L3845D1013TR [STMICROELECTRONICS]
SPECIALTY TELECOM CIRCUIT, PDSO8, SO-8;型号: | L3845D1013TR |
厂家: | ST |
描述: | SPECIALTY TELECOM CIRCUIT, PDSO8, SO-8 电信 光电二极管 电信集成电路 |
文件: | 总8页 (文件大小:482K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
L3845
®
TRUNK INTERFACE
ON CHIP POLARITY GUARD
MEETS DC LINE CHARACTERISTICS OF
EITHER CCITT AND EIA RS 464 SPECS
PULSE FUNCTION
HIGH AC IMPEDANCE
OFF HOOK-STATUS DETECTION OUTPUT
LOW EXTERNAL COMPONENT COUNT
Minidip
SO8
SO20W
(12+4+4)
DESCRIPTION
The circuit provides DC loop termination for ana-
log trunk lines.
ORDERING NUMBERS:
L3845B
L3845D
L3845-20
The V-I characteristics is equivalent to a fixed
voltage drop (zener like characteristic) in series
with an external resistance that determines the
slope of the DC characteristic.
An external low voltage electrolytic capacitor
causes the circuit to exhibit a very high imped-
ance to all AC signal above a minimum frequency
that is determined by the capacitor itself and by a
20 K nominal resistor integrated on the chip.
The Off-Hook status is detected all the time a
typic of 8 mA is flowing into the circuit. In this con-
dition a constant current generator is activated to
supply an external device (typically an optocou-
pler) withouaffecting the AC characteristic of the
circuit.
When Pulse Dialing is required the PULSE input
(3) connected to V- causes the device to re-
duce the fixed DC voltage drop and to exhibit a
pure resistive impedance equal to the external re-
sistor.
BLOCK DIAGRAM
8
1
V+
IN1
3
PULSE
DC LINE
TERMINATION
POLARITY
GUARD
OF HOOK
4
DETECTION
CIRCUIT
HD0
7
IN2
5
6
2
ACT
DCT
V-
R2
R3
C1
S2
R1
S1
D96TL263
September 2003
1/8
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
L3845
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
20
Unit
V
VL
IL
Max Line Voltage (pulse duration 10 ms max)
Max Line Current
150
mA
mW
°C
Ptot
Total Power Dissipation at Tamb = 70 °C
Operating Temperature
800
Top
– 40 to + 70
– 55 to + 150
Tsrg, Tj
Storage and Junction Temperature
°C
PIN CONNECTION
(Top view)
SO20
MINIDIP and SO8
PULSE
HD0
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V-
IN1
NC
NC
IN1
V-
1
2
3
4
8
7
6
5
V+
SUBS
SUBS
SUBS
SUBS
NC
SUBS
SUBS
SUBS
SUBS
NC
IN2
PULSE
HD0
DCT
ACT
DIP8
ACT
V+
DCT
IN2
SO20
SUBS = the pin is electrically and thermally in good contact with the chip sustrate. Connect to PCB copper tracks, for heat dissipation the
tracks shall preferably be electrically connected to pin 20 (internally bonded to the chip substrate) or left floating. A higher track
density and/or area assures a Rth j-amb towards the lower limit.
THERMAL DATA
Symbol
Parameter
Minidip
SO8
SO20
Unit
Rth j-amb
Thermal Resistance Junction-ambient (*)
Max.
80
140 to 180
50 to 70
°C/W
(*) Mounted on FR4 Boards
2/8
L3845
DC ELECTRICAL CHARACTERISTICS
unless otherwise specified)
Ω
°
(IL = 10 mA to 100 mA, R1 = 56 , S1 = Open, Tamb = + 25 C,
Symbol
Parameter
Line Voltage
Test Condition
PULSE = Open
Min.
Typ.
Max.
Unit
VL
(normal mode)
IL = 10 mA
IL = 20 mA
IL = 100 mA
5
6
12
V
V
V
VLP
Line Voltage
(pulse mode)
PULSE = V–
IL = 20 mA
IL = 35 mA
IL = 80 mA
4
5.5
9.5
V
V
V
Ihn
ON/OFF-Hook
Line Current Detection
Threshold
6.5
5
9.5
9.2
mA
Ihf
OFF/ON-Hook
Line Current Detection
Threshold
mA
IOUT
OFF-Hook
Output Drive Current at Pin
HDO
IL = 10 mA
IL ≥ 20 mA
1.5
1.8
mA
mA
VPM
IPM
Pulse Input Low Voltage
0.8
20
V
Pull-up Input Current at Pin
PULSE (pulse mode)
IL = 100 mA
Pulse = V–
µA
INM
Imput Current at Pin Pulse
(normal mode)
3
µA
AC ELECTRICAL CHARACTERISTICS
Ω
Ω
Ω
(IL = 10mA to 100mA, R1 = 56 , R2 = 470K , R3 = 130 K ,
°
T
amb = + 25 C, unless otherwise specified)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
ZL
AC Line Impedance
S1 = Open, S2 = Open
C1 = 2.2mF
20
KΩ
f = 1KHz
Sending/Receiving Distortion
S1 = Open, S2 = Open
f = 1KHz
VAC-L = 775mVrms
2
%
IL = 15 to 100mA
Sending/Receiving Distortion
Sending/Receiving Distortion
S1 = Closed; S2 = Open
V
AC-L = 1.3Vrms
S1 = Open; S2 = Closed
AC-L = 1.9Vrms
2
%
%
2(*)
V
(*) Not tested, guaranteed only by design.
APPLICATION INFORMATION
Figure 1 gives the typical application circuit ; it is
worth to note that the TRUNK TERMINATION
CIRCUIT, together with the LS5018 transient sup-
pressor provides a compact and low cost module
fully protected against lightning or overvoltages
frequently present on telephone lines.
The PULSE input when connected to V- allows
the device to reduce the Line Voltage and to
show a resistive impedance equal to R1 to the
line. When PULSE input is left open, this function
is disable.
With the use of this circuit it is possible to termi-
nate an analog trunk so that all the DC current
component is flowing in the TRUNK TERMINA-
TION CIRCUIT while the AC component is de-
coupled with a low voltage capacitor and can be
used with a small and low cost audio coupler
transformer to provide the AC balancing termina-
tion and two to four wire conversion.
Therefore it is usefull both for MODEM and PABX
systems.
3/8
L3845
Figure 1:
Typical Application.
4/8
L3845
mm
inch
DIM.
OUTLINE AND
MECHANICAL DATA
MIN.
TYP. MAX. MIN.
3.32
TYP. MAX.
0.131
A
a1
B
0.51
1.15
0.020
1.65 0.045
0.55 0.014
0.304 0.008
10.92
0.065
0.022
b
0.356
0.204
b1
D
E
0.012
0.430
7.95
9.75 0.313
2.54
0.384
e
0.100
e3
e4
F
7.62
0.300
7.62
0.300
6.6
0.260
I
5.08
0.200
L
3.18
3.81 0.125
1.52
0.150
Minidip
Z
0.060
5/8
L3845
mm
inch
DIM.
OUTLINE AND
MECHANICAL DATA
MIN. TYP. MAX. MIN. TYP. MAX.
A
a1
a2
a3
b
1.75
0.069
0.010
0.065
0.033
0.019
0.010
0.020
0.1
0.25 0.004
1.65
0.65
0.35
0.19
0.25
0.85 0.026
0.48 0.014
0.25 0.007
b1
C
0.5
0.010
c1
D (1)
E
45° (typ.)
4.8
5.8
5.0
6.2
0.189
0.228
0.197
0.244
e
1.27
3.81
0.050
0.150
e3
F (1)
L
3.8
0.4
4.0
0.15
0.157
0.050
0.024
1.27 0.016
0.6
M
SO8
S
8° (max.)
(1) D and F do not include mold flash or protrusions. Mold flash or
potrusions shall not exceed 0.15mm (.006inch).
6/8
L3845
mm
inch
OUTLINE AND
MECHANICAL DATA
DIM.
MIN. TYP. MAX. MIN. TYP. MAX.
A
A1
B
C
D
E
e
2.35
0.1
2.65 0.093
0.3 0.004
0.104
0.012
0.020
0.013
0.512
0.299
0.33
0.23
12.6
7.4
0.51 0.013
0.32 0.009
13
0.496
0.291
7.6
1.27
0.050
H
h
10
0.25
0.4
10.65 0.394
0.75 0.010
0.419
0.030
0.050
L
1.27 0.016
SO20
K
0˚ (min.)8˚ (max.)
L
h x 45˚
A
B
A1
K
C
e
H
D
20
11
E
1
01
SO20MEC
7/8
L3845
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics.
All other names are the property of their respective owners
© 2003 STMicroelectronics - All rights reserved
STMicroelectronics GROUP OF COMPANIES
Australia – Belgium - Brazil - Canada - China – Czech Republic - Finland - France - Germany - Hong Kong - India - Is-
rael - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United
States
www.st.com
8/8
相关型号:
©2020 ICPDF网 联系我们和版权申明