- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄361376 > TC500 (Microchip Technology Inc.) Precision Analog Front Ends PDF資料下載
參數(shù)資料
| 型號： | TC500 |
| 廠商： | Microchip Technology Inc. |
| 英文描述： | Precision Analog Front Ends |
| 中文描述： | 精密模擬前端 |
| 文件頁數(shù)： | 10/17頁 |
| 文件大小： | 209K |
| 代理商： | TC500 |
3-28
TELCOM SEMICONDUCTOR, INC.
PRECISION ANALOG FRONT ENDS
TC500
TC500A
TC510
TC514
APPLICATIONS
Component Value Selection
The procedure outlined below allows the user to arrive
at values for the following TC5xx design variables:
(1) Integration Phase Timing
(2) Integrator Timing Components (R
INT
, C
INT
)
(3) Auto Zero and Reference Capacitors
(4) Voltage Reference
Select Integration Time
Integration time must be picked as a multiple of the
period of the line frequency. For example, t
INT
times of
33msec, 66msec and 132msec maximize 60Hz line rejec-
tion.
D
INT
and I
Z
Phase Timing
The duration of the DINT phase is a function of the
amount of voltage stored on the integrator during TINT, and
the value of V
REF
. The DINT phase must be initiated imme-
diately following I
NT
and terminated when an integrator
output zero-crossing is detected. In general, the maximum
number of counts chosen for DINT is twice that of INT (with
V
REF
chosen at V
IN
(max)/2).
Calculate Integrating Resistor
(R
INT
)
The desired full-scale input voltage and amplifier output
current capability determine the value of R
INT
. The buffer
and integrator amplifiers each have a full-scale current of
20
μ
A.
The value of R
INT
is therefore directly calculated as
follows:
R
INT
(in M
) = V
IN MAX
20
where: V
IN MAX
= Maximum input voltage (full count voltage)
R
INT
=Integrating Resistor (in M
)
For loop stability, R
INT
should be
≥
50k
.
Select Reference (C
REF
) and Auto Zero (C
AZ
) Capacitors
C
REF
and C
AZ
must be low leakage capacitors (such as
polypropylene). The slower the conversion rate, the larger
the value C
REF
must be. Recommended capacitors for C
REF
and C
AZ
are shown in Table 1. Larger values for C
AZ
and
C
REF
may also be used to limit roll-over errors.
Table 1. C
REF
and C
AZ
Selection
Conversions Typical Value of Suggested *
Per Second
C
REF
, C
AZ
(
μ
F)
>7
0.1
2 to 7
0.22
2 or less
0.47
*WIMA Corp. listing on the last page of this data sheet.
Part Number
WIMA MK12 .1/63/20
WIMA MK12 .22/63/20
WIMA MK12 .47/63/20
Calculate Integrating Capacitor
(C
INT
)
The integrating capacitor must be selected to maximize
integrator output voltage swing. The integrator output volt-
age swing is defined as the absolute value of V
DD
(or V
SS
)
less 0.9V (i.e.,
V
DD
– 0.9V
or
V
SS
+0.9V
). Using the 20
μ
A
buffer maximum output current, the value of the integrating
capacitor is calculated using the following equation.
C
INT
= (in
μ
F) =
where: t
INT
= Integration Period
V
S
= Applied Supply Voltage
It is critical that the integrating capacitor has a very low
dielectric absorption. Polypropylene capacitors are an ex-
ample of one such chemistry. Polyester and Polybicarbonate
capacitors may also be used in less critical applications.
Table 2 summarizes recommended capacitors for C
INT
.
Table 2. Recommend Capacitor for C
INT
Value
Suggested Part Number*
0.1
0.22
0.33
0.47
WIMA MK12 .1/63/20
WIMA MK12 .22/63/20
WIMA MK12 .33/63/20
WIMA MK12 .47/63/20
*WIMA Corp. listing on the last page of this data sheet.
Calculate V
REF
The reference deintegration voltage is calculated
using:
V
REF
(in Volts) = (V
S
– 0.9) (C
INT
) (R
INT
)
2(t
INT
)
(t
INT
) (20 x 10
–6
)
(V
S
– 0.9)
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TC500A | Precision Analog Front Ends |
| TC500ACPE | Precision Analog Front Ends |
| TC514COI | Precision Analog Front Ends |
| TC500CPE | PRECISION ANALOG FRONT ENDS |
| TC514CPJ | PRECISION ANALOG FRONT ENDS |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| TC-500 | 制造商:Thomas & Betts 功能描述:COVER |
| TC500_06 | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:Precision Analog Front Ends |
| TC500_08 | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:Precision Analog Front Ends with Dual Slope ADC |
| TC50015A | 制造商:CORNELL DUBILIER ELECTRONICS 功能描述:ALUM ELECT/M: Capacitance: 150, Voltage: |
| TC50025A | 制造商:Mallory Sonalert Products Inc 功能描述:AXIAL LEADED ALUMINUM ELECTROLYTIC CAPACITORS 85 DGREE, HIGH RIPPLE, GENERAL PURPOSE CAPACITOR 制造商:CORNELL DUBILIER ELECTRONICS 功能描述:ALUM ELECT/M: Capacitance: 250, Voltage: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。