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MAX8645YETI+T

P1-P3P4-P6P7-P9P10-P12P13-P14
EVALUATION KIT
AVAILABLE
General Description
The MAX8645X/MAX8645Y charge pumps drive up to
eight white LEDs with regulated constant current for uni-
form intensity. The main group of LEDs (M1–M6) can be
driven up to 30mA per LED for backlighting. The flash
group of LEDs (F1 and F2) is independently controlled
and can be driven up to 200mA per LED (or 400mA total).
Two 200mA LDOs are on-board to provide power for
camera functions. The LDOs’ output voltages are pin pro-
grammable to meet different camera-module require-
ments. The MAX8645X and MAX8645Y differ only in LDO
output voltages. By utilizing adaptive 1x/1.5x/2x charge-
pump modes and very-low-dropout current regulators,
the MAX8645X/MAX8645Y achieve high efficiency over
the full 1-cell lithium-battery voltage range. The 1MHz
fixed-frequency switching allows for tiny external compo-
nents, and the regulation scheme is optimized to ensure
low EMI and low input ripple.
The MAX8645X/MAX8645Y are available in a 28-pin TQFN,
4mm x 4mm (0.8mm max height) lead-free package.
Applications
Camera Phones and Smartphones
Backlighting and Flash
PDAs, Digital Cameras, and Camcorders
Features
♦ Power Up to Eight LEDs
Up to 30mA/LED Drive for Backlight
Up to 400mA Total Drive for Flash
♦ Two Internal Low-Noise 200mA LDOs
♦ 94% Max/85% Avg Efficiency (P
LED
/P
BATT
) over Li+
Battery Discharge
♦ 0.2% Typical LED Current Matching
♦ Adaptive 1x/1.5x/2x Mode Switchover
♦ Single-Wire, Serial-Pulse Interface for Brightness
Control (32 Steps)
♦ Thermal T
A
Derating Function
♦ Low Input Ripple and EMI
♦ 2.7V to 5.5V Supply Voltage Range
♦ Soft-Start, Overvoltage, and Thermal-Shutdown
Protection
♦ 28-Pin TQFN, 4mm x 4mm Package
MAX8645X/MAX8645Y
1x/1.5x/2x White LED Charge Pumps with
Two LDOs in 4mm x 4mm TQFN
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
19-3978; Rev 4; 6/08
PART TEMP RANGE PIN-PACKAGE
MAX8645XETI+ -40°C to +85°C
28 TQFN-EP
4mm x 4mm
MAX8645YETI+ -40°C to +85°C
28 TQFN-EP
4mm x 4mm
Pin Configuration appears at end of data sheet.
MAIN ON/OFF
AND DIMMING
MAX8645X
MAX8645Y
1μF
10μF
0.01μF
10μF
PIN
IN
PGND
GND
P1
P2
OUT
MAIN
FLASH
OUTPUT
UP TO 580mA
1μF1μF
LDO1
LDO2
C2P C2N
1μF
C1P C1N
REFSETM SETF
CAMERA
MODULE
DUAL-LDO
VOLTAGE
SELECTION
INPUT
2.7V TO 5.5V
ENM2
ENM1
ENF
ENLDO
M1
M2
M3
M4
M5
M6
F1
F2
FLASH ON/OFF
DUAL-LDO ON/OFF
Typical Operating Circuit
EP = Exposed pad.
+
Denotes a lead-free package.
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.
MAX8645X/MAX8645Y
1x/1.5x/2x White LED Charge Pumps with Two
LDOs in 4mm x 4mm TQFN
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= 3.6V, V
GND
= V
PGND
= 0V, ENM1 = ENM2 = ENF = IN, R
SETM
= R
SETF
= 6.8kΩ, P1 = P2 = unconnected, C
REF
= 0.01µF,
T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
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.
PIN, IN, OUT, REFBP to GND................................-0.3V to +6.0V
SETF, SETM, ENLDO, ENM1, ENM2, ENF,
P1, P2, LDO1, LDO2 to GND....................-0.3V to (V
IN
+ 0.3V)
M1, M2, M3, M4, M5, M6, F1,
F2 to GND.............................................-0.3V to (V
OUT
+ 0.3V)
C1N, C2N to GND ......................................... -0.3V to (V
IN
+ 1V)
C1P, C2P
to GND........ -0.3V to the greater of (V
OUT
+ 1V) or (V
IN
+ 1V)
PGND to GND .......................................................-0.3V to +0.3V
OUT, LDO1, LDO2 Short Circuit to GND ...................Continuous
Continuous Power Dissipation (T
A
= +70°C)
28-Pin TQFN 4mm x 4mm
(derate 20.8mW/°C above +70°C).............................1666mW
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
PARAMETER CONDITIONS MIN TYP MAX UNITS
IN Operating Voltage 2.7 5.5 V
Undervoltage-Lockout Threshold V
IN
rising or falling 2.25 2.45 2.60 V
Undervoltage-Lockout Hysteresis 130 mV
1MHz switching, no load, 1.5x or 2x mode 4.0 5.5
1x mode 10% setting, ENF = GND, V
ENLDO
= V
IN
,
I
LDO1
= I
LDO2
= 0A
0.4
mA
Supply Current
ENM1 = ENM2 = ENF = GND, V
ENLDO
= V
IN
,
I
LDO1
= I
LDO2
= 0A
110 µA
T
A
= +25°C 0.01 5
Shutdown Supply Current ENM1 = ENM2 = ENF = ENLDO = GND
T
A
= +85°C 0.1
µA
EN_ High Voltage V
IN
= 2.7V to 5.5V 1.4 V
EN_ Low Voltage V
IN
= 2.7V to 5.5V 0.4 V
T
A
= +25°C 0.01 1
EN_ Input Current V
EN_
= 0V or 5.5V
T
A
= +85°C 0.1
µA
ENM_ or ENF Low Shutdown
Delay t
SHDN
See Figure 1 2.5 ms
ENM_ or ENF t
LO
See Figure 1 0.5 250.0 µs
ENM_ or ENF t
HI
See Figure 1 0.5 µs
Initial ENM_ or ENF t
HI
Only required for first ENM_ or ENF pulse; see Figure 1 200 µs
P1, P2 Shutdown Input Current 1µA
P1, P2 Input Impedance 150 kΩ
Thermal-Shutdown Threshold Temperature rising +160 °C
Thermal-Shutdown Hysteresis 20 °C
CHARGE PUMP
Overvoltage-Protection Threshold V
OUT
rising 5 V
Soft-Start Time 2ms
MAX8645X/MAX8645Y
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 3.6V, V
GND
= V
PGND
= 0V, ENM1 = ENM2 = ENF = IN, R
SETM
= R
SETF
= 6.8kΩ, P1 = P2 = unconnected, C
REF
= 0.01µF,
T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER CONDITIONS MIN TYP MAX UNITS
1x to 1.5x or 1.5x to 2x Mode
Transition Threshold
90 100 110 mV
Input Voltage-Mode Transition
Hysteresis
150 mV
Charge-Pump Maximum OUT
Current
V
IN
≥ 3.15V, V
OUT
= 3.9V 580 mA
1x mode (V
IN
- V
OUT
) / I
OUT
0.3 1.0
1.5x mode (1.5V
IN
- V
OUT
) / I
OUT
1.1 4.0Open-Loop OUT Resistance
2x mode (2V
IN
- V
OUT
) / I
OUT
1.5 4.14
Ω
Charge-Pump Short-Circuit
Current
V
OUT
< 1.25V 500 mA
Switching Frequency 1 MHz
OUT Pulldown Resistance in
Shutdown
ENM_ = ENF = GND 5 kΩ
LED DRIVER
SET_ Bias Voltage T
A
= +25°C 0.6 V
T
A
= +25°C 0.01 1
SET_ Leakage in Shutdown ENM_ = ENF = GND
T
A
= +85°C 0.1
µA
SET_ Current Range 10 145 µA
SETM-to-Main LED Current Ratio
(I
M_
/I
SETM
)
100% setting, M1–M6 230 A/A
SETF-to-Flash LED Current Ratio
(I
F_
/I
SETF
)
100% setting, F1 and F2 1380 A/A
T
A
= +25°C -1.25 +1.25
M_, F_ Current Accuracy
T
A
= -40°C to current derating start temperature -4 +4
%
Maximum Main LED Sink Current R
SETM
= 4.6kΩ, for each M_ 30 mA
Maximum Flash LED Sink Current R
SETF
= 4.12kΩ, I
F1
+ I
F2
400 mA
Current-Derating-Function Start
Temperature
+40 °C
Current-Derating-Function Slope T
A
= +40°C to +85°C -1.7 %/°C
Dropout Voltage (Note 2) 40 90 mV
1.5x and 2x Regulation Voltage 150 mV
T
A
= +25°C 0.01 2
M_, F_ Leakage in Shutdown ENM_ = ENF = GND
T
A
= +85°C 0.1
µA
LDO_
Output Voltage Accuracy
I
LDO_
= 150mA, relative to V
OUT(NOM)
(Note 3) -1.7 0 +1.7 %
Output Current Range 0 200 mA
Current Limit V
LDO_
= 0V 280 475 750 mA
Soft-Start Current Limit 160 mA
1x/1.5x/2x White LED Charge Pumps with Two
LDOs in 4mm x 4mm TQFN
_______________________________________________________________________________________ 3
P1-P3P4-P6P7-P9P10-P12P13-P14

MAX8645YETI+T

Mfr. #:
Buy MAX8645YETI+T
Manufacturer:
Maxim Integrated
Description:
LED Lighting Drivers 1x/1.5x/2x White LED Charge Pump
Lifecycle:
New from this manufacturer.
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