參數(shù)資料
型號(hào): TC670ECHTR
廠商: Microchip Technology
文件頁(yè)數(shù): 7/14頁(yè)
文件大?。?/td> 354K
描述: IC FAN FAILURE DETECTOR SOT23A-6
標(biāo)準(zhǔn)包裝: 1
功能: 風(fēng)扇控制,溫度監(jiān)控器
傳感器類型: 內(nèi)部
感應(yīng)溫度: -40°C ~ 85°C
拓?fù)洌?/td> 振蕩器
輸出類型: 開(kāi)路漏極
輸出警報(bào):
輸出風(fēng)扇:
電源電壓: 3 V ~ 5.5 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: SOT-23-6
供應(yīng)商設(shè)備封裝: SOT-23-6
包裝: 標(biāo)準(zhǔn)包裝
產(chǎn)品目錄頁(yè)面: 683 (CN2011-ZH PDF)
其它名稱: TC670ECHTRDKR
?2003 Microchip Technology Inc.
DS21688C-page 7
TC670
The design of the proper input SENSE circuitry is a
matter of scaling R
SENSE
  to provide the necessary
amount of gain and proper selection of the sensing
capacitor. The following table (Table 4-1) lists some
recommended values for R
SENSE
  according to the
nominal operating current of the fan. Please note that
the current draw specified by the fan manufacturer may
be a worst-case rating and not the fans nominal oper-
ating current. If the fan current falls between two of the
values listed, it is recommended that the higher value
resistor is used.
TABLE 4-1:
RECOMMENDED VALUES
FOR R
SENSE
 PER FIGURE 4-2
A 0.1 礔   ceramic capacitor is recommended   for
C
SENSE
. Smaller capacitor values will require larger
sense resistors, whereas larger capacitors are more
expensive and occupy more board space.
4.2
THRESHOLD Input
The voltage at the THRESHOLD input sets the
equivalent minimum allowable fan speed for the appli-
cation. As shown in Section 2.0, Typical Performance
Curves, the relationship between the threshold volt-
age and minimum fan speed is also power supply and
temperature dependant.
All the values for the threshold voltage that are shown
in these graphs represent typical numbers and might
not be optimized for all fans in all applications. To
ensure accurate fan speed monitoring of a specific fan
in a specific application, the user must perform a one-
time correlation check with the prototype.
There are two techniques that can be used to calibrate
the system. One approach is to find the fans full-scale
capability and mathematically estimate the minimum
acceptable speed of the fan. A second technique is to
identify the fans minimum speed and calibrate the
threshold voltage accordingly.
4.2.1
THRESHOLD CALIBRATION USING
FANS FULL SCALE SPEED
The fan should first be run at full speed. At full speed,
the threshold voltage level should be adjusted until the
ALERT
 output is asserted. With this full-scale value of
the threshold voltage, the value can be scaled down to
the fan fault speed as a percentage of the full speed.
For example, if the fan full speed threshold voltage is
1.5V, then the fan fault threshold voltage at 30% of full
speed would be 30% x 1.5V = 0.45V.
4.2.2
THRESHOLD CALIBRATION USING
FANS MINIMUM ALLOWABLE
SPEED ESTIMATE
For a more exact fan fault trip point, the user can run
the fan at its minimum allowed speed. At this speed,
the threshold voltage can be adjusted until the ALERT
output is asserted.
4.3
CLEAR Input
The CLEAR input allows the user to reset the ALERT
pin to a high status. This is an active-high input.
Consequently, as long as CLEAR is high, ALERT
 will
always be high as well. To allow ALERT
 to operate cor-
rectly, CLEAR must be held low. This feature can be
implemented so that false fan fault conditions do not
initiate system shutdown.
4.4
ALERT
 Output
The ALERT
 output is an open-drain output capable of
sinking 2.5 mA (typ). The ALERT
  output is asserted
whenever the detected fan speed equals or falls below
the equivalent voltage set at the threshold pin. The
ALERT
 output is only deactivated once the CLEAR pin
is brought to a high state. Although the absolute
maximum sink current of this pin is 25 mA, it is
recommended that the current sinking into the ALERT
output does not exceed 20 mA.
4.5
Power Supply Input (V
DD
)
To assure proper operation of the TC670 in a noisy
environment where the fans are running, the V
DD
 pin
(Pin 4) must be decoupled with a 0.1 礔 capacitor, as
shown in Figure 4-1. This capacitor should be located
as close to the TC670 V
DD
 pin as possible, as well as
being promptly terminated to the ground plane. A
ceramic capacitor is recommended.
4.6
Ground Terminal (GND)
The GND pin (Pin 2) of the TC670 should be connected
directly to the analog ground plane of the circuit board.
Care should be taken to keep this pin away from
switching signals, such as the fan excitation signals in
order to avoid false signals on the SENSE pin.
Nominal Fan Current
(mA)
R
SENSE
 (&)
100
4.7
200
2.4
300
1.8
400
1.3
500
1.0
600
0.8
相關(guān)PDF資料
PDF描述
TC74A7-5.0VCTTRG IC DGTL THERM SNSR 5.0V SOT23A-5
TC77-5.0MOATR IC THERMAL SENSOR SPI 5V 8-SOIC
TC9402EJD IC V-FREQ/FREQ-V CONV 14CDIP
TCN75-5.0MUAG IC TEMP SENSOR SRL 5.0V 8MSOP
TEA1750T/N1,518 IC PFC CONTROLLER DCM16SOIC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TC670ECHTR 制造商:Microchip Technology Inc 功能描述:IC CONTROLLER FAN MANAGEMENT 制造商:Microchip Technology Inc 功能描述:IC, CONTROLLER, FAN MANAGEMENT
TC670ECHTR 制造商:Microchip Technology Inc 功能描述:Fan Management Controller IC Package/Cas
TC670ECHTR-CUT TAPE 制造商:Microchip 功能描述:TC670 Series 3 to 5.5 V Tiny Predictive Fan Failure Detector - SOT-23-6
TC68 功能描述:鋁質(zhì)電解電容器 - 帶引線 60uF 350V RoHS:否 制造商:Kemet 引線類型: 電容:220 uF 容差:20 % 電壓額定值:25 V 工作溫度范圍: 端接類型:Radial 外殼直徑:8 mm 外殼長(zhǎng)度:11 mm 引線間隔:5 mm 產(chǎn)品:General Purpose Electrolytic Capacitors 封裝:Bulk
TC-68.000MBD-T 功能描述:標(biāo)準(zhǔn)時(shí)鐘振蕩器 68.000MHz 3.3V 25ppm -40C to 85C RoHS:否 制造商:AVX 產(chǎn)品:Standard Clock Oscillators 封裝 / 箱體:7 mm x 5 mm 頻率:75 MHz 頻率穩(wěn)定性:50 PPM 電源電壓:2.5 V 負(fù)載電容: 端接類型:SMD/SMT 最小工作溫度:0 C 最大工作溫度:+ 70 C 輸出格式:LVDS 尺寸: 封裝:Reel 系列: