General Description

The KM7101 is single supply, general purpose,voltage-

feedback amplifier that is pin-for-pin compatible with

the National Semiconductor LMC7101. The KM7101

is fabricated on a complementary bipolar process,

features a rail-to-rail input and output, and is unity

gain stable.

The typical non-inverting circuit schematic is shown in

Figure 1.

Figure 1: Typical Non-inverting Configuration

Input Common Mode Voltage

The common mode input range extends to 250mV

below ground and to 250mV above Vs, in single supply

operation. Exceeding these values will not cause

phase reversal. However, if the input voltage exceeds

the rails by more than 0.5V, the input ESD devices will

begin to conduct. The output will stay at the rail during

this overdrive condition.

If the absolute maximum

input voltage (700mV beyond either rail) is exceeded,

externally limit the input current to ±5mA as shown in

Figure 2.

Figure 2: Circuit for Input Current Protection

Power Dissipation

The maximum internal power dissipation allowed is

directly related to the maximum junction temperature.

If the maximum junction temperature exceeds 150°C,

some performance degradation will occur. It the max-

imum junction temperature exceeds 175°C for an

extended time, device failure may occur.

Overdrive Recovery

Overdrive of an amplifier occurs when the output

and/or input ranges are exceeded. The recovery time

varies based on whether the input or output is over-

driven and by how much the ranges are exceeded.

The KM7101 will typically recover in less than 50ns

from an overdrive condition.

Figure 3 shows the

KM7101 in an overdriven condition.

Figure 3: Overdrive Recovery

Driving Capacitive Loads

at the output of the amplifier, illustrated in Figure 4,

will improve stability and settling performance.

chosen to achieve maximum bandwidth with less than

2dB of peaking. For maximum flatness, use a larger

a 50pF capacitive load without a series resistance.

Figure 4: Typical Topology for driving

a capacitive load

Driving a capacitive load introduces phase-lag into

the output signal, which reduces phase margin in the

amplifier. The unity gain follower is the most sensitive

configuration. In a unity gain follower configuration,

the KM7101 requires a 510

Ω series resistor to drive a

100pF load.

+

-

KM7101

0.01

µF

6.8

µF

Out

In

+

Time (10

µs/div)

Output

Input

G = 5

-

+

10k

Ω

KM7101

+

-

DATA SHEET

KM7101

6

REV. 1B March 2001