7

LT1460S3 (SOT-23)

Longer Battery Life

Series references have a large advantage over older shunt

style references. Shunt references require a resistor from

the power supply to operate. This resistor must be chosen

to supply the maximum current that can ever be

demanded by the circuit being regulated. When the circuit

being controlled is not operating at this maximum current,

the shunt reference must always sink this current, result-

ing in high dissipation and short battery life.

The LT1460S3 series references do not require a current

setting resistor and can operate with any supply voltage

lated does not demand current, the LT1460S3s reduce

their dissipation and battery life is extended. If the refer-

ences are not delivering load current, they dissipate only

several mW, yet the same connection can deliver 20mA of

load current when demanded.

Capacitive Loads

The LT1460S3 family of references are designed to be

stable with a large range of capacitive loads. With no

LT1460S3s. Curves from the LT1460S3-2.5 and the LT1460-10 represent the extremes of the voltage options. Characteristic curves for

other output voltages fall between these curves, and can be estimated based on their voltage output.

10V Output Noise 0.1Hz to 10Hz

TIME (2 SEC/DIV)

1460S3 G22

capacitive load, these references are ideal for fast settling

or applications where PC board space is a premium. The

test circuit shown in Figure 1 is used to measure the

response time and stability of various load currents and

load capacitors. This circuit is set for the 2.5V option. For

other voltage options, the input voltage must be scaled up

and the output voltage generator offset voltage must be

adjusted. The 1V step from 2.5V to 1.5V produces a

Figure 2 shows the response of the reference to these 1mA

and 10mA load steps with no load capacitance, and Figure

3 shows a 1mA and 10mA load step with a 0.1

µF output

capacitor. Figure 4 shows the response to a 1mA load step

LT1460S3-2.5

1460S3 F01

0.1

µF

2.5V

1.5V

Figure 1. Response Time Test Circuit

10V Output Voltage

Noise Spectrum

FREQUENCY (kHz)

0.01

0.1

1

10

110

0.1

100

1460S3 G10