TC2054/2055/2186
50mA, 100mA, and 150mA CMOS LDOs
with Shutdown and Error Output
Features
• Very Low Supply Current (55µA Typ.) for Longer
Battery Life
• Very Low Dropout Voltage: 140mV (Typ.) @
150mA
• High Output Voltage Accuracy: ±0.4% (Typ)
• Standard or Custom Output Voltages
• Power-Saving Shutdown Mode
• ERROR Output Can Be Used as a Low Battery
Detector or Processor Reset Generator
• Fast Shutdown Reponse Time: 60µsec (Typ)
• Over-Current Protection
• Space-Saving 5-Pin SOT-23A Package
• Pin Compatible Upgrades for Bipolar Regulators
General Description
The TC2054, TC2055 and TC2186 are high accuracy
(typically ±0.4%) CMOS upgrades for older (bipolar)
low dropout regulators. Designed specifically for bat-
tery-operated systems, the devices’ total supply current
is typically 55µA at full load (20 to 60 times lower than
in bipolar regulators).
The devices’ key features include ultra low noise oper-
ation, very low dropout voltage - typically 45mV
(TC2054); 90mV (TC2055); and 140mV (TC2186) at
full load - and fast response to step changes in load. An
error output (ERROR) is asserted when the devices are
out-of-regulation (due to a low input voltage or exces-
sive output current). Supply current is reduced to 0.5µA
(max) and both V
OUT
and ERROR are disabled when
the shutdown input is low. The devices also incorporate
over-current protection.
The TC2054, TC2055 and TC2186 are stable with a
low esr ceramic output capacitor of 1µF and have a
maximum output current of 50mA, 100mA and 150mA,
respectively. This LDO Family also features a fast
response time (60µsec typically) when released from
shutdown.
Applications
•
•
•
•
•
•
Battery Operated Systems
Portable Computers
Medical Instruments
Instrumentation
Cellular / GSMS / PHS Phones
Pagers
Typical Application
1
5
1µF
Device Selection Table
Part Number
TC2054-xxVCT
TC2055-xxVCT
TC2186-xxVCT
Note:
Package
5-Pin SOT-23A*
5-Pin SOT-23A*
5-Pin SOT-23A*
Junction Temp.
Range
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
2
GND
V
IN
V
IN
V
OUT
V
OUT
1µF
*5-Pin SOT-23A is equivalent to EIAJ (SC-74A).
3
Shutdown Control
(from Power Control Logic)
SHDN
TC2054
TC2055
TC2186
4
1M
Package Type
V
OUT
5
ERROR
4
ERROR
ERROR
TC2054
TC2055
TC2186
1
2
3
V
IN
GND SHDN
5-Pin SOT-23A*
TOP VIEW
2002 Microchip Technology Inc.
DS21663B-page 1
©
TC2054/2055/2186
1.0
ELECTRICAL
CHARACTERISTICS
*Stresses above those listed under “Absolute Maxi-
mum 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 operation sections of the
specifications is not implied. Exposure to Absolute
Maximum Rating conditions for extended periods my
affect device reliability.
ABSOLUTE MAXIMUM RATINGS*
Input Voltage .........................................................6.5V
Output Voltage................................(-0.3) to (V
IN
+ 0.3)
Operating Temperature .................. -40°C < T
J
< 125°C
Storage Temperature.......................... -65°C to +150°C
Maximum Voltage on Any Pin ........ V
IN
+0.3V to -0.3V
TC2054/2055/2186 ELECTRICAL SPECIFICATIONS
Electrical Characteristics:
V
IN
= V
R
+ 1V, I
L
= 100µA, C
L
= 3.3µF, SHDN > V
IH
, T
A
= 25°C, unless otherwise noted.
BOLDFACE
type specifications apply for junction temperature of -40°C to +125°C.
Symbol
V
IN
I
OUTMAX
Parameter
Input Operating Voltage
Maximum Output Current
Min
2.7
50
100
150
V
R
- 2.0%
—
—
—
-1.5
-2.5
—
—
—
—
—
—
—
160
—
—
—
Typ
—
—
—
—
V
R
± 0.4%
20
40
0.05
0.5
0.5
2
45
90
140
55
0.05
50
300
0.04
600
60
Max
6.0
—
—
—
V
R
+ 2.0%
—
—
0.5
0.5
0.5
—
70
140
210
80
0.5
—
—
—
—
—
Units
V
mA
Note 1
TC2054
TC2055
TC2186
Note 2
Test Conditions
V
OUT
TCV
OUT
∆V
OUT
/
∆V
IN
∆V
OUT
/
V
OUT
V
IN
– V
OUT
Output Voltage
V
OUT
Temperature
Coefficient
Line Regulation
Load Regulation
V
ppm/°C
Note 3
%
%
(V
R
+ 1V) < V
IN
< 6V
TC2054;TC2055
TC2186
Note 4
I
L
= 0.1mA to I
OUTMAX
I
L
= 0.1mA to I
OUTMAX
I
L
= 100µA
I
L
= 50mA
I
L
= 100mA
I
L
= 150mA
Dropout Voltage,
Note 5
mV
TC2015; TC2185
TC2185
Note 5
µA
µA
dB
mA
V/W
nV /
√Hz
µsec
SHDN = V
IH
, I
L
=0
SHDN = 0V
F
RE
≤
120kHz
V
OUT
= 0V
Note 6
I
IN
I
INSD
PSRR
I
OUTSC
∆V
OUT
∆P
D
eN
t
R
Supply Current
Shutdown Supply Current
Power Supply Rejection Ratio
Output Short Circuit Current
Thermal Regulation
Output Noise
Response Time
(from Shutdown Mode)
1:
2:
3:
I
L
= I
OUTMAX
, F = 10kHz
V
IN
= 4V
C
IN
= 1µF, C
OUT
= 10µF
I
L
= 0.1mA,
Note 9
Note
The minimum V
IN
has to meet two conditions: V
IN
= 2.7V and V
IN
= V
R
+ V
DROPOUT
.
V
R
is the regulator output voltage setting. For example: V
R
= 1.8V, 2.7V, 2.8V, 2.85V, 3.0V, 3.3V.
6
TCV
OUT
=
(
V OU TMAX
–
VOUTMIN
) ×
10
-----------------------------------------------------------------------------------------
V
× ∆T
OUT
4:
5:
6:
7:
8:
9:
Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested over a
load range from 1.0mA to the maximum specified output current. Changes in output voltage due to heating effects are covered
by the thermal regulation specification.
Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value at a 1V
differential.
Thermal Regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, exclud-
ing load or line regulation effects. Specifications are for a current pulse equal to I
MAX
at V
IN
= 6V for T = 10msec.
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature
and the thermal resistance from junction-to-air (i.e. T
A
, T
J
,
θ
JA
).
Hysteresis voltage is referenced by V
R
.
Time required for V
OUT
to reach 95% of V
R
(output voltage setting), after V
SHDN
is switched from 0 to V
IN
.
©
DS21663B-page 2
2002 Microchip Technology Inc.
TC2054/2055/2186
Electrical Characteristics:
V
IN
= V
R
+ 1V, I
L
= 100µA, C
L
= 3.3µF, SHDN > V
IH
, T
A
= 25°C, unless otherwise noted.
BOLDFACE
type specifications apply for junction temperature of -40°C to +125°C.
Symbol
SHDN Input
V
IH
V
IL
V
INMIN
V
OL
V
TH
V
HYS
t
DELAY
R
ERROR
Note
1:
2:
3:
SHDN Input High Threshold
SHDN Input Low Threshold
60
—
—
—
—
15
%V
IN
%V
IN
V
mV
V
mV
msec
Ω
V
IN
= 2.5V to 6.0V
V
IN
= 2.5V to 6.0V
V
OUT
≥
2.7V
1 mA Flows to ERROR
See Figure 4-2
Note 8
V
OUT
from V
R
= 3V to 2.8V
V
DD
= 2.5V, V
OUT
= 2.5V
Parameter
Min
Typ
Max
Units
Test Conditions
ERROR OUTPUT
Minimum V
IN
Operating Volt-
age
Output Logic Low Voltage
ERROR Threshold Voltage
ERROR Positive Hysteresis
V
OUT
to ERROR Delay
Resistance from ERROR to
GND
1.0
—
—
—
—
—
—
—
0.95 x V
R
50
2
126
—
400
—
—
—
—
The minimum V
IN
has to meet two conditions: V
IN
= 2.7V and V
IN
= V
R
+ V
DROPOUT
.
V
R
is the regulator output voltage setting. For example: V
R
= 1.8V, 2.7V, 2.8V, 2.85V, 3.0V, 3.3V.
TCV
OUT
=
6
(
V
–
V
) ×
10
OU TMAX
OUTMIN
-----------------------------------------------------------------------------------------
V OUT
× ∆
T
4:
5:
6:
7:
8:
9:
Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested over a
load range from 1.0mA to the maximum specified output current. Changes in output voltage due to heating effects are covered
by the thermal regulation specification.
Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value at a 1V
differential.
Thermal Regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, exclud-
ing load or line regulation effects. Specifications are for a current pulse equal to I
MAX
at V
IN
= 6V for T = 10msec.
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature
and the thermal resistance from junction-to-air (i.e. T
A
, T
J
,
θ
JA
).
Hysteresis voltage is referenced by V
R
.
Time required for V
OUT
to reach 95% of V
R
(output voltage setting), after V
SHDN
is switched from 0 to V
IN
.
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
Pin Number
1
2
3
PIN FUNCTION TABLE
Symbol
V
IN
GND
SHDN
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, ERROR
is open circuited and supply current is reduced to 0.5µA (max).
Out-of-Regulation Flag. (Open drain output). This output goes low when
V
OUT
is out-of-tolerance by approximately -5%.
Regulated voltage output.
Description
4
5
ERROR
V
OUT
2002 Microchip Technology Inc.
DS21663B-page 3
©
TC2054/2055/2186
3.0
DETAILED DESCRIPTION
FIGURE 3-2:
V
OUT
V
TH
HYSTERESIS (V
HYS
)
ERROR OUTPUT OPERATION
The TC2054, TC2055 and TC2186 are precision fixed
output voltage regulators. (If an adjustable version is
desired, please see the TC1070, TC1071 or TC1187
data sheets.) Unlike bipolar regulators, the TC2054,
TC2055 and TC2186 supply current does not increase
with load current. In addition, V
OUT
remains stable and
within regulation over the entire 0mA to maximum out-
put current operating load range.
Figure 3-1 shows a typical application circuit. The reg-
ulator is enabled any time the shutdown input (SHDN)
is at or above V
IH
, and shutdown (disabled) when
SHDN is at or below V
IL
. SHDN may be controlled by a
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
current decreases to 0.05µA (typical), V
OUT
falls to
zero volts, and ERROR is open-circuited.
FIGURE 3-1:
TYPICAL APPLICATION CIRCUIT
V
IN
1µF
V
OUT
1µF
C1
GND
V
OUT
ERROR
V
IH
V
OL
3.2
Output Capacitor
BATTERY
TC2054
TC2055
TC2186
V
+
ERROR
R1
1M
BATTLOW
or RESET
SHDN
Shutdown Control
(to CMOS Logic or Tie
to V
IN
if unused)
A 1µF (min) capacitor from V
OUT
to ground is required.
The output capacitor should have an effective series
resistance of 0.01Ω. to 5Ω for V
OUT
= 2.5V, and 0.05Ω.
to 5Ω for V
OUT
< 2.5V. A 1µF capacitor should be con-
nected from V
IN
to GND if there is more than 10 inches
of wire between the regulator and the AC filter capaci-
tor, or if a battery is used as the power source. Ceramic,
tantalum and aluminum electrolytic capacitors can be
used. (Since many aluminum electrolytic capacitors
freeze at approximately -30°C, solid tantalums are rec-
ommended for applications operating below -25°C).
When operating from sources other than batteries, sup-
ply-noise rejection and transient response can be
improved by increasing the value of the input and out-
put capacitors and employing passive filtering tech-
niques.
C2 Required Only
if ERROR is used as a
Processor RESET Signal
(See Text)
0.2µF
C2
3.1
ERROR Open Drain Output
ERROR is driven low whenever V
OUT
falls out of regu-
lation by more than -5% (typical). This condition may be
caused by low input voltage, output current limiting or
thermal limiting. The ERROR threshold is 5% below
rated V
OUT
regardless of the programmed output volt-
age value (e.g. ERROR = V
OL
at 4.75V (typ.) for a 5.0V
regulator and 2.85V (typ.) for a 3.0V regulator).
ERROR output operation is shown in Figure 4-2.
Note that ERROR is active when V
OUT
falls to V
TH
, and
inactive when V
OUT
rises above V
TH
by V
HYS
.
As shown in Figure 3-1, ERROR can be used as a bat-
tery low flag or as a processor RESET signal (with the
addition of timing capacitor C2). R1 x C2 should be
chosen to maintain ERROR below V
IH
of the processor
RESET input for at least 200msec to allow time for the
system to stabilize. Pull-up resistor R1 can be tied to
V
OUT
, V
IN
or any other voltage less than (V
IN
+ 0.3V).
The ERROR pin sink current is self-limiting to approxi-
mately 18mA.
©
DS21663B-page 4
2002 Microchip Technology Inc.
TC2054/2055/2186
4.0
4.1
THERMAL CONSIDERATIONS
Power Dissipation
Equation 4-1 can be used in conjunction with Equation
4-2 to ensure regulator thermal operation is within lim-
its. For example:
Given:
V
INMAX
V
OUTMIN
T
AMAX
= 3.0V ±5%
= 2.7V – 2.5%
= 55°C
The amount of power the regulator dissipates is prima-
rily a function of input and output voltage, and output
current.
The following equation is used to calculate worst case
power dissipation:
I
LOADMAX
= 40mA
EQUATION 4-1:
P
D
≈
(V
IN
– V
OUTMIN
)I
LOADMAX
Where:
P
D
V
INMAX
V
OUTMIN
=
=
=
Worst case actual power dissipation
Maximum voltage on V
IN
Minimum regulator output voltage
Maximum output (load) current
Find 1. Actual power dissapation
:
2. Maximum allowable dissapation
Actual power dissipation:
P
D
≈
(V
INMAX
– V
OUTMIN
)I
LOADMAX
= [(3.0 x 1.05) – (2.7 x .975)]40 x 10
–3
= 20.7mW
The maximum allowable power dissipation (Equation
4-2) is a function of the maximum ambient temperature
(T
AMAX
), the maximum allowable die temperature (125
°C) and the thermal resistance from junction-to-air
(θ
JA
). The 5-Pin SOT-23A package has a
θ
JA
of
approximately 220°C/Watt when mounted on a typical
two layer FR4 dielectric copper clad PC board.
Maximum allowable power dissipation:
(
T
J
–
T
A
)
M AX
MAX
= -------------------------------------
-
θ
JA
I
LOADMAX
=
P
D
MAX
EQUATION 4-2:
T
J
–
T
A
M AX
MAX
= ----------------------------------
-
θ
JA
(
125
–
55
)
--------------------------
-
220
= 318mW
In this example, the TC2054 dissipates a maximum of
only 20.7mW; far below the allowable limit of 318mW.
In a similar manner, Equation 4-1 and Equation 4-2 can
be used to calculate maximum current and/or input
voltage limits.
P
D
MAX
Where all terms are previously defined
4.2
Layout Considerations
The primary path of heat conduction out of the package
is via the package leads. Therefore, layouts having a
ground plane, wide traces at the pads, and wide power
supply bus lines combine to lower
θ
JA
and, therefore,
increase the maximum allowable power dissipation
limit.
2002 Microchip Technology Inc.
DS21663B-page 5
©
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