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11/12/98

SPT9110

GENERAL DESCRIPTION

The SPT9110 is a low cost 100 MSPS track-and-hold ampli-

fier with single ended (75 mW) or differential output (120 mW).

It consists of three components. The first is a single-ended

track-and-hold amplifier (THA) with a 1.5 to 3.5 V input range

and PECL clock inputs. The second is an inverting op amp

with gain of -1 to provide the differential output (OUT-). The

third component is a 2.5 V bandgap reference for the inverter.

PARTITIONED POWER SUPPLY MANAGEMENT

Three separate +5 V supply connections power the THA,

inverting the op amp and bandgap reference. Unused com-

ponents can be powered off to minimize power dissipation.

The single-ended mode requires use of only the THA and

output on the OUT+ pin. In this mode the reference and

inverter may be powered down.

The differential mode requires use of all three components

(unless an external reference is supplied). The output is

measured between OUT+ and OUT- in this mode.

Figure 2 - Typical Output Response to Step Input

1.0 ns/Division

Out+ — Out-

Out+

Inp ut

Out-