MIC94325 DATA SHEET (11/09/2015) DOWNLOAD

MIC94325/45/55
500mA LDO with
Ripple Blocker Technology
General Description
Features
The MIC943x5 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
MIC943x5 maintains high power supply ripple rejection
(PSRR) with input voltages operating near the output
voltage level to improve overall system efficiency. A lowvoltage logic enable pin facilitates ON/OFF control at
typical GPIO voltage levels.
The MIC943x5 operates from an input voltage of 1.8V to
3.6V. The MIC943x5 options include fixed (MIC94345/55)
or adjustable (MIC94325) output voltages. The MIC94355
version offers an auto-discharge to discharge the output
capacitor when the part is disabled.
Packaged in a 0.84mm x 1.32mm 6-ball CSP or a 6-pin
1.6mm x 1.6mm Thin DFN, the MIC943x5 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.
 1.8V to 3.6V input voltage range
 Active noise rejection over a wide frequency band
 >50dB from 10Hz to 5MHz at 500mA load
 Rated to 500mA output current
 Fixed and adjustable output voltages
 Optional output auto-discharge when disabled
 Current-limit and thermal-limit protected
 Ultra-small 0.84mm x 1.32mm 6-ball CSP
 1.6mm x 1.6mm, 6-pin Thin DFN
 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
MIC94355 PSRR
COUT = 4.7µF
0
VIN = 2.8V + 40mVpp
-20
VOUT = 1.8V
PSRR (dB)
COUT = 4.7µF
-40
500mA
-60
10mA
-80
-100
200mA
-120
10
100
1,000
1K
10,000
10K 100,00
100K 1,000,0
1M 10,000,
10M
0
00
000
FREQUENCY (Hz)
Ripple Blocker is a trademark of Micrel, 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
October 2012
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Ordering Information
Marking Code
Output Voltage
Auto Discharge
Package1
Lead Finish
2R
ADJ
─
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94345-4YCS*
L4
1.2V
─
0.84mm x 1.32mm CSP
Pb-Free
MIC94345-FYCS*
LF
1.5V
─
0.84mm x 1.32mm CSP
Pb-Free
MIC94345-GYCS*
X1
1.8V
─
0.84mm x 1.32mm CSP
Pb-Free
MIC94345-MYCS*
X2
2.8V
─
0.84mm x 1.32mm CSP
Pb-Free
MIC94345-SYCS*
X3
3.3V
─
0.84mm x 1.32mm CSP
Pb-Free
MIC94345-4YMT*
4L
1.2V
─
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94345-FYMT*
FL
1.5V
─
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94345-GYMT*
1X
1.8V
─
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94345-MYMT*
2X
2.8V
─
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94345-SYMT*
3X
3.3V
─
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94355-4YCS*
G9
1.2V
Yes
0.84mm x 1.32mm CSP
Pb-Free
MIC94355-FYCS*
G0
1.5V
Yes
0.84mm x 1.32mm CSP
Pb-Free
MIC94355-GYCS*
G1
1.8V
Yes
0.84mm x 1.32mm CSP
Pb-Free
MIC94355-MYCS*
G2
2.8V
Yes
0.84mm x 1.32mm CSP
Pb-Free
MIC94355-SYCS*
G3
3.3V
Yes
0.84mm x 1.32mm CSP
Pb-Free
MIC94355-4YMT*
9G
1.2V
Yes
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94355-FYMT*
0G
1.5V
Yes
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94355-GYMT
2G
1.8V
Yes
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94355-MYMT*
7G
2.8V
Yes
1.6mm x 1.6mm Thin DFN
Pb-Free
MIC94355-SYMT*
8G
3.3V
Yes
1.6mm x 1.6mm Thin DFN
Pb-Free
Part Number
MIC94325YMT
Notes:
1.
Thin DFN is a GREEN RoHS-compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.

Contact Micrel Marketing for availability.
October 2012
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M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Pin Configuration
6-Ball 0.84mm  1.32mm CSP (CS)
Ball View
6-Pin 1.6mm  1.6mm Thin DFN (MT)
Top View
Note:
1.
Thin DFN ▲ = Pin 1 identifier.
Pin Description
Pin Number
(Thin DFN)
Pin Number
(Thin DFN)
Fixed
Adjustable
Fixed
1, 2
1
A2, B2
VOUT
-
2
-
ADJ
Adjust input. Connect to resistive divider at VOUT to set the output
voltage. Do not leave floating.
3
3
C2
GND
Ground.
4
4
C1
EN
Enable Input. A logic HIGH signal on this pin enables the part. Logic
LOW disables the part. Do not leave floating.
5, 6
5, 6
A1, B1
VIN
Power Switch Input And Chip Supply.
EP
EP
–
ePad
October 2012
Ball Number
(CSP)
Pin Name
Pin Name
Power Switch Output.
Exposed Heatsink Pad. Connect to Ground plane for best thermal
performance.
3
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Functional Block Diagrams
MIC94325 Adjustable Output
MIC94345 Fixed Output
October 2012
4
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Functional Block Diagrams (Continued)
MIC94355 Fixed Output with Auto-Discharge
October 2012
5
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
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 DFN (JA) ...................................................92°C/W
CSP (JA) .........................................................160°C/W
Electrical Characteristics(4)
VIN = VEN = VOUT + 500mV (VIN = VEN = 3.6V for VOUT ≥ 3.1V); IOUT = 1mA; COUT = 4.7µF; TA = 25°C,
bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted.
Parameter
Condition
Min.
Input Voltage
Typ.
Max.
Units
1.8
3.6
V
3.4
V
+3
%
Output Voltage Range
MIC94325
1.2
Output Voltage Accuracy
Variation from nominal VOUT
–3
Adjust Reference
MIC94325
1.1
VIN to VOUT dropout at 50mA output current
10
VIN to VOUT dropout at 500mA output current
100
Load Regulation
1mA to 500mA
10
Line Regulation
VIN = VOUT + 500mV to 3.6V, IOUT = 100mA
0.1
1
%
Ground Current
IOUT = 100µA
170
250
µA
Shutdown Current
VEN = 0V
0.2
5
µA
f = 100Hz
85
f = 1KHz
85
f = 100KHz
57
f = 1MHz
60
f= 5MHz
50
Dropout Voltage
VIN Ripple Rejection
Current Limit
VOUT = 0V
Total Output Noise
10Hz to 100kHz
530
800
V
200
100
VIN = 3.6V, VEN = 0V, IOUT = -3mA
dB
1100
mA
μVRMS
150
50
MIC94355 Only
mV
mV
83
Turn-On Time
Auto Discharge NFET
Resistance
±1
μs
Ω
Enable
0.35
Input Logic Low
1.0
Input Logic High
Input Current
V
V
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.
October 2012
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Micrel, Inc.
MIC94325/45/55
Typical Characteristics
MIC94325 PSRR
COUT = 4.7µF CFF = 3.3nF
-20
-20
-30
-30
-40
-40
-50
500mA
-60
-60
300mA
-80
V IN = 2.4V + 40mvpp
V OUT = 2.2V
-110
10mA
-120
10
1.00E+01
100
1K
0
PSRR (dB)
-80
10mA
-90
10mA
10
10
100
100
1K
1,000
10K 100,00
100K 1,000,0
1M 10,000,
10M
10,000
0
00
000
-20
100
VOUT = 1.8V
10mA
10mA
PSRR (dB)
-60
200mA
500mA
-60
-80
MIC94355 PSRR
COUT = 10µF
10K 100,00
100K 1,000,0
1M 10,000,
10M
10,000
0
00
000
10
10
V IN = 2.8V + 40mVpp
V OUT = 1.8V
-20
COUT = 10µF
200mA
-40
500mA
-80
10mA
-100
-120
-120
10,000
10K 100,00
100K 1,000,0
1M 10,000,
10M
0
00
000
-60
-100
-100
1,000
1K
FREQUENCY (Hz)
0
-40
500mA
October 2012
10
MIC94355 PSRR
COUT = 10µF
COUT = 10µF
200mA
FREQUENCY (Hz)
200mA
-120
VIN = 2.5V + 40mVpp
-40
1K
1,000
10mA
-80
-100
0
VOUT = 1.8V
100
500mA
-60
FREQUENCY (Hz)
VIN = 3.6V + 40mVpp
10
-40
200mA
MIC34355 PSRR
COUT = 4.7µF
-80
VOUT = 1.8V
COUT = 4.7µF
500mA
-80
FREQUENCY (Hz)
COUT = 4.7µF
10K 100,00
100K 1,000,0
1M 10,000,
10M
10,000
0
00
000
VIN = 2.8V + 40mVpp
-60
-120
-20
1K
1,000
MIC94355 PSRR
COUT = 4.7µF
-20
-40
100 1,000
1K 10,000
10K 100,00
100K1,000,0
1M 10,000,
10M
100
0
00
000
0
100
100
0
-100
1010
10
10
FREQUENCY (Hz)
VOUT = 1.8V
500mA
-110
CFF = 10nF
10mA
-120
MIC94355 PSRR
COUT = 4.7µF
COUT = 4.7µF
-100
PSRR (dB)
1K
10K
100K
1M
10M
1,000 10,000 100,00 1,000,0 10,000,
0
00
000
FREQUENCY (Hz)
-20
300mA
-70
V OUT = 2.2V
COUT = 4.7µF
VIN = 2.5V + 40mvpp
CFF = 100nF
-60
100
100
10M
COUT = 4.7µF
-50
V IN = 2.7V + 40mvpp
-110
10
10
1.00E+07
VOUT = 2.2V
-40
-120
-90
VIN = 2.7V + 40mvpp
-30
-80
-100
MIC94325 PSRR
COUT = 4.7µF CFF = 100nF
-20
300mA
-70
-100
-120
1M
10mA
500mA
-60
-90
CFF = 10nF
100K
300mA
-80
COUT = 4.7µF
10K
-50
-70
-110
1.00E+03
1.00E+05
FREQUENCY (Hz)
-40
CFF = 3.3nF
PSRR (dB)
-90
COUT = 4.7µF
PSRR (dB)
-70
-100
PSRR (dB)
PSRR (dB)
PSRR (dB)
-50
-30
V OUT = 2.2V
500mA
MIC94325 PSRR
COUT = 4.7µF , CFF = 10nF
-20
V IN = 2.7V + 40mvpp
PSRR (dB)
MIC94325 PSRR
COUT = 4.7µF , CFF = 10nF
-120
100
100
1,000
1K
10,000
10K 100,00
100K 1,000,0
1M 10,000,
10M
0
00
000
FREQUENCY (Hz)
7
10
100
1,000
1K
10,000
10K 100,00
100K 1,000,0
1M 10,000,
10M
0
00
000
FREQUENCY(Hz)
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Typical Characteristics (Continued)
MIC94355 PSRR
COUT = 10µF
VOUT = 1.8V
200mA
-80
100mA
-100
1.9
1.85
1.8
1.75
1.7
10
100
1K
1,000
10K 100,00
100K 1,000,0
1M 10,000,
10M
10,000
0
00
000
GROUND CURRENT (µA)
190
185
180
175
170
165
160
0
50 100 150 200 250 300 350 400 450 500
OUTPUT CURRENT (mA)
October 2012
30
20
VOUT = 1.8V
CIN = COUT = 4.7µF
0
50 100 150 200 250 300 350 400 450 500
Ground Current
vs. Input Voltage
MIC94355YMT
Output Noise Spectral Density
10
500mA
200
300mA
1
190
180
170
100mA
50mA
160
150
0.1
0.01
VIN = VEN = 3V
140
COUT = 4.7µF/10V
CIN = COUT = 1µF
0.001
120
150
40
LOAD (mA)
130
155
50
OUTPUT CURRENT (mA)
210
195
60
50 100 150 200 250 300 350 400 450 500
220
200
70
0
0
Ground Current
vs. Output Current
80
10
CIN = COUT = 4.7µF
1.6
FREQUENCY (Hz)
GROUND CURRENT (µA)
VIN = 2.8V
1.65
-120
DROPOUT VOLTAGE (mV)
PSRR (dB)
10mA
-40
-60
90
1.95
COUT = 10µF
OUTPUT VOLTAGE (V)
-20
100
2
VIN = 3.6V + 40mVpp
MOISE µV/√Hz
0
Dropout Voltage
vs. Load
Output Voltage
vs. Output Current
1.8
2
2.2
2.4
2.6
2.8
3
3.2
INPUT VOLTAGE (V)
8
3.4
3.6
1010
100 1,0001K 10,000
10K100,00
100K
1M10,000,
10M
100
1,000,0
0
00
000
FREQUENCY (Hz)
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Functional Characteristics
October 2012
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M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Application Information
Enable/Shutdown
Forcing the enable (EN) pin low disables the MIC943x5
and sends it into a “zero” off mode current state. In this
state, current consumed by the MIC943x5 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.
For the MIC94325 adjustable part, the turn-on time is
affected by the selection of the external feedback resistors
and feed-forward capacitor. The relationship is
approximately 2.2 x R2 x Cff, where R2 is the bottom
resistor (connected from ADJ to GND) and Cff is the
capacitor connected across R1 (from VOUT to ADJ). For
stability, the feed-forward capacitor must be greater than
1nF. 10nF is recommended for best performance.
When disabled, the MIC94355 switches a 50Ω (typical)
load on the regulator output to discharge the external
capacitors.
The MIC943x5 family of products is a very-high PSRR,
fixed-output, 500mA LDO utilizing Ripple Blocker
technology. The MIC943x5 is fully protected from
damage due to fault conditions, offering linear current
limiting and thermal shutdown.
Input Capacitor
The MIC943x5 is a high-performance, high-bandwidth
device. An input capacitor of 4.7µF 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 MIC943x5 requires an
output capacitor of 4.7µF or greater. For optimal input
voltage ripple rejection performance a 4.7µF capacitor is
recommended. The design is optimized for use with lowESR ceramic chip capacitors. High-ESR capacitors are
not recommended because they may cause highfrequency oscillation. The output capacitor can be
increased, but performance has been optimized for a
4.7µF 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.
Adjustable Regulator Application
The MIC94325 output voltage can be adjusted by using
two external resistors (Figure 1). The resistors set the
output voltage based on the following equation:
R1 

VOUT  VADJ1 

R2


VADJ = 1.1V
Figure 1. Adjustable Output Voltage
Thermal Considerations
The MIC943x5 is designed to provide 500mA 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 = 500mA. The
actual power dissipation of the Ripple Blocker™ can be
determined using the equation:
No Load Stability
The MIC943x5 will remain stable and in regulation with
no load. This is especially important in CMOS RAM
keep-alive applications.
October 2012
10
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
PD = (VIN – VOUT1) I OUT + VIN IGND
For more information about Micrel’s Ripple Blocker
products, go to:
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.
http://www.micrel.com/index.php/en/products/powermanagement-ics/ldos/linear-power-filters.html
PD = (2.5V – 1.8V) × 500mA
http://www.micrel.com/index.php/en/products/powermanagement-ics/ldos/linear-power-filters/article/1mic94300.html
PD = 0.35W
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:
 TJ(max)  TA
PD(MAX)  
θ JA

http://www.micrel.com/index.php/en/products/powermanagement-ics/ldos/linear-power-filters/article/3mic94310.html




TJ(max) = 125°C, the maximum junction temperature of the
die, θJA thermal resistance = 160°C/W for the YCS
package and 92°C/W for the Thin DFN 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.
For example, when operating the MIC94325-GYMT at
an input voltage of 2.5V and 500mA load with a
minimum footprint layout, the maximum ambient
operating temperature TA can be determined as follows:
0.35W = (125°C – TA)/(92°C/W)
TA = 92°C
Therefore, the maximum ambient operating temperature
allowed in a 1.6mm x 1.6mm Thin DFN package is 92°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.pdf
http://www.micrel.com/_PDF/other/LDO%20SG.B.pdf
October 2012
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M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Typical Application Schematic (Adjustable Output)
Bill of Materials
Item
Part Number
CIN, COUT
CL10A475K08NNNC
CFF
C1608X7R2AP/NK
R1, R2
CRCW0402100KFKED
U1
MIC94325YMT
Manufacturer
Samsung
(1)
TDK(2)
Vishay(3)
(4)
Micrel, Inc.
Description
Qty.
Capacitor, 4.7µF Ceramic, 16V, X5R, Size 0603
2
Capacitor, 10nF Ceramic, 50V, X7R, Size 0603
1
Resistor, 100kΩ, Size 0603
2
500mA LDO with Ripple Blocker Technology
1
Notes:
1. Samsung: http://www.semlcr.com.
2. TDK: www.tdk.com.
3. Vishay: www.vishay.com.
4. Micrel, Inc.: www.micrel.com.
October 2012
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M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Typical Application Schematic (Fixed Output)
Bill of Materials
Item
CIN, COUT
U1
Part Number
CL10A475K08NNNC
MIC94345-xxYMT
MIC94355-xxYMT
Manufacturer
Samsung
(1)
Micrel, Inc.(2)
Description
Qty.
Capacitor, 4.7µF Ceramic, 16V, X5R, Size 0603
2
500mA LDO with Ripple Blocker Technology
1
Notes:
1. Samsung: http://www.semlcr.com/.
2. Micrel, Inc.: www.micrel.com.
October 2012
13
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Package Information(1)
6-Ball 0.84mm  1.32mm WL-CSP (CS)
Note:
1.
Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com.
October 2012
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M9999-102512-A
Micrel, Inc.
MIC94325/45/55
Package Information(1) (Continued)
6-Pin 1.6mm  1.6mm Thin DFN (MT)
Note:
1.
Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com.
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15
M9999-102512-A
Micrel, Inc.
MIC94325/45/55
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
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© 2012 Micrel, Incorporated.
October 2012
16
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