7

LTC1443/LTC1444/LTC1445

OUT D (Pin 15): Comparator D Output. (Open-drain

output for LTC1444). Output can source up to 40mA

(LTC1443, LTC1445) and sink 5mA.

OUT C (Pin 16): Comparator C Output. (Open-drain output

for LTC1444). Output can source up to 40mA (LTC1443,

LTC1445) and sink 5mA.

The LTC1443/LTC1444/LTC1445 is a family of quad

micropower comparators with a built-in reference (1.182V

for the LTC1443 and 1.221V for the LTC1444/LTC1445).

Features include programmable hysteresis (LTC1444/

LTC1445), wide supply voltage range (2V to 11V) and the

ability of the reference to drive up to a 0.01

µF capacitor

without oscillation. The comparator CMOS outputs

(LTC1443/LTC1445) can source up to 40mA while the

current glitches that normally occur when the comparator

output switches states have been eliminated.

Power Supplies

The comparator family operates from a single 2V to 11V

supply. The LTC1443 includes a separate ground for the

comparator output stage, allowing a split supply ranging

from

allows single supply operation. If the comparator output

is required to source more than 1mA or the supply source

µF

capacitor.

Comparator Inputs

The comparator inputs can swing from the negative sup-

is only

±10pA.

Comparator Outputs

The LTC1443 comparator output swings between GND

The outputs are capable of sourcing up to 40mA (LTC1443/

LTC1445) and sinking up to 5mA while still maintaining

microampere quiescent currents. The output stage does

not generate crowbar switching currents during transi-

tions which helps minimize parasitic feedback through the

supply pins.

Voltage Reference

The internal bandgap reference has a voltage of 1.182V for

LTC1443 or 1.221V for LTC1444/LTC1445 referenced to

°C to 85°C.

It can source up to 200

µA and sink up to 15µA with a 5V

supply. The reference can drive a bypass capacitor of up to

0.01

µF without oscillation and by inserting a series resistor,

capacitance values up to 100

µF can be used (Figure 1).

Figure 2 shows the resistor value required for different

capacitor values to achieve critical damping.

CAPACITOR VALUE (

µF)

0.001

0.1

10

1000

0.01

0.1

10

1

LTC1443/44/45 • F02

1

100

Figure 2. Damping Resistance vs Bypass Capacitor Value

LTC144X

REF

R1

C1

REFERENCE

OUTPUT

LTC1443/44/45 • F01

Figure 1. Damping the Reference Output

PI FU CTIO S

APPLICATIO S I FOR ATIO