MAX8831EWE+T Maxim Integrated Products, MAX8831EWE+T Datasheet

IC LED DRIVR WHITE BCKLGT 16-WLP

MAX8831EWE+T

Manufacturer Part Number
MAX8831EWE+T
Description
IC LED DRIVR WHITE BCKLGT 16-WLP
Manufacturer
Maxim Integrated Products
Type
Backlight, White LED (I²C Interface)r
Datasheet

Specifications of MAX8831EWE+T

Topology
Linear (LDO), PWM, Step-Up (Boost)
Number Of Outputs
5
Internal Driver
Yes
Type - Primary
Backlight
Type - Secondary
White LED
Frequency
1.8MHz ~ 2.2MHz
Voltage - Supply
1.6 V ~ 5.5 V
Mounting Type
Surface Mount
Package / Case
16-WLP
Operating Temperature
-40°C ~ 85°C
Internal Switch(s)
Yes
Efficiency
90%
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Voltage - Output
-
Current - Output / Channel
-
Lead Free Status / Rohs Status
 Details
Other names
MAX8831EWE+T
The MAX8831 integrates a 60mA, 28V PWM DC-DC
step-up converter with five low-dropout LED current
regulators for display and keypad backlighting in cell
phones, PDAs, and other portable devices. The IC pro-
vides up to 90% efficiency over the entire input voltage
range of 2.7V to 5.5V. The step-up converter operates
at a fixed 2MHz switching frequency, enabling the use
of very small external components to achieve a com-
pact circuit area. For improved efficiency, the step-up
converter automatically transitions to pulse-skipping
mode at light loads.
Each of the five current regulators accommodates up to
9 series LEDs (depending on LED string forward volt-
age), and is independently programmed using an I
interface. Two of the current regulators (LED1, LED2)
are intended to support display backlight functions and
are programmable up to 25mA using a 128-step loga-
rithmic dimming scheme. The other three regulators
(LED3, LED4, LED5) are suitable for keyboard backlight
functions or for driving signal indicators, and are pro-
grammable up to 5mA using a 32-step logarithmic dim-
ming scheme. The low-current regulators (LED3, LED4,
LED5) can be operated from the step-up converter or
from a separate low-voltage source.
The I
current regulators, including: on/off state, LED current,
ramp-up/ramp-down timers, and blink rate timers
(LED3, LED4, LED5). The MAX8831 write/read address-
es are factory programmed at 0x9A/0x9B (contact the
factory for other address options).
The MAX8831 features open/short LED fault detection,
output overvoltage protection, thermal shutdown, and
open-circuit Schottky diode detection, with the status of
each fault monitored continually for readback through
the I
The MAX8831 is available in a tiny 2mm x 2mm, 16-bump
WLP package.
19-4370; Rev 1; 7/09
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.
2
2
C interface.
High-Efficiency, White LED Step-Up Converter
C interface controls all operational aspects of the
Cell Phones
PDAs
Smartphones
________________________________________________________________ Maxim Integrated Products
with I
General Description
EVALUATION KIT
AVAILABLE
Applications
2
C Interface in 2mm x 2mm WLP
2
C
o 28V Step-Up DC-DC Converter
o I
o Two 25mA Regulators for Display Backlighting
o Three 5mA Current Regulators for Keypad
o Open/Short LED and Open-Circuit Diode
o Thermal-Shutdown and Output Overvoltage
o Ultra-Low 0.1µA Shutdown Current
o Tiny 2mm x 2mm, 16-Bump WLP Package
+ Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
MAX8831EWE+T
Compatible with 1.8V Logic
Detection
Protection
2
C Programmable (0x9A Write/0x9B Read),
Integrated NMOS Power Switch
> 90% Efficiency
Fixed 2MHz Switching
Pulse Skipping for Improved Light-Load
Tiny External Components
I
128-Step Logarithmic Dimming
Individually Programmable Ramp (Up/Down)
Low Dropout (200mV max)
I
32-Step Logarithmic Dimming
Individually Programmable Ramp (Up/Down)
Individual Blink Rate and Duty Cycle Timers
Low Dropout (150mV max)
2
2
C-Programmable Output Current (50µA to
C-Programmable Output Current (50µA to
PART
Efficiency
25.25mA)
Timers
Lighting
5.0mA)
Timers
-40°C to +85°C
TEMP RANGE
Ordering Information
PIN-PACKAGE
2mm x 2mm
Features
16 WLP
1

Related parts for MAX8831EWE+T

MAX8831EWE+T Summary of contents

Page 1

... Open/Short LED and Open-Circuit Diode Detection o Thermal-Shutdown and Output Overvoltage Protection o Ultra-Low 0.1µA Shutdown Current o Tiny 2mm x 2mm, 16-Bump WLP Package PART Applications MAX8831EWE+T + Denotes a lead(Pb)-free/RoHS-compliant package Tape and reel. Features Ordering Information TEMP RANGE PIN-PACKAGE 16 WLP -40°C to +85°C ...

Page 2

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP ABSOLUTE MAXIMUM RATINGS IN to GND ..............................................................-0.3V to +6. COMP to GND.....................................-0. SDA, SCL to GND.......................................-0. OUT, LX, ...

Page 3

High-Efficiency, White LED Step-Up Converter with I ELECTRICAL CHARACTERISTICS (continued 3.6V 0V 1.8V GND PGND DD PARAMETER LX Leakage Current V IN OSCILLATOR Operating Frequency Maximum Duty Cycle V LED1 ...

Page 4

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP INTERFACE TIMING CHARACTERISTICS (V = 1.6V to 5.5V -40°C to +85°C, unless otherwise noted.) (Note PARAMETER SYMBOL ...

Page 5

High-Efficiency, White LED Step-Up Converter with 3.6V 1.8V 1µ OUT 5mA, unless otherwise noted.) LED3 LED4 LED5 CONVERTER EFFICIENCY vs. INPUT VOLTAGE (LED1 ...

Page 6

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP (V = 3.6V 1.8V 1µ OUT 5mA, unless otherwise noted.) LED3 ...

Page 7

High-Efficiency, White LED Step-Up Converter with 3.6V 1.8V 1µ OUT 5mA, unless otherwise noted.) LED3 LED4 LED5 LED1 RAMP-UP I LED1 RAMP-UP TIMES ...

Page 8

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP PIN NAME 25mA LED Current Regulator. Connect LED1 to the cathode of the LED1 diode string. LED1 is high A1 LED1 impedance in shutdown. Analog ...

Page 9

High-Efficiency, White LED Step-Up Converter with I IN UVLO AND BIAS GND COMP INTERFACE SDA SCL MAX8831 Figure 1. MAX8831 Functional Diagram _______________________________________________________________________________________ 2 C Interface in 2mm x 2mm WLP OSC PWM LOGIC REF ...

Page 10

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP The other three regulators (LED3, LED4, LED5) are suit- able for keyboard backlight functions or for driving sig- nal indicators, and are programmable up to ...

Page 11

High-Efficiency, White LED Step-Up Converter with I Table 1. LED1, LED2 Programmable Current Levels and Register Values ILED_CNTRL I (mA) LED_ REGISTER VALUE 0x00 0.05 0x01 0.1 0x02 0.2 0x03 0.25 0x04 0.35 0x05 0.45 0x06 0.55 0x07 0.65 0x08 ...

Page 12

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP Table 1. LED1, LED2 Programmable Current Levels and Register Values (continued) ILED_CNTRL I (mA) LED_ REGISTER VALUE 0x26 5.25 0x27 5.45 0x28 5.6 0x29 5.8 ...

Page 13

High-Efficiency, White LED Step-Up Converter with I Table 2. LED3, LED4, and LED5 Programmable Current Levels and Register Values ILED_CNTRL ILED_CNTRL REGISTER I (mA) REGISTER LED_ VALUE VALUE 0x00 0.05 0x10 0x01 0.1 0x11 0x02 0.15 0x12 0x03 0.20 0x13 ...

Page 14

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP ENABLE BIT CLEARED FOR FAULTED LED_ STRING AND STAT1 REGISTER IS UPDATED WITH FAULT CONDITION. ENABLE BIT TSD OR OVP FAULT CLEARED FOR ALL LED_, ...

Page 15

High-Efficiency, White LED Step-Up Converter with I SDA t SU,DAT t LOW SCL t HIGH t HD,STA START CONDITION 2 Figure Interface Timing Diagram SDA SCL S START CONDITION 2 Figure START and STOP ...

Page 16

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP SDA SCL DATA LINE STABLE, CHANGE OF DATA DATA IS VALID IS ALLOWED 2 Figure Bit Transfer 1 0 SDA MSB SCL ...

Page 17

High-Efficiency, White LED Step-Up Converter with I 7-BIT SLAVE S ADDRESS LAST DATA BYTE 2 Figure 11 Multiple-Byte Write 7-BIT SLAVE S ADDRESS DATA BYTE 2 Figure 12 Single-Byte Read 7-BIT SLAVE S ADDRESS FIRST DATA ...

Page 18

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP LED_ current regulator. Write the LED#_EN bit to disable that LED_ current regulator. Overvoltage, open Schottky diode, and thermal-shutdown faults automati- cally ...

Page 19

High-Efficiency, White LED Step-Up Converter with I The typical value for the input capacitor is 1µF, and the typical value for the output capacitor is 1µF. Higher value capacitors can reduce input and output ripple, but at the expense of ...

Page 20

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP Table 3. MAX8831 Register Map COMMAND/ REGISTER ADDRESS BYTE (HEX) ON/OFF_CNTL 0x00 LED1_RAMP_CNTL 0x03 LED2_RAMP_CNTL 0x04 LED3_RAMP_CNTL 0x05 LED4_RAMP_CNTL 0x06 LED5_RAMP_CNTL 0x07 ILED1_CNTL 0x0B ILED2_CNTL ...

Page 21

High-Efficiency, White LED Step-Up Converter with I Table 4. ON/OFF_CNTL Register (Address 0x00) BIT NAME B7 (MSB) — Reserved for future use B6 — Reserved for future use B5 — Reserved for future use 0 = Disable LED5 current regulator ...

Page 22

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP Table 6. ILED#_CNTL Registers for LED1, LED2 (Addresses: 0x0B, 0x0C) BIT NAME DESCRIPTION B7 (MSB) — Reserved for future use Programs LED# ...

Page 23

High-Efficiency, White LED Step-Up Converter with I Table 9. BOOST_CNTL Register (Address: 0x1D) BIT NAME B7 (MSB) — Reserved for future use B6 — Reserved for future use B5 — Reserved for future use 0 = LED5 is powered fr ...

Page 24

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP Table 11. STAT2 Register (Address 0x2E) BIT NAME DESCRIPTION B7 (MSB) Reserved for future use B6 Reserved for future use B5 Reserved for future use ...

Page 25

High-Efficiency, White LED Step-Up Converter with 10μH 2.7V TO 5.5V C1 1μ SCL SDA 1.6V TO 5.5V C3 0.1μF COMP C4 0.22μF Figure 15. MAX8831 Applications Circuit ______________________________________________________________________________________ 2 C ...

Page 26

High-Efficiency, White LED Step-Up Converter 2 with I C Interface in 2mm x 2mm WLP VIN 10μH 2.7V TO 5.5V 1μ 1.6V TO 5.5V 0.1μF 0.22μF 26 ______________________________________________________________________________________ V OUT UP TO 28V LX OUT LX 1μF MAX8831 ...

Page 27

High-Efficiency, White LED Step-Up Converter with I Pin Configuration TOP VIEW (BUMPS ON BOTTOM MAX8831 LED1 GND LED3 LED2 LED4 LED5 SDA PGND ...

Page 28

... 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. 28 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2009 Maxim Integrated Products ...

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