MAXIM MAX8804Z

19-0785; Rev 0; 4/07
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
The MAX8804Y/MAX8804Z intelligent, dual-input,
stand-alone, constant-current, constant-voltage
(CCCV), thermally regulated linear chargers are
designed for a single-cell lithium-ion (Li+) battery. They
integrate the current-sense circuit, MOS pass element,
thermal-regulation circuitry, and overvoltage protection
(OVP), and eliminate the reverse-blocking Schottky
diode to create a simple and small charging solution for
handheld equipment.
The MAX8804Z functions as a stand-alone charger to
control the charging sequence from the prequalification
state through fast-charge, top-off charge, and fullcharge indication. The MAX8804Y eliminates the prequalification state to allow startup into a load without a
battery. Proprietary thermal-regulation circuitry limits
the die temperature when fast-charging or while
exposed to high ambient temperatures, allowing maximum charging current without damaging the IC.
The MAX8804Y/MAX8804Z achieve high flexibility by
providing an adjustable DC/USB fast-charge current
through a simple single-wire interface (SET input). The
chargers automatically select between either a USB or
AC adapter input source. The AC adapter charge current is programmable from 400mA to 700mA in 50mA
steps through a serial interface. The USB charge current is programmable to 95mA, 380mA, or 475mA
through the same interface. Other features include an
active-low battery charging-status indicator (CHG), an
active-low power-OK indicator (POK), and an active-low
USB input detection output (USBPWR).
The MAX8804Y/MAX8804Z accept a 4.15V to 30V DC
source voltage or a 4.15V to 16V USB input voltage, but
disable charging when either input voltage exceeds
7.5V to protect against unqualified or faulty input
sources. The MAX8804Y/MAX8804Z operate over the
extended temperature range (-40°C to +85°C) and are
available in a tiny 8-pin thermally enhanced 2mm x
3mm TDFN package.
Applications
Features
♦ Complete Chargers for Single-Cell Li+ Battery
♦ Dual-Input, 30V AC Adapter/16V USB
♦ No External FET, Blocking Diode, or Sense
Resistor Required
♦ Automatic USB/AC Adapter Input Selection
♦ Easy Programmable Fast-Charge Current and
Top-Off Threshold
♦ Proprietary Die Temperature Regulation Control
♦ ±5% Fast-Charge Current-Limit Accuracy
♦ Power-Present and Charger-Status Outputs
♦ No Prequalification Charge (MAX8804Y)
♦ Tiny 2mm x 3mm Thermally Enhanced TDFN
Package
♦ USB Charging Protected by US Patent #6,507,172
Ordering Information
PART
PINPACKAGE
PKG
CODE
TOP
MARK
MAX8804YETA+
8 TDFN-EP*
T823+1
AAD
MAX8804ZETA+
8 TDFN-EP*
T823+1
AAC
*EP = Exposed paddle.
+Denotes a lead-free package.
Note: All devices are specified to operate over the -40°C to
+85°C operating temperature range.
Typical Application Circuit
+3.3V
AC
ADAPTER
DC
GND
Cell Phones/Smartphones
Digital Cameras
Portable Media Players
CHG
1μF
USB
PORT
USB
POK
USBPWR
1μF
BAT
MP3 Players
Other Handheld Devices
MAX8804Y
MAX8804Z
2.2μF
ENABLE/DISABLE
AND PROGRAMMING
Li+
SET
Pin Configuration appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX8804Y/MAX8804Z
General Description
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
ABSOLUTE MAXIMUM RATINGS
DC to GND .............................................................-0.3V to +30V
USB to GND ...........................................................-0.3V to +16V
BAT, CHG, SET, POK, USBPWR to GND ..............-0.3V to +5.5V
Continuous Power Dissipation (TA = +70°C)
8-Pin TDFN 2mm x 3mm (derate 16.7mW/°C above +70°C)
(multilayer board) .......................................................1333mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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
((VDC = 5V, VSET = 0V) or (VUSB = 5V, VSET = 5V), VBAT = unconnected, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
DC AND USB
DC Input Voltage Range
0
28
V
USB Input Voltage Range
0
14
V
(Notes 2, 3)
4.15
7.00
V
Input Undervoltage Threshold
VIN rising, 500mV hysteresis (typ) (Note 2)
3.85
4.0
4.15
V
Input Overvoltage Threshold
VIN rising, 200mV hysteresis (typ) (Note 2)
7.2
7.5
7.8
V
VUSB = 0V, IBAT = 0mA, charge mode
800
1200
VSET = 5V, standby mode
300
550
VDC = VBAT = 4.3V, shutdown mode
300
550
VDC = 0V, VSET = 5V, IBAT = 0mA, charge mode
800
1200
Input Operating Range
DC Input Supply Current
USB Input Supply Current
VSET = 0V, standby mode
300
550
VUSB = VBAT = 4.3V, shutdown mode
300
550
µA
µA
DC to BAT On-Resistance
VDC = 3.7V, VBAT = 3.6V
0.55
1.0
Ω
USB to BAT On-Resistance
VUSB = 3.7V, VBAT = 3.6V
0.65
1.2
Ω
Input to BAT Comparator
Threshold (Note 2)
VIN rising
260
385
145
VIN falling
55
mV
BAT
BAT Regulation Voltage
IBAT = 0mA
Battery Removal Detection
Threshold
VBAT rising
DC Charging Current
2
TA = +25°C
4.179
4.200
4.221
TA = -40°C to +85°C
4.158
4.200
4.242
4.40
4.67
4.90
Hysteresis
VUSB = 0V,
VBAT = 3.6V,
rising edge detection
on SET
0.1
Default and 1st to 3rd interface
pulse
475
500
525
4th to 7th interface pulse
523
550
578
8th to 11th interface pulse
570
600
630
12th to 15th interface pulse
428
450
473
16th to 19th interface pulse
380
400
420
20th to 23rd interface pulse
618
650
683
24th to 27th interface pulse
665
700
735
_______________________________________________________________________________________
V
V
mA
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
((VDC = 5V, VSET = 0V) or (VUSB = 5V, VSET = 5V), VBAT = unconnected, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
USB Charging Current
CONDITIONS
VDC = 0V,
VBAT = 3.6V, rising
edge detection on SET
MIN
TYP
MAX
Default
90
95
100
1st interface pulse
360
380
400
2nd interface pulse
450
475
500
2.35
2.50
Soft-Start Time
Ramping time from 0 to 500mA
BAT Prequal Threshold
MAX8804Z only, VBAT rising, 300mV hysteresis (typ)
250
BAT Prequal Charge Current
MAX8804Z only
BAT Leakage Current
VDC = VUSB = 0V, VBAT = 4.2V
UNITS
mA
µs
2.65
95
V
mA
2
µA
SET
Logic Input Thresholds
VSET rising
1.6
VSET falling
0.4
V
Logic-High Time
Pulse width required to program DC charge current
1
1000
µs
Logic-Low Time
Pulse width required to program USB charge current
1
1000
µs
SET DC Mode Shutdown Delay
VUSB = 0V, VDC = 5V, measured from VSET low to high
1.5
2
2.5
ms
SET USB Mode Shutdown Delay
VDC = 0V, VUSB = 5V, measured from VSET high to low
1.5
2
2.5
ms
2
4
MΩ
60
500
mV
TA = +25°C
0.001
1
TA = +85°C
0.01
SET Internal Pulldown Resistor
POK, CHG, USBPWR
Logic Output-Voltage Low
I POK = I CHG = I USBPWR = 5mA
Logic Output-Current High
V POK = V CHG =
V USBPWR = 5.5V,
VDC = VUSB = 0V
µA
CHG
VDC = 0V, VUSB = 5V
60
80
100
60
80
100
67.5
90
112.5
2nd, 6th, 10th,
14th, 18th, 22nd,
26th interface pulse
75
100
125
3rd, 7th, 11th, 15th,
19th, 23rd, 27th
interface pulse
52.7
70
87.5
Default, 4th, 8th,
12th, 16th, 20th,
24th, 28th interface
pulse
CHG Top-Off Threshold
IBAT falling, battery is
charged, rising edge
on SET
VDC = 5V,
VUSB = 0V
1st, 5th, 9th, 13th,
17th, 21st, 25th
interface pulse
mA
_______________________________________________________________________________________
3
MAX8804Y/MAX8804Z
ELECTRICAL CHARACTERISTICS (continued)
ELECTRICAL CHARACTERISTICS (continued)
((VDC = 5V, VSET = 0V) or (VUSB = 5V, VSET = 5V), VBAT = unconnected, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
DC mode
57
USB mode
51
CHG Hysteresis
IBAT rising after top-off
is detected (Note 4)
CHG Detection Delay
IBAT falls below top-off threshold
3
4
MAX
UNITS
mA
5
ms
THERMAL LOOP
Thermal-Regulation Set Point
Junction temperature when the charge current is reduced,
TJ rising
Thermal-Regulation Gain
Reduction of IBAT for
increase of TJ
+105
DC charging
-40
USB charging
-24
°C
mA/°C
Note 1: Devices are 100% production tested at TA = +25°C. Limits over the operating temperature range are guaranteed by design
and characterization.
Note 2: VIN refers to the input for the IC. For the MAX8804Y/MAX8804Z, VIN is VDC with VUSB = 0V or VUSB with VDC = 0V.
Note 3: Guaranteed by undervoltage and overvoltage threshold testing. For charge completion, the input voltage must be greater
than 4.28V.
Note 4: This hysteresis is for all charge current except 95mA. In the case of 95mA charge current, voltage-mode to current-mode
detection gives indication of charge mode.
Typical Operating Characteristics
(VBAT = 3.6V; DC charge mode: VDC = 5V, VUSB = 0V, VSET = 0V or unconnected; USB charge mode: VUSB = 5V, VDC = 0V, VSET =
5V; TA = +25°C, unless otherwise noted.)
0.4
0.2
SUPPLY CURRENT (mA)
0.6
0.6
0.4
0.2
0
0
0
3
6
9 12 15 18 21 24 27 30
INPUT VOLTAGE (V)
MAX8804Y/Z toc03
0.8
MAX8804Y/Z toc02
0.8
SUPPLY CURRENT (mA)
0.8
4
1.0
MAX8804Y/Z toc01
1.0
DISABLED-MODE SUPPLY CURRENT
vs. INPUT VOLTAGE (DC CHARGING MODE)
SUPPLY CURRENT vs. INPUT VOLTAGE
(USB CHARGING MODE)
SUPPLY CURRENT vs. INPUT VOLTAGE
(DC CHARGING MODE)
SUPPLY CURRENT (mA)
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
0.6
0.4
0.2
0
0
2
4
6
8
10 12
INPUT VOLTAGE (V)
14
16
0
5
10
15
20
INPUT VOLTAGE (V)
_______________________________________________________________________________________
25
30
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
500
0.4
0.2
400
300
200
0
0
2
4
6
8
10 12
INPUT VOLTAGE (V)
14
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
BATTERY VOLTAGE (V)
CHARGE CURRENT
vs. DC INPUT VOLTAGE
0
CHARGE CURRENT
vs. USB INPUT VOLTAGE
CHARGE CURRENT (mA)
MAX8804Y/Z toc09
400
300
200
MAX8804Y/Z toc08
500
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
BATTERY VOLTAGE (V)
CHARGE CURRENT vs. SET PULSE
(USB CHARGING MODE)
120
MAX8804Y/Z toc07
600
90
VSET
1V/div
60
475mA
380mA
475mA
100
475mA
200mA/div
95mA
0
380mA
ICHG
30
95mA
95mA
0
5
10
15
20
INPUT VOLTAGE (V)
25
30
0
2
4
6
8
10 12
INPUT VOLTAGE (V)
14
16
2ms/div
CHARGE CURRENT
vs. INPUT VOLTAGE HEADROOM
CHARGE CURRENT vs. SET PULSE
(DC CHARGING MODE)
MAX8804Y/Z toc10
600
INPUT VOLTAGE DECREASING
500
VSET
1V/div
700mA
ICHG
550mA
500mA
650mA
600mA
700mA
200mA/div
450mA
500mA
400mA
MAX8804Y/Z toc11
0
CHARGE CURRENT (mA)
CHARGE CURRENT (mA)
80
0
0
16
120
40
100
0
160
CHARGE CURRENT (mA)
0.6
200
MAX8804Y/Z toc05
MAX8804Y/Z toc04
600
CHARGE CURRENT (mA)
SUPPLY CURRENT (mA)
0.8
CHARGE CURRENT vs. BATTERY VOLTAGE
(USB CHARGING MODE)
CHARGE CURRENT vs. BATTERY VOLTAGE
(DC CHARGING MODE)
MAX8804Y/Z toc06
STANDBY-MODE SUPPLY CURRENT
vs. INPUT VOLTAGE (USB CHARGING MODE)
400
DC MODE
300
200
USB MODE
100
0
2ms/div
MAX8804Y/MAX8804Z
Typical Operating Characteristics (continued)
(VBAT = 3.6V; DC charge mode: VDC = 5V, VUSB = 0V, VSET = 0V or unconnected; USB charge mode: VUSB = 5V, VDC = 0V, VSET =
5V; TA = +25°C, unless otherwise noted.)
0
100
200
300
400
INPUT VOLTAGE HEADROOM (mV)
500
_______________________________________________________________________________________
5
Typical Operating Characteristics (continued)
(VBAT = 3.6V; DC charge mode: VDC = 5V, VUSB = 0V, VSET = 0V or unconnected; USB charge mode: VUSB = 5V, VDC = 0V, VSET =
5V; TA = +25°C, unless otherwise noted.)
BATTERY REGULATION VOLTAGE
vs. AMBIENT TEMPERATURE
DC MODE
500
400
4.186
300
4.180
200
MAX8804Y/Z toc14
MAX8804Y/Z toc13
600
4.30
BATTERY REGULATION VOLTAGE (V)
4.198
4.192
700
CHARGE CURRENT (mA)
USB MODE
4.204
BATTERY REGULATION VOLTAGE
vs. LOAD CURRENT
CHARGE CURRENT
vs. AMBIENT TEMPERATURE
MAX8804Y/Z toc12
4.210
BATTERY REGULATION VOLTAGE (V)
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
4.25
4.20
4.15
DC CHARGE MODE 650mA
-40
-15
10
35
60
AMBIENT TEMPERATURE (°C)
85
550mA CHARGE-CURRENT SETTING
4.10
-40
-15
10
35
60
AMBIENT TEMPERATURE (°C)
85
0
100
200 300 400 500
LOAD CURRENT (mA)
600
700
Pin Description
6
PIN
NAME
FUNCTION
1
BAT
Battery Connection. The IC delivers charging current and monitors battery voltage using BAT. Bypass BAT to
GND with a 2.2µF or larger ceramic capacitor. BAT is high impedance when the IC is disabled.
2
USBPWR
USB Power Status Output. USBPWR is internally pulled low if a valid voltage is present at USB, otherwise it is
high impedance. USBPWR circuitry is active regardless of SET and charger on/off status.
3
POK
Power-OK Monitor. POK is an open-drain output that is internally pulled low when a valid charging source is
detected at either DC or USB. POK is high impedance when both input voltages are less than VUVLO or VBAT.
4
DC
DC Input Supply. Connect DC to a 4.15V to 7V charging source. Bypass DC to GND with a 1µF or larger
ceramic capacitor. DC takes priority over USB when both are valid.
5
USB
USB Input Source. Connect USB to a USB port. Bypass USB to GND with a 1µF or larger ceramic capacitor.
6
CHG
Charging-Status Output. CHG is internally pulled low when the battery is being charged. CHG is high
impedance when the charger is in top-off mode or disabled.
7
SET
Enable/Disable, Charging Current, and Top-Off Threshold Set Input. Drive SET low to enable DC charge
mode and drive high to enable USB charge mode. If both DC and USB inputs are present, SET is used for
the DC charge mode only and USB charge is disabled. SET is also used for programming the charge current
and top-off threshold. See the DC/USB Mode and Charging Current Setting section for details.
8
GND
Ground
—
EP
Exposed Paddle. Connect to the GND plane for optimum thermal dissipation.
_______________________________________________________________________________________
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
MAX8804Y/MAX8804Z
4.15V TO 30V
BAT
DC
Li+
4.15V TO 16V
USB
+105°C
DC AND USB OUTPUT CONTROL
TEMP
SENSOR
VOLTAGE
LOOP
MAX8804Y
MAX8804Z
OVERVOLTAGE
PROTECTION
DC
POK
SET
CHG
LOGIC
CONTROL
USB
POK
REF
POK
USBPWR
BIAS
CIRCUIT
GND
Figure 1. Functional Diagram
Detailed Description
The MAX8804Y/MAX8804Z dual-input linear battery
chargers use voltage, current, and thermal-control loops
to charge and protect a single Li+ battery. When a Li+
battery with a cell voltage below 2.5V is inserted, the
MAX8804Z charger enters the prequalification stage
where it precharges that cell with 95mA (Figure 2). The
CHG indicator output is driven low to indicate entry into
the prequalification state. When battery voltage exceeds
2.5V, the charger soft-starts as it enters the fast-charge
stage. The MAX8804Y eliminates the prequalification
state and enters fast-charge when the battery is inserted.
In the MAX8804Y/MAX8804Z, the fast-charge current
level is programmed by a simple single-wire interface.
As the battery voltage approaches 4.2V, the charging
current is reduced. If the battery current drops below the
top-off current threshold, the CHG indicator goes high
impedance, signaling that the battery is fully charged.
The ICs then enter a constant voltage-regulation mode to
maintain the battery at full charge.
The MAX8804Y/MAX8804Z automatically select between
either a USB or AC adapter input source. The AC
adapter charge current is programmable from 400mA to
700mA in 50mA steps through a simple single-wire interface. The USB charge current is programmable to 95mA,
380mA, or 475mA through the same interface.
_______________________________________________________________________________________
7
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
ASYNCHRONOUS
FROM ANYWHERE
tSET = HIGH > 2ms
FOR DC MODE
tSET = LOW > 2ms
FOR USB MODE
STANDBY MODE
CHARGER = OFF
POK = LOW
CHG = HIGH IMPEDANCE
MAX8804Z
VBAT < 2.5V
SHUTDOWN
CHARGER = OFF
POK = HIGH IMPEDANCE*
CHG = HIGH IMPEDANCE
tSET = LOW > 2ms
FOR DC MODE
tSET = HIGH > 2ms
FOR USB MODE
PREQUALIFICATION
DEFAULT CHARGE CURRENT
POK = LOW
CHG = LOW
VBAT < 2.2V
MAX8804Z
VUVLO < VIN < VOVP
AND VIN > VBAT
VIN < VUVLO
OR VIN > VOVP
OR VBAT > VIN
ASYNCHRONOUS
FROM ANYWHERE
VIN < VUVLO
OR VIN > VOVP
OR VBAT > VIN
MAX8804Y
tSET = LOW > 2ms
FOR DC MODE
tSET = HIGH > 2ms
FOR USB MODE
VBAT > 2.5V
FAST-CHARGE
100% CHARGE CURRENT
POK = LOW
CHG = LOW
ICHG > ITOP-OFF + 57mA FOR ALL FASTCHARGE OPTIONS EXCEPT 95mA
ICHG< ITOP-OFF
CV MODE TO CC MODE FOR 95mA
FAST-CHARGE OPTION
FULL BAT
VBAT = 4.2V
POK = LOW
CHG = HIGH IMPEDANCE
*POK = LOW WHEN VIN > VOVP
Figure 2. Charger State Diagram
DC Charging
USB Charging
The MAX8804Y/MAX8804Z are designed to charge a
single-cell Li+ battery from a DC source voltage
between 4.15V and 7V and withstand up to 30V maximum input voltage. The charge current and top-off
threshold are programmed with the SET input.
The MAX8804Y/MAX8804Z contain a USB input that
allows operation from a USB port with voltages between
4.15V and 7V and can withstand up to 16V maximum
input voltage. Pulsing SET allows programming a 95mA,
380mA, or 475mA maximum charging current when
using the USB input.
8
_______________________________________________________________________________________
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
SET
VDC
VUSB
0
Invalid
Invalid
0
Invalid
Valid
CHARGER STATUS
Off
Off
0
Valid
Invalid
DC charging mode enabled,
USB charging mode disabled
0
Valid
Valid
DC charging mode enabled,
USB charging mode disabled
1
Invalid
Invalid
1
Invalid
Valid
1
Valid
Invalid
Off
1
Valid
Valid
Off
Off
DC charging mode disabled,
USB charging mode enabled
DC Charge Mode
Drive SET low or leave it unconnected to enable DC
charging mode. Subsequent pulses on SET program the
charging current and the top-off threshold. There are
seven fast-charge current options and four top-off threshold options. Default fast-charge current and top-off
threshold current are 500mA and 80mA. Pulse SET high
(1µs to 1ms pulse width) subsequently to realize charging
current and top-off threshold programming and transition.
After the 28th pulse, the MAX8804Y/MAX8804Z go into
the default mode and start a new cycle. See Table 2 and
Figure 3 to set the desired charging current and top-off
threshold. Drive SET high longer than 2ms to disable DC
charging-control circuitry.
DC/USB Mode and
Charging Current Setting
SET is a logic input that sets DC/USB charging mode
and charging current. Drive SET low or leave it unconnected to enable DC charging mode. Drive SET high to
enable USB charging mode (see Table 1). SET can
also be driven by series pulses to program the charging current in both DC and USB mode.
Table 2. DC Charging Current Programming by Series Pulses
PULSE
NUMBER
DEFAULT
1st
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
12th
13th
14th
ICHG (mA)
500
500
500
500
550
550
550
550
600
600
600
600
450
450
450
Top-Off Current
Threshold (mA)
80
90
100
70
80
90
100
70
80
90
100
70
80
90
100
PULSE
NUMBER
—
15th
16th
17th
18th
19th
20th
21st
22nd
23rd
24th
25th
26th
27th
28th
ICHG (mA)
—
450
400
400
400
400
650
650
650
650
700
700
700
700
500
Top-Off Current
Threshold (mA)
—
70
80
90
100
70
80
90
100
70
80
90
100
70
80
_______________________________________________________________________________________
9
MAX8804Y/MAX8804Z
Table 1. SET Truth Table
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
DC
POK
1
2
3
4
24
25
26
27
28
> 2ms
SET
tHIGH
700mA
2ms tSOFTSTART
DELAY
550mA
500mA
ICHG
TOP-OFF
CURRENT
THRESHOLD
500mA
0mA
0mA
90mA
100mA
90mA
80mA
80mA
80mA
70mA
100mA
70mA
80mA
Figure 3. DC Charging Current and Top-Off Threshold Programming
USB Charge Mode
Drive SET high to enable USB charging mode when the
USB input is valid. Subsequent low pulses with 1µs to
1ms pulse width on SET program the fast charging current from 95mA, 380mA, to 475mA and then repeat
new cycle as shown in Table 3. Drive SET low or leave
it unconnected longer than 2ms to disable USB charging-control circuitry.
10
Table 3. USB Charging Current
Programming by Series Pulses
PULSE NUMBER
DEFAULT
1st
2nd
3rd
ICHG (mA)
95
380
475
95
Top-Off Current
Threshold (mA)
80
80
80
80
______________________________________________________________________________________
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
MAX8804Y/MAX8804Z
USB
POK
USBPWR
1
2
3
> 2ms
SET
tLOW
2ms
t
DELAY SOFTSTART
ICHG
475mA
380mA
95mA
95mA
0mA
0mA
TOP-OFF
CURRENT
THRESHOLD
80mA
Figure 4. USB Charging Current Programming
Soft-Start
Charging-Status Output (CHG)
The soft-start circuitry activates when entering fastcharge mode. In the MAX8804Y, soft-start is entered
directly after being enabled, and the charging current
ramps up in 250µs from 0 to 500mA (95mA in USB
mode). This reduces the inrush current on the input
supply. Note that the MAX8804Z has a prequalification
state and the charging current ramps up when the prequalification state is complete (VBAT exceeds 2.5V).
CHG is an open-drain output that indicates charger status. CHG goes low during charge cycles where the
MAX8804Y/MAX8804Z are in prequalification or fastcharge mode. CHG goes high impedance when the
charge current reaches the top-off threshold for more
than 4ms, indicating charging is done. The CHG status
is latched after the top-off threshold is reached. The
latch is reset by toggling the SET input, recycling input
power, or increasing the charging current to the top-off
threshold plus 57mA (typ).
When the MAX8804Y/MAX8804Z are used in conjunction with a microprocessor (µP), connect a pullup resistor between CHG and the logic I/O voltage to indicate
charge status to the µP. Alternatively, CHG can sink up
to 5mA for an LED charge indicator.
Thermal Regulation Control
The thermal-regulation loop limits the MAX8804Y/
MAX8804Z die temperature to +105°C by reducing the
charge current as necessary. This feature not only protects the ICs from overheating, but also allows a higher
charge current at room temperature without risking
damage to the system.
______________________________________________________________________________________
11
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
Power-OK Monitor (POK)
Thermal Considerations
The MAX8804Y/MAX8804Z contain an open-drain POK
output that goes low when a valid input source is
detected at either DC or USB. A valid input source is
one whose voltage is greater than 4.15V and exceeds
the battery voltage by 250mV. After a valid input has
been established, charging is sustained with inputs as
low as 3.5V as long as the input voltage remains above
the battery voltage by at least 40mV. POK status is
maintained regardless of SET status.
When the MAX8804Y/MAX8804Z are used in conjunction with a µP, connect a pullup resistor between POK
and the logic I/O voltage to indicate power-OK to the
µP. Alternatively, POK can sink up to 5mA for an LED
power-OK indicator.
The MAX8804Y/MAX8804Z are available in a thermally
enhanced TDFN package with an exposed paddle.
Connect the exposed paddle to a large copper ground
plane to provide a thermal contact between the device
and the PCB for increased power dissipation. The
exposed paddle transfers heat away from the device,
allowing the IC to charge the battery with maximum current, while minimizing the die temperature increase.
USB Power Status Output (USBPWR)
USBPWR is internally pulled low when VUSB > VUVLO
and VUSB - VBAT > 250mV. Otherwise, it is high impedance. USBPWR indicates the USB input presence
regardless of SET status and charger status.
When the MAX8804Y/MAX8804Z are used in conjunction
with a µP, connect a pullup resistor between USBPWR
and the logic I/O voltage to indicate USB power status
to the µP. Alternatively, USBPWR can sink up to 5mA
for an LED USB power status indicator.
Applications Information
Capacitor Selection
Connect a 2.2µF ceramic capacitor from BAT to GND for
proper stability. Connect a 1µF ceramic capacitor from
DC to GND. If using the USB input, bypass USB to GND
with a 1µF ceramic capacitor. Use a larger input bypass
capacitor for high charging currents to reduce supply
noise. All capacitors should be X5R dielectric or better.
Be aware that some capacitors have large voltage and
temperature coefficients and should be avoided.
12
Input Sources
The MAX8804Y/MAX8804Z operate from well-regulated
input sources. The operating input voltage range is
4.15V to 7V. The device survives DC input supply voltages up to 30V and USB input source voltages up to
16V without damage to the IC. If the input voltage is
greater than 7.5V (typ), the IC stops charging. An
appropriate power supply must provide at least 4.2V
plus the voltage drop across the internal pass transistor
when sourcing the desired maximum charging current:
VIN(MIN) > 4.2V + ICHARGE(MAX) x RON
where R ON is the input-to-BAT resistance (typically
0.55Ω for DC or 0.65Ω for USB). Failure to meet this
requirement results in an incomplete charge or
increased charge time.
Application Circuits
Stand-Alone Li+ Charger
The MAX8804Y/MAX8804Z provide a complete Li+
charging solution. The Typical Application Circuit
shows the MAX8804Y/MAX8804Z as a stand-alone Li+
battery charger. The LED indicates when either fastcharge or prequalification has begun. When the battery
is fully charged, the LED turns off.
Microprocessor-Interfaced Li+ Charger
Figure 5 shows the MAX8804Y/MAX8804Z as a µPinterfaced Li+ battery charger. The µP drives SET to
enable/disable DC/USB mode charging. CHG can be
used to detect the charge status of a battery.
______________________________________________________________________________________
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
MAX8804Y/MAX8804Z
SYSTEM I/O
AC
ADAPTER
DC
CHG
1μF
USB PORT
USB
MAX8804Y
MAX8804Z
1μF
μP
USBPWR
BAT
Li+
POK
SET
2.2μF
GND
Figure 5. Microprocessor-Interfaced Li+ Charger with the MAX8804Y/MAX8804Z
Pin Configuration
Layout and Bypassing
Connect the input capacitors as close as possible to
the IC. Provide a large copper GND plane to allow the
exposed paddle to sink heat away from the IC. Connect
the battery to BAT as close as possible to the IC to provide accurate battery voltage sensing. Make all highcurrent traces short and wide to minimize voltage
drops. A sample layout is available in the MAX8804Z
evaluation kit to speed designs.
TOP VIEW
GND
SET
CHG
USB
8
7
6
5
MAX8804Y
MAX8804Z
Chip Information
PROCESS: BiCMOS
+
1
2
3
BAT USBPWR POK
4
DC
TDFN
2mm × 3mm
______________________________________________________________________________________
13
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.)
8L, TDFN.EPS
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
PACKAGE OUTLINE
8L TDFN, EXPOSED PAD, 2x3x0.8mm
21-0174
14
______________________________________________________________________________________
B
1
2
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
DIMENSIONS
SYMBOL
A
E
D
A1
L
k
A2
MIN.
0.70
NOM.
0.75
MAX.
0.80
2.95
3.00
3.05
1.95
0.00
2.00
0.02
2.05
0.05
0.30
0.40
0.20 MIN.
0.20 REF.
0.50
N
e
b
0.18
8
0.50 BSC
0.25
EXPOSED PAD PACKAGE
E2
D2
PKG.
CODE
MIN.
NOM.
MAX.
MIN.
NOM.
MAX.
T823-1
1.60
1.75
1.90
1.50
1.63
1.75
0.30
PACKAGE OUTLINE
8L TDFN, EXPOSED PAD, 2x3x0.8mm
21-0174
B
2
2
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 ____________________ 15
© 2007 Maxim Integrated Products
Heaney
is a registered trademark of Maxim Integrated Products, Inc.
MAX8804Y/MAX8804Z
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.)