LTC6409 Linear Technology, LTC6409 Datasheet
LTC6409
Available stocks
Related parts for LTC6409
LTC6409 Summary of contents
Page 1
... For example, the amplifier could be externally compensated in a no-overshoot configuration, which is desired in certain time-domain applications. The LTC6409 is stable in a differential gain of 1. This al- lows for a low output noise in applications where gain is not desired. It draws 52mA of supply current and has a hardware shutdown feature which reduces current con- sumption to 100µ ...
Page 2
... TAPE AND REEL LTC6409CUDB#TRMPBF LTC6409CUDB#TRPBF LTC6409IUDB#TRMPBF LTC6409IUDB#TRPBF LTC6409HUDB#TRMPBF LTC6409HUDB#TRPBF TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on lead based finish parts. ...
Page 3
... 5V –20mA 3V, 5V 3V, 5V 20mA ≤ 0.6V SHDN 0.5V SHDN LTC6409 = 1.25V open OCM ICM SHDN + V )/ defined as (V +IN –IN OUTDIFF +OUT MIN TYP ...
Page 4
... The LTC6409C is designed, characterized and expected to meet specified performance from –40°C to 85°C, but is not tested or QA sampled at these temperatures. The LTC6409I is guaranteed to meet specified performance from –40°C to 85°C. The LTC6409H is guaranteed to meet specified performance from –40°C to 125°C. ...
Page 5
... INPUT COMMON MODE VOLTAGE (V) 6409 G01 Supply Current vs SHDN Voltage 5.5 0 0.5 1 1.5 2 2.5 3 SHDN VOLTAGE (V) 6409 G04 LTC6409 Common Mode Offset Voltage vs Temperature 2 OCM FIVE REPRESENTATIVE UNITS 1.0 0 85° 70° 25°C 0 ...
Page 6
... LTC6409 Typical perForMance characTerisTics Differential Output Voltage Noise vs Frequency 1000 150 I F INCLUDES 100 FREQUENCY (Hz) CMRR vs Frequency 100 1.25V OCM 150 , C = 1.3pF 0.1% FEEDBACK NETWORK RESISTORS 100 1000 FREQUENCY (MHz) Large Signal Step Response 0 ...
Page 7
... R = 150 I F – OUTDIFF P-P DIFFERENTIAL INPUTS –60 –70 –80 HD3 –90 –100 –110 1000 0.5 1 1.5 2 2.5 OUTPUT COMMON MODE VOLTAGE (V) 6409 G19 LTC6409 Frequency Response vs Load Capacitance 0pF 0.5pF 1pF 1.5pF 2pF L 0 – ...
Page 8
... FuncTions +IN, –IN (Pins 2, 6): Non-Inverting and Inverting Input Pins. SHDN (Pin 3): When SHDN is floating or directly tied the LTC6409 is in the normal (active) operating mode. When the SHDN pin is connected to V and draws approximately 100µA of supply current. www.DataSheet4U.com + – ...
Page 9
... IC. SHDN Pin The SHDN pin is a CMOS logic input with a 150k internal pull-up resistor. If the pin is driven low, the LTC6409 pow- ers down. If the pin is left unconnected or driven high, the part is in normal active operation. Some care should be taken to control leakage currents at this pin to prevent inadvertently putting the LTC6409 into shutdown ...
Page 10
... The Electrical Characteristics table specifies the OCM valid range that can be applied to the V Input Common Mode Voltage Range The LTC6409’s input common mode voltage (V www.DataSheet4U.com defined as the average of the two input pins The valid range that can be used for V – ...
Page 11
... Feedback factor mismatch from using 1% resistors or better, has a negligible effect on distortion. However, in single supply level shifting applications where I2 there is a voltage difference between the input common + R F2 mode voltage and the output common mode voltage, LTC6409 + INP – ...
Page 12
... Equation (3): V ≈ (V – V OSDIFF(APPARENT) CM OCM Using the LTC6409 in a single 5V supply application with 0.1% resistors, the input common mode grounded, and the V pin biased at 1.25V, the worst case mismatch OCM can induce 1.25mV of apparent offset voltage. Noise and Noise Figure The LTC6409’ ...
Page 13
... Figure 7 specifies the measured total output noise ( OCM no excluding the noise contribution of source resistance, and – noise figure (NF) of LTC6409 configured at closed loop gains (A the left column use termination resistors and transform ers to match to the 50Ω source resistance, while the nRF R F circuits in the right column do not have such matching ...
Page 14
... V IN 100 Figure 7. LTC6409 Measured Output Noise and Noise Figure at Different Closed Loop Gains with and without Source Impedance Matching the input of the ADC to 50Ω can actually be detrimental to system performance. The definition of 3rd order intermodulation distortion (IMD3) is shown in Figure 8. Also, a graphical repre- ...
Page 15
... S www.DataSheet4U.com LOSS Figure 10. Equivalent Schematic of the Top Half of the LTC6409 Demo Board results in a lower intercept point. Therefore impor- tant to consider the impedance seen by the output of the LTC6409 when working with intercept points. Comparing linearity specifications between different am- IMD3 = P – ...
Page 16
... LTC6409. GBW vs f –3dB Gain-bandwidth product (GBW) and –3dB frequency (f have been both specified in the Electrical Characteristics table as two different metrics for the speed of the LTC6409. GBW is obtained by measuring the gain of the amplifier at a specific frequency (f ) and calculate gain • f TEST To measure gain, the feedback factor (i ...
Page 17
... ADC decouples the sampling transient of the ADC (see Figure 11). The capacitance serves to provide the bulk of the charge during the sampling process, while the two resistors at the outputs of the LTC6409 are used to dampen and attenuate any charge injected by the ADC. The RC filter gives the additional benefit of band limiting broadband output noise ...
Page 18
... V IN 150 150 2 +IN SHDN SHDN 0.1µF||1000pF V OCM 5 0.1µF –IN 6 150 150 www.DataSheet4U.com 18 1.3pF 33.2 1 –OUT LTC6409 – V – 0.1µF||1000pF + + OCM – 0.1µF||1000pF – V – +OUT 7 6409 F11 33.2 1.3pF Figure 11. Driving an ADC CONTROL ...
Page 19
... R40 +OUT –IN – – V OPT SHDN – C17 1.3pF R29 150 , 0.1% Figure 12. Demo Board DC1591A Schematic LTC6409 T2 TCM4-19 4:1 C18 R3 XFMR MINI-CIRCUITS 0.1µF 100 –OUT P C29 C19 0.1µ 0.1µ +OUT – ...
Page 20
... LTC6409 applicaTions inForMaTion www.DataSheet4U.com 20 Figure 13. Demo Board DC1591A Layout 6409fa ...
Page 21
... Typical applicaTions LT5575 1900MHz –10dBm 200mV P-P LO 1920MHz 0dBm Q Single-Ended to Differential Conversion Using LTC6409 and 50MHz Lowpass Filter (Only One Channel Shown) 3.3V 0.8pF 0.1µF 150 474 INPUT 66 +IN –OUT + LTC6409 –IN – +OUT 150 474 SHDN 0.8pF 49.9 66.5 GND www.DataSheet4U.com DC-Coupled Level Shifting of an I/Q Demodulator Output ...
Page 22
... LTC6409 package DescripTion 2.50 ±0.05 1.10 ±0.05 0.75 ±0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 0.20 REF www.DataSheet4U.com 22 UDB Package 10-Lead Plastic QFN (3mm × 2mm) (Reference LTC DWG # 05-08-1848 Rev A) 0.95 ± 0.05 0.65 ±0.05 DETAIL B PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 0.85 ± 0.05 3.50 ±0.05 0.40 ± 0.10 0.80 2.00 ± 0.05 BSC 0.50 ± 0.10 3.00 ± 0.05 0.25 ± ...
Page 23
... Revised Typical Application drawing www.DataSheet4U.com Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC6409 PAGE NUMBER 21 6409fa 23 ...
Page 24
... LTC6409 Typical applicaTions LTC6409 Externally Compensated for Maximum Gain Flatness and for No-Overshoot Time-Domain Response 1/2 AGILENT 0.1µF 75 E5071A 150 PORT 1.25V 0.1µF OCM PORT 2 150 50 75 0.1µ 1.25V 0.1µF OCM 0.4V – V P-P IN 49.9 relaTeD parTs PART NUMBER DESCRIPTION LTC6400-8/LTC6400-14/ 1.8GHz Low Noise, Low Distortion, Differential ADC Drivers – ...