13

EL5210C/EL5410C

30MHz Rail-to-Rail Input-Output Op Amps

Figure 3. Package Power Dissipation vs

Ambient Temperature

Figure 4. Package Power Dissipation vs

Ambient Temperature

Unused Amplifiers

It is recommended that any unused amplifiers in a dual

and a quad package be configured as a unity gain fol-

lower. The inverting input should be directly connected

to the output and the non-inverting input tied to the

ground plane.

Driving Capacitive Loads

The EL5210C and EL5410C can drive a wide range of

capacitive loads. As load capacitance increases, how-

ever, the -3dB bandwidth of the device will decrease and

the peaking increase. The amplifiers drive 10pF loads in

parallel with 1k

Ω with just 1.2dB of peaking, and 100pF

with 6.5dB of peaking. If less peaking is desired in these

applications, a small series resistor (usually between 5

Ω

and 50

Ω) can be placed in series with the output. How-

ever, this will obviously reduce the gain slightly.

Another method of reducing peaking is to add a "snub-

ber" circuit at the output. A snubber is a shunt load

consisting of a resistor in series with a capacitor. Values

of 150

Ω and 10nF are typical. The advantage of a snub-

ber is that it does not draw any DC load current or

reduce the gain

Power Supply Bypassing and Printed Circuit

Board Layout

The EL5210C and EL5410C can provide gain at high

frequency. As with any high-frequency device, good

printed circuit board layout is necessary for optimum

performance. Ground plane construction is highly rec-

ommended, lead lengths should be as short as possible

and the power supply pins must be well bypassed to

reduce the risk of oscillation. For normal single supply

be connected in parallel, placed in the region of the

amplifier. One 4.7µF capacitor may be used for multiple

devices. This same capacitor combination should be

placed at each supply pin to ground if split supplies are

to be used.

50

150

400

800

Ambient Temperature (°C)

0

100

0

1200

25

75

1000

600

200

125

85

TSSOP14

SO8

Packages Mounted on a JEDEC JESD51-7 High

Effective Thermal Conductivity Test Board

1.0W

1.136W

909mW

833mW

SO14

MSOP8

50

150

400

800

Ambient Temperature (°C)

0

100

0

125

1200

25

75

1000

600

200

85

TSSOP14

SO8

MSOP8

SO14

Packages Mounted on a JEDEC JESD51-3 Low

Effective Thermal Conductivity Test Board

833mW

606mW

625mW

485mW