19-6038; Rev 1; 5/12
TION KIT
EVALUA BLE
AVAILA
Step-Up Converter
for Handheld Applications
Features
S
Compact Layout
Small, 1.25mm x 1.25mm WLP Package
3MHz PWM Switching Frequency
Small External Components
S
Safe and Efficient Step-Up Mode
Up to 1A Output Current
2.5V to 5.5V Input Voltage Range
3.3V to 5V Ouput Voltage Range
Over 90% Efficiency with Internal Synchronous
Rectifier
Low 45µA No-Load Quiescent Current
Soft-Start Controls Inrush Current
True Shutdown™
Low 1µA Shutdown Current
S
Track Mode
1A Current Limited
130mI On-Resistance
Low 30µA No Load Quiescent Current
S
Automatic Track Mode
130mI On-Resistance
Low 60µA No-Load Quiescent Current
Boost Circuitry Enabled for Fast Transition into
Boost
General Description
The MAX8969 is a simple 1A step-up converter in a small
package that can be used in any single-cell Li-ion appli-
cation. This IC provides protection features such as input
undervoltage lockout, short circuit, and overtemperature
shutdown.
The IC transitions to skip mode seamlessly under light-
load conditions to improve efficiency. Under these
conditions, switching occurs only as needed, reducing
switching frequency and supply current to maintain high
efficiency.
When the input voltage is sufficient to drive the load, the
IC can be operated in track mode or automatic track
mode (ATM). In track mode, the p-channel MOSFET acts
as a current-limited load switch and quiescent current is
as low as 30µA under a no-load condition. In ATM mode,
the p-channel MOSFET acts as a current-limited load
switch and quiescent current is as low as 60µA under a
no-load condition. In ATM mode, the internal boost cir-
cuitry is enabled, allowing for fast transitions into boost
mode.
The IC is available in a small, 1.25mm x 1.25mm, 9-bump
WLP (0.4mm pitch) package.
MAX8969
Applications
Cell Phones
Smartphones
Mobile Internet Devices
GPS, PND
eBooks
Typical Operating Circuit
L1
1µH
INPUT
2.5V TO 5.5V
C
IN
4.7µF
OUTPUT
3.7V, 1A
C
OUT
22µF
Ordering Information
PART
MAX8969EWL33+
MAX8969EWL35+
MAX8969EWL37+
MAX8969EWL42+
MAX8969EWL50+
V
OUT
(V)
3.3
3.5
3.7
4.25
5.0
TEMP RANGE
-40NC to +85NC
-40NC to +85NC
-40NC to +85NC
-40NC to +85NC
-40NC to +85NC
PIN-
PACKAGE
9 WLP
9 WLP
9 WLP
9 WLP
9 WLP
IN
LX_
OUT_
MAX8969
EN
TREN
GND_
Note:
The output voltage range is from 3.3V to 5V. Contact the
factory for output options and availability.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
True Shutdown is a trademark of Maxim Integrated Products, Inc.
_______________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Step-Up Converter
for Handheld Applications
MAX8969
ABSOLUTE MAXIMUM RATINGS
IN, OUT_ to GND_ ................................................-0.3V to +6.0V
EN, TREN to GND_ ............ -0.3V to lower of (V
IN
+ 0.3V) or 6V
Total LX_ Current........................................................... 3.2A
RMS
OUT_ Short Circuit to GND_ .....................................Continuous
Continuous Power Dissipation (T
A
= +70NC)
WLP (derate 12mW/NC above +70NC).........................960mW
Operating Temperature Range .......................... -40NC to +85NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Soldering Temperature (reflow) (Note 1) ........................+260NC
Note 1:
This device is constructed using a unique set of packaging techniques that impose a limit on the thermal profile that the
device can be exposed to during board level solder attach and rework. This limit permits only the use of the solder pro-
files recommended in the industry-standard specification JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and Convection
reflow. Preheating is required. Hand or wave soldering is not allowed.
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.
PACKAGE THERMAL CHARACTERISTICS (Note 2)
WLP
Junction-to-Ambient Thermal Resistance (B
JA
) ..........83NC/W
Junction-to-Case Thermal Resistance (B
JC
) ...............50NC/W
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
www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V
IN
= 2.6V, T
A
= -40NC to +85NC, unless otherwise noted. Typical values are T
A
= +25NC.) (Note 3)
PARAMETER
Operating Input Voltage Range
Minimum Startup Voltage
Undervoltage Lockout Threshold (UVLO)
Shutdown Supply Current
Thermal Shutdown
BOOST MODE
Peak Output Current
V
IN
> 2.5V (Note 4)
V
OUT
= 3.3V
V
OUT
= 3.5V
Continuous Output Current
V
IN
> 2.5V, pulse
load
V
OUT
= 3.7V
V
OUT
= 4.25V
V
OUT
= 4.7V
V
OUT
= 5.0V
Switching Frequency
(Note 4)
No load, V
OUT
_
TARGET
= 3.3V
No load, V
OUT
_
TARGET
= 3.5V
Output Voltage Accuracy
No load, V
OUT
_
TARGET
= 3.7V
No load, V
OUT
_
TARGET
= 4.25V
No load, V
OUT
_
TARGET
= 5V
3.175
3.40
3.64
4.10
4.85
1
0.9
0.8
0.7
0.7
0.7
0.7
3
3.30
3.50
3.75
4.25
5.00
3.40
3.60
3.85
4.35
5.10
V
MHz
A
A
V
IN
falling, 75mV hysteresis
V
EN
= V
TREN
= V
OUT
= 0V,
V
IN
= 4.8V
T
A
rising, 20NC hysteresis
T
A
= +25NC
T
A
= +85NC
2.1
CONDITIONS
MIN
2.5
2.3
2.2
0.8
1
+165
2.3
5
TYP
MAX
5.5
UNITS
V
V
V
FA
NC
2
______________________________________________________________________________________
Step-Up Converter
for Handheld Applications
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 2.6V, T
A
= -40NC to +85NC, unless otherwise noted. Typical values are T
A
= +25NC.) (Note 3)
PARAMETER
CONDITIONS
2.5V < V
IN
< V
ATMRT
, conditions emulating 0 <
I
OUT
< 1A, C
OUT
= 22FF, L = 1FH,
V
OUT
_
TARGET
= 3.3V
2.5V < V
IN
< V
ATMRT
, conditions emulating 0 <
I
OUT
< 1A, C
OUT
= 22FF, L = 1FH,
V
OUT
_
TARGET
= 3.5V
Steady-State Output Voltage
(Notes 5, 6)
2.5V < V
IN
< V
ATMRT
, conditions emulating 0 <
I
OUT
< 1A, C
OUT
= 22FF, L = 1FH,
V
OUT
_
TARGET
= 3.7V
2.5V < V
IN
< V
ATMRT
, conditions emulating 0 <
I
OUT
< 600mA, C
OUT
= 22FF, L = 1FH,
V
OUT
_
TARGET
= 4.25V
2.5V < V
IN
< V
ATMRT
, conditions emulating 0 <
I
OUT
< 500mA, C
OUT
= 22FF, L = 1FH,
V
OUT
_
TARGET
= 5V
LX_ Leakage Current
Skip-Mode Supply Current
pMOS Turn-Off Current (Zero-Cross Current)
LX_ nMOS Current Limit
Maximum Duty Cycle
Minimum Duty Cycle
V
OUT
= 3.3V
V
OUT
= 3.5V
pMOS On-Resistance
V
OUT
= 3.7V
V
OUT
= 4.25V
V
OUT
= 5V
V
OUT
= 3.3V
V
OUT
= 3.5V
nMOS On-Resistance
V
OUT
= 3.7V
V
OUT
= 4.25V
V
OUT
= 5V
Minimum Output Capacitance for Stable
Operation (Actual)
V
OUT
= 3.3V
Maximum Output Capacitance (Actual)
0 < I
OUT
< 0.3A
during startup
V
OUT
= 3.5V
V
OUT
= 3.7V
V
OUT
= 4.25V
V
OUT
= 5V
0
120
115
110
100
91
65
63
60
55
51
8
70
55
45
30
20
FF
FF
mI
mI
V
LX
= 0V, 4.8V
T
A
= +25NC
T
A
= +85NC
MIN
3.00
TYP
MAX
3.45
UNITS
MAX8969
3.15
3.65
3.35
3.85
V
3.95
4.35
4.50
0.1
0.2
45
10
2.6
83
5.10
5
FA
FA
mA
EN = high, I
OUT
= 0A, 1FH inductor (TREN is
low, not switching)
3.2
A
%
%
_______________________________________________________________________________________
3
Step-Up Converter
for Handheld Applications
MAX8969
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 2.6V, T
A
= -40NC to +85NC, unless otherwise noted. Typical values are T
A
= +25NC.) (Note 3)
PARAMETER
Output Voltage Ripple
Soft-Start Interval
TRACK MODE
pMOSFET On-Resistance
Track Current Limit
Track Mode Quiescent Current
AUTOMATIC TRACK MODE (ATM)
ATM Supply Current
V
IN
= 5.4V
V
OUT
_
TARGET
= 3.3V
V
OUT
_
TARGET
= 3.5V
ATM V
IN
Rising Threshold (V
ATMRT)
V
OUT
_
TARGET
= 3.7V
V
OUT
_
TARGET
= 4.25V
V
OUT
_
TARGET
= 5V
V
OUT
_
TARGET
= 3.3V
V
OUT
_
TARGET
= 3.5V
ATM V
IN
Falling Threshold (V
ATMFT)
V
OUT
_
TARGET
= 3.7V
V
OUT
_
TARGET
= 4.25V
V
OUT
_
TARGET
= 5V
Boost to ATM Transition Time
ATM to Boost Transition Time
LOGIC CONTROL
EN, TREN Logic Input High Voltage
EN, TREN Logic Input Low Voltage
EN, TREN Leakage Current
2.3V < V
IN
< 5.5V
2.3V < V
IN
< 5.5V
V
EN
= V
TREN
= 0V
T
A
= +25NC
T
A
= +85NC
-1
0.01
0.1
1.05
0.4
+1
V
V
FA
(Note 7)
65
3.15
3.35
3.55
4.04
4.74
3.10
3.29
3.5
3.99
4.69
1
1
Fs
Fs
V
V
FA
I
OUT
= 500mA, V
IN
= 2.7V
I
OUT
= 500mA, V
IN
= 3.2V
V
OUT
= 3.6V
EN = low, TREN = high
1
130
110
2
30
mI
A
FA
CONDITIONS
I
OUT
= 150mA, circuit of Figure 1
I
OUT
= 10mA, see the
Output Capacitor
Selection
section
MIN
TYP
20
MAX
UNITS
mV
P-P
Fs
Note 3:
Specifications are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by
design and characterization.
Note 4:
Continuous operation with 1A at elevated ambient temperature and low voltage is not guaranteed. Under worst-case con-
ditions, die thermal protection cannot be activated after 100ms of 1A load application. See the continuous output current
parameter for a conservative estimate of current that can be maintained at T
A
= +85°C.
Note 5:
Switching frequency decreases if input voltage is > 83% of the output voltage selected. This allows duty factor to drop to
values necessary to boost output voltage less than 25% without the use of pulse widths less than 60ns.
Note 6:
Contact factory for other options.
Note 7:
The output voltage regulation is a direct function of the peak current in the nMOS power switch. The inductor current (I
LX
)
described in the conditions of the steady-state output voltage specification corresponds to the peak inductor current.
Note 8:
Once ATM threshold is reached boost switching stops in 1µs (typ), but the transition to ATM does not occur until V
OUT
has
fallen equal to V
IN
.
4
______________________________________________________________________________________
Step-Up Converter
for Handheld Applications
Typical Operating Characteristics
(V
IN
= 3.6V, C
OUT
= 22µF, X5R, 6.3V local and 10µF, X5R, 6.3V, 1µH inductor, circuit of Figure 1, T
A
= +25NC, unless otherwise noted.)
EFFICIENCY vs. OUTPUT CURRENT
(V
OUT
= 5V)
V
IN
= 4.3V
MAX8969 toc01
MAX8969
EFFICIENCY vs. OUTPUT CURRENT
(V
OUT
= 3.7V)
98
96
EFFICIENCY (%)
94
92
90
88
86
84
82
80
1000
1
10
V
IN
= 2.5V
V
IN
= 3.1V
MAX8969 toc02
NO-LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE
70
60
50
40
30
20
10
0
1000
2.5
3.0
3.5
4.0
4.5
5.0
5.5
INPUT VOLTAGE (V)
V
OUT
= 3.7V
MAX8969 toc03
100
95
90
EFFICIENCY (%)
85
80
75
70
65
60
1
100
80
NO-LOAD SUPPLY CURRENT (uA)
V
OUT
= 5V
V
IN
= 3.1V
V
IN
= 2.5V
V
IN
= 3.6V
L = TOKO DFE252012 1µH
10
100
L = TOKO DFE252012 1µH
100
LOAD CURRENT (mA)
LOAD CURRENT (mA)
MAXIMUM OUTPUT CURRENT
vs. INPUT VOLTAGE
MAX8969 toc04
OUTPUT VOLTAGE (V
OUT
= 5V)
vs. OUTPUT CURRENT
MAX8969 toc05
OUTPUT VOLTAGE (V
OUT
= 3.7V)
vs. OUTPUT CURRENT
MAX8969 toc06
3000
MAXIMUM OUTPUT CURRENT (mA)
V
OUT
, 5V
≥
4.5V
2500
2000
1500
1000
500
2.5
3.0
3.5
4.0
4.5
5.0
5.05
5.00
4.95
OUTPUT VOLTAGE (V)
4.90
4.85
4.80
4.75
4.70
4.65
4.60
V
IN
= 2.5V
0
200
400
600
800
4.55
V
IN
= 3.2V
V
IN
= 3.6V
V
IN
= 4.3V
4.4
4.2
OUTPUT VOLTAGE (V)
4.0
3.8
3.6
3.4
3.2
0
200
400
600
800
V
IN
= 3.6V
V
IN
= 4.3V
V
IN
= 3.2V
V
IN
= 2.5V
V
OUT
, 3.7V
≥
3.35V
5.5
1000
1000
INPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V
OUT
= 5V)
vs. INPUT VOLTAGE
I
OUT
= 10mA I
OUT
= 100mA I
OUT
= 600mA
MAX8969 toc07
OUTPUT VOLTAGE (V
OUT
= 3.7V)
vs. INPUT VOLTAGE
MAX8969 toc08
5.5
5.0
OUTPUT VOLTAGE (V)
4.5
5.0
4.5
OUTPUT VOLTAGE (V)
4.0
3.5
I
OUT
= 600mA
3.0
2.5
AUTOMATIC
FREQUENCY
ADJUSTMENT
3.5
INPUT VOLTAGE (V)
4.0
AUTOMATIC
TRACK MODE
I
OUT
= 10mA
TRANSITION
I
OUT
= 100mA
I
OUT
= 1000mA
4.0
3.5
3.0
2.5
3.0
AUTOMATIC
FREQUENCY AUTOMATIC
ADJUSTMENT TRACK MODE
TRANSITION
I
OUT
= 1000mA
3.5
4.0
4.5
5.0
5.5
2.5
3.0
4.5
INPUT VOLTAGE (V)
_______________________________________________________________________________________
5
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