7
LTC1968
1968f
GND (Pin 1): Ground. The power return pin.
IN1 (Pin 2): Differential Input. DC coupled (polarity is
irrelevant).
IN2 (Pin 3): Differential Input. DC coupled (polarity is
irrelevant).
V
OUT
(Pin 5): Output Voltage. Pin 5 is high impedance. The
RMS averaging is accomplished with a single shunt ca-
pacitor from Pin 5 to OUT RTN. The transfer function is
given by:
V
OUTRTN Average IN IN
OUT
(
)
=
(
)
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
2 1
2
U
U
PI FU CTIO S
OUT RTN (Pin 6): Output Return. The output voltage is
created relative to this pin. The V
OUT
and OUT RTN pins
are not balanced and this pin should be tied to a low
impedance, both AC and DC. Although Pin 6 is often tied
to GND, it can also be tied to any arbitrary voltage:
GND < OUT RTN < (V
+
Max Output)
V
+
(Pin 7): Positive Voltage Supply. 4.5V to 5.5V.
ENABLE (Pin 8): An Active-Low Enable Input. LTC1968 is
debiased if open circuited or driven to V
+
. For normal
operation, pull to GND.
APPLICATIO S I FOR ATIO
U
U
U
RMS-TO-DC CONVERSION
Definition of RMS
RMS amplitude is the consistent, fair and standard way to
measure and compare dynamic signals of all shapes and
sizes. Simply stated, the RMS amplitude is the heating
potential of a dynamic waveform. A 1V
RMS
AC waveform
will generate the same heat in a resistive load as will 1V DC.
Mathematically, RMS is the Root of the Mean of the
Square :
V V
RMS
=
2
+
R
1V DC
R
1968 F01
SAME
HEAT
1V AC
RMS
R
1V (AC + DC) RMS
Figure 1
Alternatives to RMS
Other ways to quantify dynamic waveforms include peak
detection and average rectification. In both cases, an
average (DC) value results, but the value is only accurate
at the one chosen waveform type for which it is calibrated,
typically sine waves. The errors with average rectification
are shown in Table 1. Peak detection is worse in all cases
and is rarely used.
Table 1. Errors with Average Rectification vs True RMS
AVERAGE
RECTIFIED
WAVEFORM
V
RMS
(V) ERROR*
Square Wave
1.000 1.000 11%
Sine Wave
1.000 0.900 *Calibrate for 0% Error
Triangle Wave 1.000 0.866 3.8%
SCR at 1/2 Power, 1.000 0.637 29.3%
?= 90?/DIV>
SCR at 1/4 Power, 1.000 0.536 40.4%
?= 114?/DIV>
The last two entries of Table 1 are chopped sine waves as
is commonly created with thyristors such as SCRs and
Triacs. Figure 2a shows a typical circuit and Figure 2b
shows the resulting load voltage, switch voltage and load
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
LTC3100EUD#TRPBF
IC REG BUCK/BOOST/LINEAR 16-QFN
LTC3104IMSE#TRPBF
IC REG DL BCK/LINEAR SYNC 16MSOP
LTC3445EUF#TRPBF
IC REG TRPL BUCK/LINEAR 24-QFN
LTC3446IDE#PBF
IC REG TRPL BCK/LINEAR 14-DFN
LTC3537EUD#TRPBF
IC REG DL BST/LINEAR SYNC 16-QFN
LTC3541EDD#TRPBF
IC REG DL BCK/LINEAR SYNC 10-DFN
LTC3670EDDB#TRPBF
IC REG TRPL BCK/LINEAR 12DFN
LTC3672BEDC-1#TRPBF
IC REG TRPL BCK/LINEAR 8-DFN
相关代理商/技术参数
LTC1980EGN
功能描述:IC PWM BATT CHARGER/CONV 24-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program 标准包装:2,500 系列:- 功能:电池监控器 电池化学:碱性，锂离子，镍镉，镍金属氢化物 电源电压:1 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-6 包装:带卷 (TR)
LTC1980EGN#PBF
功能描述:IC PWM BATT CHARGER/CONV 24-SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program 标准包装:2,500 系列:- 功能:电池监控器 电池化学:碱性，锂离子，镍镉，镍金属氢化物 电源电压:1 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-6 包装:带卷 (TR)
LTC1980EGN#TR
功能描述:IC PWM BATT CHARGER/CONV 24-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program 标准包装:2,500 系列:- 功能:电池监控器 电池化学:碱性，锂离子，镍镉，镍金属氢化物 电源电压:1 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-6 包装:带卷 (TR)
LTC1980EGN#TRPBF
功能描述:IC PWM BATT CHARGER/CONV 24-SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program 标准包装:2,500 系列:- 功能:电池监控器 电池化学:碱性，锂离子，镍镉，镍金属氢化物 电源电压:1 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-6 包装:带卷 (TR)
LTC1981ES5
制造商:Linear Technology 功能描述:MOSFET DRVR 1-OUT Hi Side 5-Pin TSOT-23
LTC1981ES5#PBF
制造商:Linear Technology 功能描述:MOSFET DRVR 1-OUT Hi Side 5-Pin TSOT-23 制造商:Linear Technology 功能描述:DP-Power Controller, CUT TAPE Single Micropower Hi Side Sw Controller 制造商:Linear Technology 功能描述:DRIVER, MOSFET, HIGH/LOW SIDE, SOT-23, Device Type:MOSFET, Module Configuration:High Side, Low Side, Supply Voltage Min:1.8V, Supply Voltage Max:5.5V, Driver Case Style:SOT-23, No. of Pins:5, Operating Temperature Min:-40C , RoHS Compliant: Yes
LTC1981ES5#TR
功能描述:IC HI-SIDE SW CTRL SNGL TSOT23-5 RoHS:否 类别:集成电路 (IC) >> PMIC - MOSFET，电桥驱动器 - 外部开关 系列:- 标准包装:50 系列:- 配置:低端 输入类型:非反相 延迟时间:40ns 电流 - 峰:9A 配置数:1 输出数:1 高端电压 - 最大（自引导启动）:- 电源电压:4.5 V ~ 35 V 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:TO-263-6，D²Pak（5 引线+接片），TO-263BA 供应商设备封装:TO-263 包装:管件
LTC1981ES5#TRM
功能描述:IC HI-SIDE SW CTRL SNGL TSOT23-5 RoHS:否 类别:集成电路 (IC) >> PMIC - MOSFET，电桥驱动器 - 外部开关 系列:- 标准包装:50 系列:- 配置:高端 输入类型:非反相 延迟时间:200ns 电流 - 峰:250mA 配置数:1 输出数:1 高端电压 - 最大（自引导启动）:600V 电源电压:12 V ~ 20 V 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:8-DIP（0.300"，7.62mm） 供应商设备封装:8-DIP 包装:管件 其它名称:*IR2127