参数资料
型号: LT1184FIS#TRPBF
厂商: Linear Technology
文件页数: 10/24页
文件大小: 0K
描述: IC SW REG CCFL CONTRAST 16-SOIC
标准包装: 2,500
应用: 转换器,CCFL
输入电压: 3 V ~ 30 V
输出数: 1
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 16-SOIC(0.154",3.90mm 宽)
供应商设备封装: 16-SOIC
包装: 带卷 (TR)
LT1182/LT1183/LT1184/LT1184F
PI N FU N CTIO N S
LT1182/LT1183/LT1184/LT1184F
CCFL PGND (Pin 1): This pin is the emitter of an internal
NPN power switch. CCFL switch current flows through
this pin and permits internal, switch-current sensing. The
regulators provide a separate analog ground and power
ground(s) to isolate high current ground paths from low
current signal paths. Linear Technology recommends the
use of star-ground layout techniques.
I CCFL (Pin 2): This pin is the input to the CCFL lamp current
programming circuit. This pin internally regulates to 450mV
(LT1182/LT1183) or 465mV (LT1184/LT1184F). The pin
accepts a DC input current signal of 0 μ A to 100 μ A full
scale. This input signal is converted to a 0 μ A to 500 μ A
source current at the CCFL V C pin. By shunt regulating the
I CCFL pin, the input programming current can be set with
DAC, PWM or potentiometer control. As input program-
ming current increases, the regulated lamp current in-
creases. For a typical 6mA lamp, the range of input
programming current is about 0 μ A to 50 μ A.
DIO (Pin 3): This pin is the common connection between
the cathode and anode of two internal diodes. The remain-
ing terminals of the two diodes connect to ground. In a
grounded lamp configuration, DIO connects to the low
voltage side of the lamp. Bidirectional lamp current flows
in the DIO pin and thus the diodes conduct alternately on
half cycles. Lamp current is controlled by monitoring one-
half of the average lamp current. The diode conducting on
negative half cycles has one-tenth of its current diverted to
the CCFL V C pin. This current nulls against the source
current provided by the lamp-current programmer circuit.
A single capacitor on the CCFL V C pin provides both stable
loop compensation and an averaging function to the half-
wave-rectified sinusoidal lamp current. Therefore, input
programming current relates to one-half of average lamp
current. This scheme reduces the number of loop com-
pensation components and permits faster loop transient
response in comparison to previously published circuits.
If a floating-lamp configuration is used, ground the DIO
pin.
CCFL V C (Pin 4): This pin is the output of the lamp current
programmer circuit and the input of the current compara-
10
tor for the CCFL regulator. Its uses include frequency
compensation, lamp-current averaging for grounded lamp
circuits, and current limiting. The voltage on the CCFL V C
pin determines the current trip level for switch turnoff.
During normal operation this pin sits at a voltage between
0.95V (zero switch current) and 2.0V (maximum switch
current) with respect to analog ground (AGND). This pin
has a high impedance output and permits external voltage
clamping to adjust current limit. A single capacitor to
ground provides stable loop compensation. This simpli-
fied loop compensation method permits the CCFL regula-
tor to exhibit single-pole transient response behavior and
virtually eliminates transformer output overshoot.
AGND (Pin 5): This pin is the low current analog ground.
It is the negative sense terminal for the internal 1.24V
reference and the I CCFL summing voltage in the LT1182/
LT1183/LT1184/LT1184F. It is also a sense terminal for
the LCD dual input error amplifier in the LT1182/LT1183.
Connect external feedback divider networks that terminate
to ground and frequency compensation components that
terminate to ground directly to this pin for best regulation
and performance.
SHUTDOWN (Pin 6): Pulling this pin low causes complete
regulator shutdown with quiescent current typically re-
duced to 35 μ A. The nominal threshold voltage for this pin
is 0.85V. If the pin is not used, it can float high or be pulled
to a logic high level (maximum of 6V). Carefully evaluate
active operation when allowing the pin to float high.
Capacitive coupling into the pin from switching transients
could cause erratic operation.
CCFL V SW (Pin 16): This pin is the collector of the internal
NPN power switch for the CCFL regulator. The power
switch provides a minimum of 1.25A. Maximum switch
current is a function of duty cycle as internal slope com-
pensation ensures stability with duty cycles greater than
50%. Using a driver loop to automatically adapt base drive
current to the minimum required to keep the switch in a
quasi-saturation state yields fast switching times and high
efficiency operation. The ratio of switch current to driver
current is about 50:1.
相关PDF资料
PDF描述
RSC20DRYS-S734 CONN EDGECARD 40POS DIP .100 SLD
AP1186K5-18L-13 IC REG LDO 1.8V 1.5A TO263-5L
GEM40DRMT-S288 CONN EDGECARD 80POS .156 EXTEND
AP1186K5-18L-U IC REG LDO 1.8V 1.5A TO263-5
GSC30DRTS-S13 CONN EDGECARD 60POS .100 EXTEND
相关代理商/技术参数
参数描述
dsPIC33FJ256GP510T-I/PF 功能描述:数字信号处理器和控制器 - DSP, DSC 16B MCU DSP 100LD 40MIPS 256KB FLASH RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT
dsPIC33FJ256GP510T-I/PT 功能描述:数字信号处理器和控制器 - DSP, DSC 16B MCU DSP 100LD 40MIPS 256KB FLASH RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT
dsPIC33FJ256GP710A-E/PF 功能描述:数字信号处理器和控制器 - DSP, DSC 16Bit 40MIPS 256KB Flash RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT
dsPIC33FJ256GP710A-E/PT 功能描述:数字信号处理器和控制器 - DSP, DSC 16Bit 40MIPS 256KB Flash RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT
dsPIC33FJ256GP710A-H/PF 功能描述:数字信号处理器和控制器 - DSP, DSC 16 bit DSC 20MIPS 256KB Flash RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT