MIC5315
Low Voltage Dual 300mA LDO
with Voltage Select
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
July 2008 M9999-070208-A
General Description
The MIC5315 is a high performance, dual low input
voltage, low dropout regulator with voltage select. Major
features include two 300mA LDOs, input voltage down to
1.7V, ultra low drop out of 85mV at full load, and voltage
select. Each LDO has its own low voltage input for system
flexibility. The low input voltages and low drop out
operation provides high efficiency by reducing the input to
output voltage step which minimizes the regulator power
loss. Voltage select is incorporated into the second output,
which reduces the output voltage to a lower level to further
save power while in stand-by mode.
Ideal for battery operated applications; the MIC5315 offers
1% accuracy and low ground current to increase light load
efficiency. The MIC5315 can also be put into a zero-off-
mode current state, drawing virtually no current when
disabled.
The MIC5315 is available in fixed output voltages in the
10-pin 2mm x 2mm Thin MLF
®
leadless package.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• 300mA output current for each LDO
• Dual low voltage regulator inputs: 1.7V to 5.5V
• Low output voltage range: 0.8V to 2.0V
• Ultra-low dropout voltage of 85mV @ 300mA
• Voltage select function
• Stable with 1µF ceramic output capacitors
• Very fast transient response
• Thermal shutdown and current limit protection
• Tiny 10-pin 2mm x 2mm Thin MLF
®
package
Applications
• Mobile Phones
• GPS and Navigation Devices
• Portable Media Players
• Digital still and video cameras
• PDAs
• Portable electronics
___________________________________________________________________________________________________________
Typical Application
VBAT
CBIAS
1µF
VIN1
CBYP
VIN2
EN2
VBIAS
EN1
VOUT2
VOUT1
MIC5315-xxyYMT
GND 10nF
1µF 1µF
CIN
1µF
MIC23031-1.8YMT
DC-to-DC
Converter
VI/O
VCORE1
VCORE2
µProcessor
/VSC2
Micrel, Inc. MIC5315
July 2008 2 M9999-070208-A
Ordering Information
Part Number Manufacturing
Part Number Marking
(1)
VOUT1
(2)
VOUT2
(2)
Junction
Temp. Range Package
(3)
MIC5315-1.5/1.2/1.0YMT MIC5315-F4CYMT F4C 1.5V 1.2V/1.0V –40°C to +125°C 10-Pin 2mm x 2mm
Thin MLF
®
MIC5315-1.5/1.3/1.0YMT MIC5315-F5CYMT F5C 1.5V 1.3V/1.0V –40°C to +125°C 10-Pin 2mm x 2mm
Thin MLF
®
MIC5315-1.8/1.6/1.1YMT MIC5315-GW3YMT GW3 1.8V 1.6V/1.1V –40°C to +125°C 10-Pin 2mm x 2mm
Thin MLF
®
MIC5315-1.8/1.8/1.0YMT MIC5315-GGCYMT GGC 1.8V 1.8V/1.0V –40°C to +125°C 10-Pin 2mm x 2mm
Thin MLF
®
Notes:
1. Pin 1 identifier = ▲.
2. For other voltage option, contact Micrel Marketing for details
3. MLF
®
is a GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Pin Configur ation
EN2 GND5
1VIN1
VIN2
V
BIAS
EN1
10 VOUT1
VOUT2
/VSC2
CBYP
9
8
7
2
3
4
6
10-Pin 2mm × 2mm Thin MLF
®
(MT)
Pin Description
Pin Number Pin Name Pin Function
1 VIN1 Voltage Input for LDO1.
2 VIN2 Voltage Input for LDO2.
3 VBIAS Bias Input Voltage.
4 EN1
Enable Input for LDO1. Active High Input. Logic High = On; Logic Low = Off; Do
not leave floating.
5 EN2
Enable Input for LDO2. Active High Input. Logic High = On; Logic Low = Off; Do
not leave floating.
6 GND Ground.
7 CBYP Bypass: Connect a capacitor to ground to improve output noise and PSRR.
8 /VSC2
Voltage Select Input for LDO2. Active Low Input. Logic High = Full Output
Voltage; Logic Low = Low Output Voltage. Do not leave floating.
9 VOUT2 Output of regulator 2.
10 VOUT1 Output of regulator 1.
Micrel, Inc. MIC5315
July 2008 3 M9999-070208-A
Absolute Maximum Ratings(1)
Main Input Voltage (V
IN1
, V
IN2
)..........................0V to V
BIAS
Bias Supply Voltage (V
BIAS
)...............................0V to +6V
Enable Input Voltage (V
EN1
, V
EN2
) ....................0V to V
BIAS
Voltage Select Input Voltage (V
/VSC2
) ...............0V to V
BIAS
Power Dissipation ...............................Internally Limited
(3)
Lead Temperature (soldering, 3sec.)......................260°C
Storage Temperature (T
s
) ..................... –65°C to +150°C
ESD Rating
(4)
...............................................................2kV
Operating Ratings(2)
Supply voltage (V
IN1
, V
IN2
)...........................+1.7V to V
BIAS
Bias Supply Voltage (V
BIAS
) ........................ 2.5V to +5.5V
Enable Input Voltage (V
EN1
, V
EN2
) ...................0V to V
BIAS
Voltage Select Input Voltage (V
/VSC2
)............... 0V to V
BIAS
Junction Temperature (T
J
) .....................–40°C to +125°C
Junction Thermal Resistance
2mm x 2mm Thin MLF-10 (θ
JA
).............................80°C/W
Electrical Characteristics(4)
V
BIAS
= 3.6V; V
IN1
= V
IN2
= V
OUT
(Highest of two regulators) + 1V; C
BIAS
=C
OUT
= 1.0µF, C
BYP
=0.01µF, I
OUT
= 100µA;
T
J
= 25ºC, bold values indicate –40ºC to + 125ºC; unless noted.
Parameter Condition Min Typ Max Units
Variation from nominal V
OUT1
& V
OUT2
–1.0 +1.0 % Output Voltage Accuracy
Variation from nominal V
OUT1
& V
OUT2
–2.0 +2.0 %
V
OUT2
, V
/VSC2
= Logic Low -3.0 +3.0 % Select Mode Output Voltage
Accuracy V
OUT2
, V
/VSC2
= Logic Low
-4.0 +4.0 %
V
IN
Line Regulation V
IN
= V
OUT
+1V to 5.5V, V
BIAS
= 5.5V 0.02 0.3 %/V
V
BIAS
Line Regulation V
BIAS
= 3.6V to 5.5V, V
IN
= V
OUT
+1V 0.02 0.3 %/V
Load Regulation I
OUT
= 100µA to 300mA 0.4 1.0 %
Dropout Voltage I
OUT
= 150mA
I
OUT
= 300mA
40
85
100
200
mV
mV
Ground Pin Current V
IN1
,V
IN2
V
EN1
= High; V
EN2
= Low; I
OUT1
= 100µA to 300mA
V
EN1
= Low; V
EN2
= High; I
OUT2
= 100µA to 300mA
7
7
12
12
µA
µA
Ground Pin Current V
BIAS
I
OUT1
= I
OUT2
= 100µA to 300mA 30 46 µA
Ground Pin Current in
Shutdown
V
EN
≤ 0.2V 0.01 1.0 µA
V
IN
Ripple Rejection f = 1kHz; C
OUT
= 1.0µF; C
BYP
= 0.01µF
f = 20kHz; C
OUT
= 1.0µF; C
BYP
= 0.01µF
65
40
dB
dB
Current Limit V
OUT
= 0V 350 550 mA
Output Voltage Noise C
OUT
=1µF, C
BYP
=0.01µF, 10Hz to 100kHz 30 µV
RMS
Enable
Logic Low 0.2 V Enable Input Voltage
Logic High 1.2 V
V
IL
≤ 0.2V 0.02 1 µA Enable Input Current
V
IH
≥ 1.2V 0.2 1 µA
Turn-on Time C
OUT
= 1µF; C
BYP
= 0.01µF 150 300 µs
Micrel, Inc. MIC5315
July 2008 4 M9999-070208-A
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, 1.5kΩ in series with 100pF.
5. Specification for packaged product only.
Micrel, Inc. MIC5315
July 2008 5 M9999-070208-A
Typical Characteristics
0
Power Supply
Rejection Ratio (VIN)
100
FREQUENCY (Hz)
10 1k 10k 1M
300mA
150mA
100k
V
IN
= V
OUT
+1V
V
OUT
= 1.8V
C
OUT
= 1µF
C
BYP
= 10nF
0
Power Supply
Rejection Ratio (VBIAS)
100
FREQUENCY (Hz)
10 1k 10k 1M
V
IN
= V
OUT
+1V
V
OUT
= 1.8V
C
OUT
= 1µF
C
BYP
= 10nF
300mA
150mA
100k
10
11
12
13
14
15
16
Ground Current (VIN)
vs. Temperature
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
V
IN
= V
OUT
+1V
V
BIAS
= 3.6V
V
OUT1
= 1.5V
V
OUT2
= 1.2V
C
OUT
= 1µF
C
BYP
= 10nF
I
OUT1
= I
OUT2
= 300mA
0 50 100 150 200 250 300
OUTPUT CURRENT (mA)
12.0
12.5
13.0
13.5
14.0
14.5
15.0
15.5
16.0
Ground Current (VIN)
vs. Output Current
V
IN
= V
OUT
+1V
V
BIAS
= 3.6V
V
OUT1
= 1.5V
V
OUT2
= 1.2V
C
OUT
= 1µF
C
BYP
= 10nF
24
25
26
27
28
29
30
0 50 100 150 200 250 300
OUTPUT CURRENT (mA)
Ground Current (VBIAS)
vs. Output Current
V
IN
= V
OUT
+1V
V
BIAS
= 3.6V
V
OUT1
= 1.5V
V
OUT2
= 1.2V
C
OUT
= 1µF
C
BYP
= 10nF
12
13
14
15
16
1.5 2.5 3.5 4.5 5.5
INPUT VOLTAGE (V)
2.0 3.0 4.0 5.0
Ground Current (VIN)
vs. Input Voltage
V
BIAS
= 3.6V
V
OUT1
= 1.5V
V
OUT2
= 1.2V
C
OUT
= 1µF
C
BYP
= 10nF
300mA
10mA
0
20
40
60
80
100
120
Dropout Voltage
vs. Temperature
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
V
OUT
= 1.5V
C
OUT
= 1µF
300mA
10mA
150mA
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
0 50 100 150 200 250 300
LOAD CURRENT (mA)
Dropout Voltage
vs. Load Current
V
BIAS
= 3.6V
V
OUT
= 1.8V
C
OUT
= 1µF
1.30
1.35
1.40
1.45
1.50
1.55
1.60
1.65
1.70
Output Voltage
vs. Temperature
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
V
IN
= V
OUT
+1V
V
BIAS
= 3.6V
EN = V
IN
V
OUT
= 1.5V
C
OUT
= 1µF
1.30
1.35
1.40
1.45
1.50
1.55
1.60
1.65
1.70
0 50 100 150 200 250 300
OUTPUT CURRENT (mA)
Output Voltage
vs. Output Current
VIN = VOUT +1V
VBIAS = 3.6V
VOUT = 1.5V
COUT = 1µF
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
INPUT VOLTAGE (V)
Output Voltage
vs. Input Volta ge
VBIAS = 5.5V
IOUT = 10mA
COUT1 = 1µF
COUT2 = 1µF
1.8V
1.1V
450
470
490
510
530
550
570
590
610
630
650
1.5 2 2.5 3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
Current Limit
vs. Input Volta ge
VBIAS = 5.5V
VOUT = 1.5V
COUT = 1µF
Micrel, Inc. MIC5315
July 2008 6 M9999-070208-A
Typical Characteristics (continued)
0.001
0.01
0.1
1
Output Noise
Spectral Density
100
FREQUENCY (Hz)
10 1k 10k 1M100k
COUT = 1µF
CBYP = 10nF
Micrel, Inc. MIC5315
July 2008 7 M9999-070208-A
Functional Characteristics
Micrel, Inc. MIC5315
July 2008 8 M9999-070208-A
Functional Diagram
EN1
VIN1
VBIAS
GND
VOUT1
VOUT2
LDO1
THERMAL
LIMIT
QUICK START
REFERENCE
CURRENT
LIMIT
EN2
VIN2
LDO2
CBYP
/VSC2
MIC5315 Block Diagram
Micrel, Inc. MIC5315
July 2008 9 M9999-070208-A
Application Information
The MIC5315 is a high performance, dual low input
voltage, ultra-low dropout regulator designed for low
applications requiring very fast transient response. The
MIC5315 utilizes two input supplies (V
IN
and V
BIAS
),
significantly reducing the dropout voltage.
The MIC5315 regulator is fully protected from damage
due to fault conditions, offering linear current limiting and
thermal shutdown.
Bias Supply Voltage
V
BIAS
, requiring relatively light current, provides power to
the control portion of the MIC5315. Bypassing on the
bias pin is recommended to improve performance of the
regulator during line and load transients. A 1µF ceramic
capacitor from V
BIAS
-to-ground is recommended to help
reduce the high frequency noise from being injected into
the control circuitry.
Input Supply Voltage
V
IN1
and V
IN2
, provide the supply to power the LDOs
independently. The minimum input voltage is 1.7V
allowing conversion from low voltage supplies. The low
input voltage provides high efficiency by reducing the
input to output voltage step which minimizes the
regulator power loss.
Input Capacitor
The MIC5315 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.
X5R or X7R dielectrics are recommended for the input
capacitor. Y5V dielectrics lose most of their capacitance
over temperature and are therefore, not recommended.
Output Capacitor
The MIC5315 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
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 bypass pin-to-ground
to reduce the output voltage noise. The capacitor
bypasses the internal reference. A 0.01µF 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 the bypass
capacitance. A unique, quick-start circuit allows the
MIC5315 to drive a large capacitor on the bypass pin
without significantly slowing turn-on time.
No-Load Stability
Unlike many other voltage regulators, the MIC5315 will
remain stable and in regulation with no load. This is
especially important in CMOS RAM keep-alive
applications.
Enable/Shutdown
The MIC5315 is provided with dual active-high enable
pins that allow each regulator to be disabled
independently. 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.
Voltage Select
The MIC5315 incorporates voltage select technology to
set LDO2’s voltage output to a preset lower level. The
/VSC2 pin is an active low input. A logic high signal sets
V
OUT2
to the full output voltage; while a logic low signal
sets V
OUT2
to the lower output voltage.
Thermal Considerations
The MIC5315 is designed to provide 300mA of
continuous current for both outputs in a very small
package. Maximum ambient operating temperature can
be calculated based upon the output current and the
voltage drop across the part. Given that the input voltage
is 1.8V, the output voltage is 1.5V for V
OUT1
, 1.0V for
V
OUT2
and the output current = 300mA for each output.
The actual power dissipation of the regulator circuit can
be determined using the equation:
P
D
= (V
IN
– V
OUT1
) I
OUT1
+ (V
IN
– V
OUT2
) I
OUT2
+ V
BIAS
I
GND
Because this device is CMOS and the ground current is
Micrel, Inc. MIC5315
July 2008 10 M9999-070208-A
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
= (1.8V – 1.5V) × 300mA + (1.8V – 1.0V) × 300mA
P
D
= 0.33W
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:
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛−
=
JA
AJ(MAX)
D(MAX)
θ
TT
P
T
J(max)
= 125°C, the maximum junction temperature of
the die. The junction-to-ambient thermal resistance for
the minimum footprint, is θ
JA
= 80°C/W.
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 maximum power dissipation must not be exceeded
for proper operation.
For example, when operating the MIC5315-F5CYMT at
an input voltage of 1.8V and 300mA, loads at each
output with a minimum footprint layout, the maximum
ambient operating temperature T
A
can be determined as
follows:
0.33W = (125°C – T
A
)/(80°C/W)
T
A
= 98.6°C
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 information can be found on
Micrel's website at:
http://www.micrel.com/_PDF/other/LDOBk_ds.pdf
Micrel, Inc. MIC5315
July 2008 11
M9999-070208-A
MIC5315 Typical Application Circuit
J1
VIN
C3
10nF
VIN1
1
/VSC2
8
VIN2
2
EN2
6
VBIAS
3
EN1
5
VOUT2
9
VOUT1
10
U
1
MIC5315-xxyYMT
GND
4
J3
V
BIAS
J4
EN1
J5
EN2
J2
GND
C5
1µF
C4
1µF
J7
VO1
J8
VO2
J9
GND
CBYP
7
C2
1µF
C1
1µF
VIN
J10
VSC
Bill of Materials
Item Part Number Manufacturer Description Qty
C1, C2, C4, C5 C1608X5R1A105K TDK
(1)
Capacitor, 1µF Ceramic, 10V, X5R, Size 0603 4
C3 VJ0603Y103KXACW1BC Vishay
(2)
Capacitor, 0.01µF, 50V, X7R, Size 0603 1
U1 MIC5315-xxyYMT Micrel
(3)
Low Voltage Dual 300mA LDO with V
SCALE
1
Notes:
1. TDK: www.tdk.com
2. Vishay: www.vishay.com
3. Micrel, Inc.: www.micrel.com
Micrel, Inc. MIC5315
July 2008 12
M9999-070208-A
PCB Layout Recommendations
Top Layer
Bottom Layer
Micrel, Inc. MIC5315
July 2008 13
M9999-070208-A
Package Information
10-Pin 2mm × 2mm Thin MLF
®
(MT)
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.
© 2008 Micrel, Incorporated.
