TS612
DUAL WIDE BAND OPERATIONAL AMPLIFIER
WITH HIGH OUTPUT CURRENT
■ LOW NOISE : 3nV/√Hz, 1.2pA/√Hz
■ HIGH OUTPUT CURRENT : 200mA
■ VERY LOW HARMONIC AND INTERMODU-
LATION DISTORTION
■ HIGH SLEW RATE : 40V/µs
■ SPECIFIED FOR 25Ω LOAD
DESCRIPTION
The TS612 is a du al operational amplifier featuring a high output current (200mA min.), large
gain-bandwidth product (130 MHz) and capable of
driving a 25Ω load with a 160mA output current at
±6V power supply.
This device is particularly intended for applications
where multiple carriers must be amplified simultaneously with very low intermodulation products.
The TS612 is housed in SO20 batwing plastic
package for a very low thermal resistance.
The TS612 is fitted o ut with P ower Dow n f unction
in order to decrease the consumption.
D
SO-20 Batwing
(Plastic Micropackage)
PIN CONNECTIONS (top view)
Power Down 1
Inverting input 1
Non-inverting input 1
Vcc -
1
2
3
4
_
+
20
19
18
17
Vcc+ 1
Output 1
Vcc-
Vcc -
APPLICATION
■ UPSTREAM line driver for Assymetric Digital
Subscriber Li ne (ADS L) (NT).
ORDER CODE
Package
Part Number Temperature Range
D
TS612ID -40, +85°C •
D = Small Outline Package (SO) - also available in Tape & Reel (DT)
May 2000
Vcc -
Vcc -
Vcc -
Non-Inverting input 2
Inverting input 2
Power Down 2
5
6
7
8
9
10
+
_
Top view
16
15
14
13
12
11
Vcc -
Vcc -
Vcc -
GND
Output 2
Vcc+ 2
1/11
TS612
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
T
T
R
R
P
Supply voltage
CC
V
Differential Input Voltage
id
V
Input Voltage Range
in
Operating Free Air Temperature Range TS612ID -40 to + 85 °C
oper
Storage Temperature -65 to +150 °C
std
T
Maximum Junction Temperature 150 °C
j
Thermal Resistance Junction to Case 25 °C/W
thjc
Thermal Resistance Junction to Ambient Area 45 °C/W
thja
Maximum Power Dissipation (@25°C) 2.6 W
max.
Output Short Circuit Duration
1. All voltages values, except differential voltage are with respect to network terminal.
2. Differential voltages are non-inverting input terminal with respect to the inverting input terminal.
3. The magnitude of input and output voltages must never exceed V
4. An output current limitat io n protects the ci rcuit from transient cu rrents. Short-circui ts can cause excessive hea ting.
Destruct i ve dissipati on can resu l t f rom short circ ui t o n am plifiers.
OPERATING CONDITIONS
Symbol Parameter Value Unit
V
V
Supply Voltage ±2.5 to ±6 V
CC
Common Mode Input Voltage
icm
1)
2)
3)
+0.3V.
CC
(V
±7 V
±2 V
±6 V
4)
) +2 to (V
CC
CC
+
) -1
V
2/11
TS612
ELECTRICAL CHARACTERISTICS VCC = ±6Volts, T
= 25°C (unless otherwise specified)
amb
Symbol Parameter Test Condition Min. Typ. Max Unit
DC PERFORMANCE
V
Input Offset Voltage
io
∆V
Differential Input Offset Voltage
io
I
Input Offset Current
io
I
Input Bias Current
ib
CMR Common Mode Rejection Ratio
SVR Supply Voltage Rejection Ratio
I
Total Supply Current per Operator
CC
T
amb
< T
T
min.
T
amb
T
amb
T
min.
T
amb
T
min.
= 2V to 2V, T
V
ic
T
min.
= ±6V to ±4V, T
V
ic
T
min.
No load, V
amb
= 25°C
< T
amb
< T
amb
< T
amb
< T
amb
< T
< T
< T
< T
< T
out
= 0
max.
max.
max.
amb
max.
max.
amb
-6 -1 6
90 108
70
70 88
50
10
6mV
0.2 3
5
515
30
14 mA
DYNAMIC PERFORMANCE
I
= 160mA
V
High Level Output Voltage
OH
V
Low Level Output Voltage
OL
A
Large Signal Voltage Gain
VD
GBP Gain Bandwidth Product
SR Slew Rate
I
Output Short Circuit Current ±320 mA
out
I
Output Sink Current
sink
I
source
ΦM14
ΦM6
Output Source Current
Phase Margin at A
Phase Margin at A
VCL
VCL
= 14dB RL = 25Ω//15pF
= 6dB RL = 25Ω//15pF
out
connected to GND
R
L
I
= 160mA
out
connected to GND
R
L
= 7V peak
V
out
R
= 25Ω, T
L
T
min.
A
VCL
= 100Ω
R
L
A
VCL
= ±6V, T
V
ic
T
min.
= ±6V, T
V
ic
T
min.
amb
< T
< T
amb
= +11, f = 20MHz
= +7, RL = 50Ω
amb
< T
< T
amb
amb
< T
< T
amb
4 4.5 V
-4.5 -4 V
6500 11000
max.
5000
80 130 MHz
23 40 V/µs
max.
max.
+200
+180
60 °
40 °
-200
-180
mV
µA
µA
dB
dB
V/V
mA
mA
3/11
TS612
ELECTRICAL CHARACTERISTICS (continued)
Symbol Parameter Test Condition Min. Typ. Max Unit
NOISE AND DISTORTION
en Equivalent Input Noise Voltage f = 100kHz 3 nV/√Hz
in Equivalent Input Noise Current f = 100kHz 1.2 pA/√Hz
V
= 4Vpp, f = 100kHz
out
A
THD Total Harmonic Distortion
HD2
HD2
HD3
HD3
IM2
IM3
2nd Harmonic Distortion
-10
2nd Harmonic Distortion
+2
3rd Harmonic Distortion
+2
3rd Harmonic Distortion
-10
2nd Order Intermodulation Product
-10
3rd Order Intermodulation Produ ct
-10
= -10
VCL
= 25Ω//15pF
R
L
V
= 4Vpp, f = 100kHz
out
= -10
A
VCL
Load =25Ω//15pF
V
= 4Vpp, f = 100kHz
out
= +2
A
VCL
Load =25Ω//15pF
V
= 4Vpp, f = 1MHz
out
= +2
A
VCL
Load =25Ω//15pF
V
= 4Vpp, f = 100kHz
out
= -10
A
VCL
Load =25Ω//15pF
F1 = 80kHz, F2 = 70kHz
V
= 8Vpp, A
out
VCL
= -10
Load = 25Ω//15pF
F1 = 80kHz, F2 = 70kHz
V
= 8Vpp, A
out
VCL
= -10
Load = 25Ω//15pF
-69 dB
-70 dBc
-74 dBc
-79 dBc
-80 dBc
-77 dBc
-77 dBc
4/11
TS612
t
POWER DOWN MODE
V
= ±6Volts, T
CC
Symbol Parameter Min. Typ. Max Unit
V
Icc
R
C
Pin (1)(7) Thershold Voltage for Power Down Mode
pdw
High Level 2 3.3
Power Down Mode Current Consumption 75 µA
pdw
Power Down Mode Ouput Impedance 3 Ω
pdw
Power Down Mode Output Capacitance TBD µA
pdw
= 25°C
amb
STANDBY CONTROL OPERATOR STATUS
V Low Level 0 0.8
pin (1)
operator 1
V
high level
V
high level
V
low level
V
low level
pin (7)
operator 2
V
low level
V
high level
V
low level
V
high level
POWER DOWN EQUIVALENT SHEMATIC
+
V
cc
.
32:(5
'2:1
.
+
V
..
_
-
cc
.
Oupu
operator 1 operator 2
Standby Active
Standby Standby
Active Active
Active Standby
OUPUT IMPEDANCE IN POWER DOWN MODE
In Power Down Mode the output of the d river is in
"high impedance" state. It is really the case for the
static mode. Regarding the dynamic mode, the impedance decreas es due to a capacitive effect of
the collector-substrat and bas e collector junction.
The impedance behaviour com es capac itive, typically: 1.4MΩ // 33pF.
5/11
TS612
INTERMODULATION DISTORTION
The curves shown below are the measurements results of a single operator wired as an adder with a gain
of 15dB.
The operational amplifier is supplied by a symmetric ±6V and is loaded with 25Ω.
Two synthesizers (Rhode & S chwartz SME) generate two frequencies (tones) (70 & 80kHz or 180 &
280kHz).
An HP3585 spectrum analyzer measures the spurious level at different frequencies.
The curves are traced for different output levels (the value in the X ax is the value of each tone).
The output levels of the two tones are the same.
The generators and spectrum analyzer are phase locked to enhance mea su remen t precision.
3rd ORDER INTERMODULATION
(2 tones : 70kHz and 80kHz)
0
-10
-20
-30
IM3 (dBc)
-40
-50
-60
-70
-80
-90
-100
90kHz
230kHz
60kHz
220kHz
11,522,533,544,5
Vout peak (V)
2nd ORDER INTERMODULATION
Spurious measurement @ 100kHz
(2 tones : 180kHz and 280kHz)
3rd ORDER INTERMODULATION
(2 tones : 180kHz and 280kHz)
0
-10
-20
-30
-40
IM3 (dBc)
-50
-60
-70
-80
-90
-100
80kHz
380kHz
640kHz
740kHz
11,522,533,544,5
Vout peak (V)
-55
-60
IM2 (dBc)
-65
-70
1,522,533,544,5
Vout peak (V)
6/11
TS612
Closed Loop Gain and Phase vs. Frequency
Gain=+2, Vcc=
10
Gain
0
Phase
-10
Gain (dB)
-20
-30
10kHz 100kHz 1MHz 10MHz 100MHz
±6V, RL=25Ω
Frequency
Closed Loop Gain and Phase vs. Frequency
Gain=+11, Vcc=
30
Gain
20
10
Phase
0
Gain (dB)
-10
-20
±6V, RL=25Ω
200
100
0
-100
-200
200
100
0
-100
Closed Loop Gain and Phase vs. Frequency
Gain=+6, Vcc=
Phase (degrees)
20
Gain
15
10
5
Phase
0
Gain (dB)
-5
-10
-15
-20
10kHz 100kHz 1MHz 10MHz 100MHz
±6V, RL=25Ω
Frequency
Equivalent Input Voltage Noise
Gain=+100, Vcc=
Phase (degrees)
20
15
10
en (nV/VHz)
5
±6V, no load
100
200
100
0
Phase (degrees)
-100
-200
+
_
10k
-30
10kHz 100kHz 1MHz 10MHz 100MHz
Frequency
Maximum Output Swing
±6V, RL=25Ω
Vcc=
5
4
3
2
1
0
-1
swing (V)
-2
-3
-4
-5
0246810
input
Time (µs)
7/11
output
-200
0
100Hz 1kHz 10kHz 100kHz 1MHz
Frequency
Channel Separation (Xtalk) vs. Frequency
XTalk=20Log(V2/V1), Vcc=
VIN
100Ω
100Ω
49.9Ω
49.9Ω
+
_
1kΩ
+
_
1kΩ
100kHz
Xtalk (dB)
-100
-10
-20
-30
-40
-50
-60
-70
-80
-90
10kHz
±6V, RL=25Ω
V1
25Ω
V2
25Ω
1MHz
Frequency
10MHz
TYPICAL APPLICATION : TS612 AS DRIVER
FOR ADSL LINE INTERFACES
A SINGLE SUPPLY IMPLEMENTATION WITH PASS IVE
OR ACTIVE IMPEDANC E MATCHING
by C. PRUGNE
ADSL CONCEPT
Asymmetric Digital Subscriber Line (ADSL), is a
new modem technology, which converts the existing twisted-pair telephone lines into ac cess paths
for multimedia and high speed data communications.
ADSL transmits more than 8 Mbps to a subscriber,
and can reach 1Mbps from the subscriber to the
central office. ADSL can literally transform the actual public information network by bringing movies, television, video catalogs, remote CD-ROMs,
LANs, and the Internet into homes.
An ADSL modem is connected to a twisted-pair
telephone line, creating three information channels: a high speed downstream channel (up to
1.1MHz) depending on the implementation of the
ADSL architecture, a medium speed upstream
channel (up to 130kHz) and a POTS (Plain Old
Telephone Service), split off from the modem by
filters.
THE LINE INTERFACE - ADSL Remote
Terminal (RT):
The TS612 is used as a dual line driver for the upstream signal.
For the remote terminal it is required to create an
ADSL modem easy to plug in a PC. In such an application, the driver should be imple men ted with a
+12 volts single power supply. This +12V supply is
available on PCI connector of purchase.
The figure 2 shows a single +12V sup ply circuit
that uses the TS612 as a remote terminal transmitter in differential mode.
Figure 2 : TS612 as a differential line driver with
a +12V single supply
12.5
12.5
1µ
10n
Vo
25Ω 100Ω
1:2
Hybrid
&
Transformer
100n
+12V
1k
Vi
Vi Vo
100n
10µ 100n
1k
GND
47k
47k
20
3
+
_
2
R2
R1
R3
11
9
+
_
8
4,5,6,7,14,15,16,17,18
+12V
+12V
GND
19
12
The Figure1 shows a typ ical analog lin e interface
used for ADSL. The upstream and downstream
signals are separat ed from the telephone line by
using an hybrid circuit and a line transformer. On
this note, the accent will be made on the emission
path.
Figure 1 : Typical ADSL Line Interface
high output
current
upstream
impedance
matching
downstream
HYBRID
CIRCUIT
twisted-pair
telephone
line
8/11
digital to
analog
digital
treatment
analog to
digital
emission
(analog)
reception
(analog)
LP filter
TS612
Line Driver
reception
circuits
The driver is biased with a m id supply (nominaly
+6V), in order to maintain the DC component of
the signal at +6V. Th is allows the maximum dynamic range between 0 and +12 V. Several options are possible to provide this bias supply (such
as a virtual ground using an operational amplifier),
such as a two-resistance divider which is the
cheapest solution. A high resistance value is required to limit the current consumption. On the
other hand, the current must be high enough to
bias the inverting input of the TS612. If we consider this bias current (5µA) as the 1% of the current
through the resistance divi der (500µA) to keep a
stable mid supply, two 47kΩ resistances can be
used.
The input provides two high pass filters with a
break frequency of about 1.6kHz whi ch is necessary to remove the DC component of the input signal. To avoid DC current flowing in the primary of
the transformer, an output capac itor is used. The
TS612
1µF capacitance provides a path for low frequ encies, the 10nF capacitance provides a path for
high end of the spectrum.
In differential mode the TS612 is able to deliver a
typical amplitude signal of 18V peak to peak.
The dynamic li ne i mpe danc e is 100Ω . The typical
value of the amplitude sign al required on the line
is up to 12.4V peak t o peak. B y us ing a 1 :2 transformer ratio the reflected impedance back t o the
primary will be a quarter (25Ω ) and therefore the
amplitude of the signal required with this impedance will be the half (6.2 V peak to peak). Assuming the 25Ω series resistance (12.5Ω for both outputs) necessary for impedance matching, the output signal amplitude required is 12.4 V peak to
peak. This value is acc eptable for the TS612. In
this case the load impedance is 25Ω for each driver.
For the ADSL up stream path, a lowpass filter is
absolutely necessary t o cuto ff the high er frequ encies from the DAC analog output. In this simple
non-inverting amplification configuration, it will be
easy to implement a Sallen-Key lowpass filter by
using the TS612. For AD SL over POTS, a maximum frequency of 135kHz is reached. For ADSL
over ISDN, the maximum frequency will be
276kHz.
INCREASING THE LINE LEVEL BY USING AN
ACTIVE IMPEDANCE MATCHING
With passive matching, the output signal amplitude of the driver must be twice the amplitude on
the load. To go beyond this limitation an active
maching impedan ce can be used. With this tec hnique it is possible to keep good impedance
matching with an amplitude on the load higher
than the half of the oup ut driver amplitude. This
concept is shown in figure3 for a differential line.
Figure 3 : TS612 as a differential line driver with
an active impedance matching
100n
+12V
1k
Vi
Vi Vo
100n
10µ 100n
1k
GND
47k
47k
20
3
+
_
2
R2
R3
R1
R5
R4
11
9
+
_
8
4,5,6,7,14,15,16,17,18
+12V
+12V
GND
12.5
19
Vo°
Vo°
12.5
12
1µ
10n
Vo
1:2
Hybrid
&
Transformer
100Ω
Ω
25
Compon ent calc ulatio n:
Let us consider the equivalent c ircuit for a single
ended configuration, figure4.
Figure 4 : Single ended equivalent circuit
+
Rs1
Vi
R1
1/2
Let us consider the unloaded system . Assuming
the currents through R1, R2 and R3
as respectively:
As Vo° equals Vo without load, the gain in this
case becomes :
The gain, for the loaded system will be (1):
GL
As shown in figure5, this system is an ideal generator with a synthesized impedance as the i nterna l
impedance of the system. From this, the output
voltage becomes:
with Ro the synthesized impedance and Iout the
output current. On the other hand Vo can be expressed as:
_
R2
2
Vi
---------
,
1
R
()
Vo noload
G
-------------------------------
()
Vo withload
------------------------------------
Vi
Vo ViG
1
Vi
Vo
---------------------------------------------- -
Vo°
-1
R3
()
Vi Vo°–
--------------------------
2
R
Vi
()
2R2
---------- -
1
R
2
R
1
------ -–
3
R
()
Vi Vo+
----------------------- -
and
2R2
1
---------- -
R
-----------------------------------==
1
2R2
1
---------- -
1
-- -
-----------------------------------
2
1
()
RoIout
–=
2
R
------ -++
3
R
Rs1Iout
---------------------
1
Vo
3
R
R
-------++
1
R
2
R
------ -–
3
R
R
-------++
1
R
R
2
R
------ -–
3
R
2()
,
2
R
------ -–
3
R
2
3
,–=
2
3
,==
3()
1/2
1()
RL
9/11
TS612
By identification of both e quat ions (2) a nd (3), the
synthesized impedance is, with Rs1=Rs2=Rs:
Ro
---------------- -
1
4()
,=
2
R
------ -–
3
R
Rs
Figure 5 : Equivalent schematic. Ro is the syn-
thesized impedance
Ro
Vi.Gi
Iout
1/2
RL
Unlike the level Vo° required for a passive impedance, Vo° will be smaller than 2Vo in our case. Let
us write Vo°=kVo with k the matching factor varying between 1 and 2. Assum ing that the current
through R3 i s negligeable, it comes the fo llowing
resistance divider:
Ro
kVoRL
---------------------------=
RL2Rs
+
1
After choosing the k factor, Rs will equal to
1/2RL(k-1).
A good impedance matching assume s:
1
-- -
Ro
5()
RL
,=
2
From (4) and (5) it becomes:
2
R
------ -
R
2
3
Rs
--------- -
1
RL
,–=
6()
By fixing an arbitrary value for R2, (6) gives:
2
R
3
R
-------------------=
2
Rs
1
--------- -–
RL
Finally, the values of R2 and R3 allow us to extract
R1 from (1), and it comes:
---------------------------------------------------------
1
R
21
2R2
2
R
------ -–
R
3
GL1–
7()
,=
2
R
------ -–
3
R
GL (gain for the
loaded system)
R1 2R2/[2(1-R2/R3)GL-1-R2/R3]
R2 (=R4) Abritra ry fixed
R3 (=R5) R2/(1-Rs/0.5RL)
Rs 0.5RL(k-1)
GL is fixed for the application requirements
GL=Vo/Vi=0.5(1+2R2/R1+R2/R3)/(1-R2/R3)
CAPABILITIES
The table below shows the calculated components for different values of k. In this case
R2=1000Ω and the gain=16dB. The last column
displays the maximu m amplitude level on the line
regarding the TS612 maximum output capabilities
(18Vpp diff.) and a 1:2 line transformer ratio.
Active matching
TS612 Output
R1
k
(Ω)R3(Ω)Rs(Ω)
1.3 820 1500 3.9 8 27.5
1.4 490 1600 5.1 8.7 25.7
1.5 360 2200 6.2 9.3 25.3
1.6 270 2400 7.5 9.9 23.7
1.7 240 3300 9.1 10.5 22.3
Passive matching 12.4 18
Level to get
12.4Vpp on
the line
(Vpp diff)
Maximum
Line level
(Vpp diff)
MEASUREMENT OF THE POWER
CONSUMPTION IN THE ADSL APPLICATION
Conditions:
Passive impedance matching
Transformer turns ratio: 2
Maximun level required on the line: 12.4Vpp
Maximum output level of the driver: 12.4Vpp
Crest factor: 5.3 (Vp/Vrms)
The TS612 power consumption during emission
on 900 and 4550 meter twisted pair telephone
lines: 450mW
with GL the required gain.
10/11
TS612
PACKAGE MECHANICAL DATA
8 PINS - PLASTIC MICROPACKAGE (SO)
Dim.
Millimeters Inches
Min. Typ. Max. Min. Typ. Max.
A 2.65 0.104
a1 0.1 0.3 0.004 0.012
a2 2.45 0.096
b 0.35 0.49 0.014 0.019
b1 0.23 0.32 0.009 0.013
C 0.5 0.020
c1 45° (typ.)
D 12.6 13.0 0.496 0.512
E 10 10.65 0.394 0.419
e 1.27 0.050
e3 11.43 0.450
F 7.4 7.6 0.291 0.299
L 0.5 1.27 0.020 0.050
M 0.75 0.030
S 8° (max.)
Information furnished is bel ieved to be accurate and reliable. However, STMicroe lectronics 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 li cense is granted by implication or otherwise unde r any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication ar e subject to change without notice. This publication supersedes and replaces all information
previously supplied. S TMicroelectronics products are not authorized for use as critica l components in life suppo rt devices or
systems without express written approval of STMicroelectronics.
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11/11
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