TS635DW

TS635 DUAL WIDE BAND OPERATIONAL AMPLIFIER FOR ADSL LINE INTERFACE s LOW NOISE : 3.2nV/√Hz, 1.5pA/√Hz s HIGH OUTPUT CURRENT : 160mA min. s VERY LOW HARMONIC AND INTERMODULATION DISTORTION s HIGH SLEW RATE : 40V/µs s SPECIFIED FOR 25Ω LOAD DESCRIPTION This device is particularly intended for applications where multiple carriers must be amplified simultaneously with very low intermodulation products. It has been mainly designed to fit with ADSL chip-set such as ST70134 or ST70135. The TS635 is a high output current dual operational amplifier, with a large gain-bandwidth product (130MHz) and capable of driving a 25Ω load at 12V power supply. The TS635 is fitted out with Power Down function in order to decrease the consumption. The TS635 is housed in a SO8 plastic package and a SO8 Exposed-Pad plastic package. APPLICATION D SO8 (Plastic Micropackage) DW SO8 Exposed-Pad (Plastic Micropackage) PIN CONNECTIONS (top view) Output1 1 Inverting Input1 2 Non Inverting Input1 3 VCC - 4 _ + _ + 8 VCC + 7 Output2 6 Inverting Input2 5 Non Inverting Input2 s UPSTREAM line driver for Asymmetric Digital Subscriber Line (ADSL) (NT). ORDER CODE Part Number TS635ID TS635IDW Temperature Range -40, +85°C -40, +85°C Package D • • DW Cross Section View Showing Exposed-Pad This pad can be connected to a (-Vcc) copper area on the PCB D = Small Outline Package (SO) - also available in Tape & Reel (DT) DW = Small Outline Package in Exposed-Pad (SO) - also available in Tape & Reel (DWT) December 2002 1/10 TS635 ABSOLUTE MAXIMUM RATINGS Symbol VCC Vid Vin Toper Tstd Tj SO8 Rthjc Rthja Pmax. Supply voltage 1) 2) Parameter Value ±7 ±2 ±6 -40 to + 85 -65 to +150 150 28 175 715 16 60 2000 Unit V V V °C °C °C °C/W °C/W mW °C/W °C/W mW Differential Input Voltage Input Voltage Range 3) Operating Free Air Temperature Range TS635ID Storage Temperature Maximum Junction Temperature Thermal Resistance Junction to Case Thermal Resistance Junction to Ambient Area Maximum Power Dissipation (@25°C) SO8 Exposed-Pad Rthjc Thermal Resistance Junction to Case Rthja Pmax. Thermal Resistance Junction to Ambient Area Maximum Power Dissipation (@25°C) 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 VCC +0.3V. OPERATING CONDITIONS Symbol VCC Vicm Supply Voltage Common Mode Input Voltage Parameter Value ±2.5 to ±6 (VCC) +2 to (VCC+) -1 Unit V V APPLICATION: ADSL LINE INTERFACE ASCOT ADSL CHIP-SET TX emission LP filter (analog signal) TS635 Line Driver upstream ST70135 ST70134 Power Down HYBRID CIRCUIT RX reception (analog signal) twisted-pair telephone line VGA downstream TS636 Receiver 4-bit Gain Control 2/10 TS635 ELECTRICAL CHARACTERISTICS. Symbol Parameter Differential Input Offset Voltage Input Offset Current Input Bias Current Common Mode Rejection Ratio Supply Voltage Rejection Ratio Total Supply Current per Operator High Level Output Voltage Low Level Output Voltage Large Signal Voltage Gain VCC = ±6V, Tamb = 25°C (unless otherwise specified). Test Condition Tamb = 25°C Tamb Tmin. < Tamb < Tmax. Tamb Tmin. < Tamb < Tmax. Vic = 2V to 2V, Tamb Tmin. < Tamb < Tmax. Vic = ±6V to ±4V, Tamb Tmin. < Tamb < Tmax. No load, Vout = 0 Iout = 160mA, RL to GND Iout = 160mA, RL to GND Vout = 7V peak RL = 25Ω, Tamb Tmin. < Tamb < Tmax. AVCL = +7, f = 20MHz RL = 100Ω AVCL = +7, RL = 50Ω Vid = ±1V, Tamb Tmin. < Tamb < Tmax. RL = 25Ω//15pF RL = 25Ω//15pF f = 100kHz f = 100kHz Vout = 4Vpp, f = 100kHz AVCL = -10 RL = 25Ω//15pF F1 = 80kHz, F2 = 70kHz Vout = 8Vpp, AVCL = -10 Load = 25Ω//15pF F1 = 80kHz, F2 = 70kHz Vout = 8Vpp, AVCL = -10 Load = 25Ω//15pF 90 70 70 50 Min. Typ. Max 6 3 5 15 30 Unit mV µA µA dB dB 15 mA V -4 V V/V DC PERFORMANCE ∆Vio Iio Iib CMR SVR ICC VOH VOL AVD GBP SR Iout Isink Isource ΦM14 ΦM6 en in THD 0.2 5 108 88 11 4 4.5 -4.5 6500 5000 130 23 ±160 ±140 60 40 3.2 1.5 -69 40 ±240 MHz V/µs mA mA ° ° nV/√Hz pA/√Hz dB 11000 DYNAMIC PERFORMANCE Gain Bandwidth Product Slew Rate Output Short Circuit Current Output Current Phase Margin at AVCL = 14dB Phase Margin at AVCL = 6dB Equivalent Input Noise Voltage Equivalent Input Noise Current Total Harmonic Distorsion NOISE AND DISTORTION IM2-10 2nd Order Intermodulation Product -77 dBc IM3-10 3rd Order Intermodulation Product -77 dBc 3/10 TS635 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 & Schwartz SME) generate two frequencies (tones) (70 & 80kHz ; 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 measurement precision. 3rd ORDER INTERMODULATION Gain=15dB, Vcc=±6V, RL=25Ω, 2 tones 70kHz/ 80kHz 3rd ORDER INTERMODULATION Gain=15dB, Vcc=±6V, RL=25Ω, 2 tones 180kHz/ 280kHz 0 -10 -20 0 -10 -20 -30 IM3 (dBc) -30 IM3 (dBc) -40 -50 -60 -70 -80 -90 -100 1 -40 -50 -60 -70 -80 80kHz 380kHz 90kHz 230kHz 60kHz 220kHz 1,5 2 2,5 3 3,5 4 4,5 640kHz 740kHz -90 -100 1 1,5 2 2,5 3 3,5 4 4,5 Vout peak (V) Vout peak (V) 4/10 TS635 Closed Loop Gain and Phase vs. Frequency Gain=+2, Vcc=±6V, RL=25Ω Closed Loop Gain and Phase vs. Frequency Gain=+6, Vcc=±6V, RL=25Ω 10 200 20 200 Gain 15 0 100 Phase (degrees) 10 Gain 100 Phase (degrees) Gain (dB) -10 Phase Gain (dB) 5 Phase 0 -5 0 0 -20 -100 -10 -15 -100 -30 -200 -20 -200 10kHz 100kHz 1MHz 10MHz 100MHz 10kHz 100kHz 1MHz 10MHz 100MHz Frequency Frequency Closed Loop Gain and Phase vs. Frequency Gain=+11, Vcc=±6V, RL=25Ω Equivalent Input Voltage Noise Gain=+100, Vcc=±6V, no load 30 200 20 Gain 20 100 15 en (nV/VHz) + _ 10k 10 Phase 0 0 Phase (degrees) Gain (dB) 10 100 -10 -20 -30 -100 5 -200 0 100Hz 1kHz 10kHz 100kHz 1MHz Frequency 10kHz 100kHz 1MHz 10MHz Frequency 100MHz Maximum Output Swing Vcc=±6V, RL=25Ω Channel Separation (Xtalk) vs. Frequency XTalk=20Log(V2/V1), Vcc=±6V, RL=25Ω 5 4 3 2 -20 VIN output -30 -40 -50 -60 -70 -80 + 49.9Ω _ V1 1k Ω 25Ω 100Ω swing (V) 1 0 -1 -2 -3 -4 -5 0 2 input Xtalk (dB) + 49.9Ω _ V2 1k Ω 25Ω 100Ω 4 6 8 10 10kHz 100kHz 1MHz 10MHz Time (µs) Frequency 5/10 TS635 THE TS635 AS LINE DRIVER ON ADSL LINE INTERFACE. SINGLE SUPPLY IMPLEMENTATION WITH PASSIVE OR ACTIVE IMPEDANCE MATCHING. THE LINE INTERFACE - ADSL Remote Terminal (RT): The Figure1 shows a typical analog line interface used for ADSL service. On this note, the accent will be made on the emission path. The TS635 is used as a dual line driver for the upstream signal. Figure 1 : Typical ADSL Line Interface namic 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 TS635. If we consider this bias current (5µA) as the 1% of the current through the resistance divider (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 which is necessary to remove the DC component of the input signal. To avoid DC current flowing in the primary of the transformer, an output capacitor is used. The this case the load impedance is 25Ω for each driver. HYBRID CIRCUIT ASCOT ADSL Chip-Set emission (analog) high output current LP filter upstream impedance matching ST70135 ST70134 TS635 Line Driver twisted-pair telephone line reception (analog) VGA TS636 Receiver downstream For the ADSL upstream path necessary to avoid any distortion. In this simple non-inverting amplification configuration, it will be easy to implement a Sallen-Key lowpass filter by using the TS635. For ADSL 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 impedance can be used. With this technique it is possible to keep good impedance matching with an amplitude on the load higher than the half of the ouput driver amplitude. This concept is shown in Figure 3 for a differential line. Figure 3 : TS635 as a differential line driver with an active impedance matching 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 implemented with a +12 volts single power supply. This +12V supply is available on PCI connector of purchase. The Figure 2 shows a single +12V supply circuit that uses the TS635 as a remote terminal transmitter in differential mode. Figure 2 : TS635 as a differential line driver with a +12V single supply 1µ 100n + +12V 1k _ +12V GND R2 12.5 10n Vi 1:2 47k 1/2 R1 Vo Vcc/2 1µ 100n 25Ω Vo Hybrid & Transformer 100Ω Vcc+ 1k + _ Vcc+ GND Rs1 10n 1/2 R1 Vi 1k 10µ 47k 100n + _ GND R3 +12V GND Vi 1/2 R1 R2 Vo° Vo 1:n Hybrid & Transformer 12.5 R3 Vcc/2 RL Vo 100Ω 100n 1/2 R1 R5 Vi 1k 10µ 100n GND + _ R4 Vcc+ GND Vo° Rs2 The driver is biased with a mid supply (nominaly +6V), in order to maintain the DC component of the signal at +6V. This allows the maximum dy6/10 100n TS635 Component calculation: Let us consider the equivalent circuit for a single ended configuration, Figure 4. Figure 4 : Single ended equivalent circuit By identification of both equations (2) and (3), the synthesized impedance is, with Rs1=Rs2=Rs: Rs Ro = ---------------- ,( 4 ) R2 1 – -----R3 + Rs1 Vi Figure 5 : Equivalent schematic. Ro is the synthesized impedance _ R2 Vo° Vo -1 R3 1/2R1 1/2RL Ro Iout Vi.Gi 1/2RL Let us consider the unloaded system. Assuming the currents through R1, R2 and R3 as respectively: 2 Vi – + -------- , ( Vi Vo ° ) and ( Vi Vo ) - ----------------------------------------------R1 R2 R3 As Vo° equals Vo without load, the gain in this case becomes : 2R2 R2 1 + ---------- + -----R1 R3 Vo ( noload ) G = ------------------------------ = ---------------------------------R2 Vi 1 – -----R3 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. Assuming that the current through R3 is negligeable, it comes the following resistance divider: kVoRL Ro = --------------------------RL + 2 Rs 1 The gain, for the loaded system will be (1): 2R2 R2 1 + ---------- + -----1 Vo ( withload ) R1 R3 ----------------------------------- = -- ---------------------------------- ,( 1 ) GL = 2 R2 Vi 1 – -----R3 After choosing the k factor, Rs will equal to 1/2RL(k-1). A good impedance matching assumes: 1 R o = -- RL ,( 5 ) 2 As shown in Figure 5, this system is an ideal generator with a synthesized impedance as the internal impedance of the system. From this, the output voltage becomes: Vo = ( ViG ) – ( RoIout ) ,( 2 ) From (4) and (5) it becomes: 2 Rs R2 ------ = 1 – --------- ,( 6 ) R3 RL with Ro the synthesized impedance and Iout the output current. On the other hand Vo can be expressed as: 2R2 R2 Vi  1 + ---------- + ------   R 1 R 3 Rs 1 Iout Vo = ---------------------------------------------- – --------------------- ,( 3 ) R2 R2 1 – -----1 – -----R3 R3 By fixing an arbitrary value for R2, (6) gives: R2 R 3 = ------------------2 Rs 1 – --------RL Finally, the values of R2 and R3 allow us to extract R1 from (1), and it comes: 2R2 R 1 = --------------------------------------------------------- ,( 7 ) R 2 R2 2  1 – ------ GL – 1 – ----- R 3 R3 with GL the required gain. GL (gain for the loaded system) R1 R2 (=R4) R3 (=R5) Rs GL is fixed for the application requirements GL=Vo/Vi=0.5(1+2R2/R1+R2/R3)/(1-R2/R3) 2R2/[2(1-R2/R3)GL-1-R2/R3] Abritrary fixed R2/(1-Rs/0.5RL) 0.5RL(k-1) 7/10 TS635 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 maximum amplitude level on the line regarding the TS635 maximum output capabilities (18Vpp diff.) and a 1:2 line transformer ratio. Active matching R1 (Ω) 820 490 360 270 240 Passive R3 (Ω) Rs (Ω) TS635 Output Level to get 12.4Vpp on the line (Vpp diff) 8 8.7 9.3 9.9 10.5 12.4 Maximum Line level (Vpp diff) 27.5 25.7 25.3 23.7 22.3 18 MEASUREMENT OF THE POWER CONSUMPTION Conditions: Power Supply: 12V 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 TS635 power consumption during emission on 900 and 4550 meter twisted pair telephone lines: 360mW k 1.3 1.4 1.5 1.6 1.7 1500 3.9 1600 5.1 2200 6.2 2400 7.5 3300 9.1 matching 8/10 TS635 PACKAGE MECHANICAL DATA 8 PINS - PLASTIC MICROPACKAGE (SO) Millimeters Dim. Min. A a1 a2 a3 b b1 C c1 D E e e3 F L M S 0.1 0.65 0.35 0.19 0.25 4.8 5.8 1.27 3.81 3.8 0.4 4.0 1.27 0.6 8° (max.) 0.150 0.016 Typ. Max. 1.75 0.25 1.65 0.85 0.48 0.25 0.5 45° (typ.) 5.0 6.2 0.189 0.228 Min. 0.004 0.026 0.014 0.007 0.010 Inches Typ. Max. 0.069 0.010 0.065 0.033 0.019 0.010 0.020 0.197 0.244 0.050 0.150 0.157 0.050 0.024 9/10 TS635 PACKAGE MECHANICAL DATA 8 PINS - PLASTIC MICROPACKAGE (SO Exposed-Pad) Millimeters Dim. Min. A A1 A2 B C D E e H h L k ddd 1.350 0.000 1.100 0.330 0.190 4.800 3.800 1.270 5.800 0.250 0.400 0d 6.200 0.500 1.270 8d 0.100 0.228 0.010 0.016 0d Typ. Max. 1.750 0.250 1.650 0.510 0.250 5.000 4.000 Min. 0.053 0.001 0.043 0.013 0.007 0.189 0.150 Inches Typ. Max. 0.069 0.010 0.065 0.020 0.010 0.197 0.157 0.050 0.244 0.020 0.050 8d 0.004 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 © 2002 STMicroelectronics - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco Singapore - Spain - Sweden - Switzerland - United Kingdom http://www.st.com 10/10