tld4012 Tripath Technology Inc., tld4012 Datasheet - Page 10

• Manufacturer Part Number: tld4012
• Description: Adsl Line Driver Using Tripath Digital Power Processing Dpp ?
• Manufacturer: Tripath Technology Inc.

From Analog
Front End
T E S T / A P P L I C A T I O N C I R C U I T
S y n t h e s i z e d O u t p u t I m p e d a n c e
Device TLD4012 employs synthesized output impedance with a synthesis factor of 2.55. As with any line
driver, using synthesized impedance reduces power consumption, but may compromise receive-signal
strength in some applications. The 10: matching resistors will properly terminate a 100: line when a
1:1.4 transformer is used (see Figure 1). Note that, for simplicity, the hybrid and other filtering associated
with the receive signal path are not shown.
10
Controller
C
C
IN
IN
Micro
R
AUTO_CLR
IN
RESETB
LOPWR
C
R
R
R
R
TLD4012
EN_AC
Test/Application Circuit – with synthesized output impedance, TLD4012
IN
IN
S
EXT
LINE
INN
= 10 :
INP
G0
G3
G2
G1
= 0.1 PF
= 5 k:
= 24 K:
= 100 :
T1 = 1:1.4 Transformer
D1 = One UPS840 schottky diode or equivalent per 48 drivers.
3
4
9
8
7
6
14
15
1
31
Control
Logic
VDD5
&
VDD5
25
10PF
0.1 PF
2
GND
VSS5
VSS5
16
10PF
Processing
GND
5
Power
Block
Figure 1

0.1 PF
28
GND
VDD15
VDD15
21
FORC_BIAS TH_FAULT
12
1PF
Output
current
limit
0.1 PF
D1
13
T r i p a t h T e c h n o l o g y , I n c . - T e c h n i c a l I n f o r m a t i o n
VSS15
TLD4012 – JB/Rev. 2.0a/05.02
VSS15
20
1PF
30
23
18
29
27
11
FBP
OUTP
OUTN
FBN
R
FAULT
EXT
0.1 PF
R
LOAD
25k
R
EXT
V
LOGIC
R
R
S
S
T1
R
LINE