MICROCHIP TC1269 Technical data
TC1269
300mA CMOS LDO with Shutdown and V
Features
• Very Low Ground Current for Longer Battery Life
• Very Low Dr opout Voltage
• 300mA Output Circuit
• High Output Voltage Accuracy
• Standard or Custom Output Voltages
• Power Saving Shutdown Mode
• Bypass Input for Ultra Quiet Operation
• Over Current and O ver Temperature Protection
• Space-Saving MSOP Package
Applications
• Battery Operated Systems
• PortableComputers
• Medical Instruments
• Instrumentation
• Cellular/GSM/PHSPhones
• Linear Post-Regulator for SMPS
• Pagers
• Digital Cameras
Device Selection Table
Output*
Part Number
TC1269-2.5VUA 2.5 8-Pin MSOP -40°C to +125°C
TC1269-2.8VUA 2.8 8-Pin MSOP -40°C to +125°C
TC1269-3.0VUA 3.0 8-Pin MSOP -40°C to +125°C
TC1269-3.3VUA 3.3 8-Pin MSOP -40°C to +125°C
TC1269-5.0VUA 5.0 8-Pin MSOP -40°C to +125°C
*Other output voltages are available. Please contact Microchip
Technology Inc. for details.
Voltage
(V)
Package
Junction
Temp. Range
Bypass
REF
General Description
The TC1269 is a fixed output, high accuracy (typically
±0.5%) CMOS upgrade for older (bipolar) low dropout
regulators. Total supply current is typically 50µAatfull
load (20 to 60 times lower than in bipolar regulators).
TC1269 key features include ultra low noise operation
(plus optional Bypass input); very low dropout voltage
(typically240mV at full load),and fast responseto step
changes in load. Supply current i s reduced to 0.05µA
(typical) and V
falls to zero when the shutdown
OUT
input is low.
The TC1269 incorporates both over temperature and
over current protection. The TC1269 is stable with an
output capacitor of only 1µF and has a maximum
output current of 300mA.
Typical Application
V
OUT
1
V
C1
1µF
OUT
2
NC
+
TC1269
3
NC
4
GND
V
SHDN
NC
Bypass
8
V
IN
IN
7
Shutdown Control
(from Power
Control Logic)
6
C
BYPASS
470pF
(Optional)
Package Type
8-Pin MSOP
V
2002 Microchip TechnologyInc. DS21380B-page 1
1
OUT
2
NC
NC
GND
TC1269
3
45
8
7
6
V
IN
SHDN
NC
Bypass
TC1269
1.0 ELECTRICAL
CHARACTERISTICS
*Stresses above those listed under "Absolute Maximum
Ratings" may cause permanent damage to the device. These
are stress ratings only and functional operation of the device
at these or any other conditions above those indicated in the
Absolute Maximum Ratings*
Input Voltage .........................................................6.5V
Output Voltage.................... (V
Maximum Voltage on Any Pin ........V
–0.3)to(VIN+0.3V)
SS
+0.3V to -0.3V
IN
operation sections of the specifications is not implied.
Exposure to Absolute Maximum Rating conditions for
extended periods may affectdevice reliability.
Power Dissipation................Internally Limited (Note 6)
Operating Temperature ...............-40°C < T
< +125°C
J
Storage Temperature..........................-65°C to +150°C
TC1269 ELECTR ICAL SPECI FICATIONS
Electrical Characteristics: VIN=V
type specifications apply for junctiontemperaturesof -40°C to +125°C.
Symbol Parameter Min Typ Max Units Test Conditions
V
IN
I
OUTMAX
V
OUT
∆V
OUT
∆V
OUT
∆V
OUT/VOUT
VIN-V
I
SS1
I
SS2
OUT
InputOperatingVoltage — — 6.0 V
MaximumOutputCurrent 300 ——mA
Output Voltage —
/∆TV
Temperature Coefficient — 40 —ppm/°CNote 2
OUT
/∆VINLine Regulation — 0.05 0.35 %(VR+1V)≤ VIN ≤ 6V
Load Regulation — 0.5 2.0 %IL=0.1mAtoI
Dropout Voltage —
Supply Current — 50 90 µA SHDN =V
ShutdownSupply Current — 0.05 0.5 µA SHDN =0V
PSRR Power Supply Rejection Ratio — 50 — dB F
I
OUTSC
∆V
OUT
Output Short Circuit Current — 550 650 mA V
/∆PDThermalRegulation — 0.04 — V/W Note 5
eN Output Noise — 260 — nV/√Hz
Input
SHDN
V
IH
V
IL
Note 1: VRis the regulator output voltage setting.
2:
3: Regulation is measuredat a constant junctiontemperature using low dutycyclepulse testing. Load regulatio nis tested over a load rangefrom
4: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at a 1V differen-
5: Thermal Regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, excluding load or
6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature and the
SHDN Input High Threshold 45 ——%V
SHDN Input Low Threshold — — 15 %V
TCV
=(V
OUT
OUTMAX–VOUTMIN
V
x ∆T
OUT
0.1mA to the maximum specified output current. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
tial.
line regulation effects. Specifications are for a current pulse equal to I
thermal resistance from junction-to-air (i.e., T
thermal shutdown. Please see Section 4.0 Thermal Considerations for more details.
+1V,IL=0.1µA, CL=3.3µF,SHDN >VIH,TA= 25°C, unless otherwise noted. Boldface
OUT
)x10
±0.5%
V
V
R
–2.5%
R
—
20
—
—
6
, θJA). Exceeding the maximum allowable power dissipation causes the device to initiate
A,TJ
80
240
V
R
—
+2.5%
30
V Note 1
mV I
160
480
at VIN= 6V for T = 10 msec.
LMAX
=0.1mA
L
I
=100mA
L
I
=300mA(Note 4)
L
RE
OUT
F=1kHz,C
IN
IN
≤ 120Hz
=0V
IH
OUT
OUTMAX
=1µF, R
LOAD
=50Ω
DS21380B-page 2
2002 Microchip TechnologyInc.
2.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1: PIN FUNCTION TABLE
TC1269
Pin No.
(8-Pin SOIC)
1V
2 NC No connect.
3 NC No connect.
4 GND Ground terminal.
5 Bypass Reference bypass input. Connectinga 470pF to this input furtherreduces output noise.
6 NC No connect.
7 SHDN
8V
Symbol Description
OUT
IN
Regulated voltage output.
Shutdown control input. The regulator is fully enabled when a logic high is applied to this input.
The regulator is fully enabledwhena logic high is appliedto this input.Theregulator entersshutdown when a logic low is applied to this input. During shutdown, output voltage falls to zero and
supply current is reduced to 0.05µA(typical).
Unregulatedsupply input.
2002 Microchip TechnologyInc. DS21380B-page 3
TC1269
3.0 DETAILED DESCRIPTION
The TC1269 is a precision regulator available in fixed
voltages. Unlike the bipolar regulators, the TC1269
supply current does not increase with load current. In
addition, V
over the entire 0mA to I
range, (an i mportant consideration in RTC and CMOS
RAM battery backup applications).
Figure 3-1 shows a typical application circuit. The
regulator is enabled any time the shutdown input
(SHDN
) is at or above VIH, and shutdown (disabled)
when SHDN
controlled by a CMOS logic gate, or I/O port of a
microcontroller. If the SHDN
should be connected directly to the input supply.While
in shutdown, supply current decreases to 0.05µA
(typical), V
FIGURE 3-1: TYPICAL APPLICATION
V
OUT
+
remains stable and w ithin regulation
OUT
OUTMAX
operating load current
is at or below VIL. SHDN may be
input is not required, it
fallsto zero.
OUT
CIRCUIT
C1
1µF
1
V
OUT
2
NC
TC1269
3
NC
4
GND
V
SHDN
NC
Bypass
8
IN
7
6
+
C1
1µF
Shutdown Control
(from Power
Control Logic)
C
BYPASS
470pF
(Optional)
Battery
+
–
3.1 Bypass Input
A 470pF capacitor connected from the Bypass input to
ground reduces noise present on t he internal
reference, which i n turn significantly reduces output
noise.Ifoutputnoiseisnota concern,thisinputmaybe
left unconnected. Larger capacitor values may be
used, but resultsin a longer time period to rated output
voltagewhen power is initially applied.
3.2 Output Capacitor
A1µF(min)capacitorfromV
recommended. The output capacitor should have an
effective series resistance greater than 0.1Ω and less
than 5.0Ω, and a resonant frequency above 1MHz. A
1µF capacitor should be connected from V
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 capacitor types can be used. (Since many
aluminum electrolytic capacitors f reeze 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.
to ground is
OUT
to GND if
IN
DS21380B-page 4
2002 Microchip TechnologyInc.
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