Datasheet MAX4100, MAX4101 (Maxim) - 8

500MHz, Low-Power Op Amps _______________Detailed Description
Regardless of whether a constant-impedance board is used, it is best to observe the following guidelines The MAX4100/MAX4101 are low-power, high-bandwidth when designing the board. Wire-wrap boards are much operational amplifiers optimized for driving back-termi- too inductive, and breadboards are much too capaci- nated cables in composite video, RGB, and RF systems. tive; neither should be used. IC sockets increase para- The MAX4100 is unity-gain stable, and the MAX4101 is sitic capacitance and inductance, and should not be optimized for closed-loop gains greater than or equal to used. In general, surface-mount components give bet- 2V/V (AVCL ≥ 2V/V). While consuming only 5mA (6mA ter high-frequency performance than through-hole max) supply current, both devices can drive 50Ω back- components. They have shorter leads and lower para- terminated cables to ±3.1V minimum. sitic reactances. Keep lines as short and as straight as The MAX4100 features a bandwidth in excess of 500MHz possible. Do not make 90° turns; round all corners. and a 0.1dB gain flatness of 65MHz. It offers differential High-frequency bypassing techniques must be observed gain and phase errors of 0.06%/0.04°, respectively. The to maintain the amplifier accuracy. The bypass capaci- MAX4101 features a -3dB bandwidth of 200MHz, a 0.1dB tors should include a 1000pF ceramic capacitor between bandwidth of 50MHz, and 0.07%/0.04° differential gain each supply pin and the ground plane, located as close and phase. to the package as possible. Next, place a 0.01µF to Available in small 8-pin SO and µMAX packages, these 0.1µF ceramic capacitor in parallel with each 1000pF ICs are ideally suited for use in portable systems (in
MAX4100/MAX4101
capacitor, and as close to each as possible. Then place RGB, broadcast, or consumer video applications) that a 10µF to 15µF low-ESR tantalum at the point of entry (to benefit from low power consumption. the PC board) of the power-supply pins. The power-sup-
__________Applications Information
ply trace should lead directly from the tantalum capacitor to the VCC and VEE pins. To minimize parasitic induc-
Layout and Power-Supply Bypassing
tance, keep PC traces short and use surface-mount The MAX4100/MAX4101 have an RF bandwidth and, components. consequently, require careful board layout. Depending on the size of the PC board used and the frequency of operation, it may be desirable to use constant-imped- RG R ance microstrip or stripline techniques. F To realize the full AC performance of this high-speed amplifier, pay careful attention to power-supply bypass- ing and board layout. The PC board should have at least two layers: a signal and power layer on one side, MAX4100 VOUT and a large, low-impedance ground plane on the other MAX4101 side. The ground plane should be as free of voids as VIN possible. With multilayer boards, locate the ground plane on a layer that incorporates no signal or power VOUT = [1 + (RF / RG)]VIN traces. Figure 1b. Noninverting Gain Configuration RG RF 24Ω VIN MAX4100 VOUT MAX4100 VOUT MAX4101 MAX4101 VIN VOUT = (RF / RG)VIN VOUT = VIN Figure 1a. Inverting Gain Configuration Figure 1c. MAX4100 Unity-Gain Buffer Configuration
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