參數(shù)資料
型號: ADM1026JST-REEL
廠商: ANALOG DEVICES INC
元件分類: 電源管理
英文描述: Complete Thermal and System Management Controller
中文描述: 4-CHANNEL POWER SUPPLY SUPPORT CKT, PQFP48
封裝: 7 X 7 MM, 1.40 MM HEIGHT, PLASTIC, MS-026BBC, LQFP-48
文件頁數(shù): 18/56頁
文件大?。?/td> 634K
代理商: ADM1026JST-REEL
ADM1026
Voltage Measurement Inputs
The internal structure for all the analog inputs is shown in
Figure 27. Each input circuit consists of an input protection
diode, an attenuator, plus a capacitor to form a first-order low-
pass filter that gives each voltage measurement input immunity
to high frequency noise. The 12 V input also has a resistor
connected to the on-chip reference to offset the negative voltage
range so that it is always positive and can be handled by the
ADC. This allows most popular power supply voltages to be
monitored directly by the ADM1026 without requiring any
additional resistor scaling.
Rev. A | Page 18 of 56
109.4k
18.5pF
21.9k
+V
CCP
9.3pF
V
REF
17.5k
114.3k
–12V
49.5k
82.7k
4.5pF
V
BAT
*SEE TEXT
A
IN0
– A
IN5
(0V – 3V)
109.4k
4.6pF
21.9k
A
– A
(0V – 2.5V)
4.6pF
52.5k
50k
4.6pF
83.5k
+5V
21k
9.3pF
113.5k
+12V
MUX
0
Figure 27. Voltage Measurement Inputs
Setting Other Input Ranges
A
IN0
to A
IN9
can easily be scaled to voltages other than 2.5 V or
3 V. If the input voltage range is zero to some positive voltage, all
that is required is an input attenuator, as shown in Figure 28.
R1
R2
V
IN
A
IN(0–9)
0
Figure 28. Scaling A
IN0
A
IN9
However, when scaling A
IN0
to A
IN5
, it should be noted that
these inputs already have an on-chip attenuator, because their
primary function is to monitor SCSI termination voltages. This
attenuator loads any external attenuator. The input resistance of
the on-chip attenuator can be between 100 k and 200 k. For
this tolerance not to affect the accuracy, the output resistance
of the external attenuator should be very much lower than
this, that is, 1 k in order to add not more than 1% to the
total unadjusted error (TUE). Alternatively, the input can be
buffered using an op amp.
(
IN0
A
R2
0
(
IN6
A
R2
5
)
(
)
IN5
fs
A
V
R1
to
for
0
=
)
(
)
IN9
fs
A
V
R1
to
for
5
=
Negative and bipolar input ranges can be accommodated by
using a positive reference voltage to offset the input voltage
range so that it is always positive. To monitor a negative input
voltage, an attenuator can be used as shown in Figure 29.
R1
R2
V
IN
A
IN(0–9)
0
Figure 29. Scaling and Offsetting A
IN0
A
IN9
for Negative Inputs
This offsets the negative voltage so that the ADC always sees a
positive voltage. R1 and R2 are chosen so that the ADC input
voltage is zero when the negative input voltage is at its
maximum (most negative) value, that is:
OS
fs
V
V
R2
R1
=
This is a simple and low cost solution, but note the following:
Because the input signal is offset but not inverted, the input
range is transposed. An increase in the magnitude of the
negative voltage (going more negative) causes the input
voltage to fall and give a lower output code from the ADC.
Conversely, a decrease in the magnitude of the negative
voltage causes the ADC code to increase. The maximum
negative voltage corresponds to zero output from the ADC.
This means that the upper and lower limits are transposed.
For the ADC output to be full scale when the negative
voltage is zero, V
OS
must be greater than the full-scale
voltage of the ADC, because V
OS
is attenuated by R1 and
R2. If V
OS
is equal to or less than the full-scale voltage of
the ADC, the input range is bipolar but not necessarily
symmetrical.
This is a problem only if the ADC output must be full scale
when the negative voltage is zero.
相關(guān)PDF資料
PDF描述
ADM1026JSTZ-REEL Complete Thermal and System Management Controller
ADM1026JST Circular Connector; No. of Contacts:28; Series:LJT06R; Body Material:Aluminum; Connecting Termination:Crimp; Connector Shell Size:19; Circular Contact Gender:Pin; Circular Shell Style:Straight Plug; Insert Arrangement:19-28
ADM1030ARQ Intelligent Temperature Monitor and PWM Fan Controller
ADM1030 Circular Connector; No. of Contacts:66; Series:LJT06R; Body Material:Aluminum; Connecting Termination:Crimp; Connector Shell Size:19; Circular Contact Gender:Socket; Circular Shell Style:Straight Plug; Insert Arrangement:19-35
ADM1033 Thermal Monitor and Fan Speed (RPM) Controller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADM1026JST-REEL7 功能描述:IC CNTRL SYS REF/EEPROM 48LQFP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標準包裝:1 系列:- 功能:溫度監(jiān)控系統(tǒng)(傳感器) 傳感器類型:內(nèi)部和外部 感應溫度:-40°C ~ 125°C,外部傳感器 精確度:±2.5°C 本地(最大值),±5°C 遠程(最大值) 拓撲:ADC,比較器,寄存器庫 輸出類型:2 線 SMBus? 輸出警報:無 輸出風扇:無 電源電壓:2.7 V ~ 5.5 V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-8 供應商設備封裝:SOT-23-8 包裝:Digi-Reel® 其它名稱:296-22675-6
ADM1026JSTZ 功能描述:PMIC 解決方案 HI INT SYS MONITR IC RoHS:否 制造商:Texas Instruments 安裝風格:SMD/SMT 封裝 / 箱體:QFN-24 封裝:Reel
ADM1026JSTZ-R7 功能描述:PMIC 解決方案 HI INT SYS MONITR IC RoHS:否 制造商:Texas Instruments 安裝風格:SMD/SMT 封裝 / 箱體:QFN-24 封裝:Reel
ADM1026JSTZ-REEL 功能描述:板上安裝溫度傳感器 HI INT SYS MONITR IC RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風格: 封裝 / 箱體: 設備功能:Temperature and Humidity Sensor
ADM1026JSTZ-REEL7 制造商:Analog Devices 功能描述:IC SYSTEM MONITOR 制造商:ON Semiconductor 功能描述:IC SYSTEM MONITOR