OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

MAX8678ETE+T

P1-P3P4-P6P7-P9P10-P12P13-P13
General Description
The MAX8678 integrates a charge pump for white light-
emitting diodes (LEDs) with an audio loudspeaker
amplifier. The high-efficiency, adaptive charge pump
drives up to four LEDs with constant current for uniform
brightness. The LED current is adjustable from
0.1mA/LED to 24mA/LED in 31 pseudo-logarithmic
steps through a single-wire serial-pulse interface. High
accuracy and LED-to-LED current matching are main-
tained throughout the adjustment range. Individual
adaptive mode switching for each LED provides high
efficiency with a wide range of LED forward voltages.
The mono class AB audio amplifier directly drives an 8Ω
loudspeaker with 1.1W RMS continuous power from a 5V
supply with less than 1% THD+N. The gain is adjustable
from -9dB to +18dB in ten 3dB steps through a single-
wire serial-pulse interface. Clicks and pops are sup-
pressed during on/off and all gain adjustments.
Differential inputs improve common-mode noise rejection.
The MAX8678 includes soft-start, thermal shutdown,
open-circuit and short-circuit protection, and is avail-
able in the 16-pin, 3mm x 3mm Thin QFN package
(0.8mm max height).
Applications
Cell Phones and Smartphones
Camera Phones
PDAs, Digital Cameras, Camcorders
Features
♦ High-Efficiency White LED Charge Pump
Individual Adaptive Supply for Each LED
4 Low-Dropout LED Current Regulators
24mA to 0.1mA Dimming Range
Single-Wire, Serial-Pulse Dimming Interface
1% (typ) Accuracy
Low 140µA Quiescent Current
♦ Mono Class AB Audio Amplifier
1.1W RMS Mono BTL Output (8Ω, V
IN
= 5V)
Low 0.004% THD+N at 1kHz
High 90dB PSRR at 1kHz
Fully Differential Inputs
-9dB to +18dB Gain Settings in 3dB Steps
Integrated Click/Pop Suppression
Low Quiescent Current
♦ Soft-Start Limits Inrush Current
♦ Thermal Shutdown, Open- and Short-Circuit
Protection
♦ 16-Pin, 3mm x 3mm Thin QFN Package
MAX8678
White LED Charge Pump with
1.1W Audio Amplifier
________________________________________________________________
Maxim Integrated Products
1
15
16
14
13
6
5
7
GND
A-
8
IN
LED3
LED1
LED4
12
C-
4
12 11 9
C+
+
ENLED
BIAS
OUT-
OUT+
ENAMP
MAX8678
A+ LED2
3
10
NEG
THIN QFN
3mm × 3mm
TOP VIEW
Pin Configuration
MAX8678
C+
INPUT
2.7V TO 5.5V
LED ON/OFF
AND DIMMING
AMP ON/OFF
AND GAIN
DIFFERENTIAL
AUDIO
INPUT
C-
LED1
LED2
LED3
IN
BACKLIGHT
OR FLASH
0.1mA TO
24mA
LOUDSPEAKER
8Ω
GND
ENLED
LED4
BIAS
OUT+
OUT-
NEGEP
0.1μF
1μF
1μF
4.7μF
ENAMP
A+
A-
Typical Operating Circuit
19-0786; Rev 0; 4/07
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.
EVALUATION KIT
AVAILABLE
Ordering Information
PART
PIN-PACKAGE TOP MARK
PKG CODE
MAX8678ETE+
16 Thin QFN
3mm x 3mm
AFF T1633-5
+
Denotes a lead-free package.
Note: The device is specified over the -40°C to +85°C extend-
ed temperature range.
MAX8678
White LED Charge Pump with
1.1W Audio Amplifier
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= 3.6V, V
GND
= 0V, 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.
IN to GND ..............................................................-0.3V to +6.0V
IN to NEG ..............................................................-0.3V to +6.0V
ENLED, ENAMP, LED_, C+, A+, A-, OUT+, OUT-,
BIAS to GND…….....................................-0.3V to (V
IN
+ 0.3V)
ENLED, ENAMP, LED_, C+, A+, A-, OUT+, OUT-,
BIAS, C- to NEG...................................…-0.3V to (V
IN
+ 0.3V)
GND to NEG ......................................................…-0.3V to +6.0V
GND to C-..............................................................-0.3V to +6.0V
OUT+, OUT- Short Circuit to GND or IN ....................Continuous
Continuous Power Dissipation (T
A
= +70°C)
16-Pin Thin QFN 3mm x 3mm
(derate 17.5mW/°C above +70°C)............................1398mW
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 (UVLO) Threshold V
IN
rising 2.25 2.45 2.65 V
UVLO Hysteresis 100 mV
T
A
= +25°C 0.1 1.5
Shutdown Supply Current
(All Outputs Off)
ENLED = ENAMP =
GND
T
A
= +85°C 0.1
µA
Charge pump inactive, LED_ = 1.6mA
ENAMP = GND, T
A
= +25°C
140 200 µA
Charge pump active, 1MHz switching, LEDs at
24mA setting, ENAMP = GND
0.45
No-Load Supply Current
ENAMP = IN, ENLED = GND 3
mA
Thermal Shutdown +160 °C
Thermal-Shutdown Hysteresis 20 °C
SERIAL-PULSE INTERFACE (EN_)
V
IN
= 2.7V to 4.2V 1.4
Logic Input-High Voltage
V
IN
= 4.2V to 5.5V 1.5
V
Logic Input-Low Voltage V
IN
= 2.7V to 5.5V 0.4 V
T
A
= +25°C 0.01 1
Logic Input Current
V
IL
= 0V or
V
IH
= 5.5V
T
A
= +85°C 0.1
µA
t
SHDN
See Figures 2 and 3 3.2 ms
t
HOLD
See Figures 2 and 3 3.2 ms
t
LO
See Figures 2 and 3 0.5 500 µs
t
HI
See Figures 2 and 3 0.5 500 µs
CHARGE PUMP
Switching Frequency 1 MHz
Soft-Start Time 0.1 ms
Regulation Voltage (OVP) (V
IN
- V
NEG
)5V
Open-Loop NEG Output Resistance
((V
NEG
-V
IN
)/I
NEG
)
10 23 Ω
Guaranteed Output Current LED V
F
= 3.9V, V
IN
= 3.2V 96 mA
NEG Discharge Resistance in Shutdown All LEDs off, ENLED = GND 10 kΩ
MAX8678
White LED Charge Pump with
1.1W Audio Amplifier
_______________________________________________________________________________________ 3
Note 1: Limits are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by design.
Note 2: Dropout voltage is defined as the LED_ to GND (charge pump inactive) or LED_ to NEG (charge pump active) voltage at
which current into LED_ drops 10% from the value at V
LED_
= 0.5V.
Note 3: Output power is specified by a combination of a functional output current test and characterization analysis.
PARAMETER CONDITIONS MIN TYP MAX UNITS
LED DRIVER
Current-Setting Range 0.1 24.0 mA
24mA setting, T
A
= +25°C -2 ±1 +2
24mA setting, T
A
= -40°C to +85°C -5 +5
Current Accuracy
1.6mA setting, T
A
= +25°C ±5
%
Charge pump inactive 72 120
LED_ Dropout 24mA setting (Note 2)
Charge pump active 132 360
mV
LED_ Voltage-Mode Transition Threshold
(1x to 2x)
V
LED_
falling 125 150 175 mV
LED_ Voltage-Mode Transition
Hysteresis
100 mV
T
A
= +25°C 0.01 1
LED_ Leakage in Shutdown All LEDs off
T
A
= +85°C 0.1
µA
AUDIO AMPLIFIER
Common-Mode Bias Voltage -5% V
IN
/ 2 +5%
Output Offset Voltage V
A+
= V
A-
= V
BIAS
, gain ≤ 12dB -25 ±1 +25 mV
Common-Mode Input Voltage 0.5
(V
IN
-
1.2)
V
Input Impedance (R
IN
) Table 2 10 67 140 kΩ
V
IN
= 3.2V 50 60
Common-Mode Rejection Ratio
f = 1kHz, V
IN
= 3.2V 70
dB
f = 217Hz 93
Power-Supply Rejection Ratio
V
A+
= V
A-
= V
BIAS
,
200mV
P-P
at IN
f = 1kHz 90
dB
R
L
= 8Ω, V
IN
= 3.2V 0.36 0.5
R
L
= 4Ω, V
IN
= 3.2V 0.65Output Power
THD+N = 1%,
f = 1kHz (Note 3)
R
L
= 8Ω, V
IN
= 5V 0.8 1.1
W
Output Current Limit 0.6 1 1.6 A
-9dB ≤ Gain ≤ 15dB ±0.13
Gain Accuracy
Gain = 18dB ±0.17
dB
Total Harmonic Distortion + Noise R
L
= 8Ω, f = 1kHz, P
OUT
= 0.25W, V
IN
= 3.2V 0.004 %
Signal-to-Noise Ratio R
L
= 8Ω, f = 1kHz, P
OUT
= 0.25W, V
IN
= 3.2V 104 dB
Maximum Capacitive Drive 500 pF
Power-Up from Shutdown Time, t
UP
See Figure 3 10 ms
Shutdown Time, t
PD
See Figure 3 3.5 µs
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 3.6V, V
GND
= 0V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
P1-P3P4-P6P7-P9P10-P12P13-P13

MAX8678ETE+T

Mfr. #:
Buy MAX8678ETE+T
Manufacturer:
Maxim Integrated
Description:
LED Lighting Drivers White LED Charge Pump w/1.1W Aud Amp
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet