10
SO
SSOP
SMBus is a trademark of Intel Corp.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Chemistry-Independent Battery Chargers
ABSOLUTE MAXIMUM RATINGS
DCIN to AGND..........................................................-0.3V to 30V
DCIN to IOUT...........................................................-0.3V to 7.5V
BST to AGND............................................................-0.3V to 36V
BST, DHI to LX............................................................-0.3V to 6V
LX to AGND ..............................................................-0.3V to 30V
THM, CCI, CCV, DACV, REF,
PGND to AGND.....................................................-0.3V to +0.3V
SDA, INT Current ................................................................50mA
VL Current...........................................................................50mA
Continuous Power Dissipation (T = +70°C)
A
16-Pin SO (derate 8.7mW/°C above +70°C).................696mW
20-Pin SSOP (derate 8mW/°C above +70°C) ...............640mW
Operating Temperature Range
MAX1647EAP, MAX1648ESE ...........................-40°C to +85°C
Storage Temperature.........................................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
DLO to AGND................................................-0.3V to (VL + 0.3V)
VL, SEL, INT, SDA, SCL to AGND (MAX1647) ...........-0.3V to 6V
SETV, SETI to AGND (MAX1648)................................-0.3V to 6V
BATT, CS+ to AGND.................................................-0.3V to 20V
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
(V
= 18V, V
= 4.096V, T = 0°C to +85°C. Typical values are at T = +25°C, unless otherwise noted.)
DCIN
REF
A
A
PARAMETER
CONDITIONS
MIN
7.5
TYP
MAX
UNITS
SUPPLY AND REFERENCE
DCIN Input Voltage Range
DCIN Quiescent Current
VL Output Voltage
28.0
6
V
mA
V
7.5V < V
7.5V < V
< 28V, logic inputs = VL
< 28V, no load
4
DCIN
DCIN
5.15
5.4
5.65
100
5.15
4.07
700
VL Load Regulation
I
= 10mA
mV
V
LOAD
VL AC_PRESENT Trip Point
REF Output Voltage
MAX1647
0µA < I
3.20
3.74
4
< 500µA
3.9
V
SOURCE
REF Overdrive Input Current
SWITCHING REGULATOR
Oscillator Frequency
µA
200
89
250
93
4
300
kHz
%
DHI Maximum Duty Cycle
DHI On-Resistance
High or low
High or low
VL < 3.2V, V
7
14
5
Ω
DLO On-Resistance
6
Ω
= 12V
1
BATT
BATT Input Current (Note 1)
CS Input Current (Note 1)
µA
VL < 5.15V, V
= 12V
350
1
500
5
BATT
VL < 3.2V, V = 12V
CS
µA
V
VL < 5.15V, V = 12V
CS
170
400
19
BATT, CS Input Voltage Range
0
CS to BATT Single-Count
Current-Sense Voltage
MAX1647, SEL = open,
ChargingCurrent( ) = 0x0020
2.94
185
mV
MAX1647, SEL = open,
ChargingCurrent( ) = 0x07F0;
CS to BATT Full-Scale
Current-Sense Voltage
170
200
mV
%
MAX1648, V
= 1.024V
SETI
MAX1647, ChargingVoltage( ) = 0x1060,
ChargingVoltage( ) = 0x3130; MAX1648,
Voltage Accuracy
-0.65
+0.65
V
SETV
= 3.15V, V
= 1.05V
SETV
2
_______________________________________________________________________________________
Chemistry-Independent Battery Chargers
ELECTRICAL CHARACTERISTICS (continued)
(V
= 18V, V
= 4.096V, T = 0°C to +85°C. Typical values are at T = +25°C, unless otherwise noted.)
DCIN
REF
A
A
PARAMETER
ERROR AMPLIFIERS
CONDITIONS
MIN
TYP
MAX
UNITS
GMV Amplifier Transconductance
GMI Amplifier Transconductance
1.4
0.2
mA/V
mA/V
GMV Amplifier Maximum
Output Current
80
200
80
µA
µA
GMI Amplifier Maximum
Output Current
CCI Clamp Voltage with
Respect to CCV
1.1V < V
1.1V < V
< 3.5V
25
25
200
200
mV
mV
CCV
CCI
CCV Clamp Voltage with
Respect to CCI
< 3.5V
80
TRIP POINTS AND LINEAR CURRENT SOURCES
% of
BATT POWER_FAIL Trip Point
MAX1647
MAX1647
86.5
89.5
74
89
91
91.5
92.5
77
V
DCIN
THM THERMISTOR_OR
Over-Range Trip Point
% of
V
REF
THM THERMISTOR_COLD
Trip Point
% of
75.5
23.5
V
REF
THM THERMISTOR_HOT
Trip Point
% of
22
25
V
REF
THM THERMISTOR_UR
Under-Range Trip Point
% of
MAX1647
MAX1647,
3
4.5
31
6
V
REF
ChargingCurrent( ) = 0x001F
ChargingCurrent( ) = 0x0000
25
38
mA
IOUT Output Current
V
DCIN
V
IOUT
= 7.5V,
= 0V
10
µA
V
IOUT Operating Voltage Range
With respect to DCIN voltage
-7.5
-1.0
CURRENT- AND VOLTAGE-SETTING DACs (MAX1647)
CDAC Current-Setting DAC Resolution Guaranteed monotonic
VDAC Voltage-Setting DAC Resolution Guaranteed monotonic
SETV, SETI (MAX1648)
6
Bits
Bits
10
SETV Input Bias Current
1
5
µA
µA
V
SETI Input Bias Current
SETV Input Voltage Range
0
0
4.2
1.024
SETI Input Voltage Range
V
LOGIC LEVELS (MAX1647)
SDA, SCL Input Low Voltage
0.8
+1
V
V
SDA, SCL Input High Voltage
2.8
-1
6
SDA, SCL Input Bias Current
µA
mA
SDA Output Low Sink Current
V
SDA
= 0.6V
Note 1: When DCIN is less than 4V, VL is less than 3.2V, causing the battery current to be typically 2µA (CS plus BATT input
current).
_______________________________________________________________________________________
3
Chemistry-Independent Battery Chargers
ELECTRICAL CHARACTERISTICS
(V
= 18V, V
= 4.096V, T = -40°C to +85°C. Typical values are at T = +25°C, unless otherwise noted. Limits over this
REF A A
DCIN
temperature range are guaranteed by design.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
SUPPLY AND REFERENCE
DCIN Quiescent Current
VL Output Voltage
7.5V < V
< 28V, logic inputs = VL
< 28V, no load
4
6
mA
V
DCIN
DCIN
7.5V < V
5.15
3.74
5.4
3.9
5.65
4.07
REF Output Voltage
SWITCHING REGULATOR
Oscillator Frequency
DHI Maximum Duty Cycle
DHI On-Resistance
DLO On-Resistance
BATT Input Current
CS Input Current
0µA < I
< 500µA
V
SOURCE
200
89
250
310
kHz
%
High or low
High or low
VL < 3.2V, V
4
6
7
14
5
Ω
Ω
= 12V
µA
µA
BATT
VL < 3.2V, V = 12V
CS
5
MAX1647, SEL = open,
ChargingCurrent( ) = 0x07F0;
CS to BATT Full-Scale
Current-Sense Voltage
160
185
200
mV
%
MAX1648, V
= 1.024V
SETI
MAX1647, ChargingVoltage( ) = 0x1060,
ChargingVoltage( ) = 0x3130; MAX1648,
Voltage Accuracy
-0.65
+0.65
V
SETV
= 3.15V, V
= 1.05V
SETV
ERROR AMPLIFIERS
GMV Amplifier Transconductance
GMI Amplifier Transconductance
1.4
0.2
mA/V
mA/V
GMV Amplifier Maximum
Output Current
130
320
µA
µA
GMI Amplifier Maximum
Output Current
TRIP POINTS AND LINEAR CURRENT SOURCES
THM THERMISTOR_OR
MAX1647
% of
89.5
74
22
3
91
92.5
77
25
6
V
REF
Over-Range Trip Point
THM THERMISTOR_COLD
Trip Point
% of
75.5
23.5
4.5
V
REF
THM THERMISTOR_HOT
Trip Point
% of
V
REF
THM THERMISTOR_UR
MAX1647
% of
V
REF
Under-Range Trip Point
SETV, SETI (MAX1648)
SETV Input Bias Current
1
5
µA
µA
SETI Input Bias Current
LOGIC LEVELS (MAX1647)
SDA, SCL Input Low Voltage
SDA, SCL Input High Voltage
SDA, SCL Input Bias Current
0.8
+1
V
V
2.8
-1
6
µA
mA
SDA Output Low Sink Current
V
SDA
= 0.6V
4
_______________________________________________________________________________________
Chemistry-Independent Battery Chargers
TIMING CHARACTERISTICS—MAX1647
(T = 0°C to +85°C, unless otherwise noted.)
A
PARAMETER
SCL Serial-Clock High Period
SCL Serial-Clock Low Period
Start-Condition Setup Time
Start-Condition Hold Time
SYMBOL
CONDITIONS
MIN
4
TYP
MAX
UNITS
µs
t
HIGH
t
4.7
4.7
4
µs
LOW
t
µs
SU:STA
HD:STA
t
µs
SDA Valid to SCL Rising-Edge
Setup Time, Slave Clocking in Data
t
250
0
ns
ns
µs
SU:DAT
HD:DAT
SCL Falling Edge to SDA Transition
t
SCL Falling Edge to SDA Valid,
Master Clocking in Data
t
1
DV
TIMING CHARACTERISTICS—MAX1647
(T = -40°C to +85°C, unless otherwise noted. Limits over this temperature range are guaranteed by design.)
A
PARAMETER
SCL Serial-Clock High Period
SCL Serial-Clock Low Period
Start-Condition Setup Time
Start-Condition Hold Time
SYMBOL
CONDITIONS
MIN
4
TYP
MAX
UNITS
µs
t
HIGH
t
4.7
4.7
4
µs
LOW
t
µs
SU:STA
HD:STA
t
µs
SDA Valid to SCL Rising-Edge
Setup Time, Slave Clocking in Data
t
250
0
ns
ns
µs
SU:DAT
HD:DAT
SCL Falling Edge to SDA Transition
t
SCL Falling Edge to SDA Valid,
Master Clocking in Data
t
1
DV
_______________________________________________________________________________________
5
Chemistry-Independent Battery Chargers
__________________________________________Typical Operating Characteristics
(Circuit of Figure 3, T = +25°C, unless otherwise noted.)
A
MAX1647
BATT LOAD TRANSIENT
MAX1647
BATT LOAD TRANSIENT
MAX1647/48-02
MAX1647/48-01
1.1A TO 0.9A TO 1.1A
CCI
CCV
CCI
CCI
V
V
CCV
CCI
100mV/div
2.3V
12V
CCV
CCV
CCV
V
V
CCI
CCV
200mV/div
2.4V
12V
CCI
CCI
CCV
V
BATT
1V/div
V
BATT
5V/div
0.9A TO 1.9A TO 0.9A
1ms/div
2ms/div
ChargingVoltage( ) = 0x2EE0 = 12000mV
ChargingCurrent( ) = 0x03E8 = 1000mA
ACDCIN = 18.0V, SEL = OPEN, C1 = 68µF,
C2 = 0.1µF, C3 = 47nF, R1 = 0.1Ω
ChargingVoltage( ) = 0x2EE0 = 12000mV
ChargingCurrent( ) = 0xFFFF = MAX VALUE
ACDCIN = 18.0V, SEL = OPEN, R1 = 0.1Ω
R2 = 10kΩ, C1 = 68µF, C2 = 0.1µF, C3 = 47nF
R2 = 10kΩ, L1 = 22µH, V
= 4.096V
L1 = 22µH, V
= 4.096V
REF
REF
VL VOLTAGE vs. LOAD CURRENT
INTERNAL REFERENCE VOLTAGE
5.5
5.0
3.86
3.84
3.82
3.80
3.78
3.76
3.74
3.72
3.70
4.5
4.0
3.5
CIRCUIT OF FIGURE 3
DCIN
V
= 6.6V
0
0
10
20
30
40
50
0
0.5
1.0
1.5
2.0
LOAD CURRENT (mA)
LOAD CURRENT (mA)
MAX1647
OUTPUT V-I CHARACTERISTIC
OUTPUT VOLTAGE ERROR
INPUT AND OUTPUT POWER
0.001
0.01
0.8
0.6
0.4
0.2
0
40
35
30
25
20
15
10
5
V
V
= 28V
DCIN
BATT
BATT NO-LOAD
= 12.6V
OUTPUT VOLTAGE = 16.384V
ChargingCurrent( ) = 0xFFFF
ChargingVoltage( ) = 0xFFFF
3mA LOAD
0.1
1
POWER INTO
CIRCUIT
300mA LOAD
10
V
= 28V, V
= 4.096V
REF
POWER TO BATT
DCIN
-0.2
-0.4
ChargingVoltage( ) = 0xFFFF
ChargingCurrent( ) = 0xFFFF
100
0
0
500
1000
1500
2000 2500
4500
8500
12,500
16,500
PROGRAMMED VOLTAGE CODE IN DECIMAL
500
CURRENT INTO BATT (mA)
0
1000
1500
2000
2500
LOAD CURRENT (mA)
6
_______________________________________________________________________________________
Chemistry-Independent Battery Chargers
______________________________________________________________Pin Description
PIN
NAME
FUNCTION
MAX1647
MAX1648
1
2
3
4
5
—
1
IOUT
DCIN
VL
Linear Current-Source Output
Input Voltage for Powering Charger
2
Chip Power Supply. 5.4V linear regulator output from DCIN.
Voltage-Regulation-Loop Compensation Point
Current-Regulation-Loop Compensation Point
3
CCV
CCI
4
Current-Range Selector. Tying SEL to VL sets a 4A full-scale current. Leaving SEL open
sets a 2A full-scale current. Tying SEL to AGND sets a 1A full-scale current.
6
—
SEL
7
5
CS
BATT
REF
Current-Sense Positive Input
8
6
Battery Voltage Input and Current-Sense Negative Input
3.9V Reference Voltage Output or External Reference Input
Analog Ground
9
7
10
—
11
—
12
13
14
15
16
17
18
19
20
8
AGND
SETI
INT
10
—
11
9
Current-Regulation-Loop Set Point
Open-Drain Interrupt Output
SETV
THM
SCL
Voltage-Regulation-Loop Set Point
Thermistor Sense Voltage Input
Serial Clock
—
—
—
12
13
14
15
16
SDA
DACV
PGND
DLO
DHI
Serial Data
Voltage DAC Output
Power Ground
Low-Side Power MOSFET Driver Output
High-Side Power MOSFET Driver Output
Power Connection for the High-Side Power MOSFET Driver
Power Connection for the High-Side Power MOSFET Driver
LX
BST
_______________________________________________________________________________________
7
Chemistry-Independent Battery Chargers
MOST SIGNIFICANT
ADDRESS BIT (A6)
CLOCKED INTO SLAVE
A5 CLOCKED
INTO SLAVE
A4 CLOCKED
INTO SLAVE
A3 CLOCKED
INTO SLAVE
START
CONDITION
SCL
t
t
HIGH
LOW
t
HD:STA
SDA
t
t
t
HD:DAT
t
t
SU:STA
HD:DAT
SU:DAT
SU:DAT
Figure 1. SMBus Serial Interface Timing—Address
MOST SIGNIFICANT BIT
OF DATA CLOCKED
INTO MASTER
ACKNOWLEDGE
BIT CLOCKED
INTO MASTER
RW BIT
CLOCKED
INTO SLAVE
SCL
SLAVE PULLING
SDA LOW
SDA
t
t
DV
DV
Figure 2. SMBus Serial Interface Timing—Acknowledge
_______________________________________________________________________________________
8
Chemistry-Independent Battery Chargers
4
6
GND
2
VIN
MAX874
VOUT
D5
10
9
1
Q1
AGND
REF
IOUT
C9
2
C4
DCIN
SEL
VL
6
3
N.C.
R6
R7
D6
R3
R5
C5
D4*
R4
(NOTE 2)
12
5
C6
THM
CCI
MAX1647
D2
20
18
BST
DHI
DC SOURCE
M1
C3
C7
7.5V–28V
19
17
LX
L1
D1
M2
DLO
4
CCV
16
7
D3
PGND
CS
(NOTE 1)
C1
R2
C2
R1A
R1B
8
15
BATT
SCL
DACV
13
C8
14
11
SDA
INT
= HIGH-CURRENT TRACES (8A MAX)
-
T
D
C
+
NOTE 1: C6, M2, D1, AND C1 GROUNDS MUST CONNECT TO
THE SAME RECTANGULAR PAD ON THE LAYOUT.
NOTE 2: C5 MUST BE PLACED WITHIN 0.5cm OF THE MAX1647,
WITH TRACES NO LONGER THAN 1cm CONNECTING
VL AND PGND.
SMART BATTERY
STANDARD CONNECTOR
HOST AND LOAD
*OPTIONAL (SEE NEGATIVE INPUT VOLTAGE PROTECTION SECTION).
Figure 3. MAX1647 Typical Application Circuit
_______________________________________________________________________________________
9
Chemistry-Independent Battery Chargers
Table 1a. Component Selection for Figure 3 Circuit (Also Use for Figure 4)
DESIGNATION
QTY
UNITS
NOTES
SOURCE/TYPE
Sprague, 595D476X0020D7T, D case
AVX, TPSE476M020R0150, E case
C1
47
µF
20V, ESR at 250kHz ≤ 0.4Ω
C2, C4, C7, C9
0.1
47
1
22
22
µF
nF
µF
µF
nF
C3
C5
C6
C8
10V, ceramic or low ESR
35V
10V
NIEC, NSQ03A04, FLAT-PAK (SMC)
NIEC, 30VQ04F, TO-252AA (SMD)
Motorola, MBRS340T3, SMC
Motorola, MBRD340T4, DPAK
Diodes Inc., SK33, SMC
3A I , 30V Schottky diode,
DC
D1, D3, D4
P
D
> 0.8W, 1N5821 equivalent
IR, 30BQ040, SMC
50mA I , 40V fast-recovery diode,
DC
1N4150 equivalent
D2, D5
D6
4.3V zener diode,
1N4731 or equivalent
Sumida, RCH-110/220M, 10mm x 10mm x 10mm
Coiltronics, UP2-220, 0.541" x 0.345" x 0.231"
Coilcraft, DO3340P-223, 0.510" x 0.370" x 0.450"
Coilcraft, DO5022P-223, 0.730" x 0.600" x 0.280"
20%, 3A I
Note: size in L x W x H
SAT
L1
22
µH
Motorola, MMSF5N03HD, SO-8
Motorola, MMDF3N03HD, SO-8
Motorola, MTD20N03HDL, DPAK
IR, IRF7201, SO-8
R
≤ 0.1Ω, V
≥ 30V,
DSS
DS, ON
M1
P
D
> 0.5W, logic level, N-channel
IR, IRF7303, SO-8
power MOSFET
IR, IRF7603, Micro8
Siliconix, Si9410DY, SO-8
Siliconix, Si9936DY, SO-8
Siliconix, Si6954DQ, TSSOP-8
Motorola, 2N7002LT1, SOT23
Motorola, MMBF170LT1, SOT23
Diodes Inc., 2N7002, SOT23
Diodes Inc., BS870, SOT23
Zetex, ZVN3306F, SOT23
Central Semiconductor, 2N7002, SOT23
R
≤ 10Ω, V
≥ 30V,
DSS
DS, ON
M2
Q1
logic level, N-channel power
MOSFET, 2N7002 equivalent
V
≤ -30V, 50mA I
,
CE, MAX
C, CONT
2N3906 equivalent
IRC, CHP1100R100F13, 2512
IRC, LR251201R100F, 2512
Dale, WSL-2512/0.1Ω/ 1%, 2512
R1A
R1B
100
1
mΩ
1%, 1W
Ω
5%, 1/8W
R2, R4
R3
10
10
10
10
kΩ
kΩ
Ω
5%, 1/16W
1%, 1/16W
5%, 1/16W
5%, 1/8W
R5, R7
R6
kΩ
10 ______________________________________________________________________________________
Chemistry-Independent Battery Chargers
_______________Detailed Description
Table 1b. Component Suppliers
MANUFACTURER
AVX
PHONE
FAX
Output Characteristics
The MAX1647/MAX1648 contain both a voltage-
regulation loop and a current-regulation loop. Both
loops operate independently of each other. The volt-
age-regulation loop monitors BATT to ensure that its
voltage never exceeds the voltage set point (V0). The
current-regulation loop monitors current delivered to
BATT to ensure that it never exceeds the current-limit
set point (I0). The current-regulation loop is in control
as long as BATT voltage is below V0. When BATT volt-
age reaches V0, the current loop no longer regulates,
and the voltage-regulation loop takes over. Figure 5
shows the V-I characteristic at the BATT pin.
803-946-0690
516-435-1110
847-639-6400
561-241-7876
605-668-4131
310-322-3331
512-992-7900
805-867-2555
408-988-8000
603-224-1961
847-956-0666
516-543-7100
803-626-3123
516-435-1824
847-639-1469
561-241-9339
605-665-1627
310-322-3332
512-992-3377
805-867-2698
408-970-3950
603-224-1430
847-956-0702
516-864-7630
Central Semiconductor
Coilcraft
Coiltronics
Dale
IR
IRC
NIEC
Siliconix
Sprague
Sumida
Zetex
C4
C5
R3
REF
VL
R4
THM
R5
D2
MAX1648
CCI
C3
DCIN
D4
C6
M1
DC SOURCE
7.5V–28V
DHI
BST
L1
C7
CCV
LX
D3
D1
R2
M2
DLO
C2
PGND
CS
R8
SETI
R1
BATT
R10
R9
C1
SETV
AGND
BATTERY
R11
T
Figure 4. MAX1648 Typical Operating Circuit
______________________________________________________________________________________ 11
Chemistry-Independent Battery Chargers
Whether the MAX1647 is controlling the voltage or cur-
rent at any time depends on the battery’s state. If the
battery has been discharged, the MAX1647’s output
reaches the current-regulation limit before the voltage
limit, causing the system to regulate current. As the bat-
tery charges, the voltage rises until the voltage limit is
reached, and the charger switches to regulating voltage.
The transition from current to voltage regulation is done
by the charger, and need not be controlled by the host.
BATT
VOLTAGE
V0
V0 = VOLTAGE SET POINT
I0 = CURRENT-LIMIT SET POINT
Voltage Control
The internal GMV amplifier controls the MAX1647’s out-
put voltage. The voltage at the amplifier’s noninverting
input amplifier is set by a 10-bit DAC, which is controlled
by a ChargingVoltage( ) command on the SMBus (see
the MAX1647 Logic section for more information). The
battery voltage is fed to the GMV amplifier through a 4:1
resistive voltage divider. With an external 4.096V refer-
ence, the set voltage ranges between 0 and 16.38V with
16mV resolution.
AVERAGE CURRENT
THROUGH THE RESISTOR
BETWEEN CS AND BATT
I0
Figure 5. Output V-I Characteristic
This poses a challenge for charging four lithium-ion
cells in series: because the lithium-ion battery’s typical
per-cell voltage is 4.2V maximum, 16.8V is required. A
larger reference voltage can be used to circumvent
this. Under this condition, the maximum battery voltage
no longer matches the programmed voltage. The solu-
tion is to use a 4.2V reference and host software.
Contact Maxim’s applications department for more
information.
Setting V0 and I0 (MAX1647)
Set the MAX1647’s voltage and current-limit set points
through the Intel System Management Bus (SMBus) 2-
wire serial interface. The MAX1647’s logic interprets the
serial-data stream from the SMBus interface to set inter-
nal digital-to-analog converters (DACs) appropriately.
See the MAX1647 Logic section for more information.
Setting V0 and I0 (MAX1648)
Set the MAX1648’s voltage- and current-limit set points
(V0 and I0, respectively) using external resistive dividers.
Figure 6b is the MAX1648 block diagram. V0 equals four
times the voltage on the SETV pin. I0 equals the voltage
on SETI divided by 5.5, divided by R1 (Figure 4).
The GMV amplifier’s output is connected to the CCV
pin, which compensates the voltage-regulation loop.
Typically, a series-resistor/capacitor combination can
be used to form a pole-zero couplet. The pole intro-
duced rolls off the gain starting at low frequencies. The
zero of the couplet provides sufficient AC gain at mid-
frequencies. The output capacitor then rolls off the mid-
frequency gain to below 1, to guarantee stability before
encountering the zero introduced by the output capaci-
tor’s equivalent series resistance (ESR). The GMV
amplifier’s output is internally clamped to between one-
fourth and three-fourths of the voltage at REF.
_____________________Analog Section
The MAX1647/MAX1648 analog section consists of a
current-mode PWM controller and two transconduc-
tance error amplifiers: one for regulating current and
the other for regulating voltage. The MAX1647 uses
DACs to set the current and voltage level, which are
controlled through the SMBus interface. The MAX1648
eliminates the DACs and controls the error amplifiers
directly from SETI (for current) and SETV (for voltage).
Since separate amplifiers are used for voltage and cur-
rent control, both control loops can be compensated
separately for optimum stability and response in each
state. The following discussion relates to the MAX1647;
however, MAX1648 operation can easily be inferred
from the MAX1647.
Current Control
The internal GMI amplifier and an internal current
source control the battery current while the charger is
regulating current. Since the regulator current’s accura-
cy is not adequate to ensure full 11-bit accuracy, an
internal linear current source is used in conjunction with
the PWM regulator to set the battery current. The cur-
rent-control DAC’s five least significant bits set the
12 ______________________________________________________________________________________
Chemistry-Independent Battery Chargers
REF
DCIN
10kΩ
10kΩ
10kΩ
10kΩ
16mA
5
8mA
4mA
2mA
1mA
THERMISTOR_OR
THERMISTOR_COLD
THERMISTOR_HOT
THERMISTOR_UR
IOUT
THERM_SHUT
SEL
THERMAL
SHUTDOWN
LOGIC
BLOCK
THM
SCL
SDA
INT
DCIN
VL
AC_PRESENT
5.4V LINEAR
REGULATOR
INTERNAL 3.9V
REFERENCE
REF
30kΩ
3kΩ
100kΩ
500Ω
AGND
CCV
AGND
CCV_LOW
3R
REF
CS
CURRENT-SENSE
LEVEL SHIFT AND
GAIN OF 5.5
R
AGND
BATT
REF
3/8 REF = ZERO CURRENT
NOTE: APPROX. REF/4 + V
BST
FROM LOGIC
BLOCK
6
THRESH
THRESH
6-BIT DAC
TO 3/4 REF + V
CCI
LEVEL
SHIFT
R
R
DRIVER
DHI
GMI
NOTE: REF/4 TO 3/4 REF
LX
SUMMING
COMPARATOR
BLOCK
R
R
FROM LOGIC BLOCK
BATT
MIN
VOLTAGE_INREG
CURRENT_INREG
VL
TO LOGIC BLOCK
TO LOGIC BLOCK
AGND
CLAMP
TO REF
(MAX)
CLAMP
R
DRIVER
DLO
FROM LOGIC
BLOCK
AGND
GMV
PGND
R
R
R
CCV
REF
10-BIT DAC
AGND
AGND
FROM LOGIC BLOCK
10
DACV
POWER_FAIL
TO LOGIC BLOCK
DCIN/4.5
Figure 6a. MAX1647 Block Diagram
______________________________________________________________________________________ 13
Chemistry-Independent Battery Chargers
REF
10kΩ
10kΩ
THERMISTOR_COLD
THERMISTOR_HOT
THM
30kΩ
3kΩ
AGND
DCIN
VL
AC_PRESENT
5.4V LINEAR
REGULATOR
INTERNAL 3.9V
REFERENCE
REF
CS
CURRENT-SENSE
LEVEL SHIFT AND
GAIN OF 5.5
BATT
AGND
ON
BST
LEVEL
SHIFT
DRIVER
DHI
CCI
GMI
LX
SETI
REF / 2 =
ZERO CURRENT
SUMMING
COMPARATOR
BLOCK
BATT
MIN
ON
CLAMP
VL
R
R
DRIVER
DLO
AC_PRESENT AND
NOT (THERMISTOR_HOT
OR THERMISTOR_COLD)
GMV
PGND
R
R
CCV
AGND
SETV
Figure 6b. MAX1648 Block Diagram
14 ______________________________________________________________________________________
Chemistry-Independent Battery Chargers
internal current sources’ state, and the six most signifi-
The PWM comparator compares the current-sense
amplifier’s output to the higher output voltage of either
the GMV or the GMI amplifier (the error voltage). This
current-mode feedback corrects the duty ratio of the
switched voltage, regulating the peak battery current
and keeping it proportional to the error voltage. Since
the average battery current is nearly the same as the
peak current, the controller acts as a transconductance
amplifier, reducing the effect of the inductor on the out-
put filter LC formed by the output inductor and the bat-
tery’s parasitic capacitance. This makes stabilizing the
circuit easy, since the output filter changes from a com-
plex second-order RLC to a first-order RC. To preserve
the inner current-control loop’s stability, slope compen-
sation is also fed into the comparator. This damps out
perturbations in the pulse width at duty ratios greater
than 50%.
cant bits control the switching regulator’s current. The
internal current source supplies 1mA resolution to the
battery to comply with the smart-battery specification.
When the current is set to a number greater than 32,
the internal current source remains at 31mA. This guar-
antees that battery-current setting is monotonic regard-
less of current-sense resistor choice and current-sense
amplifier offset.
The GMI amplifier’s noninverting input is driven by a 4:1
resistive voltage divider, which is driven by the 6-bit
DAC. If an external 4.096V reference is used, this input
is approximately 1.0V at full scale, and the resolution is
16mV. The current-sense amplifier drives the inverting
input to the GMI amplifier. It measures the voltage
across the current-sense resistor (R
) (which is
SEN
between the CS and BATT pins), amplifies it by approx-
imately 5.45, and level shifts it to ground. The full-scale
At heavy loads, the PWM controller switches at a fixed
frequency and modulates the duty cycle to control the
battery voltage or current. At light loads, the DC current
through the inductor is not sufficient to prevent the cur-
rent from going negative through the synchronous recti-
fier (Figure 3, M2). The controller monitors the current
current is approximately 0.2V / R
, and the resolution
SEN
is 3.2mV / R
.
SEN
The current-regulation-loop is compensated by adding
a capacitor to the CCI pin. This capacitor sets the cur-
rent-feedback loop’s dominant pole. The GMI amplifier’s
output is clamped to between approximately one-fourth
and three-fourths of the REF voltage. While the current is
in regulation, the CCV voltage is clamped to within
80mV of the CCI voltage. This prevents the battery volt-
age from overshooting when the DAC voltage setting is
updated. The converse is true when the voltage is in
regulation and the current is not at the current DAC set-
ting. Since the linear range of CCI or CCV is about 1.5V
to 3.5V or about 2V, the 80mV clamp results in a rela-
tively negligible overshoot when the loop switches from
voltage to current regulation or vice versa.
through the sense resistor R
; when it drops to zero,
SEN
the synchronous rectifier turns off to prevent negative
current flow.
MOSFET Drivers
The MAX1647 drives external N-channel MOSFETs to
regulate battery voltage or current. Since the high-side
N-channel MOSFET’s gate must be driven to a voltage
higher than the input source voltage, a charge pump is
used to generate such a voltage. The capacitor C7
(Figure 3) charges to approximately 5V through D2
when the synchronous rectifier turns on. Since one side
of C7 is connected to the LX pin (the source of M1), the
high-side driver (DHI) can drive the gate up to the volt-
age at BST, which is greater than the input voltage,
when the high-side MOSFET turns on.
PWM Controller
The battery voltage or current is controlled by the cur-
rent-mode, pulse-width-modulated (PWM), DC-DC con-
verter controller. This controller drives two external
N-channel MOSFETs, which switch the voltage from the
input source. This switched voltage feeds an inductor,
which filters the switched rectangular wave. The con-
troller sets the pulse width of the switched voltage so that
it supplies the desired voltage or current to the battery.
The synchronous rectifier behaves like a diode, but with
a smaller voltage drop to improve efficiency. A small
dead time is added between the time that the high-side
MOSFET turns off and the synchronous rectifier turns
on, and vice versa. This prevents crowbar currents (cur-
rents that flow through both MOSFETS during the brief
time that one is turning on and the other is turning off).
Connect a Schottky rectifier from ground to LX (across
the source and drain of M2) to prevent the synchronous
rectifier’s body diode from conducting. The body diode
typically has slower switching-recovery times, so allow-
ing it to conduct would degrade efficiency.
The heart of the PWM controller is the multi-input com-
parator. This comparator sums three input signals to
determine the pulse width of the switched signal, set-
ting the battery voltage or current. The three signals are
the current-sense amplifier’s output, the GMV or GMI
error amplifier’s output, and a slope-compensation sig-
nal, which ensures that the controller’s internal current-
control loop is stable.
______________________________________________________________________________________ 15
Chemistry-Independent Battery Chargers
The synchronous rectifier may not be completely
replaced by a diode because the BST capacitor
charges while the synchronous rectifier is turned on.
Without the synchronous rectifier, the BST capacitor
may not fully charge, leaving the high-side MOSFET
with insufficient gate drive to turn on. However, the
synchronous rectifier can be replaced with a small
MOSFET, such as a 2N7002, to guarantee that the BST
capacitor is allowed to charge. In this case, most of the
current at high currents is carried by the diode and not
by the synchronous rectifier.
BOLD LINE INDICATES THAT
ACK
THE MAX1647 PULLS SDA LOW
D8
D9
ChargingMode( ) = 0 x 12
ChargingVoltage( ) = 0 x 15
ChargingCurrent( ) = 0 x 14
AlarmWarning( ) = 0 x 16
ChargerStatus( ) = 0 x 13
D10
D11
D12
D13
D14
D15
ACK
Internal Regulator and Reference
The MAX1647 uses an internal low-dropout linear regula-
tor to create a 5.4V power supply (VL), which powers its
internal circuitry. VL can supply up to 20mA. A portion of
this current powers the internal circuitry, but the remain-
ing current can power the external circuitry. The current
used to drive the MOSFETs comes from this supply,
which must be considered when calculating how much
power can be drawn. To estimate the current required to
drive the MOSFETs, multiply the total gate charge of
each MOSFET by the switching frequency (typically
250kHz). The internal circuitry requires as much as 6mA
from the VL supply. To ensure VL stability, bypass the VL
pin with a 1µF or greater capacitor.
ACK
D0
D1
THERMISTOR_OR
THERMISTOR_COLD
D2
D3
THERMISTOR_HOT
THERMISTOR_UR
D4
D5
D6
D7
ALARM_INHIBITED
POWER_FAIL
BATTERY_PRESENT
AC_PRESENT
ACK
ACK
1
ACK
CMD0
CHARGE_INHIBITED
The MAX1647 has an internal 2% accurate 3.9V refer-
ence voltage. An external reference can be used to
increase the charger’s accuracy. Use a 4.096V reference,
such as the MAX874, for compliance with the Intel/
Duracell smart-battery specification. Voltage-setting
accuracy is 0.65%, so the total voltage accuracy is the
accuracy added to the reference accuracy. For 1% total
voltage accuracy, use a reference with 0.35% or greater
accuracy. If the internal reference is used, bypass it with
a 0.1µF or greater capacitor.
CMD1
CMD2
CMD3
1
0
0
MASTER_MODE
VOLTAGE_NOTREG
CURRENT_NOTREG
CMD4
CMD5
CMD6
1
0
0
LEVEL_2
LEVEL_3
CURRENT_OR
CMD7
0
ACK
W
VOLTAGE_OR
ACK
W
1
ACK
R
MAX1647 Logic
The MAX1647 uses serial data to control its operation. The
serial interface complies with the SMBus specification (see
System Management Bus Specification, from Intel
Architecture Labs; http://www.intel.com/IAL/power-
mgm.html; Intel Architecture Labs: 800-253-3696).
Charger functionality complies with the Intel/Duracell
Smart Charger Specification for a level 2 charger.
1
1
0
0
0
0
0
0
1
0
0
0
1
1
0
0
0
0
0
0
The MAX1647 uses the SMBus Read-Word and Write-
Word protocols to communicate with the battery it is
charging, as well as with any host system that monitors
the battery to charger communications. The MAX1647
never initiates communication on the bus; it only
receives commands and responds to queries for status
information. Figure 7 shows examples of the SMBus
Write-Word and Read-Word protocols.
START
START
REPEATED
START
Figure 7. Write-Word and Read-Word Examples
16 ______________________________________________________________________________________
Chemistry-Independent Battery Chargers
Each communication with the MAX1647 begins with a
ChargingVoltage( )
The ChargingVoltage( ) command uses Write-Word
protocol. The command code for ChargingVoltage( ) is
0x15; thus, the CMD7–CMD0 bits in Write-Word proto-
col should be 0b00010101. The 16-bit binary number
formed by D15–D0 represents the voltage set point
(V0) in millivolts; however, since the MAX1647 has only
16mV resolution in setting V0, the D0, D1, D2, and D3
bits are ignored. For D15 = D14 = 0:
start condition that is defined as a falling edge on SDA
with SCL high. The device address follows the start
condition. The MAX1647 device address is 0b0001001
(0b indicates a binary number), which may also be
denoted as 0x12 (0x indicates a hexadecimal number)
for Write-Word commands, or 0x13 in hexadecimal for
Read-Word commands (note that the address is only
seven bits, and the hexadecimal representation uses
R/W as its least significant bit).
VDAC
210
VOLTAGE_OR = 0 and V0 in Volts = 4 x REF x
(
)
ChargerMode( )
The ChargerMode( ) command uses Write-Word proto-
col. The command code for ChargerMode( ) is 0x12;
thus the CMD7–CMD0 bits in Write-Word protocol
should be 0b00010010. Table 2 describes the functions
of the 16 different data bits (D0–D15). Bit 0 refers to the
D0 bit in the Write-Word protocol (Figure 7).
In equation 1, VDAC is the decimal equivalent of the
binary number represented by bits D13, D12, D11,
D10, D9, D8, D7, D6, D5, and D4 programmed with the
ChargingVoltage( ) command. For example, if D4–D13
are all set, VDAC is the decimal equivalent of
0b1111111111 (1023). If either D15 or D14, or both
D15 and D14, are set, all the bits in the voltage DAC
(Figure 6a) are set, regardless of D13–D0, and the
status register’s VOLTAGE_OR bit is set. For D15 = 1
and/or D14 = 1:
Whenever the BATTERY_PRESENT status bit is clear,
the HOT_STOP bit is set, regardless of any previous
ChargerMode( ) command. To charge a battery that
has a thermistor impedance in the HOT range (i.e.,
THERMISTOR_HOT = 1 and THERMISTOR_UR = 0),
the host must use the ChargerMode( ) command to
clear HOT_STOP after the battery is inserted. The
HOT_STOP bit returns to its default power-up condition
(‘1’) whenever the battery is removed.
210 -1
210
VOLTAGE_OR = 1 and V0 in Volts = 4 x REF x
(
)
Table 2. ChargerMode( ) Bit Functions
BIT
POSITION*
POR
VALUE**
BIT NAME
FUNCTION
0 = Allow normal operation; clear the CHG_INHIBITED status bit.
1 = Turn the charger off; set the CHG_INHIBITED status bit.
INHIBIT_CHARGE
ENABLE_POLLING
0
1
0
—
Not implemented. Write 0 into this bit.
0 = No change in any non-ChargerMode( ) settings.
POR_RESET
2
—
1 = Change the voltage and current settings to 0xFFFF and 0x00C0
respectively; clear the THERMISTOR_HOT and ALARM_INHIBITED bits.
RESET_TO_ZERO
N/A
3
—
—
Not implemented. Write 0 into this bit.
4, 7, 8, 9,
11–15
Not implemented. Write 1 into this bit.
0 = Interrupt on either edge of the BATTERY_PRESENT status bit.
1 = Do not interrupt because of a BATTERY_PRESENT bit change.
BATTERY_PRESENT_MASK
POWER_FAIL_MASK
HOT_STOP
5
6
0
1
1
0 = Interrupt on either edge of the POWER_FAIL status bit.
1 = Do not interrupt because of a POWER_FAIL bit change.
0 = The THERMISTOR_HOT status bit does not turn the charger off.
1 = THERMISTOR_HOT turns the charger off.
10
*Bit position in the D15–D0 data.
**Power-on reset value.
N/A = Not available.
______________________________________________________________________________________ 17
Chemistry-Independent Battery Chargers
Figure 8 shows the mapping between V0 (the voltage-
regulation-loop set point) and the ChargingVoltage( )
data.
ChargingCurrent( )
The ChargingCurrent( ) command uses Write-Word
protocol. The command code for ChargingCurrent( ) is
0x14; thus, the CMD7–CMD0 bits in Write-Word proto-
col should be 0b00010100. The 16-bit binary number
formed by D15–D0 represents the current-limit set point
(I0) in milliamps. Tying SEL to AGND selects a 1.023A
maximum setting for I0. Leaving SEL open selects a
2.047A maximum setting for I0. Tying SEL to VL selects
a 4.095A maximum setting for I0.
The power-on reset value for the ChargingVoltage( )
register is 0xFFF0; thus, the first time a MAX1647 is
powered on, the BATT voltage regulates to 16.368V
with V
= 4.096V. Any time the BATTERY_PRESENT
REF
status bit is clear, the ChargingVoltage( ) register
returns to its power-on reset state.
16.368
V
= 4.096V
REF
12.592
8.400
4.192
0
0b000100000110xxxx
0x106x
0b001111111111xxxx
0x3FFx
0b000000000000xxxx
0x000x
0b001000001101xxxx 0b001100010011xxxx
0x20Dx 0x313x
0b111111111111xxxx
0xFFFx
ChargingVoltage( ) D15–D0 DATA
Figure 8. ChargingVoltage( ) Data to Voltage Mapping
18 ______________________________________________________________________________________
Chemistry-Independent Battery Chargers
Two sources of current in the MAX1647 charge the bat-
ChargingCurrent( ) command and IOUT source current.
The CCV_LOW comparator checks to see if the output
voltage is too high by comparing CCV to REF / 4. If
CCV_LOW = 1 (when CCV < REF / 4), IOUT shuts off,
preventing the output voltage from exceeding the voltage
set point specified by the ChargingVoltage( ) register.
VOLTAGE_NOTREG = 1 whenever the internal clamp
pulls down on CCV. (The internal clamp pulls down on
CCV to keep its voltage close to CCI’s voltage.)
tery: a binary-weighted linear current source sources
from IOUT, and a switching regulator controls the current
flowing through the current-sense resistor (R1). IOUT
provides a small maintenance charge current to com-
pensate for battery self-discharge, while the switching
regulator provides large currents for fast charging.
IOUT sources from 1mA to 31mA. Table 3 shows the
relationship between the value programmed with the
Table 3. Relationship Between IOUT Source Current and ChargingCurrent( ) Value
IOUT
OUTPUT
CURRENT
CHARGE_
INHIBITED
ALARM_
INHIBITED
VOLTAGE_
NOTREG
(NOTE 1)
ChargingVoltage( ) ChargingCurrent( ) CCV_LOW
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
x
1
x
0
0
0
0
0
0
0
0
1
x
x
0x0010–0xFFFF
0x0001–0x001F
0
1
1
0
1
1
x
x
x
x
x
x
0
1
x
0
1
x
x
x
x
x
1mA–31mA
0mA
0x0010–0xFFFF
0x0001–0x001F
0x0010–0xFFFF
0x0001–0x001F
1mA–31mA
31mA
0mA
0x0010–0xFFFF
0x0020–0xFFFF
0x0010–0xFFFF
0x0020–0xFFFF
0x0010–0xFFFF
0x0020–0xFFFF
31mA
0mA
x
0x0000
0x0000–0x000F
x
x
x
x
0mA
x
x
x
0mA
0mA
0mA
Note 1: Logical AND of THERMISTOR_HOT, HOT_STOP, NOT(THERMISTOR_UR).
185
SEL = OPEN OR SEL = VL
94
2.94
0b000001
0b100000
0b111111
CURRENT DAC CODE, DA5–DA0 BITS
Figure 9. Average Voltage Between CS and BATT vs. Current DAC Code
______________________________________________________________________________________ 19
Chemistry-Independent Battery Chargers
Table 4. Relationship Between Current DAC Code and the ChargingCurrent( ) Value
CURRENT
DAC
CODE
CHARGE_
INHIBITED
ALARM_
INHIBITED
SW REG
ON?
(NOTE 1)
ChargingVoltage( )
SEL
ChargingCurrent( )
(NOTE 2)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
x
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
x
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
0x0010–0xFFFF
x
0V
0V
0x0001–0x001F
0x0020–0x003F
0x0040–0x03DF
0x03E0–0x03FF
0x0400–0xFFFF
0x0001–0x001F
0x0020–0x003F
0x0040–0x07DF
0x07E0–0x07FF
0x0800–0xFFFF
0x0001–0x001F
0x0020–0x003F
0x0040–0x007F
0x0080–0x0F9F
0x0FA0–0x0FBF
0x0FC0–0x0FFF
0x0001–0xFFFF
0x0000
0
2
No
Yes
Yes
Yes
Yes
No
0
0
0V
4–60
62
62
0
0
0V
0
0V
1
open
open
open
open
open
VL
0
1
Yes
Yes
Yes
Yes
No
0
2–62
63
63
0
0
0
1
0
VL
1
Yes
Yes
Yes
Yes
Yes
Yes
No
0
VL
1
0
VL
2–62
63
63
63
0
0
VL
0
VL
0
VL
1
x
0
0x0010–0xFFFF
x
x
x
N/C
N/C
N/C
N/C
No
N/C
N/C
N/C
N/C
x
x
No
1
x
x
x
x
No
x
x
x
x
No
Note 1: Logical AND of THERMISTOR_HOT, HOT_STOP, NOT(THERMISTOR_UR).
Note 2: Value of CURRENT_OR bit in the ChargerStatus( ) register.
N/C = No change.
Table 5. Effect of SEL Pin-Strapping on the ChargingCurrent( ) Data Bits
R1
(mΩ)
SEL
D15 D14 D13 D12 D11 D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
AGND 181
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
DA5 DA4 DA3 DA2 DA1
I4
I4
I4
I3
I3
I3
I2
I2
I2
I1
I1
I1
I0
I0
I0
Open
VL
90
45
DA5 DA4 DA3 DA2 DA1 DA0
DA5 DA4 DA3 DA2 DA1 DA0
*
*When SEL = VL, D5 = 1 forces DA0 to be 1 regardless of the D6 bit value.
With the switching regulator on, the current through R1
(Figure 3) is regulated by sensing the average voltage
between CS and BATT. A 6-bit current DAC controls
the current-limit set point. DA5–DA0 denote the bits in
the current DAC code. Figure 9 shows the relationship
between the current DAC code and the average volt-
age between CS and BATT.
When the switching regulator is off, DHI is forced to
LX and DLO is forced to ground. This prevents current
from flowing through inductor L1. Table 4 shows the
relationship between the ChargingCurrent( ) register
value and the switching regulator current DAC code.
20 ______________________________________________________________________________________
Chemistry-Independent Battery Chargers
With SEL = AGND, R1 should be as close as possible to
protocol returns D15–D0 (Figure 7). Table 7 describes
the meaning of the individual bits. The latched bits,
THERMISTOR_HOT and ALARM_INHIBITED, are
cleared whenever BATTERY_PRESENT = 0 or
ChargerMode( ) is written with POR_RESET = 1.
0.185 / 1.023 = 181mΩ to ensure that the actual output
current matches the data value programmed with the
ChargingCurrent( ) command. With SEL = open, R1
should be as close as possible to 90mΩ. With SEL = VL,
R1 should be as close as possible to 45mΩ. Table 5 sum-
marizes how SEL affects the R1 value and the meaning of
data bits D15–D0 in the ChargingCurrent( ) command.
DA5–DA0 denote the current DAC code bits, and I4–I0
denote the IOUT linear-current source binary weighting
bits. Note that whenever any current DAC bits are set, the
linear-current source is set to full scale (31mA).
Interrupts and the Alert-Response
Address
An interrupt is triggered (INT goes low) whenever power
is applied to DCIN, the BATTERY_PRESENT bit changes,
or the POWER_FAIL bit changes. BATTERY_PRESENT
and POWER_FAIL have interrupt masks that can be set
or cleared via the ChargerMode( ) command. INT stays
low until the interrupt is cleared. There are two methods
for clearing the interrupt: issuing a ChargerStatus( ) com-
mand, and using the Receive Byte protocol with a 0x19
Alert-Response address. The MAX1647 responds to the
Alert-Response address with the 0x89 byte.
The power-on reset value for the ChargingCurrent( )
register is 0x000C. Irrespective of the SEL pin setting,
the MAX1647 powers on with I0 set to 12mA (i.e.,
DA5–DA0, I1, and I0 all equal to zero, and only I3 and
I2 set). Anytime the BATTERY_PRESENT status bit is
clear (battery removed), the ChargingCurrent( ) register
returns to its power-on reset state. This ensures that
upon insertion of a battery, the initial charging current is
12mA.
__________Applications Information
Using the MAX1647
with Duracell Smart Batteries
AlarmWarning( )
The AlarmWarning( ) command uses Write-Word protocol.
The command code for AlarmWarning( ) is 0x16; thus the
CMD7–CMD0 in Write-Word protocol should be
0b00010110. The AlarmWarning( ) command sets the
ALARM_INHIBITED status bit in the MAX1647 if D15, D14,
or D12 of the Write-Word protocol data equals 1. Table 6
summarizes the AlarmWarning( ) command’s function.
The ALARM_INHIBITED status bit remains set until
BATTERY_PRESENT = 0 (battery removed) or a
ChargerMode() command is written with the POR_RESET
bit set. As long as ALARM_INHIBITED = 1, the MAX1647
switching regulator and IOUT current source remain off.
The following pseudo-code describes an interrupt rou-
tine that is triggered by the MAX1647 INT output going
low. This interrupt routine keeps the host informed of
any changes in battery-charger status, such as DCIN
power detection, or battery removal and insertion.
DOMAX1647:
{ This is the beginning of the routine that handles
MAX1647 interrupts. }
{ Check the status of the MAX1647. }
TEMPWORD = ReadWord( SMBADDR = 0b00010011
= 0x13, COMMAND = 0x13 )
{ Check for the normal power-up case without a battery
installed. THERMISTOR_OR = 1, BATTERY_PRESENT =
0. Use 0b1011111011111111 = 0xBEFF as the mask. }
IF (TEMPWORD OR 0xBEFF) = 0xBFFF THEN GOTO
NOBATT:
ChargerStatus( )
The ChargerStatus( ) command uses Read-Word proto-
col. The command code for ChargerStatus( ) is 0x13;
thus, the CMD7–CMD0 bits in Write-Word protocol
should be 0b00010011. The ChargerStatus( ) com-
mand returns information about thermistor impedance
and the MAX1647’s internal state. The Read-Word
{ Check to see if the battery is installed. BATTERY_
PRESENT = 1. Use 0b1011111111111111 = 0xBFFF as
the mask. }
Table 6. Effect of the AlarmWarning( ) Command
AlarmWarning( ) WRITE-WORD PROTOCOL DATA
RESULT
D15 D14 D13 D12 D11 D10
D9
x
D8
x
D7
x
D6
x
D5
x
D4 D3 D2 D1 D0
1
x
x
x
1
x
x
x
x
x
x
1
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Set ALARM_INHIBITED
Set ALARM_INHIBITED
Set ALARM_INHIBITED
x
x
x
x
x
x
x
x
x
x
______________________________________________________________________________________ 21
Chemistry-Independent Battery Chargers
IF (TEMPWORD OR 0xBEFF) = 0xFFFF THEN GOTO
HAVEBATT:
Negative Input Voltage Protection
In most portable equipment, the DC power to charge
batteries enters via a two-conductor cylindrical power
jack. It is easy for the end user to add an adapter to
switch the DC power’s polarity. Polarized capacitor C6
would be destroyed if a negative voltage were applied.
Diode D4 in Figure 3 prevents this from happening.
GOTO ENDINT:
HAVEBATT:
{ A battery is installed. Turn the battery’s broadcast
mode off to monitor the charging process. Using the
BatteryMode( ) command, make sure the CHARGER_
MODE bit is set. }
If reverse-polarity protection for the DC input power is
not necessary, diode D4 can be omitted. This eliminates
the power lost due to the voltage drop on diode D4.
WriteWord(SMBADDR = 0b00010110 = 0x16,
COMMAND = 0X03, DATA = 0x4000)
GOTO ENDINT:
NOBATT:
Selecting External Components for the
MAX1647 4A Application
{ Notify the system that AC power is present, but no bat-
tery is present. }
The MAX1647 can be configured to charge at a maxi-
mum current of 4A (instead of 2A, as shown in Figure 3)
by changing the external power components and tying
SEL to REF. The following paragraphs discuss the selec-
tion requirements for each component in Figure 3 that
must be changed to accommodate the 4A application.
GOTO ENDINT:
ENDINT:
{ This is the end of the interrupt routine. }
The following pseudo-code describes a polling routine
that queries the battery for its desired charge voltage and
charge current, checks to make sure that the requested
charge current and charge voltage are valid, and
instructs the MAX1647 to comply with the request.
DOPOLLING:
{ This is the beginning of the polling routine. }
{ Ask the battery what voltage it wants using the bat-
tery’s ChargingVoltage( ) command. }
TEMPVOLTAGE = ReadWord( SMBADDR =
0b00010111 = 0x17, COMMAND = 0x15 )
{ Ask the battery what current it wants using the bat-
tery’s ChargingCurrent( ) command. }
TEMPCURRENT = ReadWord( SMBADDR =
0b00010111 = 0x17, COMMAND = 0x14 )
{ Now the routine can check that the TEMPVOLTAGE
and TEMPCURRENT values make sense and that the
battery is not malfunctioning. }
{ With valid TEMPVOLTAGE and TEMPCURRENT val-
ues, instruct the MAX1647 to comply with the request. }
WriteWord( SMBADDR = 0b00010010 = 0x12 ,
COMMAND = 0x15, DATA = TEMPVOLTAGE )
Diode D4 in Figure 3 has to support both the charge
current and the current required to operate the host
load (i.e., what the batteries normally power when not
charging). This means that the continuous current flow-
ing through D4 exceeds 4A. One possible choice for
D4 is the Motorola MBRD835L 8A Schottky barrier
diode in a DPAK surface-mount package. Care must
be taken in thermal management of the circuit board
when using the 4A application circuit, by mounting D4
on a three-square-inch piece of copper.
Motorola’s MBRD835L can also be used for D3. The
Siliconix Si4410DY is a good choice for M1 and M2 in the
4A application. Changing M2 from a 2N7002 (Table 1) to
a Si4410DY increases the power dissipated by the
MAX1647’s 20-pin SSOP.
High-current inductors are difficult to find in surface-mount
packages. Low-cost solutions use toroidal powdered-iron
cores with exposed windings of heavy-gauge wire. The
Coiltronics CTX20-5-52 20µH 5A inductor provides a high-
efficiency solution.
WriteWord( SMBADDR = 0b00010010 = 0x12 ,
COMMAND = 0x14, DATA = TEMPCURRENT )
ENDPOL:
R1A must also dissipate more power in the 4A applica-
tion circuit than in the circuit of Figure 3. R1A’s value
decreases to 50mΩ in the 4A application. IRC’s
LR2512-01-R050-F meets this requirement with a 1W
maximum power-dissipation rating.
{ This is the end of the polling routine. }
22 ______________________________________________________________________________________
Chemistry-Independent Battery Chargers
Table 7. ChargerStatus( ) Bit Descriptions
BIT
POSITION
NAME
LATCHED?
DESCRIPTION
0 = Ready to charge a smart battery
1 = Charger is off; IOUT current = 0mA; DLO = PGND; DHI = LX
Always returns ‘0’
CHARGE_INHIBITED
MASTER_MODE
0
1
2
Yes
N/A
No
0 = BATT voltage is limited at the voltage set point (BATT = V0).
1 = BATT voltage is less than the voltage set point (BATT < V0).
VOLTAGE_NOTREG
0 = Current through R1 is at its limit (I
1 = Current through R1 is less than its limit (I
= I0).
BATT
BATT
CURRENT_NOTREG
3
No
< I0).
LEVEL_2
LEVEL_3
4
5
N/A
N/A
Always returns 1
Always returns 0
0 = ChargingCurrent( ) value is valid for MAX1647.
1 = ChargingCurrent( ) value exceeds what MAX1647 can actually deliver.
CURRENT_OR
6
7
8
9
No
No
No
No
0 = ChargingVoltage( ) value is valid for MAX1647.
1 = ChargingVoltage( ) value exceeds what MAX1647 can actually deliver.
VOLTAGE_OR
0 = THM voltage < 91% of REF voltage
1 = THM voltage > 91% of REF voltage
THERMISTOR_OR
THERMISTOR_COLD
0 = THM voltage < 75% of REF voltage
1 = THM voltage > 75% of REF voltage
This bit reports the state of an internal SR flip-flop (denoted THERMISTOR_HOT
flip-flop). The THERMISTOR_HOT flip-flop is set whenever THM is below 23%
of REF. It is cleared whenever BATTERY_PRESENT = 0 or ChargerMode( ) is
written with POR_RESET = 1.
THERMISTOR_HOT
THERMISTOR_UR
10
11
Yes
No
0 = THM voltage > 5% of REF voltage
1 = THM voltage < 5% of REF voltage
This bit reports the state of an internal SR flip-flop (denoted ALARM_INHIBITED
flip-flop). The ALARM_INHIBITED flip-flop is set whenever the AlarmWarning( )
command is written with D15, D14, or D12 set. The ALARM_INHIBITED flip-flop
is cleared whenever BATTERY_PRESENT = 0 or ChargerMode( ) is written with
POR_RESET = 1.
ALARM_INHIBITED
12
Yes
0 = BATT voltage < 89% of DCIN voltage
1 = BATT voltage > 89% of DCIN voltage
POWER_FAIL
13
14
15
No
No
No
0 = No battery is present (THERMISTOR_OR = 1).
1 = A battery is present (THERMISTOR_OR = 0).
BATTERY_PRESENT
AC_PRESENT
0 = VL voltage < 4V
1 = VL voltage > 4V
*Bit position in the D15-D0 data.
N/A = Not applicable.
___________________Chip Information
TRANSISTOR COUNT: 3612
SUBSTRATE CONNECTED TO AGND
______________________________________________________________________________________ 23
Chemistry-Independent Battery Chargers
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
2
1
INCHES
MILLIMETERS
DIM
A
MIN
0.068
MAX
MIN
1.73
0.05
0.25
0.09
MAX
1.99
0.21
0.38
0.20
INCHES
MAX
MILLIMETERS
MAX
6.33
6.33
7.33
MIN
MIN
6.07
6.07
7.07
8.07
N
0.078
14L
16L
20L
A1
B
D
D
D
D
D
0.239 0.249
0.239 0.249
0.278 0.289
0.317 0.328
0.002 0.008
0.010 0.015
0.004 0.008
C
8.33 24L
E
H
SEE VARIATIONS
0.205 0.212 5.20
0.0256 BSC
D
0.397 0.407 10.07 10.33
28L
E
5.38
e
0.65 BSC
H
0.301 0.311 7.65
0.025 0.037 0.63
7.90
0.95
8∞
L
0∞
8∞
0∞
N
A
C
B
L
e
A1
D
NOTES:
1. D&E DO NOT INCLUDE MOLD FLASH.
2. MOLD FLASH OR PROTRUSIONS NOT TO EXCEED .15 MM (.006").
3. CONTROLLING DIMENSION: MILLIMETERS.
4. MEETS JEDEC MO150.
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, SSOP, 5.3 MM
APPROVAL
DOCUMENT CONTROL NO.
REV.
5. LEADS TO BE COPLANAR WITHIN 0.10 MM.
1
21-0056
C
1
24 ______________________________________________________________________________________
Chemistry-Independent Battery Chargers
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
INCHES
MILLIMETERS
DIM
A
MIN
MAX
0.069
0.010
0.019
0.010
MIN
1.35
0.10
0.35
0.19
MAX
1.75
0.25
0.49
0.25
0.053
0.004
0.014
0.007
N
A1
B
C
e
0.050 BSC
1.27 BSC
E
0.150
0.157
0.050
3.80
5.80
0.40
4.00
6.20
1.27
E
H
H0.2440.228
0.016
L
VARIATIONS:
INCHES
1
MILLIMETERS
DIM
D
MIN
MAX
0.197
0.344
0.394
MIN
4.80
8.55
9.80
MAX
5.00
N
8
MS012
AA
TOP VIEW
0.189
0.337
0.386
D
8.75 14
10.00 16
AB
D
AC
D
C
A
B
0∞-8∞
e
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0041
B
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________25
© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
相关型号：
MAX1649CSA+
Switching Controller, Current-mode, 1.5A, 300kHz Switching Freq-Max, BICMOS, PDSO8, 0.150 INCH, LEAD FREE, SOP-8
MAXIM
MAX1649CSA+T
Switching Controller, Current-mode, 1.5A, 300kHz Switching Freq-Max, BICMOS, PDSO8, 0.150 INCH, LEAD FREE, SOP-8
MAXIM
©2020 ICPDF网 联系我们和版权申明