参数资料
型号: LTC2991IMS#TRPBF
厂商: LINEAR TECHNOLOGY CORP
元件分类: 电源管理
英文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16
封装: LEAD FREE, PLASTIC, MSOP-16
文件页数: 8/32页
文件大小: 230K
代理商: LTC2991IMS#TRPBF
LTC2991
16
2991f
APPLICATIONS INFORMATION
below the PWM Threshold, the PWM output pin will be a
constant logic level 0. For temperatures 32 degrees above
the PWM Threshold, the PWM output pin will be a constant
logic level 1. This relationship is opposite if the PWM
invert bit is set. If the filter is enabled for the V7/V8 pair,
the filtered result is routed to the PWM block; otherwise,
the unfiltered version is used. The PWM CMOS output
drive is intended to be buffered to drive large (>100pF)
external capacitances or resistors <10k. A recommended
noninverting buffer is a NC7SZ125 to increase the drive
capability of the PWM signal.
Digital Filter
Each conversion result can be filtered using an on-chip
digital filter. The filter equation is:
OUTPUT[X] = (15 (OUTPUT[X – 1]) + SAMPLE[X])/16
where output[x] is the register value when enabled. The
filter step response is illustrated in the Typical Perfor-
mance Characteristics section. The filter can be seeded
by triggering an unfiltered conversion of each configured
measurement, then subsequently enabling the filter. This
will cause the filter to converge instantaneously to the value
of the initial unfiltered sample. The filter can be enabled
or disabled for each channel pair and internal temperature
measurements. VCC measurements cannot be filtered.
Digital Interface
The LTC2991 communicates with a bus master using
a 2-wire interface compatible with the I2C Bus and the
SMBus, an I2C extension for low power devices.
The LTC2991 is a read write slave device and supports
SMBus bus read byte data and write byte data, read word
data and write word data commands. The data formats
for these commands are shown in Tables 3 though 15.
The connected devices can only pull the bus wires LOW
and can never drive the bus HIGH. The bus wires are
externally connected to a positive supply voltage via a
current source or pull-up resistor. When the bus is free,
both lines are HIGH. Data on the I2C bus can be transferred
at rates of up to 100kbit/s in the standard mode and up to
400kbit/s in the fast mode. Each device on the I2C bus is
recognized by a unique address stored in that device and
can operate as either a transmitter or receiver, depending
on the function of the device. In addition to transmitters
and receivers, devices can also be considered as masters
or slaves when performing data transfers. A master is
the device which initiates a data transfer on the bus and
generates the clock signals to permit that transfer. At the
same time any device addressed is considered a slave.
The LTC2991 can only be addressed as a slave. Once ad-
dressed, it can receive configuration bits or transmit the
last conversion result. Therefore the serial clock line SCL
is an input only and the data line SDA is bidirectional. The
device supports the standard mode and the fast mode for
data transfer speeds up to 400kbit/s. The Timing Diagram
shows the definition of timing for fast/standard mode
devices on the I2C bus. The internal state machine cannot
update internal data registers during an I2C read operation.
The state machine pauses until the I2C read is complete.
It is therefore, important not to leave the LTC2991 in this
state for long durations, or increased conversion latency
will be experienced.
START and STOP Conditions
When the bus is idle, both SCL and SDA must be high. A
bus master signals the beginning of a transmission with
a START condition by transitioning SDA from high to low
while SCL is high. When the bus is in use, it stays busy
if a repeated START (SR) is generated instead of a STOP
condition. The repeated START (SR) conditions are func-
tionally identical to the START (S). When the master has
finished communicating with the slave, it issues a STOP
condition by transitioning SDA from low to high while SCL
is high. The bus is then free for another transmission.
I2C Device Addressing
Eight distinct bus addresses are configurable using the
ADR0, ADR1 and ADR2 pins. Table 1 shows the corre-
spondence between ADR0, ADR1 and ADR2 pin states
and addresses.
Acknowledge
The acknowledge signal is used for handshaking between
the transmitter and the receiver to indicate that the last byte
of data was received. The transmitter always releases the
SDA line during the acknowledge clock pulse. When the
slave is the receiver, it must pull down the SDA line so that
相关PDF资料
PDF描述
LTC2991IMS#PBF 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16
LTC3406AES5#TRM 1.3 A SWITCHING REGULATOR, 1800 kHz SWITCHING FREQ-MAX, PDSO5
LTC3406AES5#TR 1.3 A SWITCHING REGULATOR, 1800 kHz SWITCHING FREQ-MAX, PDSO5
LTC3406AIS5#PBF 1.3 A SWITCHING REGULATOR, 1800 kHz SWITCHING FREQ-MAX, PDSO5
LTC3406AES5#PBF 1.3 A SWITCHING REGULATOR, 1800 kHz SWITCHING FREQ-MAX, PDSO5
相关代理商/技术参数
参数描述
LTC2995CUD#PBF 功能描述:IC TEMP SENSOR VOLT MNTR 20QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:2,500 系列:SilentSense™ 功能:温度监控系统(传感器) 传感器类型:内部和外部 感应温度:-55°C ~ 125°C,外部传感器 精确度:±2°C 本地(最大),±3°C 远程(最大) 拓扑:ADC(三角积分型),比较器,寄存器库 输出类型:I²C?/SMBus? 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-TSSOP,8-MSOP(0.118",3.00mm 宽) 供应商设备封装:8-MSOP 包装:带卷 (TR) 其它名称:MIC284-2BMMTRMIC284-2BMMTR-ND
LTC2995CUD#TRPBF 功能描述:IC TEMP SENSOR VOLT MNTR 20QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:2,500 系列:SilentSense™ 功能:温度监控系统(传感器) 传感器类型:内部和外部 感应温度:-55°C ~ 125°C,外部传感器 精确度:±2°C 本地(最大),±3°C 远程(最大) 拓扑:ADC(三角积分型),比较器,寄存器库 输出类型:I²C?/SMBus? 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-TSSOP,8-MSOP(0.118",3.00mm 宽) 供应商设备封装:8-MSOP 包装:带卷 (TR) 其它名称:MIC284-2BMMTRMIC284-2BMMTR-ND
LTC2995HUD#PBF 功能描述:IC TEMP SENSOR VOLT MNTR 20QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:2,500 系列:SilentSense™ 功能:温度监控系统(传感器) 传感器类型:内部和外部 感应温度:-55°C ~ 125°C,外部传感器 精确度:±2°C 本地(最大),±3°C 远程(最大) 拓扑:ADC(三角积分型),比较器,寄存器库 输出类型:I²C?/SMBus? 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-TSSOP,8-MSOP(0.118",3.00mm 宽) 供应商设备封装:8-MSOP 包装:带卷 (TR) 其它名称:MIC284-2BMMTRMIC284-2BMMTR-ND
LTC2995HUD#TRPBF 功能描述:IC TEMP SENSOR VOLT MNTR 20QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:2,500 系列:SilentSense™ 功能:温度监控系统(传感器) 传感器类型:内部和外部 感应温度:-55°C ~ 125°C,外部传感器 精确度:±2°C 本地(最大),±3°C 远程(最大) 拓扑:ADC(三角积分型),比较器,寄存器库 输出类型:I²C?/SMBus? 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-TSSOP,8-MSOP(0.118",3.00mm 宽) 供应商设备封装:8-MSOP 包装:带卷 (TR) 其它名称:MIC284-2BMMTRMIC284-2BMMTR-ND
LTC2995IUD#PBF 功能描述:IC TEMP SENSOR VOLT MNTR 20QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:3,000 系列:- 功能:温度开关 传感器类型:内部 感应温度:85°C 分界点 精确度:±6°C(最小值) 拓扑:ADC(三角积分型),比较器,寄存器库 输出类型:开路漏极 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:SC-74A,SOT-753 供应商设备封装:SOT-23-5 包装:带卷 (TR) 其它名称:ADT6501SRJZP085RL7-ND