MIC5318
High Performance 300mA
µCap ULDO™
ULDO is a trademark of Micrel, Inc.
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
General Description
The MIC5318 is a high performance, single output
ultra low drop-out (ULDO™) regulator, offering low
total output noise in an ultra-small Thin MLF®
package. The MIC5318 is capable of sourcing 300mA
output current and offers high PSRR and low output
noise, making it an ideal solution for RF applications.
Ideal for battery operated applications, the MIC5318
offers 2% initial accuracy, extremely low dropout
voltage (110mV @ 300mA), and low ground current
(typically 85µA total). The MIC5318 can also be put
into a zero-off-mode current state, drawing no current
when disabled.
The MIC5318 is available in the 1.6mm x 1.6mm Thin
MLF® package, occupying only 2.56mm2 of PCB area,
fully a 36% reduction in board area when compared to
SC-70 and 2mm x 2mm MLF® packages.
The MIC5318 has an operating junction temperature
range of –40°C to +125°C and is available in fixed and
adjustable output voltages in lead-free (RoHS
compliant) Thin MLF® and Thin SOT23-5 packages.
Data sheets and support documentation can be found
on Micrel’s web site at: www.micrel.com.
Features
Ultra low dropout voltage 110mV @ 300mA
Input voltage range: 2.3V to 6.0V
300mA guaranteed output current
Stable with ceramic output capacitors
Ultra low output noise – 30µVrms
Low quiescent current – 85µA total
High PSRR > 70dB@1kHz
Less than 35µs turn-on time
High output accuracy
± 2% initial accuracy
± 3% over temperature
Thermal shutdown and current limit protection
Tiny 6-pin 1.6mm x 1.6mm Thin MLF® package
Thin SOT23-5 package
Applications
Mobile phones
PDAs
GPS receivers
Portable electronics
Digital still and video cameras
Typical Application
VOUTVIN
EN
GND
V
IN
1µF
1µF
MIC5318-x.xYMT
BYP
0.01µF
Portable Application
September 2010 M9999-092810-B
Micrel, Inc. MIC5318
September 2010 2 M9999-092810-B
Functional Diagram
VIN
EN
BYP
VOUT
GND
Current
Limit
LDO
Quick-
Start
VREF
Thermal
Shutdown
Error
Amp
MIC5318 Block Diagram – Fixed
VIN
EN
BYP
VOUT
GND
Current
Limit
LDO
Quick-
Start
VREF
Thermal
Shutdown
Error
Amp
ADJ
MIC5318 Block Diagram – Adjustable
Micrel, Inc. MIC5318
September 2010 3 M9999-092810-B
Ordering Information
Part Number Marking Code Output Voltage Temperature Range Package
MIC5318-1.5YMT 15D 1.5V –40°C to +125°C 6-Pin 1.6 x 1.6 Thin MLF®
MIC5318-1.8YMT 18D 1.8V –40°C to +125°C 6-Pin 1.6 x 1.6 Thin MLF®
MIC5318-2.5YMT 25D 2.5V –40°C to +125°C 6-Pin 1.6 x 1.6 Thin MLF®
MIC5318-2.8YMT 28D 2.8V –40°C to +125°C 6-Pin 1.6 x 1.6 Thin MLF®
MIC5318-3.3YMT 33D 3.3V –40°C to +125°C 6-Pin 1.6 x 1.6 Thin MLF®
MIC5318YMT DAA ADJ –40°C to +125°C 6-Pin 1.6 x 1.6 Thin MLF®
MIC5318-1.5YD5 QD15 1.5V –40°C to +125°C 5-Pin Thin SOT23
MIC5318-1.8YD5 QD18 1.8V –40°C to +125°C 5-Pin Thin SOT23
MIC5318-2.5YD5 QD25 2.5V –40°C to +125°C 5-Pin Thin SOT23
MIC5318-2.8YD5 QD28 2.8V –40°C to +125°C 5-Pin Thin SOT23
MIC5318-3.3YD5 QD33 3.3V –40°C to +125°C 5-Pin Thin SOT23
MIC5318YD5 QDAA ADJ –40°C to +125°C 5-Pin Thin SOT23
Note:
1. For availability on other voltages, please contact Micrel for details.
Micrel, Inc. MIC5318
September 2010 4 M9999-092810-B
Pin Configuration
1EN
GND
IN
6 BYP
NC
OUT
5
4
2
3
1EN
GND
IN
6 BYP
ADJ
OUT
5
4
2
3
6-Pin 1.6mm x 1.6mm Thin MLF® (MT)
Fixed (Top View)
6-Pin 1.6mm x 1.6mm Thin MLF® (MT)
Adjustable (Top View)
EN GND
BYP OUT
IN
31
5
2
4
EN GND
ADJ OUT
IN
31
5
2
4
5-Pin Thin SOT23 (D5)
Fixed (Top View)
5-Pin Thin SOT23 (D5)
Adjustable (Top View)
Pin Description
Pin No.
Thin
MLF-6
Fixed
Pin No.
Thin MLF-6
Adj.
Pin No.
Thin SOT23-5
Fixed
Pin No.
Thin SOT23-5
Adj.
Pin Name
Pin Function
1 1 3 3 EN
Enable Input. Active High. High = on, low = off.
Do not leave floating.
2 2 2 2 GND Ground
3 3 1 1 IN Supply Input.
4 4 5 5 OUT Output Voltage.
5 NC No connection.
– 5 4 ADJ
Adjust Input. Connect to external resistor voltage
divider network.
6 6 4 BYP
Reference Bypass: Connect external 0.01μF to
GND for reduced Output Noise. May be left open.
Exposed Heatsink Pad connected to ground
internally.
HS Pad HS Pad E PAD
Micrel, Inc. MIC5318
September 2010 5 M9999-092810-B
Absolute Maximum Ratings(1)
Supply Voltage (VIN) ..................................0V to +6.5V
Enable Input Voltage (VEN)........................0V to +6.5V
Power Dissipation, Internally Limited(3)
Lead Temperature (soldering, 3sec)..................260°C
Junction Temperature (TJ)................ –40°C to +125°C
Storage Temperature (TS)................ –65°C to +150°C
ESD Rating(4)
Operating Ratings(2)
Supply Voltage (VIN).............................. +2.3V to +6.0V
Enable Input Voltage (VEN).............................. 0V to VIN
Junction Temperature (TJ) ................. –40°C to +125°C
Junction Thermal Resistance
Thin MLF-6 (θJA)...................................... 100°C/W
TSOT-23-5 (θJA) ...................................... 235°C/W
Electrical Characteristics(5)
VIN = VOUT + 1.0V; COUT = 1.0µF; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C to +125°C, unless noted.
Parameter Conditions Min Typ Max Units
Variation from nominal VOUT 2.0 +2.0 %
Output Voltage Accuracy
Variation from nominal VOUT; –40°C to +125°C 3.0 +3.0
%
Line Regulation VIN = VOUT + 1V to 6.0V; IOUT = 100µA 0.02 0.6 %/V
Load Regulation, Note 6 IOUT = 100µA to 300mA 0.2 2.0 %
Dropout Voltage, Note 7
IOUT = 50mA; VOUT 2.8V
IOUT = 150mA; VOUT 2.8V
IOUT = 300mA; VOUT 2.8V
17
50
110
100
200
mV
Ground Pin Current, Note 8 IOUT = 0 to 300mA 85 150 µA
Ground Pin Current in
Shutdown VEN 0.2V 0.01 1 µA
Ripple Rejection f = up to 1kHz; COUT = 1.0µF; CBYP = 0.1µF
f = 1kHz – 20kHz; COUT = 1.0µF; CBYP = 0.1µF 75
55 dB
Current Limit VOUT = 0V 340 500 900 mA
Output Voltage Noise COUT = 1.0µF; CBYP = 0.1µF; 10Hz to 100kHz 30 µVRMS
Enable Input
Logic Low 0.2
Enable Input Voltage Logic High 1.1 V
VIL 0.2V 0.01 1
Enable Input Current VIH 1.0V 0.01 1 µA
Turn-On Time
Turn-On Time COUT = 1.0µF; CBYP = 0.1µF; IOUT = 150mA 30 100 µs
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 TA (ambient temperature) is PD(max) = (TJ(max) – TA) / θJA. 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 value measured at 1V
differential. For outputs below 2.3V, dropout voltage is the input-to-output differential with the minimum input voltage 2.3V.
8. Ground pin current is the regulation quiescent current. The total current drawn from the supply is the sum of the load current plus the ground
pin current.
Micrel, Inc. MIC5318
September 2010 6 M9999-092810-B
Typical Characteristics
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
Power Supply
Rejection Ratio
10
FREQUENCY (kHz)
10.1 100 1,000
1.5
1.6
1.7
1.9
2.1
2.0
Output Voltage
vs. Temperature
TEMPERATURE (°C)
VIN = VOUT + 1V
VOUT = 1.8V
COUT = 1µF
IOUT = 100µA
1.8
0
0.5
1.0
1.5
2.0
2.5
3.0
0 1234567
SUPPLY VOLTAGE (V)
Output Voltage
vs. Supply Voltage
VOUT = 2.8V
COUT = 1µF
300mA
100µA
300mA 150mA
50mA
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
CBYP = 0.1µF
2.70
2.75
2.80
2.85
05 0 100 150 200 250 300
OUTPUT CURRENT (mA)
2.90
Output Voltage
vs. Output Current
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
0
110
120
130
140
Dropout Voltage
TEMPERATURE (°C)
vs. Temperature
COUT = 1µF
300mA
150mA
50mA
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
110
120
05 0 100 150 200 250 300
OUTPUT CURRENT (mA)
Dropout Voltage
vs. Output Current
COUT = 1µF
VOUT = 2.8V
0
10
20
30
40
50
60
90
100
Ground Pin Current
vs. Temperature
TEMPERATURE (°C)
300mA
100µA
VIN = VOUT + 1V
VOUT = 1.8V
COUT = 1µF
70
80
0
10
20
30
40
50
60
70
80
90
100
110
05 0 100 150 200 250 300
OUTPUT CURRENT (mA)
Ground Pin Current
vs. Output Current
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
0
10
20
30
40
50
60
70
80
90
100
110
2 2.5 3 3.5 4 4.5 5 5.5 6 6.5
INPUT VOLTAGE (V)
Ground Pin Current
vs. Input Voltage
100µA 300mA
400
420
440
460
480
500
520
540
560
580
600
2 2.5 3 3.5 4 4.5 5 5.5 6
INPUT VOLTAGE (V)
Current Limit
vs. Input Voltage
0.001
0.01
0.1
1
10
Output Noise
Spectral Density
10
FREQUENCY (kHz)
10.01 100 10,0000.1 1,000
VIN = 4V
VOUT = 2.8V
COUT = 1µF
CBYP = 0.1µF
Micrel, Inc. MIC5318
September 2010 7 M9999-092810-B
Functional Characteristics
Enable Turn-On
Enable
(0.5V/div)
Output Voltag e
(1V/div)
Time (10µs/div )
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
CBYP = 0.1µF
Line Transient
Input Voltag e
(2V/div)
Output Voltag e
(50mV/div)
Time (40µs/div )
VOUT = 1.8V
COUT = 1µF
CBYP = 0.1µF
IOUT = 10mA
6V
3V
Load Transient
Output Voltage
(50mVV/div)
Output Current
(100mA/div)
Time (40µs/div )
VIN = VOUT + 1V
VOUT = 2.8V
COUT = 1µF
300mA
10mA
Micrel, Inc. MIC5318
September 2010 8 M9999-092810-B
Application Information
Enable/Shutdown
The MIC5318 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 MIC5318 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
performance 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 MIC5318 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
recommended because of their temperature perform-
ance. 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 MIC5318 to drive a large capacitor on the
bypass pin without significantly slowing turn-on time.
Refer to the Typical Characteristics subsection for
performance with different bypass capacitors.
No-Load Stability
Unlike many other voltage regulators, the MIC5318
will remain stable and in regulation with no load. This
is especially crucial for 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 MIC5318 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:
VOUT =
+R2
R1
1VREF
VREF = 1.25V
MIC5318YMT
VOUTVIN
ADJEN
GND
V
IN VOUT
R1
1µF
R2
1µF
Figure 1. Adjustable Voltage Output
Micrel, Inc. MIC5318
September 2010 9 M9999-092810-B
Substituting PD for PD(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 is 100°C/W.
Thermal Considerations
The MIC5318 is designed to provide 300mA of
continuous current. 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 3.3V, the output voltage is
2.8V and the output current = 300mA.
The maximum power dissipation must not be
exceeded for proper operation.
For example, when operating the MIC5318-2.8YMT at
an input voltage of 3.3V and 300mA load with a
minimum footprint layout, the maximum ambient
operating temperature TA can be determined as
follows:
The actual power dissipation of the regulator circuit
can be determined using the equation:
PD = (VIN – VOUT) IOUT + VIN IGND
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:
0.15W = (125°C – TA)/(100°C/W)
T
A = 110°C
Therefore, a 2.8V application with 300mA of output
current can accept an ambient operating temperature
of 110°C in a 1.6mm x 1.6mm Thin MLF® package.
For a full discussion 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 informa-
tion can be found on Micrel's website at:
PD = (3.3V – 2.8V) × 300mA
PD = 0.15W
To determine the maximum ambient operating
temperature of the package, use the junction-to-
ambient thermal resistance of the device and the
following basic equation: http://www.micrel.com/_PDF/other/LDOBk_ds.pdf
PD(MAX) =
TJ(MAX) - TA
JA
TJ(max) = 125°C, the maximum junction temperature of
the die θJA thermal resistance = 100°C/W.
The table below shows junction-to-ambient thermal
resistance for the MIC5318 in the 6-pin 1.6mm x
1.6mm Thin MLF® package.
Package θJA Recommended
Minimum Footprint
6-Pin 1.6x1.6 Thin MLF® 100°C/W
Thermal Resistance
Micrel, Inc. MIC5318
September 2010 10 M9999-092810-B
Package Information
6-Pin 1.6mm x 1.6mm Thin MLF® (MT)
5-Pin TSOT-23 (D5)
Micrel, Inc. MIC5318
September 2010 11 M9999-092810-B
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
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This
information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry,
specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any
intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel
assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including
liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual
property right
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.
© 2006 Micrel, Incorporated.
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TR MIC5318-1.5YMT TR MIC5318-2.6YD5 TR MIC5318-1.3YD5 TR MIC5318-2.85YD5 TR MIC5318-2.5YMT TR
MIC5318-3.0YD5 TR MIC5318-1.3YMT TR MIC5318-2.1YD5 TR MIC5318-2.9YD5 TR MIC5318-2.1YMT TR
MIC5318-2.8YMT TR MIC5318-2.6YMT TR MIC5318-1.5YD5 TR MIC5318-4.6YMT TR MIC5318-3.3YD5-TR
MIC5318-2.9YMT-TR MIC5318-1.5YD5-TR MIC5318-1.8YD5-TR MIC5318-2.5YD5-TR MIC5318-1.5YMT-TR
MIC5318-2.9YD5-TR MIC5318-3.0YD5-TR MIC5318YMT-TR MIC5318-1.3YMT-TR MIC5318-2.1YD5-TR MIC5318-
1.8YMT-TR MIC5318-2.1YMT-TR MIC5318-2.5YMT-TR MIC5318-3.0YMT-TR MIC5318-2.6YMT-TR MIC5318-
3.3YMT-TR MIC5318-4.6YMT-TR MIC5318-2.85YD5-TR MIC5318-2.8YMT-TR MIC5318-2.6YD5-TR MIC5318YD5-
TR MIC5318-1.3YD5-TR MIC5318-2.8YD5-TR MIC5318-4.6YD5-TR