- 您现在的位置：买卖IC网 > Datasheet目录341 > MAX8879ETG+T (Maxim Integrated)IC LED DRVR WT/RGB BCKLGT 24TQFN Datasheet资料下载
参数资料
| 型号： | MAX8879ETG+T |
| 厂商： | Maxim Integrated |
| 文件页数： | 12/16页 |
| 文件大小： | 0K |
| 描述： | IC LED DRVR WT/RGB BCKLGT 24TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 恒定电流： | 是 |
| 拓扑： | 切换式电容器（充电泵） |
| 输出数： | 11 |
| 内部驱动器： | 是 |
| 类型 - 主要： | 背光 |
| 类型 - 次要： | RGB，白色 LED |
| 频率： | 1MHz |
| 电源电压： | 2.7 V ~ 5.5 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-WFQFN 裸露焊盘 |
| 供应商设备封装： | 24-TQFN-EP（4x4） |
| 包装： | 带卷 (TR) |
| 工作温度： | -40°C ~ 85°C |
Charge Pump for Backlight/Flash/RGB LEDs
with Safety Timer
Table 4. RGB Ramp Rate
The LED cathode connections (M_, S_, and F_) can be
connected together in any combination to allow the use
CONTROL BYTE
RGB RAMP RAMP TIME FROM OFF TO
of higher current LEDs. For example, to drive a single
(HEXADECIMAL)
E0
E1
E2
E3
RATE (A/s)
58.6
0.114
0.0572
0.0286
FULL BRIGHTNESS (ms)
0.512
262
524
1048
flash LED at up to 400mA, connect F1, F2, F3, and F4
together to the cathode of the flash LED.
To avoid constantly operating in overvoltage protection
mode, any unused LED cathode connection (M_, S_, or
F_) must be connected to OUT. This disables the corre-
sponding current regulator.
*Default in bold italics .
The currents for the three sub LEDs are set indepen-
dently, allowing them to drive an RGB LED. The cur-
rent-level settings for both the main and sub LEDs
range from 0.9mA to 30mA, defaulting to 15mA each
(see Tables 1, 2, and 3).
The flash LEDs are controlled by pulsing the FSH input
low. There are two registers in the MAX8879 to set the
flash/movie current level. The Movie register sets the
F1–F4 LED current when the I 2 C interface is used to
activate the LEDs and the Flash register sets the F1–F4
LED current when the FSH input is pulsed low. The cur-
rent level settings for the flash LEDs ranges from 3.3mA
to 100mA, with a default of 25.8mA (see Tables 1, 2,
and 3). The Flash register has priority over the Movie
register when both movie and flash are on. In the event
that the flash safety timer period expires, the flash LEDs
are turned off and the movie mode ON/OFF control
bit is reset to 0. This is to prevent the MAX8879 from
going back into movie mode in the event of a safety
timer violation.
RGB Color and Ramp-Rate Settings
The three sub LED currents are controlled indepen-
dently by the I 2 C interface, allowing for use of a com-
mon anode RGB LED. Thirty-two programmable
brightness levels (5 bits) per LED provide a total of 32k
colors. To smooth the transition between different
color/brightness settings, a controlled ramp is used
when the sub LED current level is changed, when the
sub LEDs are enabled, and when the LEDs are dis-
abled. The ramp rate is set to one of four settings with
the I 2 C interface (see Table 4).
Temperature-Derating Function
The MAX8879 contains a temperature-derating function
that automatically limits the LED current at high tempera-
tures in accordance with the recommended derating
curve of popular white LEDs. The derating function
enables the safe usage of higher LED current at room
temperature, thus reducing the number of LEDs required
to backlight the display. In camera-light applications, the
derating circuit protects the LEDs and PC board from
overheating. The derating circuit limits the LED current
A
t LOW
B
t HIGH
C
D
E
F
G
H
I
J
K
L
M
SCK
SDA
t SU:STA t HD:STA
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
t SU:DAT
t HD:DAT
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE (OP/SUS BIT)
H = LSB OF DATA CLOCKED INTO SLAVE
I = SLAVE PULLS SMBDATA LINE LOW
t SU:STO t BUF
J = ACKNOWLEDGE CLOCKED INTO MASTER
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION, DATA EXECUTED BY SLAVE
M = NEW START CONDITION
E = SLAVE PULLS SMBDATA LINE LOW
Figure 2. I 2 C Timing Diagram
12
______________________________________________________________________________________
相关PDF资料 |
PDF描述 |
|---|---|
| MAX8901BETA+TCH8 | IC LED DRIVER WHITE BCKLGT 8TDFN |
| MAX8930EWJ+T | IC LED DRVR WT/RGB BCKLGT 49WLP |
| MAXQ2000-KIT | EVAL KIT FOR MAXQ2000 |
| MAXQ610-KIT# | EVALUATION KIT FOR MAXQ610 |
| MB2146-401-01A | KIT STARTER F2MC-8FX 3V |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX887EVKIT | 功能描述:直流/直流开关转换器 Evaluation Kit for the MAX887 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX887HESA | 功能描述:直流/直流开关转换器 100% Duty Step-Down DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX887HESA+ | 功能描述:直流/直流开关转换器 100% Duty Step-Down DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX887HESA+T | 功能描述:直流/直流开关转换器 100% Duty Step-Down DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX887HESA-T | 功能描述:直流/直流开关转换器 100% Duty Step-Down DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
发布紧急采购，3分钟左右您将得到回复。