MIC39150/39151/39152
1.5A, Low-Voltage Low-Dropout
Regulator
**See Thermal Design Section
Super ßeta PNP is a registered trademark of Micrel, Inc.
StrongARM is a trademark of Advanced RSIC Machines, Ltd.
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 2009 M9999-102309-A
General Description
The MIC39150, MIC39151, and MIC39152 are 1.5A LDO
voltage regulators that provide a low voltage, high current
output with a minimum of external components. Utilizing
Micrel’s proprietary Super βeta PNP® pass element, the
MIC39150/1/2 offers extremely low dropout (typically
375mV at 1.5A) and low ground current (typically 17mA at
1.5A).
The MIC39150/1/2 are ideal for PC add-in cards that need
to convert from 3.3V to 2.5V or 2.5V to 1.8V with a
guaranteed maximum dropout voltage of 500mV over all
operating conditions. The MIC39150/1/2 exhibit fast
transient response for heavy switching applications and
requires only 10µF of output capacitance to maintain
stability and achieve fast transient response.
The MIC39150/1/2 is fully protected with current limiting,
thermal shutdown, reversed-battery protection/lead
insertion, and reverse-leakage protection. The MIC39151
offers a TTL-logic compatible enable pin and an error flag
that indicates undervoltage and overcurrent conditions.
Offered in fixed voltages of 2.5V, 1.8V and 1.65V, the
MIC39150/1 comes in the TO-220 and TO-263 (D2Pak)
packages. The MIC39152 adjustable option allows
programming the output voltage anywhere between 1.24V
and 15.5V and comes in 5-Pin, TO-263 (D2Pak) and
TO-252 (D-Pak) packages.
For applications requiring input voltage greater than 16V or
automotive load dump protection, see the MIC29150/1/2/3
family.
Features
1.5A minimum guaranteed output current
500mV maximum dropout voltage over temperature
Ideal for 3.0V to 2.5V conversion
Ideal for 2.5 to 1.8V or 1.65V conversion
1% initial accuracy
Low ground current
Current limiting and Thermal shutdown
Reversed-battery and reversed lead insertion protection
Reversed-leakage protection
Fast transient response
TTL/CMOS compatible enable pin (MIC39151/2 only)
Error flag output (MIC39151 only)
Adjustable output (MIC39152 only)
Power D-Pak package (TO-252) Adjustable only
Power D2Pak package (TO-263)
Applications
Low-voltage digital ICs
LDO linear regulator for PC add-in cards
High-efficiency linear power supplies
SMPS post regulator
Low-voltage microcontrollers
StrongARM™ processor supply
Typical Application**
MIC39150 MIC39151 MIC39152 Adjustable Output Application
(*See Minimum Load Current Section)
Micrel, Inc. MIC39150/39151/39152
October 2009 2 M9999-102309-A
Ordering Information
Part Number
Standard RoHS Compliant*
Voltage Junction
Temp. Range Package
MIC39150-1.65BT MIC39150-1.65WT 1.65V –40° to +125°C 3-Pin TO-220
MIC39150-1.65BU MIC39150-1.65WU 1.65V –40° to +125°C 3-Pin TO-263
MIC39150-1.8BT MIC39150-1.8WT 1.8V –40° to +125°C 3-Pin TO-220
MIC39150-1.8BU MIC39150-1.8WU 1.8V –40° to +125°C 3-Pin TO-263
MIC39150-2.5BT MIC39150-2.5WT 2.5V –40° to +125°C 3-Pin TO-220
MIC39150-2.5BU MIC39150-2.5WU 2.5V –40° to +125°C 3-Pin TO-263
MIC39151-1.65BT MIC39151-1.65WT 1.65V –40° to +125°C 5-Pin TO-220
MIC39151-1.65BU MIC39151-1.65WU 1.65V –40° to +125°C 5-Pin TO-263
MIC39151-1.8BT MIC39151-1.8WT 1.8V –40° to +125°C 5-Pin TO-220
MIC39151-1.8BU MIC39151-1.8WU 1.8V –40° to +125°C 5-Pin TO-263
MIC39151-2.5BT MIC39151-2.5WT 2.5V –40° to +125°C 5-Pin TO-220
MIC39151-2.5BU MIC39151-2.5WU 2.5V –40° to +125°C 5-Pin TO-263
MIC39152WU Adjustable –40° to +125°C 5-Pin TO-263
MIC39152WD Adjustable –40° to +125°C 5-Pin TO-252
Note:
* RoHS compliant with ‘high-melting solder’ exemption.
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Pin Configur ation
3OUT
2GND
1IN
3OUT
2GND
1IN
MIC39150-x.xBT/WT
TO-220-3 (T)
MIC39150-x.xBU/WU
TO-263-3 (U)
5FLG
4OUT
3GND
2IN
1EN
MIC39151-x.xBT/WT
TO-220-5 (T) MIC39151-x.xBU/WU
TO-263-5 (D2Pak) (U)
MIC39152WU
TO-263-5 (D2Pak) (U)) MIC39152WD
TO-252-5 (D-Pak) (D)
Pin Description
Pin Number
MIC39150 Pin Number
MIC39151
Pin Number
MIC39152
Pin Name Pin Description
— 1 1 EN
Enable (Input): TTL/CMOS compatible input. Logic high =
enable; logic low or open = shutdown.
1 2 2 IN Unregulated Input: +16V maximum supply.
2, TAB 3, TAB 3, TAB GND Ground: Ground pin and TAB are internally connected.
3 4 4 OUT Regulator Output.
5 — FLG
Error Flag (Output): Open-collector output. Active low
indicates an output fault condition.
— 5 ADJ
Adjustable Regulator Feedback Input: Connect to the
resistor voltage divider that is placed from OUT to GND in
order to set the output voltage.
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Absolute Maximum Ratings(1)
Supply Voltage (VIN)....................................... –20V to +20V
Enable Voltage (VEN)....................................................+20V
Storage Temperature (Ts) .........................–60°C to +150°C
Lead Temperature (soldering, 5 sec.)........................ 260°C
ESD Rating................................................................ Note 3
Operating Ratings(2)
Supply Voltage (VIN).................................... +2.25V to +16V
Enable Voltage (VEN)....................................................+16V
Maximum Power Dissipation (PD(max)) ....................... Note 4
Junction Temperature (TJ) ........................ –40°C to +125°C
Package Thermal Resistance
TO-263 (θJC) ........................................................C/W
TO-220 (θJC) ........................................................C/W
TO-252 (θJC) ........................................................C/W
TO-252 (θJA) ......................................................56°C/W
Electrical Characteristics(5)
VIN = VEN = VOUT + 1V; IOUT = 10mA; TJ = 25°C, bold values indicate –40°C< TJ < +125°C, unless noted.
Symbol Parameter Condition Min Typ Max Units
Output Voltage 10mA
10mA IOUT 1.5A, VOUT + 1V VIN 8V
–1
–2
1
2
%
%
Line Regulation IOUT = 10mA, VOUT + 1V VIN 16V 0.06 0.5 %
VOUT
Load Regulation VIN = VOUT + 1V, 10mA IOUT 1.5A 0.2 1 %
VOUT/T Output Voltage Temp.
Coefficient, Note 6
20
100 ppm/°C
IOUT = 100mA, VOUT = –1% 80 200 mV
IOUT = 750mA, VOUT = –1% 260 mV
VDO Dropout Voltage, Note 7
IOUT = 1.5A, VOUT = –1% 375 500 mV
IOUT = 750mA, VIN = VOUT + 1V 4 20 mA IGND Ground Current, Note 8
IOUT = 1.5A, VIN = VOUT + 1V 17 mA
IGND(do) Dropout Ground Pin Current VIN VOUT(nominal) – 0.5V, IOUT = 10mA 1.1 mA
IOUT(lim) Current Limit VOUT = 0V, VIN = VOUT + 1V 2.8 A
IOUT(min) Minimum Load Current 7 10 mA
tSTART Start-up Time VEN = VIN, IOUT = 10mA, COUT = 47µF 35 150 µs
Enable Input (MIC39151)
logic low (off) 0.8 V VEN Enable Input Voltage
logic high (on) 2.25 V
VEN = 2.25V 1 15 30
75
µA
µA
IIN Enable Input Current
VEN = 0.8V 2
4
µA
µA
IOUT(shdn) Shutdown Output Voltage Note 9 10
20 µA
Flag Output (MIC39151)
IFLG(leak) Output Leakage Current VOH = 16V 0.01 1
2
µA
µA
VFLG(do) Output Low Voltage VIN = 2.250V, IOL = 250µA, Note 10 180
300
400
mV
mV
Low Threshold % of VOUT 93 %
High Threshold % of VOUT 99.2 %
VFLG
Hysteresis 1 %
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Symbol Parameter Condition Min Typ Max Units
Reference (Adjust Pin) – MIC39152 Only
1.228 1.240 1.252 V VADJ Reference Voltage
1.215 1.265 V
VTC Reference Voltage Temperature
Coefficient
Note 11 20
ppm/°C
40 80 nA IADJ Adjust Pin Bias Current
120 nA
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.
4. PD(max) = (TJ(max) – TA) ÷ θJA, where θJA depends upon the printed circuit layout. See “Applications Information.”
5. Specification for packaged product only.
6. Output voltage temperature coefficient is VOUT(worst case) ÷ (TJ(max) – TJ(min)) where T J(max) is +125°C and TJ(min) is –40°C.
7. VDO = VIN – VOUT when VOUT decreases to 98% of its nominal output voltage with VIN = VOUT + 1V. For output voltages below 2.25V, dropout voltage is
the input-to-output voltage differential with the minimum input voltage being 2.25V. Minimum input operating voltage is 2.25V.
8. IGND is the quiescent current. IIN = IGND + IOUT.
9. VEN 0.8V, VIN 8V, and VOUT = 0V.
10. For a 2.5V device, VIN = 2.250V (device is in dropout).
11. Thermal regulation is dened as the change in output voltage at a time t after a change in power dissipation is applied, excluding load or line
regulation effects. Specications are for a 200mA load pulse at VIN = 8V for t = 10ms.
Micrel, Inc. MIC39150/39151/39152
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Typical Characteristics
0
10
20
30
40
50
60
1E+1 1E+2 1E+3 1E+4 1E+5 1E+6
FREQUENCY (Hz)
Pow er Suppl
y
Rejec tion Ratio
ILOAD = 1.5A
COUT = 10µF
CIN = 0
VIN = 3.3V
VOUT = 2.5V
10 100 1k 10k 100k 1M
0
100
200
300
400
500
600
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Dropout Voltage
vs. Temperature
ILOAD = 1.5A
VOUT = 2.5V
VOUT = 1.8V
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
4.1
6.1
8.1
2
2.2
4.2
6.2
8.2
3
2.3
4.3
6.3
INPUT VOLTAGE (V)
Dropout C hara c te ris tic s
ILOAD = 100mA
ILOAD = 750mA
ILOAD = 1.5A
0
5
10
15
20
25
0 250 500 750 1000 12501500
OUTPUT CURRENT (mA)
Groun d Curre nt
vs. Output Current
VOUT = 2.5V
VOUT = 1.8V
0
5
10
15
20
25
30
35
40
45
50
55
60
65
024681012
SUPPLY VOLTAGE (V)
Ground Curre nt
vs. Supply Voltage
ILOAD = 750mA
ILOAD = 1500mA
ILOAD = 1000mA
0.30
0.31
0.32
0.33
0.34
0.35
0.36
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Ground Current
vs. Temperature
ILOAD = 10mA
VOUT = 2.5V
VOUT = 1.8V
0
5
10
15
20
25
-40-20 0 20406080100120
TEMPERATURE (°C)
Gr ound Curr ent
vs. Temperature
ILOAD = 1.5A
VOUT = 1.8V
VOUT = 2.5V
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Short Circui t vs .
Temperature
typical 1.8V device
typical 2.5V device
Micrel, Inc. MIC39150/39151/39152
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0
1
2
3
4
5
6
0.01 0.1 1 10 100 100010000
RESISTANCE (k )
Error Fla
g
Pull-Up Resistor
VIN = 5V
FLAG HIGH
(OK)
FLAG LOW
(FAULT)
Micrel, Inc. MIC39150/39151/39152
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Functional Characteristics
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Functional Diagram
Ref.
18V
O.V .
ILIMIT
Thermal
Shut-
down
1.240V1.180V
EN*
IN
FLAG*
GND
OUT
* MIC39151 only
Micrel, Inc. MIC39150/39151/39152
October 2009 10 M9999-102309-A
Application Information
The MIC39150/1/2 are high-performance, low-dropout
voltage regulators suitable for moderate to high-current
voltage regulator applications. Its 500mV dropout
voltage at full load and overtemperature makes it
especially valuable in battery-powered systems and as
high-efficiency noise filters in post-regulator applications.
Unlike older NPN-pass transistor designs, where the
minimum dropout voltage is limited by the base-to-
emitter voltage drop and collector-to-emitter saturation
voltage, dropout performance of the PNP output of these
devices is limited only by the low VCE saturation voltage.
A trade-off for the low dropout voltage is a varying base
drive requirement. Micrel’s Super βeta PNP® process
reduces this drive requirement to only 2% to 5% of the
load current. The MIC39150/1/2 regulators are fully
protected from damage due to fault conditions. Current
limiting is provided. This limiting is linear; output current
during overload conditions is constant. Thermal
shutdown disables the device when the die temperature
exceeds the maximum safe operating temperature.
Transient protection allows device (and load) survival
even when the input voltage spikes above and below
nominal. The output structure of these regulators allows
voltages in excess of the desired output voltage to be
applied without reverse current flow.
Thermal Design
Linear regulators are simple to use. The most
complicated design parameters to consider are thermal
characteristics. Thermal design requires the following
application-specific parameters:
Maximum ambient temperature (TA)
Output Current (IOUT)
Output Voltage (VOUT)
Input Voltage (VIN)
Ground Current (IGND)
First, calculate the power dissipation of the regulator
from these numbers and the device parameters from this
datasheet.
GNDINOUTOUTIND I VI )V(VP +=
where the ground current is approximated by using
numbers from the “Electrical Characteristics” or “Typical
Characteristics.” Then the heat sink thermal resistance is
determined with this formula:
()
CSJC
D
AJ(max)
SA θθ
P
TT
θ+
=
Where TJ(max) 125°C and θCS is between 0° and 2°C/W.
The heat sink may be significantly reduced in
applications where the minimum input voltage is known
and is large compared with the dropout voltage. Use a
series input resistor to drop excessive voltage and
distribute the heat between this resistor and the
regulator. The low dropout properties of Micrel Super
βeta PNP® regulators allow significant reductions in
regulator power dissipation and the associated heat sink
without compromising performance. When this technique
is employed, a capacitor of at least 1µF is needed
directly between the input and regulator ground.
Refer to Application Note 9 for further details and
examples on thermal design and heat sink specification.
With no heat sink in the application, calculate the
junction temperature to determine the maximum power
dissipation that will be allowed before exceeding the
maximum junction temperature of the MIC39152. The
maximum power allowed can be calculated using the
thermal resistance (θJA) of the TO-252 (D-Pak) adhering
to the following criteria for the PCB design: 2 oz. copper
and 100mm2 copper area for the MIC39152.
For example, given an expected maximum ambient
temperature (TA) of 75°C with VIN = 2.25V, VOUT = 1.75V,
and IOUT = 1.5A, first calculate the expected PD using
Equation (1);
PD = (2.25V – 1.75V)1.5A + (2.25V)(0.017A) = 0.788W
Next, calcualte the junction temperature for the expected
power dissipation.
TJ = (θJA × PD) + TA = (56°C/W × 0.788W) + 75°C
= 119.14°C
Now determine the maximum power dissipation allowed
that would not exceed the IC’s maximum junction
temperature (125°C) without the use of a heat sink by
PD(MAX) = (TJ(MAX) – TA)/θJA = (125°C – 75°C)/(56°C/W)
= 0.893W
MIC39150-x.
x
IN OUT
GND
CIN COUT
VIN VOUT
Figure 1. Capacitor Requirements
Output Capacitor
The MIC39150/1/2 requires an output capacitor to
maintain stability and improve transient response. See
Figure 1. Proper capacitor selection is important to
ensure proper operation. TheMIC39150/1/2 output
capacitor selection is dependent upon the ESR
(equivalent series resistance) of the output capacitor to
maintain stability. When the output capacitor is 10µF or
greater, the output capacitor should have an ESR less
than 2. This will improve transient response as well as
Micrel, Inc. MIC39150/39151/39152
October 2009 11 M9999-102309-A
promote stability. Ultralow ESR capacitors (<100m),
such as ceramic chip capacitors may promote instability.
These very low ESR levels may cause an oscillation
and/or underdamped transient response. A low-ESR
solid tantalum capacitor works extremely well and
provides good transient response and stability over
temperature. Aluminum electrolytics can also be used,
as long as the ESR of the capacitor is < 2.
The value of the output capacitor can be increased
without limit. Higher capacitance values help to improve
transient response and ripple rejection and reduce
output noise.
Input Capacitor
An input capacitor of 1µF or greater is recommended
when the device is more than 4 inches away from the
bulk ac supply capacitance, or when the supply is a
battery. Small, surface-mount, ceramic chip capacitors
can be used for the bypassing. The capacitor should be
placed within 1" of the device for optimal performance.
Larger values will help to improve ripple rejection by
bypassing the input to the regulator, further improving
the integrity of the output voltage.
Transient Response and 3.3V to 2.5Vor 2.5V to 1.8V
Conversion
The MIC39150/1/2 has excellent transient response to
variations in input voltage and load current. The device
has been designed to respond quickly to load current
variations and input voltage variations. Large output
capacitors are not required to obtain this performance. A
standard 10µF output capacitor, preferably tantalum, is
all that is required. Larger values help to improve
performance even further.
By virtue of its low-dropout voltage, this device does not
saturate into dropout as readily as similar NPN-based
designs. When converting from 3.3V to 2.5V, or 2.5V to
1.8V, the NPN-based regulators are already operating in
dropout, with typical dropout requirements of 1.2V or
greater. To convert down to 2.5V without operating in
dropout, NPN-based regulators require an input voltage
of 3.7V at the very least. The MIC39150/1 regulator will
provide excellent performance with an input as low as
3.0V or 2.5V, respectively. This gives the PNP-based
regulators a distinct advantage over older, NPN-based
linear regulators.
Minimum Load Current
The MIC39150 regulator is specified between finite
loads. If the output current is too small, leakage currents
dominate and the output voltage rises. A 10mA minimum
load current is necessary for proper regulation.
Error Flag
The MIC39151 version features an error flag circuit
which monitors the output voltage and signals an error
condition when the voltage 5% below the nominal output
voltage. The error flag is an open-collector output that
can sink 10mA during a fault condition.
Low output voltage can be caused by a number of
problems, including an overcurrent fault (device in
current limit) or low input voltage. The flag is inoperative
during overtemperature shutdown.
When the error flag is not used, it is best to leave it
open. A pull-up resistor from FLG to either VIN or VOUT is
required for proper operation.
Enable Input
The MIC39151/2 features an enable input for on/off
control of the device. The enable input’s shutdown state
draws “zero” current (only microamperes of leakage).
The enable input is TTL/CMOS compatible for simple
logic interface, but can be connected to up to 20V. When
enabled, it draws approximately 15µA.
Adjustable Regulator Design
Figure 2. Adjustable Regulator with Resistors
The MIC39152 allows programming the output voltage
anywhere between 1.24V and 15.5V. Two resistors are
used. The resistor values are calculated by:
×= 1
1.240
V
R2R1 OUT
Where VOUT is the desired output voltage. Figure 2
shows component denition. Applications with widely
varying load currents may scale the resistors to draw the
minimum load current required for proper operation (see
Minimum Load Current section).
Micrel, Inc. MIC39150/39151/39152
October 2009 12 M9999-102309-A
Package Information
3-Pin TO-220 (T)
5-Pin TO-220 (T)
Micrel, Inc. MIC39150/39151/39152
October 2009 13 M9999-102309-A
3-Pin TO-263 (U)
1θ
θ1
3θ
4θ
1θ
2θ
3θ4θ
2θ1θ
5-Pin TO-263 (U)
Micrel, Inc. MIC39150/39151/39152
October 2009 14 M9999-102309-A
5-Pin TO-252 (D)
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
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indemnify Micrel for any damages resulting from such use or sale.
© 2009 Micrel, Incorporated.