- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄361603 > UTC571 (友順科技股份有限公司) COMPANDER Complete compressor and expandor in one IChip PDF資料下載
參數(shù)資料
| 型號： | UTC571 |
| 廠商： | 友順科技股份有限公司 |
| 英文描述： | COMPANDER Complete compressor and expandor in one IChip |
| 中文描述： | 擴(kuò)展器完整的壓縮機(jī)和expandor一個(gè)IChip |
| 文件頁數(shù)： | 10/14頁 |
| 文件大小： | 161K |
| 代理商： | UTC571 |
UTC571
LINEAR INTEGRATED CIRCUIT
YOUWANG ELECTRONICS CO.LTD
10
VARIABLE GAIN CELL
I1
140
A
R2
20K
Q1
Q2
Q3 Q4
IG
I2(=2I1)
280
A
V+
V-
V
IN
I
IN
Note:
2
2
IN
G
1
G
OUT
R
I
V
I
IIN
L
L
L
=
=
Figure 9. Simplified
G Cell Schematic
Figure 9 is a diagram of the variable gain cell. This is a linearized two-quadrant transconductance multiplier. Q 1 ,
Q 2 and the op amp provide a predistorted drive signal for the gain control pair, Q 3 and Q 4 . The gain is
controlled by I G and a current mirror provides the output current.
The op amp maintains the base and collector of Q 1 at ground potential (V
REF
) by controlling the base of Q 2 .
The input current I
IN
(=V
IN
/R 2 ) is thus forced to flow through Q 1 along with the current I 1 , so I
C1
=I
1
+I
IN
.
Since I
2
has been set at twice the value of I
1
, the current through Q 2 is:
I
2
- (I
1
+I
IN
) = I
1
- I
IN
= I
C2
.
The op amp has thus forced a linear current swing between Q 1 and Q 2 by providing the proper drive to the
base of Q 2 . This drive signal will be linear for small signals, but very non-linear for large signals, since it is
compensating for the non-linearity of the differential pair, Q 1 and Q 2 , under large signal conditions.
The key to the circuit is that same predistorted drive signal is applied to the gain control pair, Q3 and Q4. When
two differential pairs of transistors have the same signal applied, their collector current ratios will be identical
regardless of the magnitude of the currents. This gives us :
IN
I
1
IN
I
1
C3
I
C4
I
C2
C1
I
I
I
I
+
=
=
plus the relationships
C4
I
C3
G
I
I
+
=
and
C3
I
C4
I
OUT
I
=
will yield the multiplier transfer function,
1
2
G
IN
IN
I
1
G
OUT
I
I
R
I
V
I
I
=
=
This equation is liner and temperature-insenstive, but it assumes ideal transistor.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| UTC7106 | 3/12 DIGIT,LCD DISPLAY A/D CONVERTERS |
| UTC75185 | LINEAR INTEGRATED CIRCUIT |
| UTC75323 | LINEAR INTEGRATED CIRCUIT |
| UTC7642 | ONE CHIP AM RADIO CIRCUIT |
| UTC78D | LINEAR INTEGRATED CIRCUIT |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| UTC571N | 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:COMPANDER |
| UTC571NG-S16-R | 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:COMPANDER |
| UTC571NG-S16-T | 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:COMPANDER |
| UTC571NG-S16W-R | 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:COMPANDER |
| UTC571NG-S16W-T | 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:COMPANDER |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。