®

OPA602

7

COMMON-MODE REJECTION

vs FREQUENCY

140

1

Frequency (Hz)

10

100

1k

10k

100k

1M

10M

120

100

80

60

40

20

0

POWER SUPPLY REJECTION

vs FREQUENCY

140

1

Frequency (Hz)

10

100

1k

10k

100k

1M

10M

120

100

80

60

40

20

0

+

–

BIAS AND OFFSET CURRENT

vs INPUT COMMON MODE VOLTAGE

10

1

0.1

0.01

–15

Common-Mode Voltage (V)

10

1

0.1

0.01

–10

–5

0

5

10

15

Bias Current

Offset Current

BIAS AND OFFSET CURRENT

vs TEMPERATURE

10nA

–50

Ambient Temperature (°C)

10nA

–25

0

25

50

75

100

125

1nA

100

10

1

0.1

1nA

100

10

1

0.1

APPLICATIONS INFORMATION

Unity-gain stability with good phase margin and excellent

output drive characteristics bring freedom from the subtle

problems associated with other high speed amplifiers. But

with any high speed, wide bandwidth circuitry, careful

circuit layout will ensure best performance. Make short,

direct interconnections and avoid stray wiring capacitance—

especially at the inverting input pin.

Power supplies should be bypassed with good high fre-

quency capacitors positioned close to the op amp pins. In

most cases 0.1

µF ceramic capacitors are adequate. Applica-

tions with heavier loads and fast transient waveforms may

benefit from use of additional 1.0

µF tantalum bypass capaci-

tors.

INPUT BIAS CURRENT GUARDING

Leakage currents across printed circuit boards can easily

exceed the input bias current of the OPA602. A circuit board

“guard” pattern (Figure 1) is an effective solution to difficult

leakage problems. This guard pattern must be repeated on all

layers of a multilayer board. By surrounding critical high

impedance input circuitry with a low impedance circuit

connection at the same potential, leakage currents will flow

harmlessly to the low impedance node.

Input bias current may also be degraded by improper han-

dling or cleaning. Contamination from handling parts and

circuit boards may be cleaned with appropriate solvents and

deionized water. Each rinsing operation should be followed

by a 30-minute bake at +85

°C.