19-4166; Rev 1; 4/09
KIT
ATION
EVALU
E
L
B
A
AVAIL
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
The MAX8819_ is a complete power solution for MP3
players and other handheld applications. The IC
includes a battery charger, step-down converters, and
WLED power. It features an input current-limit switch to
power the IC from an AC-to-DC adapter or USB port, a
1-cell lithium ion (Li+) or lithium polymer (Li-Poly) charger, three step-down converters, and a step-up converter
with serial step dimming for powering two to six white
LEDs. All power switches for charging and switching the
system load between battery and external power are
included on-chip. No external MOSFETs are required.
The MAX8819C offers a sequenced power-up/powerdown of OUT1, OUT2, and then OUT3.
Maxim’s Smart Power Selector™ makes the best use of
AC-to-DC adapter power or limited USB power. Battery
charge current and input current limit are independently set. Input power not used by the system charges the
battery. Charge current is resistor programmable and
the input current limit can be selected as 100mA,
500mA, or 1A. Automatic input selection switches the
system load from battery to external power. In addition,
on-chip thermal limiting reduces the battery charge rate
to prevent charger overheating.
Features
♦
♦
♦
♦
♦
♦
♦
♦
♦
Smart Power Selector
Operates with No Battery Present
USB/AC Adapter One-Cell Li+ Charger
Three 2MHz Step-Down Converters
95% Peak Efficiency
100% Duty Cycle
±3% Output Accuracy over Load/Line/
Temperature
2 to 6 Series WLED Driver with Dimming Control
Active-Low REG1 Reset Output
Short-Circuit/Thermal-Overload/Input
Undervoltage/Overvoltage Protection
Power-Up/Down Sequencing (MAX8819C)
Total Solution Size: Less Than 90mm2
Typical Operating Circuit
USB/AC-TO-DC
ADAPTER
SYS
DC
Applications
DLIM1
DLIM2
MP3 Players
BAT
Portable GPS Devices
+
ENABLE SYSTEM
Low-Power Handheld Products
Cellular Telephones
Digital Cameras
Handheld Instrumentation
EN123
ENABLE CHARGER
CEN
ENABLE BACKLIGHT
EN4
SYS
LX4
Li+/Li-Poly
BATTERY
LX1
OUT1
I/O
LX2
OUT2
MEMORY
LX3
OUT3
CORE
MAX8819_
PDAs
OVP4
Ordering Information
PART
TEMP RANGE
PINPACKAGE
SYS
VOLTAGE
(V)
MAX8819AETI+
-40°C to +85°C 28 TQFN-EP*
4.35
MAX8819BETI+
-40°C to +85°C 28 TQFN-EP*
5.3
MAX8819CETI+
-40°C to +85°C 28 TQFN-EP*
4.35
CISET
FB4
CHG
CHG
RST1
RST1
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Smart Power Selector is a trademark of Maxim Integrated
Products, Inc.
Pin Configuration appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX8819A/MAX8819B/MAX8819C
General Description
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
ABSOLUTE MAXIMUM RATINGS
DC, SYS, BAT, CISET, DLIM1, DLIM2, EN123
CEN, EN4, CHG, RST1, FB1, FB2, FB3 to GND....-0.3V to +6V
PV2 to GND ...............................................-0.3V to (VSYS + 0.3V)
PV13 to SYS...........................................................-0.3V to +0.3V
PG1, PG2, PG3, PG4 to GND................................-0.3V to +0.3V
COMP4, FB4 to GND ................................-0.3V to (VSYS + 0.3V)
LX4 to PG4 .............................................................-0.3V to +33V
OVP4 to GND .........................................................-0.3V to +33V
LX1, LX2, LX3 Continuous Current (Note 1) .........................1.5A
LX4 Current ................................................................750mARMS
Output Short-Circuit Duration.....................................Continuous
Continuous Power Dissipation (TA = +70°C)
28-Pin Thin QFN Single-Layer Board (derate 20.8mW/°C
above +70°C)...........................................................1666.7mW
28-Pin Thin QFN Multilayer Board (derate 28.6mW/°C
above +70°C)...........................................................2285.7mW
Junction-to-Case Thermal Resistance (θJC) (Note 2)
28-Lead Thin QFN...........................................................3°C/W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature........................................-40°C to +125°C
Storage Temperature.........................................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: LX1, LX2, LX3 have clamp diodes to their respective PG_ and PV_. Applications that forward bias these diodes must take
care not to exceed the package power dissipation limits.
Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to http://www.maxim-ic.com/thermal-tutorial.
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
(DC, LX_ unconnected; VEP = VGND = 0V, VBAT = 4V, DLIM[1:2] = 00, EN123 = EN4 = low, VFB1 = VFB2 = VFB3 = 1.1V, VFB4 = 0.6V,
PV13 = PV2 = SYS, TA = -40°C to +85°C, capacitors as shown in Figure 1, RCISET = 3kΩ, unless otherwise noted.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
5.5
V
DC POWER INPUT
DC Voltage Range
VDC
4.1
MAX8819A/MAX8819C
4.3
4.35
4.4
MAX8819B
5.1
5.3
5.5
SYS Regulation Voltage
VSYS_REG
VDC = 5.75V
DC Undervoltage Threshold
VUVLO_DC
VDC rising, 500mV typical hysteresis
3.95
4.00
4.05
V
DC Overvoltage Threshold
VOVLO_DC
VDC rising, 300mV typical hysteresis
VDC = 5.75V, VSYS = 5V
DLIM[1:2] = 10
for MAX8819B or VSYS =
DLIM[1:2] = 01
4V for MAX8819A/
DLIM[1:2] = 00
MAX8819C
DLIM[1:2] = 11 (suspend)
5.811
5.9
6.000
V
90
95
100
DC Current Limit
(Note 4)
DC Quiescent Current
DC-to-SYS Dropout Resistance
DC-to-SYS Soft-Start Time
IDCLIM
IDCIQ
RDS
450
475
500
900
1000
1100
0.02
0.035
DLIM[1:2] ≠ 11, ISYS = 0mA, IBAT = 0mA,
EN123 = low, EN4 = low, CEN = high,
VDC = 5.5V
1.33
DLIM[1:2] ≠ 11, ISYS = 0mA, EN123 = low,
EN4 = low, CEN = low, VDC = 5.5V
0.95
VDC = 4V, ISYS = 400mA, DLIM[1:2] = 01
0.330
tSS-D-S
DC Thermal-Limit Temperature
Die temperature where current limit is
reduced
DC Thermal-Limit Gain
Amount of input current reduction above
thermal-limit temperature
V
mA
mA
0.700
Ω
1.5
ms
100
°C
5
%/°C
SYSTEM
System Operating Voltage Range
2
VSYS
2.6
_______________________________________________________________________________________
5.5
V
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
(DC, LX_ unconnected; VEP = VGND = 0V, VBAT = 4V, DLIM[1:2] = 00, EN123 = EN4 = low, VFB1 = VFB2 = VFB3 = 1.1V, VFB4 = 0.6V,
PV13 = PV2 = SYS, TA = -40°C to +85°C, capacitors as shown in Figure 1, RCISET = 3kΩ, unless otherwise noted.) (Note 3)
PARAMETER
System Undervoltage Lockout
Threshold
BAT-to-SYS Reverse Regulation
Voltage
SYMBOL
MIN
TYP
MAX
UNITS
2.45
2.5
2.55
V
50
66
90
mV
VDC = 0V, EN123 = low, EN4 = low,
VBAT = 4V
10
20
VDC = 5V, DLIM[1:2] ≠ 11, EN123 = low,
EN4 = low, VBAT = 4V
0
10
VDC = 0V, EN123 = high, EN4 = low,
VBAT = 4V (step-down converters are not in
dropout)
128
290
VDC = 0V, EN123 = high, EN4 = high,
VBAT = 4V (step-down converters are not in
dropout)
362
730
VUVLO_SYS VSYS falling, 100mV hysteresis
VBSREG
ISYS +
IPV13 +
IPV2
Quiescent Current
CONDITIONS
DC and BAT are delivering current to SYS;
IBAT = 95mA; VDC = 4.3V,
MAX8819A/MAX8819C (only)
μA
BATTERY CHARGER (VDC = 5.0V)
BAT-to-SYS On-Resistance
BAT Regulation Voltage
(Figure 2)
RBS
VBATREG
BAT Recharge Threshold
BAT Prequalification Threshold
VBATPRQ
RCISET Resistance Range
CISET Voltage
VCISET
BAT Fast-Charge Current Limit
BAT Prequalification Current
Top-Off Threshold (Note 5)
BAT Leakage Current
VDC = 0V, VBAT = 4.2V, ISYS = 0.9A
0.073
0.165
TA = +25°C
4.174
4.200
4.221
TA = -40°C to +85°C
4.158
4.200
4.242
(Note 4)
Ω
V
-135
-100
-65
mV
VBAT rising, 180mV hysteresis, Figure 2
2.9
3.0
3.1
V
Guaranteed by BAT fast-charge current
limit
3
15
kΩ
V
RCISET = 7.5kΩ, IBAT = 267mA
0.9
1.0
1.1
DLIM[1:2] = 10, RCISET = 3kΩ
87
92
100
DLIM[1:2] = 01, RCISET = 3kΩ
450
472
500
DLIM[1:2] = 00, RCISET = 15kΩ
170
200
230
DLIM[1:2] = 00, RCISET = 7.5kΩ
375
400
425
DLIM[1:2] = 00, RCISET = 3.74kΩ
740
802
860
IPREQUAL
VBAT = 2.5V, RCISET = 3.74kΩ
60
82
105
mA
ITOPOFF
TA = +25°C, RCISET = 3.74kΩ
60
mA
ICHGMAX
82
105
VDC = 0V, EN123 = low, EN4 = low,
CEN = low, VBAT = 4V
10
20
VDC = 5V, DLIM[1:2] = 11, EN123 = low,
EN4 = low, VBAT = 4V
0
mA
μA
_______________________________________________________________________________________
3
MAX8819A/MAX8819B/MAX8819C
ELECTRICAL CHARACTERISTICS (continued)
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
ELECTRICAL CHARACTERISTICS (continued)
(DC, LX_ unconnected; VEP = VGND = 0V, VBAT = 4V, DLIM[1:2] = 00, EN123 = EN4 = low, VFB1 = VFB2 = VFB3 = 1.1V, VFB4 = 0.6V,
PV13 = PV2 = SYS, TA = -40°C to +85°C, capacitors as shown in Figure 1, RCISET = 3kΩ, unless otherwise noted.) (Note 3)
PARAMETER
Charger Soft-Start Time
SYMBOL
tSS_CHG
CONDITIONS
MIN
TYP
Slew rate
333
Time from 0 to 500mA
1.5
Time from 0 to 100mA
0.3
Time from 100mA to 500mA
1.2
Timer Accuracy
Timer Suspend Threshold
CISET voltage when the fast-charge timer
suspends; 300mV translates to 20% of the
maximum fast-charge current limit
250
Timer Extend Threshold
CISET voltage when the fast-charge timer
extends; 750mV translates to 50% of the
maximum fast-charge current limit
700
MAX
UNITS
mA/ms
ms
+15
%
300
350
mV
750
800
mV
Prequalification Time
tPREQUAL
33
min
Fast-Charge Time
tFSTCHG
660
min
Top-Off Time
tTOPOFF
33
min
2.6
ms
5
ms
+165
°C
15
°C
VSYS
V
POWER SEQUENCING (Figures 6 and 7)
REG1, REG2, REG3 Soft-Start
Time
tSS1, tSS2,
tSS3
REG4 Soft-Start Time
tSS4
CCOMP4 = 0.022μF to GND
REGULATOR THERMAL SHUTDOWN
Thermal Shutdown Temperature
TJ rising
Thermal Shutdown Hysteresis
REG1–SYNCHRONOUS STEP-DOWN CONVERTER
Input Voltage
PV13 supplied from SYS
Maximum Output Current
L = 4.7μH,
RLSR = 0.13Ω
(Note 6)
Short-Circuit Current
MAX8819A/MAX8819B
400
MAX8819C
550
mA
600
mA
Short-Circuit Detection Threshold
230
mV
Short-Circuit Foldback Frequency
fOSC/3
Hz
FB1 Voltage
L = 4.7μH, RLSR = 0.13Ω
(Note 7)
0.997
Output Voltage Range
FB1 Leakage Current
1.01
1
VFB1 = 1.01V
TA = +25°C
-50
TA = +85°C
-5
1.028
V
VSYS
V
+50
-10
nA
Load Regulation
IOUT1 = 100mA to 300mA
1
%
Line Regulation
(Note 9)
1
%/D
p-Channel On-Resistance
VPV13 = 4.0V, ILX1 = 180mA
190
mΩ
n-Channel On-Resistance
VPV13 = 4.0V, ILX1 = 180mA
250
p-Channel Current-Limit
Threshold
MAX8819A/MAX8819B
0.565
0.600
0.640
MAX8819C
0.615
0.650
0.750
4
_______________________________________________________________________________________
mΩ
A
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
(DC, LX_ unconnected; VEP = VGND = 0V, VBAT = 4V, DLIM[1:2] = 00, EN123 = EN4 = low, VFB1 = VFB2 = VFB3 = 1.1V, VFB4 = 0.6V,
PV13 = PV2 = SYS, TA = -40°C to +85°C, capacitors as shown in Figure 1, RCISET = 3kΩ, unless otherwise noted.) (Note 3)
PARAMETER
SYMBOL
Skip-Mode Transition Current
CONDITIONS
MIN
(Note 8)
n-Channel Zero-Crossing
Threshold
Maximum Duty Cycle
MAX
mA
10
mA
%
12.5
fOSC
Internal Discharge Resistance in
Shutdown
1.8
EN123 = low, resistance from LX1 to PG1
UNITS
80
100
Minimum Duty Cycle
PWM Frequency
TYP
2.0
%
2.2
MHz
1.0
kΩ
VSYS
V
REG2–SYNCHRONOUS STEP-DOWN CONVERTER
Input Voltage
PV2 supplied from SYS
Maximum Output Current
L = 4.7μH,
RLSR = 0.13Ω
(Note 6)
Short-Circuit Current
MAX8819A/MAX8819B
300
MAX8819C
500
mA
L = 4.7μH, RLSR = 0.13Ω
Short-Circuit Detection Threshold
Short-Circuit Foldback Frequency
600
mA
230
mV
fOSC/3
FB2 Voltage
(Note 7)
0.997
Output Voltage Range
1.012
1
FB2 Leakage Current
VFB2 = 1.01V
TA = +25°C
-50
TA = +85°C
-5
Hz
1.028
V
VSYS
V
+50
-50
nA
Load Regulation
IOUT2 = 100mA to 300mA
1
%
Line Regulation
(Note 9)
1
%/D
p-Channel On-Resistance
VPV2 = 4.0V, ILX2 = 180mA
290
mΩ
n-Channel On-Resistance
VPV2 = 4.0V, ILX2 = 180mA
p-Channel Current-Limit
Threshold
MAX8819A/MAX8819B
0.512
0.550
200
0.595
MAX8819C
0.565
0.600
0.700
Skip-Mode Transition Current
(Note 8)
n-Channel Zero-Crossing
Threshold
Maximum Duty Cycle
Internal Discharge Resistance in
Shutdown
REG2 Disable
mA
10
mA
%
12.5
fOSC
ΔISYS
1.8
A
80
100
Minimum Duty Cycle
PWM Frequency
mΩ
2.0
%
2.2
MHz
EN123 = low, resistance from LX2 to PG2
1.0
kΩ
VPV2 = 0V, REG2 disabled (Note 10)
-25
μA
VSYS
V
REG3–SYNCHRONOUS STEP-DOWN CONVERTER
Input Voltage
PV13 supplied from SYS
_______________________________________________________________________________________
5
MAX8819A/MAX8819B/MAX8819C
ELECTRICAL CHARACTERISTICS (continued)
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
ELECTRICAL CHARACTERISTICS (continued)
(DC, LX_ unconnected; VEP = VGND = 0V, VBAT = 4V, DLIM[1:2] = 00, EN123 = EN4 = low, VFB1 = VFB2 = VFB3 = 1.1V, VFB4 = 0.6V,
PV13 = PV2 = SYS, TA = -40°C to +85°C, capacitors as shown in Figure 1, RCISET = 3kΩ, unless otherwise noted.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
L = 4.7μH,
RLSR = 0.13Ω
(Note 6)
Maximum Output Current
Short-Circuit Current
MIN
MAX8819A/MAX8819B
300
MAX8819C
500
TYP
MAX
mA
L = 4.7μH, RLSR = 0.13Ω
Short-Circuit Detection Threshold
Short-Circuit Foldback Frequency
600
mA
230
mV
fOSC/3
FB3 Voltage
(Note 7)
0.997
Output Voltage Range
1.01
1
TA = +25°C
-50
-5
Hz
1.028
V
VSYS
V
+50
FB3 Leakage Current
VFB3 = 1.01V
Load Regulation
IOUT3 = 100mA to 300mA
Line Regulation
(Note 9)
p-Channel Current-Limit
Threshold
MAX8819A/MAX8819B
0.512
0.550
0.595
MAX8819C
0.565
0.600
0.700
Skip-Mode Transition Current
(Note 8)
TA = +85°C
-50
1.3
p-Channel On-Resistance
VPV13 = 4.0V, ILX3 = 180mA
n-Channel On-Resistance
VPV13 = 4.0V, ILX3 = 180mA
Maximum Duty Cycle
%/D
mA
10
mA
290
mΩ
120
mΩ
%
12.5
fOSC
Internal Discharge Resistance in
Shutdown
1.8
EN123 = low, resistance from LX3 to PG3
A
80
100
Minimum Duty Cycle
nA
%
1
n-Channel Zero-Crossing
Threshold
PWM Frequency
UNITS
2.0
%
2.2
1.0
MHz
kΩ
REG4–STEP-UP CONVERTER
Input Voltage
Power supplied from SYS (see Figure 1)
Output Voltage Range
VOUT4
FB4 Regulation Voltage
VFB4
FB4 Leakage
No dimming
REG4 disabled (EN4 = low)
Switching Frequency
2.4
5.5
V
VSYS
24
V
475
500
525
mV
-0.050
+0.005
+0.050
μA
0.9
1
1.1
MHz
Minimum Duty Cycle
Maximum Duty Cycle
OVP4 Overvoltage Detection
VOVP
OVP4 Input Current
OVP4 = SYS, EN4 = high
OVP4 Leakage Current
REG4 disabled (EN4 = low),
OVP4 = SYS
n-Channel On-Resistance
VSYS = 4.0V, ILX4 = 200mA
n-Channel Off-Leakage Current
VLX4 = 28V
n-Channel Current Limit
6
5
%
90
94
%
24
25
26
4
V
μA
-1
+0.001
+1
-1
+0.001
+1
μA
555
695
950
mA
395
_______________________________________________________________________________________
μA
mΩ
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
(DC, LX_ unconnected; VEP = VGND = 0V, VBAT = 4V, DLIM[1:2] = 00, EN123 = EN4 = low, VFB1 = VFB2 = VFB3 = 1.1V, VFB4 = 0.6V,
PV13 = PV2 = SYS, TA = -40°C to +85°C, capacitors as shown in Figure 1, RCISET = 3kΩ, unless otherwise noted.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
3.2
ms
500
μs
LED DIMMING CONTROL (EN4)
EN4 Low Shutdown Delay
t SHDN
EN4 High Enable Delay (Figure 8)
tHI_INIT
100
EN4 Low Time
tLO
0.5
EN4 High Time
tHI
0.5
μs
μs
RESET (RST1)
Reset Trip Threshold
VTHRST
Reset Deassert Delay Time
tDRST
Reset Glitch Filter
t GLRST
Voltage from FB1 to GND, VFB1 falling,
50mV hysteresis
0.765
0.858
0.945
V
180
200
220
ms
50
μs
LOGIC (DLIM1, DLIM2, EN123, EN4, CHG, RST1)
Logic Input-Voltage Low
VDC = 4.1V to 5.5V, VSYS = 2.6V to 5.5V
Logic Input-Voltage High
VDC = 4.1V to 5.5V, VSYS = 2.6V to 5.5V
1.2
Logic Input Pulldown Resistance
VLOGIC = 0.4V to 5.5V, CEN, EN123, EN4
400
Logic Leakage Current
VLOGIC = 0 to 5.5V, DLIM1, DLIM2
-1.0
Logic Output Voltage Low
I SINK = 1mA
Logic Output-High Leakage
Current
VLOGIC = 5.5V
-1.0
0.4
V
760
1200
k
+0.001
+1.0
μA
7
15
mV
+0.001
+1.0
μA
V
Note 3: Limits are 100% production tested at TA = +25°C. Limits over the operating temperature range are guaranteed through correlation using statistical quality control (SQC) methods.
Note 4: The charger transitions from done to fast-charge mode at this BAT recharge threshold.
Note 5: The charger transitions from fast-charge to top-off mode at this top-off threshold (Figure 2).
Note 6: The maximum output current is guaranteed by correlation to the p-channel current-limit threshold, p-channel on-resistance,
n-channel on-resistance, oscillator frequency, input voltage range, and output voltage range. The parameter is stated for
a 4.7μH inductor with 0.13Ω series resistance. See the Step-Down Converter Maximum Output Current section for more
information.
Note 7: The step-down output voltages are 1% high with no load due to the load-line architecture.
Note 8: The skip-mode current threshold is the transition point between fixed-frequency PWM operation and skip-mode operation.
The specification is given in terms of output load current for inductor values shown in the typical application circuit (Figure 1).
Note 9: Line regulation for the step-down converters is measured as ΔVOUT/ΔD, where D is the duty cycle (approximately
VOUT/VIN).
Note 10: REG2 is disabled by connecting PV2 to ground, decreasing the quiescent current.
_______________________________________________________________________________________
7
MAX8819A/MAX8819B/MAX8819C
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
0.8
0.6
FALLING
0.4
1.0
0.8
0.6
FALLING
RISING
0.4
0.2
0.2
0
0
1000
VDC = 5V
EN123 = 1
900
BATTERY LEAKAGE CURRENT (nA)
RISING
MAX8819A toc02
1.0
1.2
QUIESCENT CURRENT (mA)
MAX8819A toc01
1.2
QUIESCENT CURRENT (mA)
BATTERY LEAKAGE CURRENT
vs. BATTERY VOLTAGE
DC QUIESCENT CURRENT
vs. DC VOLTAGE (CHARGER DISABLED)
MAX8819A toc03
DC QUIESCENT CURRENT vs.
DC VOLTAGE (CHARGER ENABLED)
800
700
600
500
400
300
200
100
5
0
0
6
1
BATTERY LEAKAGE CURRENT
vs. BATTERY VOLTAGE
700
600
450
400
500
400
300
350
RCISET = 6.8kΩ
300
250
200
150
200
100
100
50
RCISET = 15kΩ
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
BATTERY VOLTAGE (V)
1
2
3
BATTERY VOLTAGE (V)
3.96
3.94
3.92
DC UNCONNECTED
VBATT = 4V
4.21
4.20
4.19
4.18
4.17
4
5
-40
-15
10
35
TEMPERATURE (°C)
4.4
VDC = 5.1V
VBATT = 4V
DLIM[1:2] = 10
4.3
4.2
4.1
4.0
3.9
3.8
3.88
0 100 200 300 400 500 600 700 800 900 1000
OUTPUT CURRENT (mA)
8
4.22
4.5
MAX8819A toc07
3.98
3.90
4.23
SYSTEM VOLTAGE
vs. SYSTEM CURRENT
SYSTEM VOLTAGE (V)
SYSTEM VOLTAGE (V)
4.00
4.24
4.15
0
SYSTEM VOLTAGE
vs. SYSTEM CURRENT
4.02
4.25
4.16
0
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
BATTERY VOLTAGE (V)
BATTERY REGULATION VOLTAGE
vs. TEMPERATURE
500
CHARGE CURRENT (mA)
800
0
6
MAX8819A toc05
VDC = 0V
EN123 = 0
900
5
CHARGE CURRENT
vs. BATTERY VOLTAGE
MAX8819A toc04
1000
2
3
4
DC VOLTAGE, VDC (V)
MAX8819A toc06
2
3
4
DC VOLTAGE (V)
MAX8819A toc08
1
BATTERY REGULATION VOLTAGE (V)
0
BATTERY LEAKAGE CURRENT (nA)
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
0 100 200 300 400 500 600 700 800 900 1000
OUTPUT CURRENT (mA)
_______________________________________________________________________________________
60
85
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
SYSTEM VOLTAGE
vs. SYSTEM CURRENT
AC-TO-DC ADAPTER CONNECT
MAX8819A toc10
MAX8819A toc09
4.5
SYSTEM VOLTAGE (V)
4.4
VDC
5V/div
4.3
4.2
4.3V
3.84V
VSYS
CDC CHARGING
IDC
4.1
VDC = 5.1V
VBATT = 4V
DLIM[1:2] = 01
IBAT
BATTERY CHARGER
SOFT-START
3.8
400μs/div
POWER-UP SEQUENCING
(MAX8819A/MAX8819B)
POWER-UP SEQUENCING
(MAX8819C)
2V/div
2V/div
0V
VV3
0V
2V/div
2V/div
VV2
0V
VV2
0V
2V/div
2V/div
0V
2V/div
0V
VV3
VV1
0V
2ms/div
1ms/div
POWER-DOWN SEQUENCING
(MAX8819C)
REG1 EFFICIENCY
vs. LOAD CURRENT (VREG1 = 3.01V)
MAX8819A toc13
VV2
90
2V/div
0V
2V/div
0V
VV1
2V/div
VRST1
MAX8819A toc14
VV3
100
0V
2V/div
0V
80
REG1 EFFICIENCY (%)
IV3 = 200mA
IV2 = 180mA
IV1 = 220mA
1A/div
MAX8819A toc12
MAX8819A toc11
VV1
1A/div
-1A
0 100 200 300 400 500 600 700 800 900 1000
OUTPUT CURRENT (mA)
VEN123
2V/div
NEGATIVE BATTERY
CURRENT FLOWS
INTO THE
BATTERY
4.0
3.9
4V
CSYS CHARGING 1A
70
60
50
40
30
20
10
0
100μs/div
0.1
1
10
100
LOAD CURRENT (mA)
1000
_______________________________________________________________________________________
9
MAX8819A/MAX8819B/MAX8819C
Typical Operating Characteristics (continued)
(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
REG1 DROPOUT VOLTAGE
vs. LOAD CURRENT
REG1 LOAD REGULATION
3.08
VOUT1 = 3V
200
DROPOUT VOLTAGE (mV)
3.07
MAX8819A toc16
250
MAX8819A toc15
3.09
REG1 OUTPUT VOLTAGE (V)
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
3.06
3.05
3.04
3.03
3.02
SYS IS 100mV BELOW THE
REG1 NOMINAL
REGULATION
VOLTAGE
150
VOUT1 = 3.3V
100
50
3.01
3.00
0
2.99
0
50
0
100 150 200 250 300 350 400
REG1 LOAD CURRENT (mA)
50 100 150 200 250 300 350 400 450
OUTPUT CURRENT (mA)
REG1 HEAVY-LOAD SWITCHING
WAVEFORMS
REG1 LIGHT-LOAD SWITCHING
WAVEFORMS
MAX8819A toc18
MAX8819A toc17
20mV/div
AC-COUPLED
VOUT1
2V/div
VLX1
20mV/div
AC-COUPLED
VOUT1
VLX1
2V/div
0V
0V
100mA/div
0mA
ILX1
ILX1
200mA/div
0mA
200mA LOAD
20mA LOAD
400ns/div
2μs/div
LINE TRANSIENT
REG1 LOAD TRANSIENT (VOUT = 3V)
MAX8819A toc19
MAX8819A toc20
300mA
5V
VSYS
4V
4V
100mA/div
2V/div
IOUT1
30mA
30mA
VOUT1
100mV/div
3V DC OFFSET
50mV/div
AC-COUPLED
VOUT1
VOUT1 = 3V
IOUT1 = 30mA
100μs/div
10
200μs/div
______________________________________________________________________________________
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
REG2 EFFICIENCY
vs. LOAD CURRENT (VREG2 = 1.82V)
60
50
40
30
20
1.84
1.83
1.82
MAX8819A toc23
90
80
REG3 EFFICIENCY (%)
1.85
70
100
MAX8819A toc22
80
REG2 OUTPUT VOLTAGE (V)
90
70
60
50
40
30
20
1.81
10
10
0
0
1.80
0.1
1
10
100
LOAD CURRENT (mA)
1000
0
50
100 150 200 250 300 350 400
REG2 LOAD CURRENT (mA)
0.1
1
10
100
LOAD CURRENT (mA)
1000
REG3 LIGHT-LOAD SWITCHING
WAVEFORMS
REG3 LOAD REGULATION
MAX8819A toc25
MAX8819A toc24
1.225
1.220
REG3 OUTPUT VOLTAGE (V)
REG2 EFFICIENCY (%)
1.86
MAX8819A toc21
100
REG3 EFFICIENCY
vs. LOAD CURRENT (VREG3 = 1.21V)
REG2 LOAD REGULATION
20mV/div
AC-COUPLED
VOUT3
1.215
1.210
VLX3
1.205
2V/div
0V
1.200
1.195
100mA/div
ILX3
1.190
0mA
20mA LOAD
1.185
0
50
100 150 200 250 300 350 400
REG3 LOAD CURRENT (mA)
2μs/div
REG3 HEAVY-LOAD SWITCHING
WAVEFORMS
REG3 LOAD TRANSIENT
MAX8819A toc27
MAX8819A toc26
320mA
20mV/div
AC-COUPLED
VOUT3
VLX3
2V/div
0V
ILX3
100mA/div
IOUT3
30mA
30mA
VOUT3
100mV/div
1.2V DC OFFSET
200mA/div
0mA
200mA LOAD
400ns/div
200μs/div
______________________________________________________________________________________
11
MAX8819A/MAX8819B/MAX8819C
Typical Operating Characteristics (continued)
(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
LED EFFICIENCY
vs. LED CURRENT (6 LEDS)
LED EFFICIENCY vs. SYS VOLTAGE
6 LEDS
80
70
LED EFFICIENCY (%)
80
75
4 LEDS
65
60
50
40
30
ILED = 25mA
INDUCTOR: TOKO 1096AS-100M
DIODE: NXP PMEG3005EB
60
55
20
VSYS = 3.6V
10
0
50
3.5
4.0
4.5
SYS VOLTAGE (V)
5.0
80
95
BOOST
90
85
EFFICIENCY (%)
70
60
50
40
80
75
LED
70
65
30
ILED = 25mA
6 LEDS
INDUCTOR: TOKO 1096AS-100M
DIODE: NXP PMEG3005EB
60
20
VSYS = 3.6V
10
55
5
10
15
LED CURRENT (mA)
20
300
250
200
150
100
6 LEDS, ILED = 25mA
3.0
3.5
4.0
4.5
SYS VOLTAGE (V)
5.0
REG4 STARTUP AND SHUTDOWN
RESPONSE
5.5
2.5
3.0
3.5
4.0
4.5
SYS VOLTAGE (V)
FB4 VOLTAGE vs. LED CURRENT
MAX8819A toc33
MAX8819A toc34
500
2V/div
VEN4
450
10V/div
0V
ILED
10mA/div
FB4 VOLTAGE (mV)
400
VOVP4
25
0
2.5
25
20
50
50
0
0
10
15
LED CURRENT (mA)
REG4 INPUT CURRENT
vs. SYS VOLTAGE
100
MAX8819A toc30
90
5
LED AND BOOST EFFICIENCY
vs. SYS VOLTAGE
LED EFFICIENCY
vs. LED CURRENT (4 LEDS)
100
0
5.5
MAX8819A toc32
3.0
MAX8819A toc31
2.5
REG4 INPUT CURRENT (mA)
LED EFFICIENCY (%)
90
85
70
MAX8819A toc29
95
90
100
MAX8819A toc28
100
LED EFFICIENCY (%)
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
350
300
250
200
150
100
0mA
50
0
2ms/div
12
0
5
10
15
LED CURRENT (mA)
20
25
______________________________________________________________________________________
5.0
5.5
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
MINIMUM LED CURRENT
vs. TEMPERATURE
MAXIMUM LED CURRENT
vs. TEMPERATURE
25.4
0.745
25.2
LED CURRENT (mA)
LED CURRENT (mA)
25.3
0.750
MAX8819A toc36
MAX8819A toc35
25.5
25.1
0.740
25.0
24.9
24.8
0.735
24.7
24.6
0.730
24.5
-40
-15
10
35
TEMPERATURE (°C)
60
85
-40
-15
10
35
TEMPERATURE (°C)
60
85
Pin Description
PIN
NAME
1
COMP4
FUNCTION
2
FB4
3
OVP4
4
PG4
REG4 Power Ground
5
LX4
Inductor Switching Node for REG4
6
GND
Analog Ground
7
EN4
REG4 Enable Input and Dimming Control Digital Input
8
RST1
Active-Low, Open-Drain Reset Output. RST1 pulls low to indicate that FB1 is below its regulation
threshold. RST1 goes high 200ms after FB1 reaches its regulation threshold. RST1 is high-impedance
when EN123 is low, and DC is unconnected.
9
BAT
Positive Battery Terminal Connection. Connect BAT to the positive terminal of a single-cell Li+/Li-Poly
battery. Bypass BAT to GND with a 4.7μF ceramic capacitor.
10
SYS
System Supply Output. Bypass SYS to GND with a 10μF ceramic capacitor. When a valid voltage is
present at DC and DLIM[1:2] ≠ 11, VSYS is limited to 4.35V (MAX8819A/MAX8819C) or 5.3V
(MAX8819B). When the system load (ISYS) exceeds the input current limit, VSYS drops 75mV
(VBSREG) below VBAT, allowing both the external power source and the battery to service SYS. SYS is
connected to BAT through an internal 70mΩ system load switch when a valid source is not present at
DC.
11
DC
DC Power Input. DC is capable of delivering 1A to SYS. DC supports both AC adapters and USB
inputs. As shown in Table 1, the DC current limit is controlled by DLIM1 and DLIM2.
12
CEN
Battery Charger Enable Input
13
FB1
Feedback Input for REG1. Connect FB1 to the center of a resistor voltage-divider from the REG1
output capacitors to GND to set the output voltage from 1V to VSYS.
External Compensation Capacitor for REG4
REG4 Feedback Input
Overvoltage Protection Node for REG4
______________________________________________________________________________________
13
MAX8819A/MAX8819B/MAX8819C
Typical Operating Characteristics (continued)
(Circuit of Figure 1, TA = +25°C, unless otherwise noted.)
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
MAX8819A/MAX8819B/MAX8819C
Pin Description (continued)
PIN
14
NAME
FUNCTION
14
CISET
Charge Rate Select Input. Connect a resistor from CISET to GND (RCISET) to set the fast-charge
current limit, prequalification-charge current limit, and top-off threshold.
15
CHG
Active-Low, Open-Drain Charge Status Output. CHG pulls low to indicate that the battery is charging.
See Figure 3 for more information.
16
PG1
REG1 Power Ground
17
LX1
Inductor Switching Node for REG1. When enabled, LX1 switches between PV13 and PG1 to regulate
the FB1 voltage to 1.0V. When disabled, LX1 is pulled to PG1 by 1kΩ in shutdown.
18
PV13
19
LX3
Inductor Switching Node for REG3. When enabled, LX3 switches between PV13 and PG3 to regulate
the FB3 voltage to 1.0V. When disabled, LX3 is pulled to PG3 by a 1kΩ internal resistor.
20
PG3
REG3 Power Ground
21
DLIM1
Input Current-Limit Selection Digital Input 1. Drive high or low according to Table 1 to set the DC input
current limit.
22
FB2
Feedback Input for REG2. Connect FB2 to the center of a resistor voltage-divider from the REG2
output capacitors to GND to set the output voltage from 1V to VSYS. FB2 must be connected to GND if
REG2 is disabled by grounding PV2.
23
FB3
Feedback Input for REG3. Connect FB3 to the center of a resistor voltage-divider from the REG3
output capacitors to GND to set the output voltage from 1V to VSYS.
24
EN123
REG1, REG2, and REG3 Enable Input. Drive EN123 high to enable REG1, REG2, and REG3. Drive EN123
low to disable REG1, REG2, and REG3. The enable/disable sequencing is shown in Figures 6 and 7.
25
PV2
Power Input for REG2. Connect PV2 to SYS for normal operation. Bypass PV2 to PG2 with a 2.2μF
ceramic capacitor. For systems that do not require REG2, connect PV2, FB2, and PG2 to GND (LX2
may be unconnected or connected to GND).
26
LX2
Inductor Switching Node for REG2. When enabled, LX2 switches between PV2 and PG2 to regulate
the FB2 voltage to 1.0V. When disabled, LX2 is pulled to PG2 by a 1kΩ internal resistor.
27
PG2
REG2 Power Ground
28
DLIM2
—
EP
Power Input for the REG1 and REG3 Converters. Connect PV13 to SYS. Bypass PV13 to PG1 with a
4.7μF ceramic capacitor.
Input Current-Limit Selection Digital Input 2. Drive high or low according to Table 1 to set the DC input
current limit.
Exposed Pad
______________________________________________________________________________________
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
SYS
C1
4.7μF
C5
10μF
DLIM1 DLIM2 DC ILIM (mA)
1000
0
0
1
0
475
0
1
95
1
SUSPEND
1
DLIM1
SMART
POWER
SELECTOR
DLIM2
GLITCH FILTER
Li+/Li-Poly
BATTERY
CHARGER AND
SYSTEM LOAD
SWITCH
SYS
BAT
C6 +
4.7μF
Li+/LiPo
BATTERY
FASTBATTERY DESIRED
CAPACITY CHARGE R7 (kΩ) CHARGE
CURRENT
(mAh)
RATE (C)
(mA)
300
14.3
210
0.7
0.7
400
280
10.7
0.7
600
7.15
420
560
800
0.7
5.36
0.7
900
632
4.75
ON
CEN
CISET
R2
CHG
CHG
PV13
PV13
OFF
OUT1
R6
470kΩ
BIAS
MAX8819A
MAX8819B
MAX8819C
MAX8819A/MAX8819B/MAX8819C
DC
AC-TO-DC
ADAPTER
SYS
C7
4.7μF
ON
EN
EN123
REG1
STEP-DOWN
DC-DC
OFF
PWM
D7
C8*
10μF
REG1/RESET
87% FALLING
50us BLANKING
92% RISING
80ms DELAY
PG4
D1
PG4
D2
UP TO 6
WLED
PG4
COMP4
PG2
EN
REG4
STEP-UP
DC-DC
REG2
STEP-DOWN
DC-DC
D5
LX2
FB4
EN
EN4
REG3
STEP-DOWN
DC-DC
PULSE
DIMMING
LX3
FB3
1.2V
300mA
L3
4.7μH
R14
20.0kΩ
PG3
EP
OUT2
R13
100kΩ
C11*
10μF
OUT3
PG3
PWM
GND
C10*
10μF
PG2
PG2
PV13
R1
20
(25mA)
R12
80.6kΩ
FB2
1.8V
200mA
L2
4.7μH
PG2
PWM
OFF
SYS
C9
2.2μF
D4
ON
RST1
PV2
D3
D6
OUT1
R10
470kΩ
RST1
C4
0.022μF
OUT1
PG1
R9
PG1 100kΩ
OVP4
PG4
C3
0.1μF
50V
X7R
R8
200kΩ
FB1
LX4
SYS
OUT4
3.0V
400mA
PG1 L1
4.7μH
PG1
L4
10μH
C2
0.1μF
LX1
R15
PG3 100kΩ
*22μF FOR MAX8819C IS RECOMMENDED.
Figure 1. Functional Diagram/Typical Applications Circuit
Detailed Description
The MAX8819_ is a complete power solution that
includes a battery charger, step-down converters, and
WLED power. As shown in Figure 1, the IC integrates a
DC power input, Li+/Li-Poly battery charger, three stepdown converters, and one step-up converter for powering
white LEDs. All three step-down converters feature
adjustable output voltages set with external resistors.
The MAX8819_ has one external power input that connects to either an AC-to-DC adapter or USB port. Logic
inputs DLIM1 and DLIM2 select the desired input current limit.
______________________________________________________________________________________
15
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
In addition to charging the battery, the IC supplies
power to the system through the SYS output. The
charging current is provided from SYS so that the set
input current limit controls the total SYS current, this is
the sum of the system load current and the batterycharging current.
In some instances, there may not be enough DC input
current to supply peak system loads. The Smart Power
Selector circuitry offers flexible power distribution from
an AC-to-DC adapter or USB source to the battery and
system load. The battery is charged with any available
power not used by the system load. If a system load
peak exceeds the input current limit, supplemental current is taken from the battery. Thermal limiting prevents
overheating by reducing power drawn from the input
source. In the past, it might have been necessary to
reduce system functionality to limit current drain when a
USB source is connected. However, with the
MAX8819_, this is no longer the case. When the DC or
USB source hits its limit, the battery supplies supplemental current to maintain the load.
The IC features overvoltage protection. Part of this protection is a 4.35V (MAX8819A/MAX8819C) or 5.3V
(MAX8819B) voltage limiter at SYS. If DC exceeds the
overvoltage threshold of 5.88V (VOVLO_DC), the input limiter disconnects SYS from DC, but battery-powered operation of all regulators is still allowed.
Input Limiter
The Smart Power Selector seamlessly distributes power
between the current-limited external input (DC), the battery (BAT), and the system load (SYS). The basic functions performed are:
With both an external power supply (DC) and battery
(BAT) connected:
• When the system load requirements are less than
the input current limit, the battery is charged with
residual power from the input.
• When the system load requirements exceed the
input current limit, the battery supplies supplemental
current to the load through the internal system load
switch.
• When the battery is connected and there is no external power input, the system (SYS) is powered from
the battery.
• When an external power input is connected and
there is no battery, the system (SYS) is powered
from the external power input.
16
A thermal-limiting circuit reduces the battery charge
rate and external power source current to prevent the
MAX8819_ from overheating.
System Load Switch
An internal 70mΩ MOSFET connects SYS to BAT when
no voltage source is available at DC. When an external
source is detected at DC, this switch opens and SYS is
powered from the valid input source through the Smart
Power Selector.
When the system load requirements exceed the input
current limit, the battery supplies supplemental current
to the load through the internal system load switch. If
the system load continuously exceeds the input current
limit, the battery does not charge, even though external
power is connected. This is not expected to occur in
most cases because high loads usually occur only in
short peaks. During these peaks, battery energy is
used, but at all other times the battery charges.
DC Power Input (DC, DLIM1, DLIM2)
DC is a current-limited power input that supplies the
system (SYS) up to 1A. The DC to SYS switch is a linear
regulator designed to operate in dropout. This linear
regulator prevents the SYS voltage from exceeding
5.3V for the MAX8819B or 4.35V for the MAX8819A/
MAX8819C. As shown in Table 1, DC supports four different current limits that are set with the DLIM1 and
DLIM2 digital inputs. These current limits are ideally suited for use with AC-to-DC wall adapters and USB power.
The operating voltage range for DC is 4.1V to 5.5V, but it
can tolerate up to 6V without damage. When the DC
input voltage is below the undervoltage threshold (4V), it
is considered invalid. When the DC voltage is below the
battery voltage it is considered invalid. The DC power
input is disconnected when the DC voltage is invalid.
Bypass DC to ground with at least a 4.7μF capacitor.
Four current settings are provided based upon the settings of DLIM1 and DLIM2, see Table 1. DLIM1 and
DLIM2 are deglitched. This deglitching prevents the
problem of major carry transitions momentarily entering
the suspend state.
Table 1. DC Current-Limit Settings
DLIM1
DLIM2
DC ILIM (mA)
0
0
1000
0
1
475
1
0
95
1
1
Suspend
______________________________________________________________________________________
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
MAX8819A/MAX8819B/MAX8819C
TOP-OFF
PREQUALIFICATION
FAST-CHARGE
(CONSTANT CURRENT)
FAST-CHARGE
(CONSTANT VOLTAGE)
DONE
BATTERY VOLTAGE
VBATREG
VBATPRQ
BATTERY CHARGE CURRENT
ICHGMAX
IPREQUAL
ITOPOFF
0
CHG
HIGH
IMPEDANCE
LOW
Figure 2. Li+/Li-Poly Charge Profile
Battery Charger
Figure 2 shows the typical Li+/Li-Poly charge profile for
the MAX8819_, and Figure 3 shows the battery charger
state diagram.
With a valid DC input that is not suspended, the battery
charger initiates a charge cycle once CEN is driven
high. It first detects the battery voltage. If the battery
voltage is less than the prequalification threshold
(3.0V), the charger enters prequalification mode and
charges the battery at 10% of the maximum fast-charge
current while deeply discharged. Once the battery voltage rises to 3.0V, the charger transitions to fast-charge
mode and applies the maximum charge current. As
charging continues, the battery voltage rises until it
approaches the battery regulation voltage (4.2V typ)
______________________________________________________________________________________
17
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
ICHGMAX = 2000 x
1.5V
RCISET
DC = INVALID
NO INPUT POWER
ICHG = 0mA
CHG = 1
DC = VALID
ANY STATE
DLIM[1:2] = 11
INPUT SUSPENDED
DLIM[1:2] = 11
ICHG = 0mA
CHG = 1
CHARGER DISABLED
ICHG = 0mA
CHG = 1
DLIM[1:2] ≠ 11
CEN = 0
CEN = 1
IC SETS TIMER = 0
TIMER FAULT
ICHG = 0mA
CHG = 2Hz SQUAREWAVE
t > tPREQUAL
PREQUALIFICATION
ICHG ≤ ICHGMAX/10
CHG = 0
VBAT < 2.82V
IC SETS TIMER = 0
t > tFSTCHG
VBAT > 3V,
IC SETS TIMER = 0
ICHG < ICHGMAX x 50%
AND VBAT < VBATREG
IC EXTENDS TIMER BY 2x
FAST-CHARGE
ICHG ≤ ICHGMAX
CHG = 0
ICHG < ICHGMAX x 20%
IC SETS TIMER = 0
TIMER EXTEND
(ICHGMAX x 20%) < ICHG < (ICHGMAX x 50%)
CHG = 0
ICHG < ICHGMAX x 10% AND VBAT
IC SETS TIMER = 0
TOP-OFF
CHG = 1
VBAT = VBATREG
ICHG ≤ ICHGMAX/10
tTOPOFF >
ICHG < ICHGMAX x 53%
OR VBAT = VBATREG
IC RESUMES TIMER
VBAT < (VBATREG
100mV)
IC SETS TIMER = 0
33min
ICHG < ISET x 23%
OR VBAT = VBATREG
ICHG < ICHGMAX x 20% IC RESUMES TIMER
AND VBAT 100μs
tSHDN
2ms (typ)
tHI
tSOFT-START
tLO
FULL
31/32
500ns TO 500μs
30/32 29/32
28/32
FULL
> 500ns
31/32
27/32
ILED
6/32
5/32
4/32
3/32
SHUTDOWN
2/32
1/32
SHUTDOWN
Figure 8. Dimming Control Timing Diagram
Table 4. REG4 Recommended Inductors
MANUFACTURER
TOKO
FDK
SERIES
INDUCTANCE
(µH)
ESR (mΩ)
CURRENT
RATING (mA)
DIMENSIONS (mm)
DE2812C
10
290
580
3.0 x 2.8 x 1.2 = (10.8mm)3
DB3018C
10
240
630
3.2 x 3.2 x 1.8 = (18.4mm)3
MIP3226
10
160
900
3.2 x 2.6 x 1 = (8.32mm)3
Table 5. REG4 Recommended Diodes
MANUFACTURER
Central Semiconductor
NXP
ON Semiconductor
26
PART NUMBER
CONTINUOUS
CURRENT
(mA)
FORWARD VOLTAGE
(mV)
BREAKDOWN
VOLTAGE
(V)
PACKAGE
CMDSH05-4
500
470
40
SOD-323
CMHSH5-4
500
510
40
SOD-123
PMEG3005EB
500
500
30
SOD-523
MBR0530L
500
430
30
SOD-123
______________________________________________________________________________________
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
Step-Up Converter Inductor Selection
The WLED boost converter switches at 1MHz, allowing
the use of a small inductor. A 10μH inductance value is
recommended for most applications. Smaller inductances require less PCB space.
Use inductors with a ferrite core or equivalent.
Powdered iron cores are not recommended for use at
high-switching frequencies. The inductor’s saturation
current rating should preferably exceed the REG4
n-channel current limit of 700mA. Choose an inductor
with a DC resistance less than 300mΩ to maintain high
efficiency. Table 4 lists recommended inductors.
Step-Up Converter Diode Selection
The REG4 diode must be fast enough to support the
switching frequency (1MHz). Schottky diodes, such as
Central Semiconductor’s CMHSH5-4 or ON Semiconductor’s MBR0530L, are recommended. Make sure that
the diode’s peak-current rating matches or exceeds the
700mA REG4 n-channel current limit. The diode’s average current rating should match or exceed the output
current. The diode’s reverse breakdown voltage must
exceed the voltage from the converter’s output to
ground. Schottky diodes are preferred due to their low
forward voltage, however, ultra high-speed silicon rectifiers are also acceptable.
Step-Up Converter Output Capacitor Selection
For most applications, a 0.1μF ceramic output filter
capacitor is suitable. Choose a voltage rating double
the maximum output voltage to minimize the effect of
the voltage coefficient on decreasing the effective
capacitance. To ensure stability over a wide temperature range, ceramic capacitors with an X5R or X7R
dielectric are recommended. Place these capacitors as
close as possible to the IC.
Soft-Start/Inrush Current
The MAX8819_ implements soft-start on many levels to
control inrush current to avoid collapsing supply voltages, and to fully comply with the USB 2.0 specifications. All DC and charging functions implement soft-start.
The DC node only requires 4.7μF of input capacitance.
Furthermore, all regulators implement soft-start to avoid
transient overload of power inputs.
Undervoltage and Overvoltage Conditions
DC UVLO
DC undervoltage lockout (UVLO) prevents an input supply from being used when its voltage is below the operating range. When the voltage from DC to GND (VDC) is
less than the DC UVLO threshold (4.0V, typ), the DC
input is disconnected from SYS, the battery charger is
disabled and CHG is high impedance. BAT is connected
to SYS through the internal system load switch in DC
UVLO mode, allowing the battery to power the SYS
node. REG1–REG4 and the LED current sinks are
allowed to operate from the battery in DC UVLO mode.
DC OVLO
DC overvoltage lockout (OVLO) is a fail-safe mechanism and prevents an input supply from being used
when its voltage exceeds the operating range. The
absolute maximum ratings state that DC withstands
voltages up to 6V. Systems must be designed so that
DC never exceeds 6V (transient and steady-state). If
the voltage from DC to GND (VDC) should exceed the
DC OVLO threshold (5.9V typ) during a fault, the DC
input is disconnected from SYS, the battery charger is
disabled, and CHG is high impedance. BAT is connected to SYS through the internal system load switch in DC
OVLO mode, allowing the battery to power SYS through
the internal system load switch in DC OVLO mode.
REG1–REG4 are allowed to operate from the battery in
DC OVLO mode. Normal operation resumes when VDC
falls within its normal operating range.
SYS UVLO
SYS undervoltage lockout (UVLO) prevents the regulators from being used when the input voltage is below
the operating range. When the voltage from SYS to
GND (VSYS) is less than the SYS UVLO threshold (2.5V,
typ), REG1–REG4, the LED current sinks, and the battery charger are disabled. Additionally, CHG, is high
impedance and RST1 is asserted.
Thermal Limiting and Overload Protection
Smart Power Selector Thermal-Overload Protection
The IC reduces the DC current limit by 5%/°C when the
die temperature exceeds +100°C. The system load
(ISYS) has priority over the charger current, so input
______________________________________________________________________________________
27
MAX8819A/MAX8819B/MAX8819C
EN4 enables REG4, disables REG4, and adjusts the voltage on FB4 in 32 linear steps. If current adjustment is not
required, EN4 acts as a simple enable/disable controller.
Driving EN4 high for at least 100μs powers up REG4 and
sets VFB4 to 0.5V. Pulling EN4 low for at least 2ms disables REG4. To adjust VFB4, apply pulses as shown in
Figure 8. Dim the WLEDs by pulsing EN4 low (500ns to
500μs pulse width). Each pulse reduces the LED current
by 1/32. Note: When REG4 is disabled, OUT4 is equal to
VSYS minus the drop from the catch diode.
In the event that the load (typically WLEDs) opens,
VOUT4 rises quickly until it reaches the overvoltage protection threshold (typically 25V). When this occurs,
REG4 stops switching and latches off until EN4 is reset
low for at least 2ms.
MAX8819A/MAX8819B/MAX8819C
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
OUT_
GATE DRIVE
TO SWITCH
RT
5V/div
0V
3.3V
FB_
3.35V
500mV/div
3V
V1 3V
RB
RD
4.2V
2V/div
RST1
100μs/div
Figure 9. Dynamic Output Voltage Control
Figure 10. Dynamic Voltage Adjustment with Example Values
current is first reduced by lowering charge current. If
the junction temperature still reaches +120°C in spite of
charge current reduction, no input current is drawn
from DC; the battery supplies the entire load and SYS is
regulated 70mV below BAT.
RD is calculated using the higher set voltage and the
following equations assuming the switch resistance is
negligible:
Regulator Thermal-Overload Shutdown
The IC disables all regulator outputs and the battery
charger when the junction temperature rises above
+165°C, allowing the device to cool. When the junction
temperature cools by approximately 15°C the regulators and charger resume the state indicated by the
enable input (EN123, EN4, and CEN) by repeating their
soft-start sequence. Please note that this thermal-overload shutdown is a fail-safe mechanism; proper thermal
design should ensure that the junction temperature of
the MAX8819_ never exceeds the absolute maximum
rating of +150°C.
Applications Information
Dynamic Output Voltage Adjustment
for Step-Down Converters
Dynamic output voltage adjustment can be implemented for the step-down converter by adding a resistor
and a switch from FB_ to GND. See Figure 9.
To calculate the resistor-divider, start with the lower
voltage desired and calculate the resistor-divider using
RT and RB only. Setting RB = 100kΩ is acceptable. Use
the following equation to calculate RT:
⎛V
⎞
RT = RB × ⎜ OUTL − 1⎟
⎝ VFB
⎠
where VOUTL is the desired lower output voltage and
VFB is the feedback regulation voltage, 1V (typ).
28
RT
VOUTH
−1
VFB
1
RD =
1
1
−
RPAR RB
RPAR =
where RPAR is the parallel resistance of RB and RD,
VOUTH is the higher set voltage, and VFB is the feedback regulation voltage, 1V (typ).
For example, if V OUTL = 3V, V OUTH = 3.3V, R B =
100kΩ, then:
RT = 100kΩ x ((3V/1V) - 1) = 200kΩ
RPAR = 200kΩ/((3.3V/1V) - 1) = 86.96kΩ
RD = 1/((1/86.96kΩ) - (1/100kΩ)) = 666.7kΩ
Choose RD = 665kΩ as the closest standard 1% value.
CH1 = gate drive to switch
CH2 = V1, 1V offset; 3V to 3.3V to 3V, 10Ω load
CH3 = RST1
The scope plot (Figure 10) shows V1 switching from 3V
to 3.3V to 3V with the resistor values of the example.
When the switch is turned on, V1 slews from 3V to 3.3V
in about 20μs, which is less than the 50μs RST1 deglitch filter, and therefore, RST1 does not trip. When the
switch is turned off, V1 soars to about 3.35V due to the
energy in the inductor. Since V1 is above the regulation
voltage, REG1 skips until V1 decays to the regulation
voltage. The decay rate is determined by the output
capacitance and the load. In this example, the output
capacitance is 10μF and the load is 10Ω, so the time
______________________________________________________________________________________
PMIC with Integrated Chargers and Smart
Power Selector in a 4mm x 4mm TQFN
PCB Layout and Routing
+ aaaa
Figure 11. Package Marking Example
PG3
LX3
PV13
LX1
PG1
CHG
TOP VIEW
DLIM1
Pin Configuration
21
20
19
18
17
16
15
FB2 22
14
CISET
FB3 23
13
FB1
12
CEN
11
DC
10
SYS
9
BAT
8
RST1
EN123 24
MAX8819A
MAX8819B
MAX8819C
PV2 25
LX2 26
PG2 27
1
2
3
4
5
6
7
GND
EN4
EXPOSED PAD (EP)
LX4
+
PG4
DLIM2 28
FB4
The top of the MAX8819_ package is laser etched as
shown in Figure 11:
“8819_ETI” is the product identification code. The full
part number is MAX8819_ETI; however, in this case, the
“MAX” prefix is omitted due to space limitations. The “_”
corresponds to the “A” or “B” version.
“yww” is a date code. “y” is the last number in the
Gregorian calendar year. “ww” is the week number in
the Gregorian calendar. For example:
• “801” is the first week of 2008; the week of
January 1st, 2008.
• “052” is the fifty-second week of 2010; the week of
December 27th, 2010.
• “aaaa” is an assembly code and lot code.
• “+” denotes lead-free packaging and marks the
pin 1 location.
TIyww
OVP4
Package Marking
8819_ETI
COMP4
Good printed circuit board (PCB) layout is necessary to
achieve optimal performance. Refer to the MAX8819A
Evaluation Kit for Maxim’s recommended layout.
Use the following guidelines for the best results:
• The LX_ rapidly switches between PV_ and PG_.
Minimize stray capacitance on LX_ to maintain high
efficiency.
• Keep the FB_ node away from noise sources such
as the inductor.
• The exposed pad (EP) is the main path for heat to
exit the IC. Connect EP to the ground plane with
thermal vias to allow heat to dissipate from the
device.
• Use short and wide traces for high-current and discontinuous current paths.
• The step-down converter power inputs are critical
discontinuous current paths that require careful
bypassing. Place the step-down converter input
bypass capacitor as close as possible to the PV_
and PG_ pins.
• Minimize the area of the loops formed by the stepdown converters’ dynamic switching currents.
Chip Information
PROCESS: S45T
Package Information
For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
28 TQFN-EP
T2844+1
21-0139
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 ____________________ 29
© 2009 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX8819A/MAX8819B/MAX8819C
constant is R x C = 100μs, and the output voltage
decays to within 1% of final value in about 500μs.
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