9-Output LED Driver with Intensity Control
and Hot-Insertion Protection
PWM Intensity Control
The MAX6965 includes an internal oscillator, nominally
32kHz, to generate PWM timing for LED intensity control
or other applications such as PWM trim DACs. PWM can
be disabled entirely for all the outputs. In this case, all
outputs are static and the MAX6965 operating current is
lowest because the internal PWM oscillator is turned off.
The MAX6965 can be configured to provide any combi-
nation of PWM outputs and glitch-free logic outputs.
Each PWM output has an individual 4-bit intensity con-
trol (Table 12). When all outputs are to be used with the
same PWM setting, the outputs can be controlled
together instead of using the global intensity control
(Table 11). Table 8 shows how to set up the MAX6965
to suit a particular application.
PWM Timing
The PWM control uses a 240-step PWM period, divided
into 15 master intensity timeslots. Each master intensity
timeslot is divided further into 16 PWM cycles (Figure 12).
The master intensity operates as a gate, allowing the indi-
vidual output settings to be enabled from 1 to 15 timeslots
per PWM period (Figures 13, 14, and 15) (Table 11).
BLINK ENABLE FLAG E
BLINK FLIP FLAG B
Each output ’s individual 4-bit intensity control only
operates during the number of timeslots gated by the
master intensity. The individual controls provide 16
intensity settings from 1/16 through 16/16 (Table 12).
Figures 16, 17, and 18 show examples of individual
intensity control settings. The highest value an individ-
ual or global setting can be set to is 16/16. This setting
forces the output to ignore the master control, and fol-
low the logic level set by the appropriate blink phase
register bit. The output becomes a glitch-free static out-
put with no PWM.
Using PWM Intensity Controls with Blink Disabled
When blink is disabled (Table 5), the blink phase 0 regis-
ter specifies each output’s logic level during the PWM on-
time (Table 6). The effect of setting an output’s blink
phase 0 register bit to 0 or 1 is shown in Table 9. With its
output bit set to zero, an LED can be controlled with 16
intensity settings from 1/16th duty through fully on, but
cannot be turned fully off using the PWM intensity control.
With its output bit set to 1, an LED can be controlled with
16 intensity settings from fully off through 15/16th duty.
Using PWM Intensity Controls with Blink Enabled
When blink is enabled (Table 5), the blink phase 0 regis-
ter and blink phase 1 register specify each output’s logic
level during the PWM on-time during the respective blink
phases (Tables 6 and 7). The effect of setting an output’s
blink phase register bit to 0 or 1 is shown in Table 10.
LEDs can be flipped between either directly on and off,
or between a variety of high/low PWM intensities.
BLINK PHASE
BLINK INPUT
REGISTERS
Figure 11. BLINK Logic
ONE PWM PERIOD IS 240 CYCLES OF THE 32kHz PWM
OSCILLATOR. A PWM PERIOD CONTAINS 15 MASTER
INTENSITY TIMESLOTS
14
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
15 16 1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
1
2
EACH MASTER INTENSITY
TIMESLOT CONTAINS 16
PWM CYCLES
Figure 12. PWM Timing
14
______________________________________________________________________________________
相关PDF资料
MAX6967ATE+ IC LED DRIVER LINEAR 16-TQFN
MAX6968AAE+ IC LED DRIVER LINEAR 16-SSOP
MAX6970AUE+ IC LED DRIVER LINEAR 16-TSSOP
MAX6971AUG+T IC LED DRIVER LINEAR 24-TSSOP
MAX6974ATL+ IC LED DRIVER LINEAR 40-TQFN
MAX6977AAE+ IC LED DRIVER LINEAR 16-SSOP
MAX6978AUE+ IC LED DVR CONST-CURR 16TSSOP
MAX6979AUG+ IC LED DRIVER LINEAR 24-TSSOP
相关代理商/技术参数
MAX6965ATE-T 功能描述:LED显示驱动器 RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube
MAX6965EVCMAXQU 功能描述:LED 照明开发工具 9-Output LED Driver with Intensity Control RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装:
MAX6965EVKIT 功能描述:LED 照明开发工具 Evaluation Kit/Evaluation System for the MAX6965 RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装:
MAX6966AEE 功能描述:LED显示驱动器 RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube
MAX6966AEE+ 功能描述:LED显示驱动器 10-Port Constant Current LED Driver RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube
MAX6966AEE+T 功能描述:LED显示驱动器 10-Port Constant Current LED Driver RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube
MAX6966AEE-T 功能描述:LED显示驱动器 RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube
MAX6966ATE 功能描述:LED显示驱动器 RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube