lt1739 Linear Technology Corporation, lt1739 Datasheet
lt1739
Available stocks
Related parts for lt1739
lt1739 Summary of contents
Page 1
... Short-circuit protection and thermal shutdown insure the device’s ruggedness. The outputs drive a 100 supplies, and 10.9V with a 250mA load. The LT1739 is a pin-for-pin replacement for the LT1794 in xDSL line driver applications and requires no circuit changes. The LT1739 is available in the very small, thermally ...
Page 2
... B 12-LEAD (4mm 3mm) PLASTIC DFN T = 125 C, JMAX UNDERSIDE METAL CONNECTED 0V 24.9k between V SHDNREF BIAS CONDITIONS f = 10kHz f = 10kHz ORDER PART NUMBER TOP VIEW LT1739CUE – LT1739IUE 2 11 OUT OUT B UE PART – MARKING UE12 PACKAGE ...
Page 3
... Note 3: The LT1739C is guaranteed to meet specified performance from and is designed, characterized and expected to meet these extended temperature limits, but is not tested at – The LT1739I is guaranteed to meet the extended temperature limits. Note 4: Thermal resistance varies depending upon the amount of PC board metal attached to the device and rate of air flow over the device ...
Page 4
... LT1739 W U TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Ambient Temperature 12V 24.9k TO SHDN BIAS SHDNREF –50 –30 – TEMPERATURE ( C) 1739 G01 Input Noise Spectral Density 100 12V S I PER AMPLIFIER = 10mA ...
Page 5
... Frequency –40 –45 –50 –55 –60 HD3 –65 –70 –75 HD2 –80 –85 – 100 1739 G16 LT1739 Frequency Response vs Supply Current 12V 2mA PER AMPLIFIER 10 10mA PER AMPLIFIER 5 15mA PER AMPLIFIER 0 –5 –10 –15 – ...
Page 6
... LT1739 W U TYPICAL PERFOR A CE CHARACTERISTICS Differential Harmonic Distortion vs Supply Current –40 –45 –50 – 1MHz, HD3 –60 – 100kHz, HD2 –70 – 100kHz, HD3 – 1MHz, HD2 – PER AMPLIFIER (mA) SUPPLY TEST CIRCUIT OUT (+) E SPLITTER IN OUT (–) 49 ...
Page 7
... The LT1739 is a high speed, 200MHz gain bandwidth product, dual voltage feedback amplifier with high output current drive capability, 500mA source and sink. The LT1739 is ideal for use as a line driver in xDSL data communication applications. The output voltage swing has been optimized to provide sufficient headroom when operating from 12V power supplies in full-rate ADSL applications ...
Page 8
... Figure 5 complete shutdown occurs in less than 10 s and, more importantly, complete recovery from the shut down output impedance to state to full operation occurs in less than 2 s. The biasing circuitry in the LT1739 reacts very quickly to bring the amplifiers back to normal operation. V SHDN SHDNREF = 0V ...
Page 9
... The quiescent current for the LT1739 is set to 10mA per amplifier. The power dissipated in the LT1739 is a combination of the quiescent power and the output stage power when driving a signal. The two amplifiers are configured to place a differential signal on to the line ...
Page 10
... AMBIENT D(FULL) is the thermal resistance from the junction of the JA LT1739 to the ambient air, which can be minimized by heat-spreading PCB metal and airflow through the enclo- sure as required. For the example given, assuming a maximum ambient temperature and keeping the junction temperature of the LT1739 to 140 C maximum, ...
Page 11
... Laminar Airflow Over the Device 0 % REDUCTION RELATIVE TO IN STILL AIR JA –10 –20 –30 –40 –50 –60 0 100 200 300 400 500 600 700 800 AIRFLOW (LINEAR FEET PER MINUTE, lfpm) 3RD LAYER BOTTOM LAYER 1739 F08a 900 1000 1739 F08b LT1739 1739fas, sn1739 11 ...
Page 12
... In general, use feedback resistors less. Compensation The LT1739 is stable in a gain 10 or higher for any supply and resistive load easily compensated for lower gains with a single resistor or a resistor plus a capacitor. ...
Page 13
... – FOR – /( 1 – LT1739 / 1739 F13 1739 F14 1739fas, sn1739 13 ...
Page 14
... DC resistance of the transformer primary. This high current can possibly cause the power supply voltage source to drop significantly impacting overall system performance. If left unchecked, the high DC current can heat the LT1739 to thermal shutdown. resistors, reducing the sensed amplitude. BT ...
Page 15
... While the LT1739 has clamps to the supply rails at the output pins, they may not be large enough to handle the significant transient energy. External clamping diodes, such as BAV99s, at each end of the transformer primary ® ...
Page 16
... DRV (–) 8 R26 OPT C17 R9 OPT 2 9 10k E10 ON/OFF R13 10k 6 3 E11 V C0NTROL R18 10k 2 V BIAS Figure 17. LT1739, LT1361 ADSL Demo Board (DC306A- 15.4 1/ 2010 U2A 18 2 LT1739CFE 5 – COILCRAFT EE X8504 ...
Page 17
... PLIFIED SCHE ATIC + V –IN – V (one amplifier shown) Q9 Q10 Q12 Q11 LT1739 Q13 Q17 C1 Q14 +IN OUT Q15 C2 Q18 Q16 1739 SS 1739fas, sn1739 17 ...
Page 18
... LT1739 PACKAGE DESCRIPTIO 6.60 0.10 4.50 0.10 SEE NOTE 4 RECOMMENDED SOLDER PAD LAYOUT 4.30 – 4.50* (.169 – .177) 0.45 – 0.75 0.09 – 0.20 (.018 – .030) (.0036 – .0079) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS 2. DIMENSIONS ARE IN 3. DRAWING NOT TO SCALE Package 20-Lead Plastic TSSOP (4.4mm) (Reference LTC DWG # 05-08-1663) Exposed Pad Variation CA 4 ...
Page 19
... U UE12 Package 12-Lead Plastic DFN (3mm 4mm) (Reference LTC DWG # 05-08-1695) 0.58 0.05 0.50 BSC 3.30 0.05 (2 SIDES) 4.00 0.10 (2 SIDES 0.20 TYP 3.00 0.10 1.70 0.10 (2 SIDES) (2 SIDES) 0.75 0.05 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD R = 0.115 0.38 0.10 TYP 7 12 PIN 1 NOTCH (UE12) DFN 0102 6 1 0.23 0.05 0.50 BSC 3.30 0.10 (2 SIDES) LT1739 1739fas, sn1739 19 ...
Page 20
... X8502-A OR EQUIVALENT – 1W DRIVER POWER DISSIPATION 13.7 1/2 1.15W POWER CONSUMPTION LT1739 SHDNREF + –12V COMMENTS 15V Operation, 1mV V ADSL CO Driver, Extended Output Swing, Low Power Shutdown/Current Set Function, ADSL CO Driver Low Noise, Low Power Differential Receiver, 4mA/Amplifier 12V Operation, 7mA/Amplifier, ADSL Modem Line Driver ...