参数资料
型号: DS3881E+T&R/C
厂商: Maxim Integrated
文件页数: 14/28页
文件大小: 0K
描述: IC AUTO CCFL CTRLR 1CH 24-TSSOP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 1,000
类型: CCFL 控制器
频率: 40 ~ 100 kHz
电流 - 电源: 12mA
电源电压: 4.75 V ~ 5.25 V
工作温度: -40°C ~ 105°C
封装/外壳: 24-TSSOP(0.173",4.40mm 宽)
供应商设备封装: 24-TSSOP
包装: 带卷 (TR)
Single-Channel Automotive CCFL Controller
Setting the Lamp and Dimming
Clock (DPWM) Frequencies
Using External Resistors
Both the lamp and dimming clock frequencies can be
set using external resistors. The resistance required for
either frequency can be determined using the following
formula:
reaching the strike voltage and could potentially cause
numerous other problems. Operating with the trans-
former voltage at too high of a level can be damaging
to the inverter components. Proper use of the SVMs
can prevent these problems. If desired, the high and/or
low SVMs can be disabled by connecting the SVMH
pin to GND and the SVML pin to V CC .
V TRIP = 2 . 0 ? 1 2 ?
R OSC =
K
f OSC
? R + R ?
? R 1 ?
where K = 1600k Ω ? kHz for lamp frequency calculations.
When calculating the resistor value for the dimming clock
frequency, K will be one of four values as determined by
the desired frequency and the POSCR0 and POSCR1 bit
settings as shown in the Control Register 2 (CR2) Table 6
in the Detailed Register Descriptions section.
Example: Selecting the resistor values to configure a
DS3881 to have a 50kHz lamp frequency and a 160Hz
dimming clock frequency: For this configuration,
POSCR0 and POSCR1 must be programmed to 1 and
0, respectively, to select 90Hz to 220Hz as the dimming
clock frequency range. This sets K for the dimming
clock resistor (R POSC ) calculation to 4k Ω ? kHz. For the
lamp frequency resistor (R LOSC ) calculation, K =
1600k Ω ? kHz, which sets the lamp frequency K value
regardless of the frequency. The formula above can
now be used to calculate the resistor values for R LOSC
and R POSC as follows:
The V CC monitor is used as a 5V supply undervoltage
lockout (UVLO) that prevents operation when the
DS3881 does not have adequate voltage for its analog
circuitry to operate or to drive the external MOSFETs.
The V CC monitor features hysteresis to prevent V CC
noise from causing spurious operation when V CC is
near the trip point. This monitor cannot be disabled by
any means.
Fault Monitoring
The DS3881 provides extensive fault monitoring. It can
detect open-lamp, lamp overcurrent, failure to strike,
and overvoltage conditions. The DS3881 can be con-
figured to disable the output if the channel enters a
fault state. Once a fault state has been entered, the
FAULT output is asserted and the channel remains dis-
abled until it is reset by a user or host control event.
See Step 4, Fault Handling for more detail. The DS3881
can also be configured to automatically attempt to clear
R LOSC =
1600 k Ω ? kHz
50 kHz
= 32 . 0 k Ω
a detected fault (except lamp overcurrent) by re-strik-
ing the lamp. Configuration bits for the fault monitoring
options are located in CR1 and CR2. The DS3881 also
R POSC =
4 k Ω ? kHz
0 . 160 kHz
= 25 . 0 k Ω
has real-time status indicator bits located in the SR1
and SR2 register (SRAM) that assert whenever a corre-
sponding fault occurs.
Supply Monitoring
The DS3881 has supply voltage monitors (SVMs) for
both the inverter’s transformer DC supply (V INV ) and its
own V CC supply to ensure that both voltage levels are
adequate for proper operation. The transformer supply
R 2
V INV
V INV
R 2
is monitored for overvoltage conditions at the SVMH pin
and undervoltage conditions at the SVML pin. External
resistor-dividers at each SVM input feed into two com-
parators (see Figure 7), both having 2V thresholds.
V TRIP
R 1
SVML
2.0V
DS3881
SVMH
2.0V
V TRIP
R 1
Using the equation below to determine the resistor val-
ues, the SVMH and SVML trip points (V TRIP ) can be
customized to shut off the inverter when the trans-
former’s supply voltage rises above or drops below
specified values. Operating with the transformer’s sup-
ply at too low of a level can prevent the inverter from
Figure 7. Setting the SVM Threshold Voltage
14
____________________________________________________________________
相关PDF资料
PDF描述
VI-212-EU CONVERTER MOD DC/DC 15V 200W
RMM28DTAD CONN EDGECARD 56POS R/A .156 SLD
VE-B1B-CV-F4 CONVERTER MOD DC/DC 95V 150W
GEM08DSXS CONN EDGECARD 16POS DIP .156 SLD
VE-B1B-CV-F3 CONVERTER MOD DC/DC 95V 150W
相关代理商/技术参数
参数描述
DS3882 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Dual-Channel Automotive CCFL Controller
DS3882_10 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Dual-Channel Automotive CCFL Controller
DS3882E 制造商:Maxim Integrated Products 功能描述:CAR DUAL CCFL CONTROL TSSOP - 28 - Rail/Tube
DS3882E/T&R 制造商:Maxim Integrated Products 功能描述:CAR DUAL CCFL CTRL TSSOP-28 T&R - Tape and Reel
DS3882E+ 功能描述:IC CCFL CNTRLR DUAL 28TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 照明,镇流器控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 类型:CCFL 控制器 频率:40 ~ 80 kHz 电流 - 电源:5mA 电流 - 输出:- 电源电压:4.5 V ~ 5.5 V 工作温度:-40°C ~ 85°C 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) 其它名称:90-3991V+V01