MIC5305
150mA µCap Ultra-Low Dropout
LDO Regulator
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
June 2007 1 M9999-062507
General Description
The MIC5305 is a high-performance, 150mA LDO regula-
tor, offering extremely high PSRR and very low noise while
consuming low ground current.
Ideal for battery-operated applications, the MIC5305
features 1% accuracy, extremely low-dropout voltage
(60mV @ 150mA), and low ground current at light load
(typically 90µA). Equipped with a logic-compatible enable
pin, the MIC5305 can be put into a zero-off-mode current
state, drawing no current when disabled.
The MIC5305 is a µCap design operating with very small
ceramic output capacitors for stability, thereby reducing
required board space and component cost.
The MIC5305 is available in fixed output voltages and
adjustable output voltages in the super-compact 6-pin
2mm × 2mm MLF
®
leadless package, our new ultra-thin
6-pin 2mm × 2mm Thin MLF
®
and thin SOT-23-5 package.
Additional voltage options are available. Contact Micrel
marketing.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Features
• Ultra-low dropout voltage of 60mV @ 150mA
• Input voltage range: 2.25 to 5.5V
• Stable with ceramic output capacitor
• 150mA guaranteed output current
• Low output noise — 20µVrms
• Low quiescent current of 90µA total
• High PSRR, up to 85dB @1kHz
• Less than 30µs turn-on time w/C
BYP
= 0.01µF
• High output accuracy:
– ±1.0% initial accuracy
– ±2.0% over temperature
• Thermal shutdown protection
• Current limit protection
• Tiny 6-pin 2mm × 2mm MLF
®
package
• Ultra-Thin 6-pin 2mm × 2mm Thin MLF
®
package
• Thin SOT-23-5 package
Applications
• Cellular phones
• PDAs
• Fiber optic modules
• Portable electronics
• Notebook PCs
• Audio Codec power supplies
Typical Application
0
10
20
30
40
50
60
70
0 20 40 60 80 100 120 140
DROPOUT VOLTAGE (mV)
OUTPUT CURRENT (mA)
Dropout Voltage
MIC5305
VOUTVIN
BYPEN
GND
3.0V
V
IN
2.85V@150mA
V
OUT
1µF0.1µF
1µF
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
PSRR (dB)
FREQUENCY (kHz)
PSR
R
(Bypass P in C ap = 0 .1µF)
150mA
50mA
100µA
1k
Micrel, Inc. MIC5305
June 2007 2
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Ordering Information
Part Number Marking
Standard Pb-Free Standard Pb-Free*
Voltage Junction
Temp. Range
(1)
Package
MIC5305-1.5BML MIC5305-1.5YML 815 815 1.5V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-1.8BML MIC5305-1.8YML 818 818 1.8V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-2.0YML 820 2.0V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-2.5BML MIC5305-2.5YML 825 825 2.5V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-2.6BML MIC5305-2.6YML 826 826 2.6V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-2.7BML MIC5305-2.7YML 827 827 2.7V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-2.8BML MIC5305-2.8YML 828 828 2.8V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-2.85BML MIC5305-2.85YML 82J 82J 2.85V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-2.9BML MIC5305-2.9YML 829 829 2.9V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-3.0BML MIC5305-3.0YML 830 830 3.0V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-3.3BML MIC5305-3.3YML 833 833 3.3V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-4.75BML MIC5305-4.75YML 84H 84H 4.75V –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305BML MIC5305YML 8AA 8AA ADJ –40°C to +125°C 6-Pin 2x2 MLF
®
MIC5305-2.8YMT 828** 2.8V –40°C to +125°C 6-Pin 2x2 Thin MLF
®
MIC5305-4.6YMT 846** 4.6V –40°C to +125°C 6-Pin 2x2 Thin MLF
®
MIC5305-1.5BD5 MIC5305-1.5YD5 N815 N815 1.5V –40°C to +125°C Thin SOT23-5
MIC5305-1.8BD5 MIC5305-1.8YD5 N818 N818 1.8V –40°C to +125°C Thin SOT23-5
MIC5305-2.5BD5 MIC5305-2.5YD5 N825 N825 2.5V –40°C to +125°C Thin SOT23-5
MIC5305-2.6BD5 MIC5305-2.6YD5 N826 N826 2.6V –40°C to +125°C Thin SOT23-5
MIC5305-2.7BD5 MIC5305-2.7YD5 N827 N827 2.7V –40°C to +125°C Thin SOT23-5
MIC5305-2.8BD5 MIC5305-2.8YD5 N828 N828 2.8V –40°C to +125°C Thin SOT23-5
MIC5305-2.85BD5 MIC5305-2.85YD5 N82J N82J 2.85V –40°C to +125°C Thin SOT23-5
MIC5305-2.9BD5 MIC5305-2.9YD5 N829 N829 2.9V –40°C to +125°C Thin SOT23-5
MIC5305-3.0BD5 MIC5305-3.0YD5 N830 N830 3.0V –40°C to +125°C Thin SOT23-5
MIC5305-3.3BD5 MIC5305-3.3YD5 N833 N833 3.3V –40°C to +125°C Thin SOT23-5
MIC5305-4.75BD5 MIC5305-4.75YD5 N84H N84H 4.75V –40°C to +125°C Thin SOT23-5
Note:
1. For other output voltage options, contact Micrel marketing.
* Underbar/Overbar symbols may not be to scale.
** Pin 1 identifier for 2x2 Thin MLF
®
is “▲” symbol.
Micrel, Inc. MIC5305
June 2007 3
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Pin Configur ation
1EN
GND
VIN
6 BYP
NC
VOUT
5
4
2
3
1EN
GND
VIN
6 BYP
ADJ
VOUT
5
4
2
3
MIC5305-x.xBML/YML (Fixed)
6-Pin 2mm x 2mm MLF
®
(ML)
(Top View)
MIC5305-x.xBML/YML (Adjustable)
6-Pin 2mm x 2mm MLF
®
(ML)
(Top View)
1EN
GND
VIN
6 BYP
NC
VOUT
5
4
2
3
VIN
VOU
T
BYP
EN
KWxx
13
45
2
GND
MIC5305-x.xYMT (Fixed)
6-Pin 2mm x 2mm Thin MLF
®
(MT)
(Top View)
MIC5305-x.xBD5/YD5 (Fixed)
TSOT-23-5 (D5)
(Top View)
Pin Description
Pin Number
MLF-6
Fixed
Pin Number
MLF-6
Adjustable
Pin Number
Thin MLF-6
Fixed
Pin Number
TSOT23-5
Fixed
Pin Name Pin Name
1 1 1 3 EN Enable Input. Active High. High = on, low = off. Do not leave
floating.
2 2 2 2 GND Ground.
3 3 3 1 VIN Supply Input.
4 4 4 5 VOUT Output Voltage.
– 5 – ADJ Adjust Input: Connect to external resistor voltage divider
network.
5 – 5 – NC No connection for fixed voltage parts.
6 6 6 4 BYP Reference Bypass: Connect external 0.1µF to GND for reduced
output noise. May be left open.
HS Pad HS Pad HS Pad – EPAD Exposed Heatsink Pad connected to ground internally.
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June 2007 4
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Absolute Maximum Ratings(1)
Supply Voltage (V
IN
)............................................... 0V to 6V
Enable Input Voltage (V
EN
)..................................... 0V to 6V
Power Dissipation (P
D
) ........................... Internally Limited
(3)
Junction Temperature (T
J
) ........................–40°C to +125°C
Lead Temperature (soldering, 5sec.)......................... 260°C
Storage Temperature (T
s
) .........................–65°C to +150°C
EDS Rating
(4)
.................................................................. 2kV
Operating Ratings(2)
Supply voltage (V
IN
) ....................................... 2.25V to 5.5V
Enable Input Voltage (V
EN
)..................................... 0V to V
IN
Junction Temperature (T
J
) ........................–40°C to +125°C
Junction Thermal Resistance
MLF-6 (θ
JA
) ........................................................93°C/W
Thin MLF-6 (θ
JA
)................................................93°C/W
TSOT-23-5 (θ
JA
) ..............................................235°C/W
Electrical Characteristics(5)
V
IN
= V
OUT
+ 1.0V; C
OUT
= 1.0µF; I
OUT
= 100µA; T
J
= 25°C, bold values indicate –40°C to +125°C, unless noted.
Parameter Condition Min Typ Max Units
Variation from nominal V
OUT
–1.0 +1.0 % Output Voltage Accuracy
Variation from nominal V
OUT
, I
OUT
= 100mA to 150mA
–2.0
+2.0
%
Output Voltage Temp.
Coefficient
40
pm/°C
Line Regulation V
IN
= V
OUT
+1V to 5.5V
0.02
0.3
%/V
Load Regulation
(6)
I
OUT
= 100µA to 150mA
0.1
0.5
%
I
OUT
= 50mA, V
OUT
> 2.8V
20
35
mV
I
OUT
= 150mA, V
OUT
> 2.8V
60
85
mV
I
OUT
= 50mA, V
OUT
> 2.8V
27
45
mV
Dropout Voltage
(7)
I
OUT
= 150mA, V
OUT
> 2.8V
85
110
mV
Ground Pin Current
(8)
I
OUT
= 0 to 150mA
90
150
µA
Ground Pin Current in
Shutdown
V
EN
≤ 0.2V
0.5
µA
f = up to 1kHz; C
OUT
= 1.0µF ceramic; C
BYP
= 0.1µF
85
dB Ripple Rejection
f = 10kHz; C
OUT
= 1.0µF ceramic; C
BYP
= 0.1µF
65
dB
Current Limit V
OUT
= 0V
300
600
900
mA
Output Voltage Noise C
OUT
=1µF, C
BYP
= 0.1µF, 10Hz to 100kHz
20
µVrms
Turn-On Time C
OUT
= 1µF; C
BYP
= 0.1µF; I
OUT
= 150mA
30
100
µs
Enable Input
Logic Low (Regulator Shutdown)
0.2
V Enable Input Voltage
Logic High (Regulator Enabled)
1.0
V
V
IL
≤ 0.2V (Regulator Shutdown) 0.01
1
µA Enable Input Current
V
IH
≥ 1.0V (Regulator Enabled) 0.01
1
µA
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.
4. Devices are ESD sensitive. Handling precautions recommended. Human body model.
5. Specification for packaged product only.
6. Regulation is measured at constant junction temperature using low duty cycle pulse testing, 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 V
OUT
. For outputs below 2.25V,
dropout voltage is the input-to-output differential with the minimum input voltage 2.25V.
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.
Micrel, Inc. MIC5305
June 2007 5
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Typical Characteristics
0
20
40
60
80
100
120
0.1 1 10 100
PSRR (dB)
FREQUENCY (kHz)
PSRR
150mA
50mA
100µA
1k
(Bypass Pin Cap = 0.01µF)
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
PSRR (dB)
FREQUENCY (kHz)
PSRR
(Bypass P in Cap = 0.1µF)
150mA
50mA
100µA
1k
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
PSRR (dB)
FREQUENCY (kHz)
150mA
50mA
100µA
1k
PSRR
(Bypass Pin Cap = 1µF)
70
75
80
85
90
0.1 1 10 100 1000
GROUND CURRENT (µA)
OUTPUT CURRENT (mA)
VIN =V
OUT
+1V
Ground Pin Current
70
72
74
76
78
80
82
84
86
88
90
92
94
-40 -20 0 20 40 60 80 100 120
GROUND CURRENT (µA)
TEMPERATURE (°C)
ILOAD =100µA
Ground Pin Current
70
72
74
76
78
80
82
84
86
88
90
92
94
-40 -20 0 20 40 60 80 100 120
GROUND CURRENT (µA)
TEMPERATURE (°C)
ILOAD =150mA
Ground Pin Current
0
10
20
30
40
50
60
70
80
90
100
0123456
GROUND CURRENT (µA)
INPUT VOLTAGE (V)
ILOAD =100µA
Ground Pin Current
0
10
20
30
40
50
60
70
80
90
100
0123456
GROUND CURRENT (µA)
INPUT VOLTAGE (V)
ILOAD = 150mA
Ground Pin Current
0
0.5
1
1.5
2
2.5
3
3.5
0123456
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
ILOAD =150mA
ILOAD =100µA
Dropout Characteristics
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
-40 -20 0 20 40 60 80 100 120
DROPOUT VOLTAGE (mV)
TEMPERATURE(°C)
IOUT =1mA
Dropout Voltage
0
10
20
30
40
50
60
70
80
90
100
-40 -20 0 20 40 60 80 100 120
DROPOUT VOLTAGE (mV)
TEMPERATURE (°C)
IOUT =50mA
Dropout Voltage
0
10
20
30
40
50
60
70
80
90
100
-40 -20 0 20 40 60 80 100 120
DROPOUT VOLTAGE (mV)
TEMPERATURE (°C)
IOUT =100mA
Dropout Voltage
Micrel, Inc. MIC5305
June 2007 6
M9999-062507
0
10
20
30
40
50
60
70
80
90
100
-40 -20 0 20 40 60 80 100 120
DROPOUT VOLTAGE (mV)
TEMPERATURE (°C)
IOUT = 150mA
Dropout Voltage
0
10
20
30
40
50
60
70
0 20 40 60 80 100 120 140
DROPOUT VOLTAGE (mV)
OUTPUT CURRENT (mA)
Dropout Voltage
0
100
200
300
400
500
600
700
800
3 3.5 4 4.5 5 5.5 6
SHORT CIRCUIT CURRENT (mA)
INPUT VOLTAGE (V)
Short Circuit Curr ent
2.85
2.86
2.87
2.88
2.89
2.9
2.91
2.92
-40 -20 0 20 40 60 80 100 120
V
OUT
(V)
TEMPERATURE (°C)
I
LOAD
= 100µA
V
OUT
=2.9V
Output Voltage
vs. Temperature
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
-40 -20 0 20 40 60 80 100 120
ENABLE THRESHOLD VOLTAGE (V)
TEMPERATURE (°C)
ILOAD =100µA
Enable Threshold
vs. Temperature
Output Noise Spectral Densit
y
Micrel, Inc. MIC5305
June 2007 7
M9999-062507
Functional Characteristics
Line Transient Response
TIME (400µs/div)
Input Voltage
(1V/div)
OutputVoltage
(1V/div)
3V
5V
C
BYP
= 0.01µF
I
OUT
= 100µA
C
OUT
= 1µF Ceramic
C
BYP
= 0.01µF
V
IN
= 4V
C
OUT
= 1µF Ceramic
Loa d Trans i e nt Re s ponse
TIME (4µs/div)
Output Current
(100mA/div)
OutputVoltage
(50mV/div)
Enable Pin De lay
TIME (10µs/div)
OutputVoltage
(1V/div)
EnableVoltage
(1V/div)
C
BYP
= 0.01µF
I
OUT
= 100µA
C
IN
= 1µF Ceramic
C
OUT
= 1µF Ceramic
Shutdown De la y
TIME (20µs/div)
OutputVoltage
(1V/div)
EnableVoltage
(1V/div)
C
BYP
= 0.01µF
I
OUT
= 100µA
V
IN
= 4V
C
IN
= 1µF Ceramic
C
OUT
= 1µF Ceramic
Micrel, Inc. MIC5305
June 2007 8
M9999-062507
Functional Diagram
VIN
EN
BYP
VOUT
GND
Current
Limit
LDO
Quick-
Start
V
REF
Thermal
Shutdown
Error
Amp
MIC5305 Block Diagram – Fi xed
VIN
EN
BYP
VOUT
GND
Current
Limit
LDO
Quick-
Start
V
REF
Thermal
Shutdown
Error
Amp
MIC5305 Block Diagram – Adju stab le
Micrel, Inc. MIC5305
June 2007 9
M9999-062507
Application Information
Enable/Shutdown
The MIC5305 comes with an active-high enable pin that
allows the regulator to be disabled. Forcing the enable
pin low disables the regulator and sends it into a “zero”
off-mode-current state. In this state, current consumed
by the regulator goes nearly to zero. Forcing the enable
pin high enables the output voltage. The active-high
enable pin uses CMOS technology and the enable pin
cannot be left floating; a floating enable pin may cause
an indeterminate state on the output.
Input Capacitor
The MIC5305 is a high-performance, high bandwidth
device. Therefore, it requires a well-bypassed input
supply for optimal performance. A 1µF capacitor is
required from the input to ground to provide stability.
Low-ESR ceramic capacitors provide optimal perform-
ance at a minimum of space. Additional high frequency
capacitors, such as small-valued NPO dielectric-type
capacitors, help filter out high-frequency noise and are
good practice in any RF-based circuit.
Output Capacitor
The MIC5305 requires an output capacitor of 1µF or
greater to maintain stability. The design is optimized for
use with low-ESR ceramic chip capacitors. High ESR
capacitors may cause high frequency oscillation. The
output capacitor can be increased, but performance has
been optimized for a 1µF ceramic output capacitor and
does not improve significantly with larger capacitance.
X7R/X5R dielectric-type ceramic capacitors are recom-
mended because of their temperature performance.
X7R-type capacitors change capacitance by 15% over
their operating temperature range and are the most
stable type of ceramic capacitors. Z5U and Y5V
dielectric capacitors change value by as much as 50%
and 60%, respectively, over their operating temperature
ranges. To use a ceramic chip capacitor with Y5V
dielectric, the value must be much higher than an X7R
ceramic capacitor to ensure the same minimum
capacitance over the equivalent operating temperature
range.
Bypass Capacitor
A capacitor can be placed from the noise bypass pin to
ground to reduce output voltage noise. The capacitor
bypasses the internal reference. A 0.1µF capacitor is
recommended for applications that require low-noise
outputs. The bypass capacitor can be increased, further
reducing noise and improving PSRR. Turn-on time
increases slightly with respect to bypass capacitance. A
unique, quick-start circuit allows the MIC5305 to drive a
large capacitor on the bypass pin without significantly
slowing turn-on time. Refer to the Typical Characteristics
section for performance with different bypass capacitors.
No-Load Stability
Unlike many other voltage regulators, the MIC5305 will
remain stable and in regulation with no load. This is
especially import in CMOS RAM keep-alive applications.
Adjustable Regulator Application
Adjustable regulators use the ratio of two resistors to
multiply the reference voltage to produce the desired
output voltage. The MIC5305 can be adjusted from
1.25V to 5.5V by using two external resistors (Figure 1).
The resistors set the output voltage based on the
following equation:
⎟
⎠
⎞
⎜
⎝
⎛+= R2
R1
1VV
REFOUT
V
REF
= 1.25V
MIC5305BML
VOUTVIN
ADJEN
GND
V
IN
V
OUT
R1
1µF
R2
1µF
Figure 1. Adjustable Voltage Application
Thermal Considerations
The MIC5305 is designed to provide 150mA of conti-
nuous current in a very small package. Maximum
ambient operating temperature can be calculated based
on the output current and the voltage drop across the
part. Given that the input voltage is 5.0V, the output
voltage is 2.9V and the output current = 150mA.
The actual power dissipation of the regulator circuit can
be determined using the equation:
P
D
= (V
IN
– V
OUT
) I
OUT
+ V
IN
I
GND
Because this device is CMOS and the ground current is
typically <100µA over the load range, the power
dissipation contributed by the ground current is < 1%
and can be ignored for this calculation.
P
D
= (5.0V – 2.9V) × 150mA P
D
= 0.32W
To determine the maximum ambient operating temp-
erature of the package, use the junction-to-ambient
thermal resistance of the device and the following basic
equation:
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛−
=
JA
AJ(max)
D(max)
θ
TT
P
T
J(max)
= 125°C, the max. junction temperature of
the die.
θ
JA
thermal resistance = 93°C/W
Micrel, Inc. MIC5305
June 2007 10 M9999-062507
Table 1 shows junction-to-ambient thermal resistance for
the MIC5305 in the 6-pin 2mm × 2mm MLF
®
package.
Package θJA Recommended
Minimum Footprint θJC
6-Pin 2x2 MLF
®
93°C/W 2°C/W
Table 1. Thermal Resistance
Substituting P
D
for P
D(max)
and solving for the ambient
operating temperature will give the maximum operating
conditions for the regulator circuit. The junction-to-
ambient thermal resistance for the minimum footprint
(the minimum amount of copper that you can solder the
part to) is 93°C/W, from Table 1. The maximum power
dissipation must not be exceeded for proper operation.
For example, when operating the MIC5305-2.9BML at
an input voltage of 5.0V and 150mA load with a
minimum footprint layout, the maximum ambient
operating temperature T
A
can be determined as follows:
C/W93
TC125
0.32W
A
°
−°
=
T
A
= 95.2°C
Therefore, a 2.9V application at 150mA of output current
can accept an ambient operating temperature of 95.2°C
in a 6-pin 2mm x 2mm MLF
®
package. For a full dis-
cussion of heat sinking and thermal effects on voltage
regulators, refer to the “Regulator Thermals” section of
Micrel’s Designing with Low-Dropout Voltage Regulators
handbook. This information can be found on Micrel's
website at:
http://www.micrel.com/_PDF/other/LDOBk_ds.pdf
Micrel, Inc. MIC5305
June 2007 11 M9999-062507
Package Information
6-Pin 2x2 MLF
®
(ML)
6-Pin 2x2 Thin MLF
®
(MT)
Micrel, Inc. MIC5305
June 2007 12 M9999-062507
5-Pin TSOT-23 (D5)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its
use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant
into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2004 Micrel, Incorporated.
