TS636IDT ,DIFFERENTIAL VARIABLE GAIN AMPLIFIER FOR ADSL LINE INTERFACEABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit1)V14 VCC Supply voltage 2)V0 to 14 Vi Inpu ..
TS636IDT ,DIFFERENTIAL VARIABLE GAIN AMPLIFIER FOR ADSL LINE INTERFACEELECTRICAL CHARACTERISTICS. V = ±6Volts, T = 25°C (unless otherwise specified). CC ambSymbol P ..
TS636IDT ,DIFFERENTIAL VARIABLE GAIN AMPLIFIER FOR ADSL LINE INTERFACETS636DIFFERENTIAL VARIABLE GAIN AMPLIFIERFOR ADSL LINE INTERFACE ■ LOW NOISE : 4.7nV/√Hz■ LOW ..
TS652ID ,DIFFERENTIAL VARIABLE GAIN AMPLIFIERELECTRICAL CHARACTERISTICS. V = ±6Volts, T = 25°C (unless otherwise specified). CC ambSymbol P ..
TS652IDT ,DIFFERENTIAL VARIABLE GAIN AMPLIFIERELECTRICAL CHARACTERISTICS. V = ±6Volts, T = 25°C (unless otherwise specified). CC ambSymbol P ..
TS652IDT ,DIFFERENTIAL VARIABLE GAIN AMPLIFIERTS652DIFFERENTIAL VARIABLE GAIN AMPLIFIER ■ LOW NOISE : 4.6nV/√Hz■ LOW DISTORTION■ HIGH SLEW R ..
UA741CD ,General purpose operational amplifierSupport &Product Order Tools &TechnicalCommunityFolder Now Documents SoftwareuA741SLOS094G–NOVEMBER ..
UA741CDR ,General-Purpose Operational AmplifierBlock Diagram ........ 10• Added caption to Figure 11 in Device Functional Modes section....... 11• ..
UA741CDT ,GENERAL PURPOSE SINGLE BIPOLAR OP-AMPSUA741GENERAL PURPOSESINGLE OPERATIONAL AMPLIFIER ■ LARGE INPUT VOLTAGE RANGE ■ NO LATCH-UP■ HI ..
UA741CH ,GENERAL-PURPOSE SINGLE OP-AMPsPIN CONFIGURATION AS THE UA709
DIP14
(Plastlc Package)
D
SOB
Dlpe (Plastic Micropackage)
(P ..
UA741CJ ,General-purpose single operational amplifierABSOLUTE MAXIMUM RATINGS S G S-THOMSON 3tilli1 1)
_ Value
Symbol _Paratmuer UA741M, A UA741I UA74 ..
UA741CN ,General purpose operational amplifierPIN CONFIGURATION AS THE UA709DESCRIPTIONThe UA741 is a high performance monolithic oper-Dational a ..
TS636-TS636ID-TS636IDT
DIFFERENTIAL VARIABLE GAIN AMPLIFIER FOR ADSL LINE INTERFACE
LOW NOISE : 4.7nV/√Hz LOW DISTORTION HIGH SLEW RATE : 90V/μs WIDE BANDWIDTH : 52MHz @ -3dB &18dB gain GAIN PROGRAMMABLE from -9dB to +30dB
with 3dB STEPS POWER DOWN FUNCTION
DESCRIPTIONThis TS636 is particularly intended for applica-
tions such as preamplification in telecommunica-
tion systems using multiple carriers. It has been
minly designed to fit with ADSL chip-sets such as
ASCOT ADSL chip-set for CPE.
The TS636 is a differential digitally controled vari-
able gain amplifier featuring a high slew rate of
90V/μs, a large bandwidth, a very low distortion
and a very low current and voltage noise.
The gain can be set from -9dB to +30dB through a
4bit digital word, with 3dB steps.
The gain monotonicity is guaranteed by design.
The TS636 comes in SO-14 plastic packages.
APPLICATION Preamplifier with automatic gain control for
Asymmetric Digital Subscriber Line (ADSL).
ORDER CODE
D = Small Outline Package (SO) - also available in Tape & Reel (DT)
PIN CONNECTIONS (top view)
TS636DIFFERENTIAL VARIABLE GAIN AMPLIFIER
FOR ADSL LINE INTERFACE
TS636
ABSOLUTE MAXIMUM RATINGS
OPERATING CONDITIONS
APPLICATION: ADSL LINE INTERFACE All voltages values are with respect to network terminal. The magnitude of input and output voltages must never exceed VCC +0.3V.
TS636ELECTRICAL CHARACTERISTICS. VCC = ±6Volts, Tamb = 25°C (unless otherwise specified).
TS636
DIGITAL INPUTS
SIMPLIFIED SCHEMATIC The TS636 consists of two independent channels.
Each channel has two stages. The first is a very low noise digitally controlled variable gain amplifier (range
0 to 18dB).
The TS636 features a high input impedance and a low noise current. To minimize the overall noise figure,
the source impedance must be less than 3kΩ.
This value gives an equal contribution of voltage and current noises.
The second stage is a gain/attenuation stage (+12dB to -9dB) featuring a low output impedance.
This output stage can drive loads as low as 500Ω.
POWER DOWN MODE POSITION
TS636BANDWIDTHThe small signal bandwidth is almost constant for gains between +18dB to 0dB and is in the order of
52MHz to 70MHz respectively. For 30dB gain the bandwidth is around 18MHz.
The power bandwidth is typically equal to 30MHz for 2V peak to peak signals.
MAXIMUM INPUT LEVEL The input level must not exceed the following values :
negative peak value: must be greater than -VCC + 1.5V
positive peak value: must be less than +VCC - 1.5V
For example, if a ±6V power supply is used, the input signal can swing between -4.5V and +4.5V.
These values are due to common mode input range limitations of the input stage of the first amplifier.
Some other limitations may occur, due to the slew rate of the first operational amplifier (typically in the or-
der of 300V/μs). This means that the maximum input signal decreases at high frequency.
SINGLE SUPPLY OPERATION The incoming signal is AC coupled to the inputs.
The TS636 can be used either with a dual or a single supply. If a single supply is used, the inputs are bi-
ased to the mid supply voltage (+VCC/2). This bias network must be carefully designed, in order to reject
any noise present on the supply rail.
The AGND pin (9) must be connected to +VCC/2. The bias current of the second stage (inverting structure)
is 8μA for both amplifiers. A resistor divider structure can be used. Two resistances should be chosen by
considering 8μA as the 1% of the total current through these resistances. For a single +12V supply volt-
age, two resistances of 7.5kΩ can be used. The differential input consists of a high pass circuit, formed by
the 1μF capacitor and a 1kΩ resistance and gives a break frequency of 160Hz.
SINGLE +12V SUPPLY OF THE TS636
TS636
GAIN CONTROLThe gain and the power down mode is programmed with a 4 bit digital word :
The gain is the same for both channels. The digital inputs are CMOS compatible. The supply voltage of the logic decoder used to transcode the digital word can be either 3.3V or 5V or VCC.
