TC2014/2015/2185

DS21662C-page 10

 2003 Microchip Technology Inc.

4.0

DETAILED DESCRIPTION

The TC2014, TC2015 and TC2185 are precision fixed

output voltage regulators (If an adjustable version is

needed, see the TC1070, TC1071 or TC1187

(DS21353) datasheet.) Unlike bipolar regulators, the

TC2014, TC2015 and TC2185 supply current does not

increase with load current. In addition, the LDO output

voltage is stable using 1 µF of ceramic or tantalum

capacitance over the entire specified input voltage

range and output current range.

Figure 4-1 shows a typical application circuit. The reg-

ulator is enabled any time the shutdown input (SHDN)

CMOS logic gate or I/O port of a microcontroller. If the

SHDN input is not required, it should be connected

directly to the input supply. While in shutdown, supply

zero volts.

FIGURE 4-1:

Typical Application Circuit.

4.1

Bypass Input

A 0.01 µF ceramic capacitor connected from the

Bypass input to ground reduces noise present on the

internal reference, which in turn significantly reduces

output noise. If output noise is not a concern, this input

may be left unconnected. Larger capacitor values may

be used, but the result is a longer time period to rated

output voltage when power is initially applied.

4.2

Output Capacitor

The output capacitor should have an esr (effective

series resistance) of 0.01

0.05

minum electrolytic capacitors can be used. When using

ceramic capacitors, X5R and X7R dielectric material

are recommended due to their stable tolerance over

temperature. However, other dielectrics can be used as

long as the minimum output capacitance is maintained.

4.3

Input Capacitor

if there is more than 10 inches of wire between the reg-

ulator and this AC filter capacitor, or if a battery is used

as the power source. Aluminum, electrolytic or tanta-

lum capacitors can be used (Since many aluminum

electrolytic capacitors freeze at approximately -30°C,

solid tantalum are recommended for applications oper-

ating below -25°C). When operating from sources other

than batteries, supply-noise rejection and transient

response can be improved by increasing the value of

the input and output capacitors and employing passive

filtering techniques.

0.01 µF

Reference

Bypass Cap

(Optional)

Shutdown Control

(from Power Control Logic)

TC2014

TC2015

TC2185

1

2

34

5

Bypass

SHDN

GND

1µF

1µF

Battery

+

+

+