- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄98180 > TC8129CKW 1-CH PROPRIETARY METHOD ADC, PQFP44 PDF資料下載
參數(shù)資料
| 型號： | TC8129CKW |
| 元件分類： | ADC |
| 英文描述： | 1-CH PROPRIETARY METHOD ADC, PQFP44 |
| 封裝： | PLASTIC, QFP-44 |
| 文件頁數(shù)： | 16/17頁 |
| 文件大?。?/td> | 137K |
| 代理商： | TC8129CKW |
8
TC8129
4C\VDigit Auto-Ranging DMM ADC
TC8129 - 3/29/96-2
2001 Microchip Technology Inc.
DS21473A
Resistance
Resistance is measured ratiometrically. The ratiometric
method uses the voltage across a known resistor as the
reference voltage and the voltage across an unknown
resistor as the input voltage. The integration time for resis-
tance measurements is 500 counts and the A/D converter
result is:
RUNKNOWN .
Count =
_________
X 500000
RREF
.
The output of this measurement is only dependent on
the ratio of the two resistors, so a precision reference
voltage is not required.
To obtain the actual resistor value, the A/D converter
result must be multiplied by two. For 40 M
measure-
ments, the integration time is reduced to 100 clock cycles
and the x2 multiplication is not required.
Diode
Diodes are measured by using the 1k
attenuator
resistor as a current source. One end of this resistor is
internally connected to V
+
S and the other end, through the
PTC protection resistor, to the diode. The integration time
for diode measurements is 100 clock cycles. The diode
forward voltage is obtained by multiplying the A/D con-
verter result by 5.45 (for 60Hz operation) or by 6.55 (for
50Hz operation).
Current
Current measurements are made by measuring the
voltage drop across external sense resistors (see typical
application schematic). If current measurements are dis-
played with 3
digits of resolution, as is the case in typical
DMM’s, the high resolution of the TC8129 can be used to
produce a two-level autorange effect. For example, full
scale voltage in the 4mA range, using a 100
sense
resistor, is 400mV. Using the same 100
resistor for a
400
A range produces a 'full scale' voltage of 40mV. The
TC8129 can measure 40mV to 3
digits of resolution.
Therefore the TC8131 formats input voltages from 0 to
40mV as the 400
A range and input voltages above 40mV
as the 4mA range.
Capacitance
Capacitors are also measured using the external resis-
tor network. 4nF, 40nF and 400nF are the three lower
ranges. 4
F and 40F are the two upper ranges. VLCTRM
and VHCTRM are the voltages for trimming the accuracy of
the lower and upper capacitance ranges. Typical voltages
for the VHCTRM and VLCTRM are 150mV and 1.4V respec-
tively. A polarized (electrolytic) capacitor should have its
negative terminal connected to the COMMON input of the
TC8129.
hFE
Transistor hFE is typically measured with a base cur-
rent of 10
A. The base current is set with an external
resistor that is nominally 260k
with a typical (V+S – COM)
voltage of 3.2V (Figure 1). Collector current is measured
across a 10
resistor, using the IRC input (with the TC8129
in measurement mode 001).
The voltage across the 10
resistor is converted to hFE
by the TC8131, using the formula:
VIRC / 10
hFE =
__________
.
10
A
TC8129
IRC
hFE = VIN(V) x 10,000
V
–
IN
V+S
10
260k
Figure 1. Typical hFE Measurement Circuit
Temperature
The TC8129 measures temperature using a type K
thermocouple (see typical application schematic). The mea-
surement range extends from – 270
°C to +1370°C.
Since thermocouples have a nonlinear output voltage
characteristic, temperature measurements require several
steps. First, the thermocouple output voltage (nominally
about +40
V/°C) is measured using the TC8129’s IRC
input. This result is transmitted to the TC8131. Then the ice
point compensation voltage is measured using a thermistor
attached to the mV/RREF input, and this value is also sent
to the TC8131. Finally the TC8131 subtracts the ice point
correction, applies a linearization process to the result, and
displays the temperature on the LCD.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TC815CBU | 1-CH DUAL-SLOPE ADC, ACCESS, PQFP64 |
| TC815CBU | 1-CH DUAL-SLOPE ADC, PQFP64 |
| TC815CBUTR | 1-CH DUAL-SLOPE ADC, PQFP64 |
| TC818ACBU | 1-CH DUAL-SLOPE ADC, ACCESS, PQFP64 |
| TC818ACBU | 1-CH DUAL-SLOPE ADC, PQFP64 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| TC-812-SC | 制造商:THOMAS & BETTS 功能描述: 制造商:Thomas & Betts 功能描述:Cable Accessories Thin Wall Conduit Fitting Zinc Die Cast |
| TC812-SC-10 | 制造商:Thomas & Betts 功能描述:3/4 CONN,COMP.,EMT,DC,INSUL,10/BG 制造商:Thomas & Betts 功能描述:ADVANTAGES OF STEEL CITY COMMERCIAL CONDUIT FITTINGS |
| TC812-TB | 制造商:THOMAS & BETTS 功能描述: 制造商:Thomas & Betts 功能描述:CABLE TIE .4X.8" MINTR SCREW MT-#10 制造商:Thomas & Betts 功能描述:Cable Accessories Mounting Base Nylon 6.6 Natural Bulk |
| TC8-13S242.5R | 制造商:TRUMPOWER 制造商全稱:Tumbler Technologies + TRUMPower 功能描述:DC/DC CONVERTERS 2:1 Input, 12.5 to 20 Watt |
| TC8-13S482.5R | 制造商:TRUMPOWER 制造商全稱:Tumbler Technologies + TRUMPower 功能描述:DC/DC CONVERTERS 2:1 Input, 12.5 to 20 Watt |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。