Datasheet LTC6406 (Analog Devices) - 10

LTC6406
TYPICAL PERFORMANCE CHARACTERISTICS (MSOP Package) Harmonic Distortion Harmonic Distortion Harmonic Distortion vs Frequency vs Input Common Mode Voltage vs Input Amplitude
–30 –40 –40 VS = 3V VS = 3V V –40 VOCM = VICM = 1.25V OCM = VICM =1.25V R f LOAD = 800Ω –50 –50 IN = 50MHz V R –50 OUTDIFF = 2VP-P LOAD = 800Ω SINGLE-ENDED INPUT RI = RF = 500Ω 2ND –60 –60 SINGLE-ENDED INPUT –60 2ND TION (dBc) –70 TION (dBc) –70 TION (dBc) –70 3RD VS = 3V –80 3RD VOCM = 1.25V DISTOR DISTOR –80 –80 f DISTOR IN = 50MHz –90 2ND, RI = RF = 150Ω RLOAD = 800Ω 2ND, RI = RF = 500Ω –90 RI = RF = 500Ω –90 –100 3RD, RI = RF = 150Ω VOUTDIFF = 2VP-P 3RD, RI = RF = 500Ω SINGLE-ENDED INPUT –110 –100 –100 10 10 100 0 0.5 1.0 1.5 2.0 2.5 3.0 –4 –2 0 2 4 6 8 10 FREQUENCY (MHz) INPUT COMMON MODE VOLTAGE (V) (0.4VP-P) INPUT AMPLITUDE (dBm) (2VP-P) 6406 G34 6406 G35 6406 G36
PIN FUNCTIONS (QFN/MSOP) SHDN (Pin 1/Pin 7):
When SHDN is fl oating or directly voltages on the +OUT and –OUT pins). The VOCM voltage tied to V+, the LTC6406 is in the normal (active) operat- is internally set by a resistive divider between the supplies, ing mode. When the SHDN pin is connected to V–, the developing a default voltage potential of 1.25V with a 3V LTC6406 enters into a low power shutdown state with supply. The VOCM pin can be overdriven by an external Hi-Z outputs. voltage capable of driving the 18kΩ Thevenin equivalent impedance presented by the pin. The V
V+, V– (Pins 2, 10, 11 and Pins 3, 9, 12/Pins 3, 6):
Power OCM pin should be bypassed with a high quality ceramic bypass capacitor of at Supply Pins. It is critical that close attention be paid to least 0.01μF, to minimize common mode noise from being supply bypassing. For single supply applications it is converted to differential noise by impedance mismatches recommended that a high quality 0.1μF surface mount both externally and internally to the IC. ceramic bypass capacitor be placed between V+ and V– with direct short connections. In addition, V– should be tied
VTIP (Pin 5/NA):
This pin can normally be left fl oating. directly to a low impedance ground plane with minimal It determines which pair of input transistors (NPN or routing. For dual (split) power supplies, it is recommended PNP or both) is sensing the input signal. The VTIP pin is that additional high quality, 0.1μF ceramic capacitors are set by an internal resistive divider between the supplies, used to bypass V+ to ground and V– to ground, again developing a default 1.55V voltage with a 3V supply. VTIP with minimal routing. For driving large loads (<200Ω), has a Thevenin equivalent resistance of approximately additional bypass capacitance may be needed for optimal 15k and can be overdriven by an external voltage. The performance. Keep in mind that small geometry (e.g. 0603 VTIP pin should be bypassed with a high quality ceramic or smaller) surface mount ceramic capacitors have a much bypass capacitor of at least 0.01μF. See the Applications higher self resonant frequency than do leaded capacitors, Information section for more details. and perform best in high speed applications.
+OUT, –OUT (Pins 7, 14/Pins 4, 5):
Unfi ltered Output
VOCM (Pin 4/Pin 2):
Output Common Mode Reference Pins. Besides driving the feedback network, each pin Voltage. The voltage on VOCM sets the output common can drive an additional 50Ω to ground with typical short- mode voltage level (which is defi ned as the average of the circuit current limiting of ±55mA. Each amplifi er output 6406fc 10