MIC5255
Micrel
MIC5255
150mA Low Noise
µ
Cap CMOS LDO
General Description
The MIC5255 is an efficient, precise CMOS voltage regulator
optimized for ultra-low-noise applications. It offers 1% initial
accuracy, extremely-low dropout voltage (135mV at 150mA)
and low ground current (typically 90µA). The MIC5255 pro-
vides a very-low-noise output, ideal for RF applications
where a clean voltage source is required. A noise bypass pin
is also available for further reduction of output noise.
Designed specifically for handheld and battery-powered de-
vices, the MIC5255 provides a TTL-logic-compatible enable
pin. When disabled, power consumption drops nearly to zero.
The MIC5255 also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in handheld wireless devices.
Key features include current limit, thermal shutdown, faster
transient response, and an active clamp to speed up device
turn-off. Available in the 6-pin 2mm
×
2mm MLF™ package,
the IttyBitty® SOT-23-5 package and the new Thin SOT-23-
5, which offers the same footprint as the standard IttyBitty®
SOT-23-5, but only 1mm tall. The MIC5255 offers a range of
output voltages.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
Features
•
•
•
•
•
•
Input voltage range: 2.7V to 6.0V
Thin SOT package: 1mm height SOT-23-5
Ultra-low output noise: 30µV(rms)
Stability with ceramic output capacitors
Ultra-low dropout: 135mV @ 150mA
High output accuracy:
1.0% initial accuracy
2.0% over temperature
Low quiescent current: 90µA
Tight load and line regulation
TTL-Logic-controlled enable input
“Zero” off-mode current
Thermal shutdown and current limit protection
•
•
•
•
•
Applications
•
•
•
•
•
Cellular phones and pagers
Cellular accessories
Battery-powered equipment
Laptop, notebook, and palmtop computers
Consumer/personal electronics
Typical Application
MIC5255-x.xBM5
1
2
3
4
5
C
IN
= 1.0µF
Ceramic
Enable
Shutdown
V
IN
V
OUT
C
OUT
= 1.0µF
Ceramic
C
BYP
= 0.01µF
ENABLE
SHUTDOWN
V
IN
EN
MIC5255-x.xBML
1
2
3
6
5
4
V
OUT
C
BYP
(optional)
C
OUT
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
Ultra-Low-Noise Regulator Application
IttyBitty is a registered trademark of Micrel, Inc.
Micro
LeadFrame and MLF are trademarks of Amkor Technology.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000• http://www.micrel.com
August, 2004
1
M0385-080204
MIC5255
Micrel
Ordering Information
Part Number
Standard
Pb-Free
MIC5255-2.5BM5
MIC5255-2.6BM5
MIC5255-2.7BM5
MIC5255-2.8BM5
MIC5255-2.8BML
MIC5255-2.9BM5
MIC5255-3.0BM5
MIC5255-3.0BML
MIC5255-3.1BM5
MIC5255-3.2BM5
MIC5255-3.3BM5
MIC5255-2.6BD5
MIC5255-2.7BD5
MIC5255-2.8BD5
MIC5255-2.9BD5
MIC5255-3.0BD5
MIC5255-3.3BD5
MIC5255-2.5YM5
MIC5255-2.6YM5
MIC5255-2.7YM5
MIC5255-2.8YM5
MIC5255-2.8YML
MIC5255-2.9YM5
MIC5255-3.0YM5
MIC5255-3.0YML
MIC5255-3.1YM5
MIC5255-3.2YM5
MIC5255-3.3YM5
MIC5255-2.6YD5
MIC5255-2.7YD5
MIC5255-2.8YD5
MIC5255-2.9YD5
MIC5255-3.0YD5
MIC5255-3.3YD5
Marking
Voltage
Standard Pb-Free
LW25
LW26
LW27
LW28
W28
LW2J
LW29
LW30
W30
LW31
LW32
LW33
NW26
NW27
NW28
NW2J
NW29
NW30
NW33
LW25
LW26
LW27
LW28
W28
LW2J
LW29
LW30
W30
LW31
LW32
LW33
NW26
NW27
NW28
NW2J
NW2J
NW2J
NW2J
2.5V
2.6V
2.7V
2.8V
2.8V
2.85V
2.9V
3.0V
3.0V
3.1V
3.2V
3.3V
2.6V
2.7V
2.8V
2.85V
2.9V
3.0V
3.3V
Temperature Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
6-Pin 2×2 MLF™
SOT-23-5
SOT-23-5
SOT-23-5
6-Pin 2×2 MLF™
SOT-23-5
SOT-23-5
SOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
MIC5255-2.85BM5 MIC5255-2.85YM5
MIC5255-2.85BD5 MIC5255-2.85YD5
August, 2004
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M0385-080204
MIC5255
Micrel
Pin Configuration
EN GND IN
3
2
1
EN GND IN
3
2
1
EN GND IN
3
2
1
LWxx
4
5
KWxx
4
5
4
NWxx
5
BYP
OUT
BYP
OUT
BYP
OUT
MIC5255-x.xBM5
(SOT-23-5)
MIC5255-x.xYM5
(SOT-23-5)
MIC5255-x.xBD5
(TSOT-23-5)
EN
1
GND
2
IN
3
6
BYP
5
NC
4
OUT
MIC5255-x.xBML
6-Pin 2mm
×
2mm MLF™ (ML)
(Top View)
Pin Description
Pin Number
SOT-23-5
TSOT-23-5
1
2
3
4
5
–
–
Pin Number
6-MLF™
3
2
1
6
4
5
EP
Pin Name
Pin Function
IN
GND
EN
BYP
OUT
NC
GND
Supply Input.
Ground.
Enable/Shutdown (Input): CMOS compatible input. Logic high = enable;
logic low = shutdown. Do not leave open.
Reference Bypass: Connect external 0.01µF
≤
C
BYP
≤
1.0µF capacitor to
GND to reduce output noise. May be left open.
Regulator Output
No internal connection.
Ground: Internally connected to the exposed pad. Connect externally to
GND pin.
August, 2004
3
M0385-080204
MIC5255
Micrel
Absolute Maximum Ratings
(1)
Supply Input Voltage (V
IN
) .................................. 0V to +7V
Enable Input Voltage (V
EN
) ................................. 0V to +7V
Power Dissipation (P
D
) ........................ Internally Limited
(3)
Junction Temperature (T
J
) ....................... –40°C to +125°C
Storage Temperature (T
S
) ....................... –65°C to +150°C
Lead Temperature (soldering, 5 sec.) ....................... 260°C
ESD
(4) ..............................................................................................
2kV
Electrical Characteristics
(5)
Symbol
V
O
∆V
LNR
∆V
LDR
V
IN
– V
OUT
Parameter
Output Voltage Accuracy
Line Regulation
Load Regulation
Dropout Voltage
(7)
Conditions
I
OUT
= 100µA
Operating Ratings
(2)
Input Voltage (V
IN
) ......................................... +2.7V to +6V
Enable Input Voltage (V
EN
) .................................. 0V to V
IN
Junction Temperature (T
J
) ....................... –40°C to +125°C
Thermal Resistance
SOT-23
(θ
JA
) .....................................................235°C/W
2×2 MLF™
(θ
JA
) ..................................................90°C/W
V
IN
= V
OUT
+ 1V, V
EN
= V
IN;
I
OUT
= 100µA; T
J
= 25°C,
bold
values indicate –40°C
≤
T
J
≤
+125°C; unless noted.
Min
–1
–2
0.02
1.5
0.1
90
135
0.2
90
117
60
60
50
160
425
30
Typical
Max
1
2
0.05
2.5
5
150
200
250
1
150
Units
%
%
%/V
%
mV
mV
mV
mV
µA
µA
µA
dB
dB
dB
mA
µV(rms)
V
IN
= V
OUT
+ 1V to 6V
I
OUT
= 0.1mA to 150mA
(6)
I
OUT
= 100µA
I
OUT
= 100mA
I
OUT
= 150mA
I
Q
I
GND
PSRR
Quiescent Current
Ground Pin Current
(8)
V
EN
≤
0.4V (shutdown)
I
OUT
= 0mA
I
OUT
= 150mA
f = 10Hz, C
OUT
= 1.0µF, C
BYP
= 0.01µF
f = 100Hz, V
IN
= V
OUT
+1
f = 10kHz, V
IN
= V
OUT
+1
Ripple Rejection
I
LIM
e
n
Enable Input
V
IL
V
IH
I
EN
Current Limit
Output Voltage Noise
V
OUT
= 0V
C
OUT
= 1.0µF, C
BYP
= 0.01µF,
f = 10Hz to 100kHz
Enable Input Logic-Low Voltage
Enable Input Logic-High Voltage
Enable Input Current
V
IN
= 2.7V to 5.5V, regulator shutdown
V
IN
= 2.7V to 5.5V, regulator enabled
V
IL
≤
0.4V, regulator shutdown
V
IH
≥
1.6V, regulator enabled
1.6
0.01
0.01
500
0.4
V
V
µA
µA
Ω
°C
°C
Shutdown Resistance Discharge
Thermal Protection
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
150
10
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. The maximum allowable power dissipation of any T
A
(ambient temperature) is P
D
(max) = (T
J
(max)–T
A
)/θ
JA
. Exceeding the maximum allowable
power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The
θ
JA
of the MIC5255-x.xBM5 (all
versions) is 235°C/W on a PC board. See
“Thermal Considerations”
section for further details.
4. Devices are ESD sensitive. Handling precautions recommended.
5. Specification for packaged product only.
6. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range
from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
7. Dropout Voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal value measured at 1V differen-
tial. For outputs below 2.7V, dropout voltage is the input-to-output voltage differential with the minimum input voltage 2.7V. Minimum input operating
voltage is 2.7V.
8. Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground pin current.
August, 2004
4
M0385-080204
MIC5255
Micrel
Typical Characteristics
Power Supply Rejection Ratio
70
60
50
PSRR (dB)
PSRR (dB)
Power Supply Rejection Ratio
70
60
50
PSRR (dB)
Power Supply Rejection Ratio
70
60
50
0µF*
0.01µF*
0.1µF*
1.0µF*
40
30
20
100µA*
50mA*
100mA*
150mA*
40
30
20
100µA*
50mA*
100mA*
150mA*
40
30
20
*I
LOAD
10 C
OUT
= 1µF Ceramic
10
10000
1000
1000000
100
100000
* I
LOAD
10 C
OUT
= 4.7µF Ceramic
10
10000
1000
1000000
100
100000
10
10000
1000
FRQUENCY (Hz)
FRQUENCY (Hz)
FRQUENCY (Hz)
PSRR vs. Voltage Drop
70
60
50
PSRR (dB)
PSRR (dB)
PSRR vs. Voltage Drop
80
I
LOAD
= 100µA
GROUND CURRENT (µA)
Ground Pin Current
130
125
120
115
110
105
100
0.1
V
IN
= V
OUT
+ 1V
1
10
100
1000
OUTPUT CURRENT (mA)
I
LOAD
= 100µA
70
60
I
LOAD
= 150mA
50
40
30
20
C
OUT
= 1µF
C
BYP
= 0
10
0
0
40
30
20
10
0
0
I
LOAD
= 150mA
C
OUT
= 1µF
C
BYP
= 0.01µF
200 400 600 800 1000
VOLTAGE DROP (mV)
200 400 600 800 1000
VOLTAGE DROP (mV)
Ground Pin Current
115
125
GROUND CURRENT (µA)
Ground Pin Current
140
GROUND CURRENT (µA)
120
100
80
60
40
20
120
115
110
105
100
95
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
I
LOAD
= 150mA
Ground Pin Current
GROUND CURRENT (µA)
113
111
109
107
105
103
101
99
97
95
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
I
LOAD
= 100µA
I
LOAD
= 100µA
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
INPUT VOLTAGE (V)
Ground Pin Current
140
3.5
OUTPUT VOLTAGE (V)
Dropout Characteristics
0.14
DROPOUT VOLTAGE (mV)
0.12
0.1
0.08
0.06
0.04
0.02
3 I
LOAD
= 100µA
2.5
2
1.5
1
0.5
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
INPUT VOLTAGE (V)
I
LOAD
= 150mA
Dropout Voltage
GROUND CURRENT (µA)
120
100
80
60
40
20
I
LOAD
= 150mA
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
INPUT VOLTAGE (V)
I
= 100µA
LOAD
0
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
August, 2004
5
M0385-080204
1000000
100
100000
0
0
* C
BYP
I
LOAD
= 50mA
10 V
IN
= V
OUT
+ 0.5V
= 1µF Ceramic
C
0
OUT
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