MIC94310
200mA LDO with
Ripple Blocker™ Technology
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
Ripple Blocker is a trademark of Micrel, Inc
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
February 2012 M9999-020612-A
General Description
The MIC94310 Ripple Blocker™ is a monolithic integrated
circuit that provides low-frequency ripple attenuation
(switching noise rejection) to a regulated output voltage.
This is important for applications where a DC/DC switching
converter is required to lower or raise a battery voltage but
where switching noise cannot be tolerated by sensitive
downstream circuits such as in RF applications. The
MIC94310 maintains high power supply ripple rejection
(PSRR) with input voltages operating near the output
voltage level to improve overall system efficiency. A low-
voltage logic enable pin facilitates ON/OFF control at
typical GPIO voltage levels.
The MIC94310 operates from an input voltage of 1.8V to
3.6V.
Packaged in a 0.88mm x 0.88mm 4-ball CSP or a 4-pin
1.2mm x 1.6mm Thin MLF®, the MIC94310 has a junction
operating temperature range of –40°C to +125°C.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• 1.8V to 3.6V input voltage range
• Active noise rejection over a wide frequency band
− >50dB from 10Hz to 10MHz at 200mA load
• Rated to 200mA output current
• Fixed output voltages
• Current-limit and thermal-limit protected
• Ultra-small 0.88mm x 0.88mm 4-ball CSP
• 1.2mm x 1.6mm, 4-pin Thin MLF®
• Logic-controlled enable pin
• −40°C to +125°C junction temperature range
Applications
• Smart phones
• Tablet PC/notebooks and webcams
• Digital still and video cameras
• Global positioning systems
• Mobile computing
• Automotive and industrial applications
_________________________________________________________________________________________________
Typical Application
PSRR C
OUT
= 1µF
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
FREQUENCY (Hz)
PSRR (dB)
I
OUT
= 200mA
I
OUT
= 100mA
I
OUT
= 10mA
V
IN
= 2.5V + 40mVpp
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
Micrel, Inc. MIC94310
February 2012 2 M9999-020612-A
Ordering Information
Part Number Marking Code Output Voltage Package2,3 Lead Finish
MIC94310-4YCS 1Z 1.2V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-FYCS 2Z 1.5V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-GYCS1 Z9 1.8V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-DYCS1 Z8 1.85V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-JYCS1 Z7 2.5V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-MYCS1 Z6 2.8V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-NYCS1 Z5 2.85V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-PYCS Z4 3.0V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-SYCS Z3 3.3V 0.88mm x 0.88mm CSP Pb-Free
MIC94310-4YMT 31T 1.2V 1.2mm x 1.6mm Thin MLF® Pb-Free
MIC94310-FYMT 32T 1.5V 1.2mm x 1.6mm Thin MLF® Pb-Free
MIC94310-GYMT 31G 1.8V 1.2mm x 1.6mm Thin MLF® Pb-Free
MIC94310-DYMT1 31D 1.85V 1.2mm x 1.6mm Thin MLF® Pb-Free
MIC94310-JYMT1 31J 2.5V 1.2mm x 1.6mm Thin MLF® Pb-Free
MIC94310-MYMT1 31M 2.8V 1.2mm x 1.6mm Thin MLF® Pb-Free
MIC94310-NYMT1 31N 2.85V 1.2mm x 1.6mm Thin MLF® Pb-Free
MIC94310-PYMT 31P 3.0V 1.2mm x 1.6mm Thin MLF® Pb-Free
MIC94310-SYMT 31S 3.3V 1.2mm x 1.6mm Thin MLF® Pb-Free
Notes:
1. Contact Micrel Marketing for availability.
2. Thin MLF® ▲ = Pin 1 identifier.
3. Thin MLF® is a GREEN RoHS-compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Micrel, Inc. MIC94310
February 2012 3 M9999-020612-A
Pin Configuration
4-Ball 0.88mm × 0.88mm CSP (CS) 4-Pin 1.2mm × 1.6mm Thin MLF® (MT)
Top View Top View
Pin Description
Pin Number
(Thin MLF®)
Ball Number
(CSP) Pin Name Pin Name
1 A2 VOUT Power switch output.
2 B2 GND Ground.
3 B1 EN
Enable input. A logic HIGH signal on this pin enables the part. Logic LOW
disables the part. Do not leave floating.
4 A1 VIN Power switch input and chip supply.
EP – ePad Exposed Heatsink Pad. Connect to Ground for best thermal performance.
Micrel, Inc. MIC94310
February 2012 4 M9999-020612-A
Functional Block Diagram
Micrel, Inc. MIC94310
February 2012 5 M9999-020612-A
Absolute Maximum Ratings(1)
Input Voltage (VIN).............................................. -0.3 to +4V
Output Voltage (VOUT) .................... –0.3 to VIN+0.3V or +4V
Enable Voltage (VEN)...................... –0.3 to VIN+0.3V or +4V
Lead Temperature (soldering, 10s)............................ 260°C
Storage Temperature (Ts).........................–65°C to +150°C
ESD Rating(3).................................................................. 3kV
Operating Ratings(2)
Input Voltage (VIN)........................................ +1.8V to +3.6V
Enable Voltage (VEN).............................................. 0V to VIN
Junction Temperature (TJ) ........................ –40°C to +125°C
Junction Thermal Resistance
Thin MLF® (θJA)................................................173°C/W
CSP (θJA) .........................................................250°C/W
Electrical Characteristics(4)
VIN = VEN = VOUT + 500mV (VIN = VEN = 3.6V for VOUT ≥ 3.1V); IOUT = 1mA; COUT = 1µF; TA = 25°C,
bold values indicate –40°C≤ TJ ≤ +125°C, unless noted.
Parameter Condition Min. Typ. Max. Units
Input Voltage 1.8 3.6 V
Output Voltage Accuracy Variation from nominal VOUT –3 ±1 +3 %
Dropout Voltage VIN to VOUT dropout at 100mA output current
VIN to VOUT dropout at 200mA output current 20
40
50
100 mV
Load Regulation 1mA to 100mA 4 mV
Line Regulation VIN = VOUT + 500mV to 3.6V 0.01 0.5 %
Ground Current No load to full load 170 250 µA
Shutdown Current VEN = 0V 0.2 5 µA
VIN Ripple Rejection
f = 100Hz, IOUT = 100mA
f = 100kHz, IOUT = 100mA
f = 1MHz, IOUT = 100mA
f = 10MHz, IOUT = 100mA
85
68
57
50
dB
Current Limit VOUT = 0V 250 400 700 mA
Total Output Noise 10Hz to 100kHz 83 μVRMS
Turn-On Time 70 μs
Enable
Input Logic Low 0.4 V
Input Logic High 1.0 V
Input Current 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. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF.
4. Specification for packaged product only.
Micrel, Inc. MIC94310
February 2012 6 M9999-020612-A
Typical Characteristics
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 0.47µF
I
OUT
= 10mA
I
OUT
= 200mA
I
OUT
= 100mA
V
IN
= 2.5V + 40mVpp
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 0.47µF
V
IN
= 3.6V
V
IN
= 2.5VV
IN
= 2.0V
V
IN
= V
IN(NOM)
+ 40mVpp
LOAD = 100mA
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 1µF
I
OUT
= 200mA
I
OUT
= 100mA
I
OUT
= 10mA
V
IN
= 2.5V + 40mVpp
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 1µF
V
IN
= 3.6V
V
IN
= 2.5V
V
IN
= 2.0V
V
IN
= V
IN(NOM)
+ 40mVpp
LOAD = 100mA
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 2.2µF
I
OUT
= 200mA
I
OUT
= 100mA
I
OUT
= 10mA
V
IN
= 2.5V + 40mVpp
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 2.2µF
V
IN
= 3.6V
V
IN
= 2.5V
V
IN
= 2.0V
V
IN
= V
IN(NOM)
+ 40mVpp
LOAD = 100mA
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 4.7µF
I
OUT
= 200mA
I
OUT
= 100mA
I
OUT
= 10mA
V
IN
= 2.5V + 40mVpp
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 4.7µF
V
IN
= 3.6V
V
IN
= 2.5V
V
IN
= 2.0V
V
IN
= V
IN(NOM)
+ 40mVpp
LOAD = 100mA
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 10µF
I
OUT
= 200mA
I
OUT
= 100mA
I
OUT
= 10mA
V
IN
= 2.5V + 40mVpp
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
Micrel, Inc. MIC94310
February 2012 7 M9999-020612-A
Typical Characteristics (Continued)
Dropout Voltage
vs. Output Current
0
5
10
15
20
25
30
35
DROPOUT VOLTAGE (mV)
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR C
OUT
= 10µF
V
IN
= 3.6V
V
IN
= 2.5V
V
IN
= 2.0V
V
IN
= V
IN(NOM)
+ 40mVpp
LOAD = 100mA
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
PSRR (dB)
FREQUENCY (Hz)
PSRR (Varying C
OUT
)
C
OUT
= 2.2µF
C
OUT
= 1µF
C
OUT
= 0.47µF
V
IN
= 2.5V + 40mVpp
LOAD = 100mA
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
PSRR (Varying C
OUT
)
-120
-100
-80
-60
-40
-20
0
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
FREQUENCY (Hz)
PSRR (dB)
C
OUT
= 2.2µF
C
OUT
= 10µF
C
OUT
= 4.7µF
V
IN
= 2.5V + 40mVpp
LOAD = 100mA
V
OUT
= 1.8V
10 100 1K 10K 100K 1M 10M
0 25 50 75 100 125 150 175 200
OUTPUT CURRENT (mA)
Output Voltage
vs. Output Current
1.700
1.725
1.750
1.775
1.800
1.825
1.850
1.875
1.900
Output Voltage
vs. Input Voltage
1.60
1.65
1.70
1.75
1.80
1.85
1.90
1.95
2.00
0 20 40 60 80 100 120 140 160 180 200
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
I
OUT
= 200mA
V
IN
= 3.6V
C
IN
= C
OUT
= 1µF
Ground Current
vs. Output Current
150
155
160
165
170
175
GROUND CURRENT (μA)
Output Noise Spectral Density
0.01
0.10
1.00
10.00
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06
FREQUENCY (Hz)
Noise µV/√Hz
V
IN
= V
EN
= 3.1V
C
IN
= C
OUT
= 1µF
V
OUT
= 1.8V
NOISE (10Hz to 100kHz)
= 82.55µV
RMS
10 100 1k 10k 100k 1M
0 20 40 60 80 100 120 140 160 180 200
OUTPUT CURRENT (mA)
V
IN
=2.8V
C
IN
= C
OUT
=1µF
Ground Current
vs. Input Voltage
120
130
140
150
160
170
180
190
GROUND CURRENT (μA)
2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6
INPUT VOLTAGE (V)
I
OUT
= 100mA
I
OUT
= 200mA
C
IN
= C
OUT
=1µF
Micrel, Inc. MIC94310
February 2012 8 M9999-020612-A
Functional Characteristics
Micrel, Inc. MIC94310
February 2012 9 M9999-020612-A
Application Information
The MIC94310 is a very-high PSRR, fixed-output,
200mA LDO utilizing Ripple Blocker™ technology. The
MIC94310 is fully protected from damage due to fault
conditions, offering linear current limiting and thermal
shutdown.
Input Capacitor
The MIC94310 is a high-performance, high-bandwidth
device. An input capacitor of 0.47µF 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
In order to maintain stability, the MIC94310 requires an
output capacitor of 0.47µF or greater. For optimal ripple
rejection performance a 1µF capacitor is recommended.
The design is optimized for use with low-ESR ceramic
chip capacitors. High-ESR capacitors are not
recommended because they 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 their value by as much
as 50% and 60%, respectively, over their operating
temperature ranges. To use a ceramic chip capacitor
with the 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.
No Load Stability
The MIC94310 will remain stable and in regulation with
no load. This is especially important in CMOS RAM
keep-alive applications.
Enable/Shutdown
Forcing the enable (EN) pin low disables the MIC94310
and sends it into a “zero” off mode current state. In this
state, current consumed by the MIC94310 goes nearly to
zero. Forcing EN high enables the output voltage. The
EN pin uses CMOS technology and cannot be left
floating as it could cause an indeterminate state on the
output.
Thermal Considerations
The MIC94310 is designed to provide 200mA of
continuous 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. For example if the input voltage is 2.5V, the output
voltage is 1.8V, and the output current = 200mA. The
actual power dissipation of the Ripple Blocker™ can be
determined using the equation:
PD = (VIN – VOUT1) I OUT + VIN IGND
Because this device is CMOS and the ground current is
typically <170µA over the load range, the power
dissipation contributed by the ground current is <1% and
can be ignored for this calculation.
P
D = (2.5V – 1.8V) × 200mA
P
D = 0.14W
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
TJ(max) = 125°C, the maximum junction temperature of the
die, θJA thermal resistance = 173°C/W for the Thin MLF®
package.
Substituting PD for PD(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.
Micrel, Inc. MIC94310
February 2012 10 M9999-020612-A
For example, when operating the MIC94310-GYMT at
an input voltage of 2.5V and 200mA load with a
minimum footprint layout, the maximum ambient
operating temperature TA can be determined as follows:
0.14W = (125°C – TA)/(173°C/W)
T
A = 101°C
Therefore, the maximum ambient operating temperature
allowed in a 1.2mm x 1.6mm Thin MLF® package is
101°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
For more information about Micrel’s Ripple Blocker™
products, go to:
http://www.micrel.com/rippleblocker/
http://www.micrel.com/page.do?page=/product-
info/products/mic94300.jsp
http://www.micrel.com/page.do?page=/product-
info/products/mic94310.jsp
Micrel, Inc. MIC94310
February 2012 11 M9999-020612-A
Evaluation Board Schematic
Bill of Materials
Item Part Number Manufacturer Description Qty.
C1, C2 GRM155R61A105KE15D Murata(1) Capacitor, 1µF Ceramic, 10V, X7R, Size 0402 2
U1 MIC94310xx-YMT Micrel, Inc.(2) 200mA Ripple Blocker™ with Fixed Output Voltage 1
Notes:
1. Murata Tel: www.murata.com.
2. Micrel, Inc.: www.micrel.com.
Micrel, Inc. MIC94310
February 2012 13 M9999-020612-A
Package Information1 (Continued)
4-Pin 1.2mm × 1.6mm 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
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
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical impla
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.
can nt
© 2012 Micrel, Incorporated.
