CAT6218
300 mA CMOS LDO
Regulator
Description
The CAT6218 is a 300 mA CMOS low dropout regulator that
provides fast response time during load current and line voltage
changes.
The quick−start feature allows the use of an external bypass
capacitor to reduce the overall output noise without affecting the
turn−on time of just 150
ms.
With zero shutdown current and low ground current of 55
mA
typical, the CAT6218 is ideal for battery−operated devices with supply
voltages from 2.3 V to 5.5 V. An internal under voltage lockout circuit
disables the output at supply voltages under 2.1 V typical.
The CAT6218 offers 1% initial accuracy and low dropout voltage,
180 mV typical at 300 mA. Stable operation is provided with a small
value ceramic capacitor, reducing required board space and
component cost.
Other features include fold−back current limit and thermal
protection.
The device is available in the low profile (1 mm max height) 5−lead
thin SOT23 package.
Features
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1
TSOT−23
TD SUFFIX
CASE 419AE
PIN CONNECTIONS
1
VIN
GND
EN
(Top View)
BYP
VOUT
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Guaranteed 300 mA Output Current
Low Dropout Voltage of 180 mV Typical at 300 mA
Stable with 1
mF
Ceramic Output Capacitor
External 10 nF Bypass Capacitor for Low Noise
Quick−start Feature
No−load Ground Current of 55
mA
Typical
Full−load Ground Current of 80
mA
Typical
±1.0%
Initial Accuracy (V
OUT
≥
2.0 V)
±2.0%
Accuracy Over Temperature (V
OUT
≥
2.0 V)
“Zero” Current Shutdown Mode
Fold−back Current Limit and Under−voltage Lockout
Thermal Protection
Thin SOT23−5 Package
These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
MARKING DIAGRAM
RUYM
RU= CAT6218 Device Code
Y = Production Year (last digit)
M = Production Month: 1
−
9, A, B, C
PIN FUNCTION
Pin #
1
2
3
4
Name
VIN
GND
EN
BYP
Function
Supply voltage input.
Ground reference.
Enable input (active high); a 2.5 MW
pull−down resistor is provided.
Optional bypass capacitor connec-
tion for noise reduction and PSRR
enhancing.
Applications
•
Cellular Phones
•
Battery−powered Devices
•
Consumer Electronics
5
VOUT LDO Output Voltage.
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 9 of this data sheet.
©
Semiconductor Components Industries, LLC, 2009
December, 2009
−
Rev. 4
1
Publication Order Number:
CAT6218/D
CAT6218
VIN
V
IN
2.3 V
to 5.5 V
C
IN
1
μF
VIN
VOUT
V
OUT
V
IN
EN
LDO
VOUT
V
OUT
CAT6218
EN
BYP
GND
C
OUT
1
μF
OFF
ON
BYP
C
BYP
(Optional)
10 nF
Reference
Shutdown
Switch
GND
Figure 1. Typical Application Circuit
Figure 2. CAT6218 Functional Block Diagram
Pin Function
VIN
is the supply pin for the LDO. A small 1
mF
ceramic
bypass capacitor is required between the V
IN
pin and ground
near the device. When using longer connections to the power
supply, C
IN
value can be increased without limit. The
operating input voltage range is from 2.3 V to 5.5 V.
EN
is the enable control logic (active high) for the regulator
output. It has a 2.5 MW pull−down resistor, which assures
that if EN pin is left open, the circuit is disabled.
VOUT
is the LDO regulator output. A small 1
mF
ceramic
bypass capacitor is required between the V
OUT
pin and
ground for stability. For better transient response, its value
can be increased to 4.7
mF.
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameter
V
IN
V
EN
, V
OUT
Junction Temperature, T
J
Power Dissipation, P
D
Storage Temperature Range, T
S
Lead Temperature (soldering, 5 sec.)
ESD Rating (Human Body Model)
The capacitor should be located near the device. ESR
domain is 5 mW to 500 mW. V
OUT
can deliver a maximum
guaranteed current of 300 mA. For input−to−output voltages
higher than 1 V, a continuous 300 mA output current might
turn−on the thermal protection. A 250
W
internal shutdown
switch discharges the output capacitor in the no−load
condition.
GND
is the ground reference for the LDO. The pin must be
connected to the ground plane on the PCB.
BYP
is the reference bypass pin. An optional 0.01
mF
capacitor can be connected between BYP pin and GND to
reduce the output noise and enhance the PSRR at high
frequency.
Rating
0 to 6.5
−0.3
to V
IN
+ 0.3
+150
Internally Limited (Note 1)
−65
to +150
260
3
Unit
V
V
_C
mW
_C
_C
kV
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
Table 2. RECOMMENDED OPERATING CONDITIONS
(Note 2)
Parameter
V
IN
V
EN
Junction Temperature Range, T
J
Package Thermal Resistance (SOT23−5),
θ
JA
Range
2.3 to 5.5
0 to V
IN
−40
to +125
235
Unit
V
V
_C
_C/W
NOTE: Typical application circuit with external components is shown above.
1. The maximum allowable power dissipation at any T
A
(ambient temperature) is P
Dmax
= (T
Jmax
−
T
A
)/q
JA
. Exceeding the maximum allowable
power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown.
2. The device is not guaranteed to work outside its operating rating.
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CAT6218
Table 3. ELECTRICAL OPERATING CHARACTERISTICS
(Note 3)
(V
IN
= V
OUT
+ 1.0 V, V
EN
= High, I
OUT
= 100
mA,
C
IN
= C
OUT
= 1
mF,
ambient temperature of 25°C (over recommended operating
conditions unless specified otherwise).
Bold numbers
apply for the entire junction temperature range.)
Symbol
V
OUT−ACC
TC
OUT
V
R−LINE
V
R−LOAD
V
DROP
I
GND
Parameter
Output Voltage Accuracy
Conditions
Initial accuracy for V
OUT
≥
2.0 V
(Note 6)
Min
−1.0
−2.0
40
V
IN
= V
OUT
+ 1.0 V to 5.5 V
I
OUT
= 100
mA
to 300 mA
I
OUT
= 300 mA
I
OUT
= 0
mA
I
OUT
= 300 mA
I
GND−SD
PSRR
Shutdown Ground Current
V
EN
< 0.4 V
f = 1 kHz, C
BYP
= 10 nF
f = 20 kHz, C
BYP
= 10 nF
I
SC
T
ON
e
N
R
OUT−SH
R
EN
V
UVLO
ESR
Output short circuit current limit
Turn−On Time
Output Noise Voltage (Note 5)
Shutdown Switch Resistance
Enable pull−down resistor
Under−voltage lock out (UVLO)
threshold
C
OUT
equivalent series resistance
Logic High Level
V
IN
= 2.3 to 5.5 V
V
IN
= 2.3 to 5.5 V, 0°C to +125°C
junction temperature
V
LO
I
EN
Logic Low Level
Enable Input Current
V
IN
= 2.3 to 5.5 V
V
EN
= 0.4 V
V
EN
= V
IN
THERMAL PROTECTION
T
SD
T
HYS
Thermal Shutdown
Thermal Hysteresis
160
10
°C
°C
0.15
1.5
5
V
OUT
= 0 V
C
BYP
= 10 nF
BW = 10 Hz to 100 kHz
64
54
180
150
45
250
2.5
2.1
500
mA
ms
mVrms
W
MW
V
mW
−0.2
−0.4
Load Regulation
0.7
±0.1
+0.2
+0.4
1.2
1.5
Dropout Voltage (Note 4)
180
250
300
Ground Current
55
75
90
80
1
2
Power Supply Rejection Ratio
dB
mA
mA
mV
%
Typ
Max
+1.0
+2.0
ppm/°C
%/V
Unit
%
Output Voltage Temp. Coefficient
Line Regulation
ENABLE INPUT
V
HI
1.8
1.6
0.4
1
4
V
mA
V
3. Specification for 2.80 V output version unless specified otherwise.
4. Dropout voltage is defined as the input−to−output differential at which the output voltage drops 2% below its nominal value measured at 1 V
differential. During test, the input voltage stays always above the minimum 2.3 V.
5. Specification for 1.8 V output version.
6. For V
OUT
< 2.0 V, the initial accuracy is
±2%
and across temperature
±3%.
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CAT6218
TYPICAL CHARACTERISTICS
(shown for 2.80 V output option)
(V
IN
= 3.85 V, I
OUT
= 100
mA,
C
IN
= C
OUT
= 1
mF,
C
BYP
= 10 nF, T
A
= 25°C unless otherwise specified.)
3.0
100mA
2.5
OUTPUT VOLTAGE [V]
2.0
300mA
1.5
1.0
0.5
0.0
0.0
1.0
2.0
3.0 4.0
5.0
INPUT VOLTAGE [V]
6.0
OUTPUT VOLTAGE [V]
2.86
2.85
2.84
2.83
2.82
2.5
3.0 3.5 4.0 4.5 5.0
INPUT VOLTAGE [V]
5.5
2.87
Figure 3. Dropout Characteristics
2.95
2.87
2.86
OUTPUT VOLTAGE [V]
2.85
2.84
2.83
2.82
0
50 100 150 200 250 300
OUTPUT LOAD CURRENT [mA]
−40
Figure 4. Line Regulation
OUTPUT VOLTAGE [V]
2.90
2.85
2.80
2.75
−10
20
50
80 110
TEMPERATURE [°C]
140
Figure 5. Load Regulation
100
90
80
70
60
50
0
25
50
75 100 125 150
OUTPUT LOAD CURRENT [mA]
Figure 6. Output Voltage vs. Temperature
65
GROUND CURRENT [mA]
GROUND CURRENT [mA]
60
55
50
45
−40
−10
20
50
80
110
TEMPERATURE [°C]
140
Figure 7. Ground Current vs. Load Current
Figure 8. Ground Current vs. Temperature
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CAT6218
TYPICAL CHARACTERISTICS
(shown for 2.80 V output option)
(V
IN
= 3.85 V, I
OUT
= 100
mA,
C
IN
= C
OUT
= 1
mF,
C
BYP
= 10 nF, T
A
= 25°C unless otherwise specified.)
3.0
2.5
GROUND CURRENT [mA]
OUTPUT VOLTAGE [V]
2.0
1.5
1.0
0.5
0.0
0
100 200 300 400 500 600 700
OUTPUT LOAD CURRENT [mA]
70
60
50
40
30
20
10
0
0.0
1.0
2.0
3.0
4.0
INPUT VOLTAGE [V]
5.0
6.0
Figure 9. Output Voltage vs. Load Current
350
300
250
200
150
100
−40
−10
20
50
80
110
TEMPERATURE [°C]
140
Figure 10. Ground Current vs. Input Voltage
300
250
DROPOUT VOLTAGE [mV]
200
150
100
50
0
0
50 100 150 200 250
OUTPUT LOAD CURRENT [mA]
300
DROPOUT VOLTAGE [mV]
Figure 11. Dropout vs. Temperature
(300 mA Load)
1.6
80
70
ENABLE THRESHOLD [V]
1.2
PSRR [dB]
60
50
40
30
20
10
0.0
2.0
2.5
3.0 3.5 4.0 4.5 5.0
INPUT VOLTAGE [V]
5.5
0
Figure 12. Dropout vs. Load Current
C
BYP
= 10 nF
0.8
C
BYP
= 0
0.4
0.01
0.1
1
10
FREQUENCY [kHz]
100
Figure 13. Enable Threshold vs. Input Voltage
Figure 14. PSRR vs. Frequency (10 mA Load)
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