LMH6503 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – Wideband, Low Power, Linear Variable Gain Amplifier

June 2004
LMH6503
Wideband, Low Power, Linear Variable Gain Amplifier
General Description
The LMH™6503 is a wideband DC coupled differential input
voltage controlled gain stage followed by a high-speed cur-
rent feedback Op Amp which can directly drive a low imped-
ance load. Gain adjustment range is more than 70dB for up
to 10MHz.
Maximum gain is set by external components and the gain
can be reduced all the way to cut-off. Power consumption is
370mW with a speed of 135MHz . Output referred DC offset
voltage is less than 350mV over the entire gain control
voltage range. Device-to-device Gain matching is within
0.7dB at maximum gain. Furthermore, gain at any V_G is
tested and the tolerance is guaranteed. The output current
feedback Op Amp allows high frequency large signals (Slew
Rate = 1800V/µs) and can also drive heavy load current
(75mA). Differential inputs allow common mode rejection in
low level amplification or in applications where signals are
carried over relatively long wires. For single ended opera-
tion, the unused input can easily be tied to ground (or to a
virtual half-supply in single supply application). Inverting or
non-inverting gains could be obtained by choosing one input
polarity or the other.
To further increase versatility when used in a single supply
application, gain control range is set to be from −1V to +1V
relative to pin 11 potential (ground pin). In single supply
operation, this ground pin is tied to a "virtual" half supply.
Gain control pin has high input impedance to simplify its
drive requirement. Gain control is linear in V/V throughout
the gain adjustment range. Maximum gain can be set to be
anywhere between 1V/V to 100V/V or higher. For linear in dB
gain control applications, see LMH6502 datasheet.
The LMH6503 is available in the SOIC-14 and TSSOP-14
package.
Features
V_S = ±5V, T_A = 25˚C, R_F = 1kΩ, R_G = 174Ω, R_L = 100Ω, A_V
= A_V(MAX) = 10, Typical values unless specified.
n -3dB BW
135MHz
n Gain control BW
100MHz
n Adjustment range (typical over temp)
70dB
n Gain matching (limit)
±0.7dB
n Slew rate
1800V/µs
n Supply current (no load)
37mA
n Linear output current
±75mA
n Output voltage (R_L = 100Ω)
±3.2V
n Input voltage noise
6.6nV/
n Input current noise
2.4pA/
n THD (20MHz, R_L = 100Ω, V_O = 2V_PP)
−57dBc
n Replacement for CLC522
Applications
n Variable attenuator
n AGC
n Voltage controller filter
n Multiplier
Typical Application
20073913
Gain vs. V_G for Various Temperature
LMH™ is a trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS200739
A_VMAX = 10V/V
20073933
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