TC1014 TelCom Semiconductor, TC1014 Datasheet - Page 3

• Manufacturer Part Number: TC1014
• Description: 50mA CMOS LDO WITH SHUTDOWN AND REFERENCE BYPASS
• Manufacturer: TelCom Semiconductor

TC1014-01-6/5/97
50mA CMOS LDO WITH SHUTDOWN
AND REFERENCE BYPASS
PIN DESCRIPTION
DETAILED DESCRIPTION
tor. (If an adjustable version is desired, please see the
TC1070 or TC1071 data sheets.) Unlike the bipolar regula-
tors, the TC1014 supply current does not increase with load
current. In addition, V
tion at very low load currents (an important consideration in
RTC and CMOS RAM battery back-up applications).
tor is enabled any time the shutdown input (SHDN) is at or
above V
below V
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 current decreases to 0.05 A
(typical) and V
Bypass Input
ground reduces noise present on the internal reference,
which in turn significantly reduces output noise. If output
(SOT-23A-5)
(to CMOS Logic or Tie to V
Pin No.
The TC1014 is a precision fixed output voltage regula-
Figure 1 shows a typical application circuit. The regula-
A 470pF capacitor connected from the Bypass input to
1
2
3
4
5
BATTERY
IL
IH
. SHDN may be controlled by a CMOS logic gate,
Shutdown Control
, and shutdown (disabled) when SHDN is at or
1 F
Figure 1. Typical Application Circuit
OUT
Symbol
falls to zero volts.
Bypass
SHDN
GND
V
V
OUT
OUT
GND
IN
SHDN
V
IN
IN
remains stable and within regula-
if Unused)
TC1014
Bypass
V
Unregulated supply input.
Ground terminal.
Shutdown control input. The regulator is fully enabled when a logic high is applied to this
input. The regulator enters shutdown when a logic low is applied to this input. During
shutdown, output voltage falls to zero, and supply current is reduced to under 1 microamp
(typical).
Reference bypass input. Connecting a 470pF to this input further reduces output noise.
Regulated voltage output.
Description
OUT
470pF
Reference
Bypass Cap
(Optional)
1 F
V
OUT
3
noise is not a concern, this input may be left unconnected.
Larger capacitor values may be used, but results in a longer
time period to rated output voltage when power is initially
applied.
Output Capacitor
mended. The output capacitor should have an effective
series resistance of 5
above 1MHz. A 1 F capacitor should be connected from V
to GND if there is more than 10 inches of wire between the
regulator and the AC filter capacitor, or if a battery is used as
the power source. Aluminum electrolytic or tantalum capaci-
tor types can be used. (Since many aluminum electrolytic
capacitors freeze at approximately – 30 C, solid tantalums
are recommended for applications operating 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.
Thermal Considerations
Thermal Shutdown
tor off when die temperature exceeds 160 C. The regulator
remains off until the die temperature drops to approximately
150 C.
Power Dissipation
rily a function of input and output voltage, and output current.
The following equation is used to calculate worst case
actual power dissipation:
A 1 F (min) capacitor from V
Integrated thermal protection circuitry shuts the regula-
The amount of power the regulator dissipates is prima-
PRELIMINARY INFORMATION
or less, and a resonant frequency
OUT
to ground is recom-
TC1014
IN