March 2008 1 M9999-032808
MIC5319 Micrel, Inc.
MIC5319
500mA µCap Ultra-Low Dropout
High PSRR LDO Regulator
General Description
The MIC5319 is a high-performance, 500mA LDO regula-
tor, offering extremely high PSRR and very low noise while
consuming low ground current.
Ideal for battery-operated applications, the MIC5319 features
1% accuracy, extremely low-dropout voltage (200mV @
500mA), and low ground current at light load (typically 90µA).
Equipped with a logic-compatible enable pin, the MIC5319
can be put into a zero-off-mode current state, drawing no
current when disabled.
The MIC5319 is a µCap design operating with very small
ceramic output capacitors for stability, thereby reducing
required board space and component cost.
The MIC5319 is available in fixed-output voltages and adjust-
able output voltages in the super-compact 2mm x 2mm MLF®
leadless package and thin SOT-23-5 package.
Additional voltage options are available. Contact Micrel
marketing.
All support documentation can be found on Micrel’s web site
at www.micrel.com.
Typical Application
Features
• Ultra-low dropout voltage 200mV @ 500mA
• Input voltage range: 2.5 to 5.5V
• Stable with ceramic output capacitor
• Low output noise — 40µVrms
• Low quiescent current of 90µA total
• High PSRR, up to 70dB @1kHz
• Fast turn-on-time — 40µs typical
• High output accuracy:
• ±1.0% initial accuracy
• ±2.0% over temperature
• Thermal shutdown protection
• Current-limit protection
• Logic-controlled Enable
• Tiny 2mm x 2mm MLF® package, 500mA continuous
• Thin SOT-23-5 package, 500mA peak
Applications
• Cellular phones
• PDAs
• Fiber optic modules
• Portable electronics
• Notebook PCs
• Audio Codec power supplies
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
MicroLeadFrame and MLF are registered trademarks of Amkor Technology, Inc.
0
10
20
30
40
50
60
70
80
90
100
FREQUENCY (Hz)
PSRR
(Bypass Pin Cap = 0.1µF)
50mA
500mA
100µA
1k
10 100 10k 100k 1M
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2µF
0
20
40
60
80
100
120
140
160
180
200
OUTPUT CURRENT (mA)
Vout = 2.8V
Cout = 2.2
µ
F
0100 200 300 400 500
Dropout Voltage
vs. Output Current
MIC5319
VOUTVIN
BYPEN
GND
VIN 2.8V@500mA
VOUT
2.2µF0.1µF
1µF
MIC5319 Micrel, Inc.
March 2008 2 M9999-032808
Ordering Information
Part Number Marking Voltage(2) Junction Temp. Range Package
Standard Pb-Free Standard Pb-Free(1)
MIC5319-1.3HYML 13H 1.375V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-1.8BML MIC5319-1.8YML 918 918 1.8V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-1.85YML 91J 1.85V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-2.5BML MIC5319-2.5YML 925 925 2.5V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-2.6YML 926 2.6V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-2.7YML 927 2.7V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-2.8BML MIC5319-2.8YML 928 928 2.8V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-2.9YML 929 2.9V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-3.0YML 930 3.0V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-3.3BML MIC5319-3.3YML 933 933 3.3V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-5.0BML MIC5319-5.0YML 950 950 5.0V –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319BML MIC5319YML 9AA 9AA ADJ –40ºC to +125ºC 6-pin 2mm x 2mm MLF®
MIC5319-1.3HYD5 N13H 1.375V –40ºC to +125ºC Thin SOT-23-5
MIC5319-1.8YD5 N918 1.8V –40ºC to +125ºC Thin SOT-23-5
MIC5319-1.85YD5 N91J 1.85V –40ºC to +125ºC Thin SOT-23-5
MIC5319-2.5YD5 N925 2.5V –40ºC to +125ºC Thin SOT-23-5
MIC5319-2.6YD5 N926 2.6V –40ºC to +125ºC Thin SOT-23-5
MIC5319-2.7YD5 N927 2.7V –40ºC to +125ºC Thin SOT-23-5
MIC5319-2.8BD5 MIC5319-2.8YD5 N928 N928 2.8V –40ºC to +125ºC Thin SOT-23-5
MIC5319-2.9YD5 N929 2.9V –40ºC to +125ºC Thin SOT-23-5
MIC5319-3.0YD5 N930 3.0V –40ºC to +125ºC Thin SOT-23-5
MIC5319-3.3BD5 MIC5319-3.3YD5 N933 N933 3.3V –40ºC to +125ºC Thin SOT-23-5
MIC5319-5.0YD5 N950 5.0V –40ºC to +125ºC Thin SOT-23-5
Notes:
1. Under-bar/Over-bar symbols may not be to scale.
2. For other output voltage options, contact Micrel marketing.
March 2008 3 M9999-032808
MIC5319 Micrel, Inc.
Pin Configuration
1EN
GND
VIN
6 BYP
NC
VOUT
5
4
2
3
MIC5319-x.xBML/YML
6-Pin 2mm x 2mm MLF™ (ML)
(Top View)
VIN
VOUTBYP
EN
KWxx
13
4 5
2
GND
MIC5319-x.xBD5/YD5
TSOT-23-5 (D5)
(Top View)
1EN
GND
VIN
6 BYP
ADJ
VOUT
5
4
2
3
MIC5319BML/YML (Adjustable)
6-Pin 2mm x 2mm MLF™ (ML)
(Top View)
Pin Description
Pin Number Pin Number Pin Number Pin Name Pin Function
MLF-6 Fixed MLF-6 Adj. TSOT-23-5 Fixed
1 1 3 EN Enable Input. Active High. High = on, low = off. Do not
leave floating.
2 2 2 GND Ground.
3 3 1 VIN Supply Input.
4 4 5 VOUT Output voltage.
– 5 – ADJ Adjust Input: Connect to external resistor voltage divider network.
5 – NC No connection for fixed voltage parts.
6 6 4 BYP Reference Bypass: Connect external 0.1µF to GND for reduced
output noise. May be left open.
HS Pad HS Pad – EPAD Exposed Heatsink Pad connected to ground internally.
MIC5319 Micrel, Inc.
March 2008 4 M9999-032808
Electrical Characteristics(5)
VIN = VOUT +1.0V; COUT = 2.2µF, IOUT = 100µA; TJ = 25°C, bold values indicate –40°C to + 125°C; unless noted.
Parameter Condition Min Typ Max Units
Output Voltage Accuracy Variation from nominal VOUT –1.0 +1.0 %
Variation from nominal VOUT, IOUT = 100ΜA to 500mA –2.0 +2.0 %
Feedback Voltage 1.2375 1.25 1.2625 V
(ADJ option) 1.225 1.25 1.275 V
Line Regulation VIN = VOUT +1V to 5.5V 0.04 0.3 %/V
Load Regulation(6) IOUT = 100µA to 500mA 0.1 0.5 %
Dropout Voltage(7)(8) IOUT = 50mA 20 40 mV
IOUT = 500mA 200 400 mV
Ground Pin Current(9) IOUT = 0 to 500mA 90 150 µA
Ground Pin Current in Shutdown VEN ≤ 0.2V 0.5 µA
Ripple Rejection f = up to 1kHz; COUT = 2.2µF ceramic; CBYP = 0.1µF 70 dB
f = 10kHz; COUT = 2.2µF ceramic; CBYP = 0.1µF 60 dB
Current Limit VOUT = 0V 600 700 mA
Output Voltage Noise COUT =2.2µF, CBYP = 0.1µF, 10Hz to 100kHz 40 µVrms
Turn-On Time COUT = 2.2µF; CBYP = 0.01µF 40 100 µs
Enable Input
Enable Input Voltage Logic Low (Regulator Shutdown) 0.2 V
Logic High (Regulator Enabled) 1.2 V
Enable Input Current VIL ≤ 0.2V (Regulator Shutdown) 0.01 1 µA
VIH ≥ 1.0V (Regulator Enabled) 0.01 1 µA
Notes:
1. Exceeding maximum ratings may damage the device.
2. The device is not guaranteed to work 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 may 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.
7. Dropout voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal VOUT. For outputs below 2.5V,
dropout voltage spec does not apply, as part is limited by minimum VIN spec of 2.5V. There may be some typical dropout degradation at VOUT <3V.
8. For ADJ option, VOUT = 3V for dropout specification.
9. 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 cur-
rent.
Absolute Maximum Ratings(1)
Supply Input Voltage (VIN) ......................................0V to 6V
Enable Input Voltage (VEN) ....................................0V to 6V
Power Dissipation (PD) .........................Internally Limited(3)
Junction Temperature(TJ) ......................... –40°C to +125°C
Storage Temperature (TS) .......................... –65°C to 150°C
Lead Temperature (soldering, 5 sec.) ........................ 260°C
ESD(4) ............................................................................................... 3kV
Operating Ratings(2)
Supply Input Voltage (VIN) ...............................2.5V to 5.5V
Enable Input Voltage (VEN) ...................................0V to VIN
Junction Temperature (TJ) ........................ –40°C to +125°C
Package Thermal Resistance
MLF™ (θJA) ......................................................... 93°C/W
TSOT-23 (θJA) ...................................................235°C/W
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MIC5319 Micrel, Inc.
Typical Characteristics
0
10
20
30
40
50
60
70
80
90
100
FREQUENCY (Hz)
PSRR
(Bypass Pin Cap = 0.01µF)
50mA
500mA
100µA
1k
10 100 10k 100k 1M
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2µF
0
10
20
30
40
50
60
70
80
90
100
FREQUENCY (Hz)
PSRR
(Bypass Pin Cap = 0.1µF)
50mA
500mA
100µA
1k
10 100 10k 100k 1M
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2µF 55
60
65
70
75
80
85
0.1 1 10 100 1000
(TNERRUCDNUORG µ )A
OUTPUT CURRENT (mA)
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2uF
Cbyp = 0.01µF
0
10
20
30
40
50
60
70
80
90
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
vs. Temperature
Iload = 50mA
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2 µF
0
10
20
30
40
50
60
70
80
90
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Iload = 150mA
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2 µF 0
10
20
30
40
50
60
70
80
90
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Iload = 300mA
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2 µF
0
10
20
30
40
50
60
70
80
90
100
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Iload = 500mA
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2 µF 0
10
20
30
40
50
60
70
80
90
100
3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
Iload = 50mA
Vout = 2.8V
Cout = 2.2 µF 0
10
20
30
40
50
60
70
80
90
100
3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
Iload = 150mA
Vout = 2.8V
Cout = 2.2 µF
0
10
20
30
40
50
60
70
80
90
3 3.5 4 4.5 5 5.5
INPUT VOLTAGE (V)
Iload = 500mA
Vout = 2.8V
Cout = 2.2µF 0
0.5
1
1.5
2
2.5
3
0123 4 5
INPUT VOLTAGE (V)
Dropout Characteristics
50mA
150mA
500mA
0
5
10
15
20
25
30
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
vs. Temperature
Iload = 50mA
Vout = 2.8V
Cout = 2.2µF
Ground Current
vs. Output Current
Ground Current
vs. Temperature
Ground Current
vs. Temperature
Ground Current
vs. Temperature
Ground Current
vs. Input Voltage
Ground Current
vs. Input Voltage
Ground Current
vs. Input Voltage
Ground Current Dropout Voltage
MIC5319 Micrel, Inc.
March 2008 6 M9999-032808
0
10
20
30
40
50
60
70
80
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
vs. Temperature
Iload = 150mA
Vout = 2.8V
Cout = 2.2µF 0
50
100
150
200
250
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Iload = 500mA
Vout = 2.8V
Cout = 2.2µF
0
20
40
60
80
100
120
140
160
180
200
OUTPUT CURRENT (mA)
Vout = 2.8V
Cout = 2.2
µ
F
0100 200 300 400 500
2.6
2.65
2.7
2.75
2.8
2.85
2.9
2.95
3
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Output Voltage
vs. Temperature
Iload = 100µA
Vout = 2.8V
Vin = Vout + 1V
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Enable Threshold
vs. Temperature
Iload = 100
µ
A
Vout = 2.8V
Vin = Vout + 1V
Cout = 2.2
µ
F
100
200
300
400
500
600
700
3 3.5 4 4.5 5 5.5 6
INPUT VOLTAGE (V)
Iload = 100µA
Vout = 2.8V
Cout = 2.2µF
0.001
0.01
0.1
1
10
FREQUENCY (Hz)
Spectral Density
Iload = 50Ω
Vout = 2.8V
Vin = 4.45V
Cout = 2.2
µ
F
Cbyp = 0.01
µF
10 100 1k 10k 100k 1M 10M
Dropout Voltage vs. Temperature
Dropout Voltage
vs. Temperature
Dropout Voltage
vs. Input Voltage
Short Circuit Current
Output Noise
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MIC5319 Micrel, Inc.
Functional Characteristics
MIC5319 Micrel, Inc.
March 2008 8 M9999-032808
Functional Diagram
VIN
EN
BYP
VOUT
GND
Current
Limit
Quick-
Start
V
REF
Thermal
Shutdown
Error
Amp
MIC5319
MIC5319 Block Diagram - Fixed
VIN
EN
BYP
VOUT
GND
Current
Limit
Quick-
Start
VREF
Thermal
Shutdown
Error
Amp
ADJ
MIC5319
MIC5319 Block Diagram - Adjustable
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MIC5319 Micrel, Inc.
Applications Information
Enable/Shutdown
The MIC5319 features an active-high enable pin that allows
the regulator to be disabled. Forcing the enable pin low dis-
ables 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, as this may cause
an indeterminate state on the output.
Input Capacitor
The MIC5319 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. Addi-
tional high frequency capacitors, such as small-valued NPO
dielectric-type capacitors, help filter out high-frequency noise
and are good design practice in any RF-based circuit.
Output Capacitor
The MIC5319 requires an output capacitor of 2.2µF 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 2.2µF
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 operat-
ing 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 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 im-
proving PSRR. Turn-on time increases slightly with respect
to bypass capacitance. A unique, quick-start circuit allows
the MIC5319 to drive a large capacitor on the bypass pin
without significantly slowing turn-on time. Refer to the “Typi-
cal Characteristics” section for performance with different
bypass capacitors.
No-Load Stability
Unlike many other voltage regulators, the MIC5319 will re-
main stable and in regulation with no load. This is especially
important 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 MIC5319 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:
Figure 1. Adjustable Voltage Application
Thermal Considerations
The MIC5319 is designed to provide 500mA of continuous
current in a very small MLF package. Maximum ambient
operating temperature can be calculated based on the output
current and the voltage drop across the part. Given an input
voltage of 3.3V, output voltage of 2.8V and output current =
500mA, 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.
PD = (3.3V – 2.8V) × 500mA
PD = 0.25W
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) = 125°C, the maximum junction temperature of
the die θJA thermal resistance = 93°C/W.
V V 1 R1
R2
V 1
.25V
OUT REF
REF
= +
=
P ( T (
max) – T
DJ A
JA
max) =
θ
MIC5319 Micrel, Inc.
March 2008 10 M9999-032808
Table 1 shows junction-to-ambient thermal resistance for the
MIC5319 in the 2mm x 2mm MLF package.
Package θJA Recommended θJC
Minimum Footprint
2 x 2 MLF® 93°C/W 2°C/W
SOT-23-5 235°C/W
Table 1. Thermal Resistance
Substituting 0.25W for PD(max) and solving for the ambient
operating temperature will give the maximum operating condi-
tions for the regulator circuit. The maximum power dissipation
must not be exceeded for proper operation.
0.25W 125 C T
93 C/W
T 101.75 C
A
A
=° −
°
= °
Therefore, a 2.8V application at 500mA of output current
can accept an ambient operating temperature of 101.75°C
in a 2mm x 2mm 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 information
can be found on Micrel's website at:
http://www.micrel.com/_PDF/other/LDOBk_ds.pdf
March 2008 11 M9999-032808
MIC5319 Micrel, Inc.
Package Information
6-Pin 2mm x 2mm MLF® (ML)
TSOT-23-5 (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 at Purchaser’s own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2004 Micrel, Incorporated.