MICREL MIC39151

MIC39150/39151
Micrel
MIC39150/39151
1.5A Low-Voltage Low-Dropout Regulator
General Description
Features
The MIC39150 and MIC39151 are 1.5A low-dropout linear
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 offers extremely low dropout (typically 375mV at
1.5A) and low ground current (typically 17mA at 1.5A).
The MIC39150/1 is ideal for PC add-in cards that need to
convert from 3.3V to 2.5V or 2.5V to 1.8V. A guaranteed
maximum dropout voltage of 500mV over all operating conditions allows the MIC39150/1 to provide 2.5V from a supply
as low as 3V or 1.8V from a supply as low as 2.3V. The
MIC39150/1 also has fast transient response for heavy
switching applications. This device requires only 10µF of
output capacitance to maintain stability and achieve fast
transient response
The MIC39150/1 is fully protected with overcurrent limiting,
thermal shutdown, reversed-battery protection, reversedlead insertion, and reverse-leakage protection. The MIC39151
offers a TTL-logic compatible enable pin and an error flag that
indicates undervoltage and over current conditions. Offered
in fixed voltages of 2.5V and 1.8V, the MIC39150/1 comes in
the TO-220 and TO-263 packages and is an ideal upgrade to
older, NPN-based linear voltage regulators.
• 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 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
• TO-263 and TO-220 packaging
• TTL/CMOS compatible enable pin (MIC39151 only)
• Error flag output (MIC39151 only)
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
For applications requiring input voltage greater than 16V or
automotive load dump protection, see the MIC29150/1/2/3
family.
Typical Application
100kΩ
MIC39150-2.5
VIN
3.3V
IN
OUT
GND
MIC39151-2.5
VOUT
2.5V
ENABLE
SHUTDOWN
VIN
3.3V
10µF
tantalum
EN
FLG
ERROR FLAG
OUTPUT
IN
OUT
VOUT
2.5V
GND
10µF
tantalum
MIC39150
MIC39151
StrongARM is a trademark of Advanced RSIC Machines, Ltd.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
May 2000
1
MIC39150/39151
MIC39150/39151
Micrel
Ordering Information
Part Number
Voltage
Temperature Range
Package
MIC39150-1.8BT
1.8V
–40°C to +125°C
3-lead TO-220
MIC39150-1.8BU
1.8V
–40°C to +125°C
3-lead TO-263
MIC39151-1.8BT
1.8V
–40°C to +125°C
5-lead TO-220
MIC39151-1.8BU
1.8V
–40°C to +125°C
5-lead TO-263
MIC39150-2.5BT
2.5V
–40°C to +125°C
3-lead TO-220
MIC39150-2.5BU
2.5V
–40°C to +125°C
3-lead TO-263
MIC39151-2.5BT
2.5V
–40°C to +125°C
5-lead TO-220
MIC39151-2.5BU
2.5V
–40°C to +125°C
5-lead TO-263
* order note & V
3
OUT
2
GND
1
IN
TAB
TAB
Pin Configuration
MIC39150-x.xBT
TO-220-3 (T)
OUT
2
GND
1
IN
MIC39150-x.xBU
TO-263-3 (U)
FLG
OUT
GND
IN
EN
5
4
3
2
1
TAB
5
4
3
2
1
TAB
3
FLG
OUT
GND
IN
EN
MIC39151-x.xBU
TO-263-5 (U)
MIC39151-x.xBT
TO-220-5 (T)
Pin Description
Pin Number
MIC39150
Pin Number
MIC39151
Pin Name
1
EN
Enable (Input): TTL/CMOS compatible input. Logic high = enable; logic low
or open = shutdown
1
2
IN
Unregulated Input: +16V maximum supply.
2, TAB
3, TAB
GND
Ground: Ground pin and TAB are internally connected.
3
4
OUT
Regulator Output
5
FLG
Error Flag (Ouput): Open-collector output. Active low indicates an output
fault condition.
MIC39150/39151
Pin Function
2
May 2000
MIC39150/39151
Micrel
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Supply Voltage (VIN) ..................................... –20V to +20V
Enable Voltage (VEN) .................................................. +20V
Storage Temperature (TS) ....................... –65°C to +150°C
Lead Temperature (soldering, 5 sec.) ....................... 260°C
ESD, Note 3
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) ......................................................... 2°C/W
TO-220 (θJC) ......................................................... 2°C/W
Electrical Characteristics
VIN = VOUT +1V; VEN = 2.4V; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted
Symbol
Parameter
Condition
VOUT
Output Voltage
10mA
10mA ≤ IOUT ≤ 1.5A, VOUT + 1V ≤ VIN ≤ 8V
Line Regulation
IOUT = 10mA, VOUT + 1V ≤ VIN ≤ 16V
Load Regulation
VIN = VOUT + 1V, 10mA ≤ IOUT ≤ 1.5A,
∆VOUT/∆T
Output Voltage Temp. Coefficient,
Note 5
VDO
Dropout Voltage, Note 6
IGND
Ground Current, Note 7
Min
Typ
Max
Units
1
2
%
%
0.06
0.5
%
0.2
1
%
20
100
ppm/°C
IOUT = 100mA, ∆VOUT = –1%
80
200
mV
IOUT = 750mA, ∆VOUT = –1%
260
IOUT = 1.5A, ∆VOUT = –1%
375
500
mV
IOUT = 750mA, VIN = VOUT + 1V
4
20
mA
IOUT = 1.5A, VIN = VOUT + 1V
17
mA
–1
–2
mV
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
0.8
V
Enable Input (MIC39151)
VEN
Enable Input Voltage
logic low (off)
logic high (on)
IIN
Enable Input Current
VEN = 2.25V
2.25
1
V
30
75
µA
µA
2
4
µA
µA
10
20
µA
15
VEN = 0.8V
IOUT(shdn)
Shutdown Output Current
Note 8
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 9
180
300
400
mV
mV
VFLG
Low Threshold
% of VOUT
High Threshold
% of VOUT
93
99.2
Hysteresis
May 2000
%
1
3
%
%
MIC39150/39151
MIC39150/39151
Micrel
Note 1.
Exceeding the absolute maximum ratings may damage the device.
Note 2.
The device is not guaranteed to function outside its operating rating.
Note 3.
Devices are ESD sensitive. Handling precautions recommended.
Note 4.
PD(max) = (TJ(max) – TA) ÷ θJA, where θJA depends upon the printed circuit layout. See “Applications Information.”
Note 5.
Output voltage temperature coefficient is ∆VOUT(worst case) ÷ (TJ(max) – TJ(min)) where TJ(max) is +125°C and TJ(min) is –40°C.
Note 6.
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.
Note 7.
IGND is the quiescent current. IIN = IGND + IOUT.
Note 8.
VEN ≤ 0.8V, VIN ≤ 8V, and VOUT = 0V.
Note 9.
For a 2.5V device, VIN = 2.250V (device is in dropout).
MIC39150/39151
4
May 2000
MIC39150/39151
Micrel
Typical Characteristics
VIN = 3.3V
VOUT = 2.5V
30
20
20
ILOAD = 1.5A
COUT = 47µF
CIN = 0
10
Dropout Voltage
vs. Temperature
200
ILOAD = 1.5A
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
ILOAD = 100mA
2.2
2.0
1.8
ILOAD = 1.5A
1.6
ILOAD = 750mA
1.4
1.2
0.6
0.4
0.2
GROUND CURRENT (mA)
ILOAD = 10mA
0
2
4
6
8
10
SUPPLY VOLTAGE (V)
12
Ground Current
vs. Temperature
7
6
VOUT = 2.5V
5
VOUT = 1.8V
3
2
1
ILOAD = 750mA
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
May 2000
25
ILOAD = 1500mA
ILOAD = 1000mA
ILOAD = 750mA
0
2
4
6
8
10
SUPPLY VOLTAGE (V)
12
5
VOUT = 2.5V
VOUT = 2.5V
15
VOUT = 1.8V
10
ILOAD = 1.5A
5
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
5
0
250 500 750 1000 1250 1500
OUTPUT CURRENT (mA)
Ground Current
vs. Temperature
0.35
0.34
VOUT = 1.8V
0.33
0.32 V
= 2.5V
OUT
0.31
ILOAD = 10mA
0.30
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Ground Current
vs. Temperature
20
VOUT = 1.8V
10
0.36
GROUND CURRENT (mA)
0.8
65
60
55
50
45
40
35
30
25
20
15
10
5
0
SHORT CIRCUIT CURRENT (A)
GROUND CURRENT (mA)
ILOAD = 100mA
1.0
15
INPUT VOLTAGE (V)
GROUND CURRENT (mA)
GROUND CURRENT (mA)
1.4
20
0
Ground Current
vs. Supply Voltage
1.6
500
1000
1500
OUTPUT CURRENT (mA)
25
2.4
1.8
1.2
0
Ground Current
vs. Output Current
2.6
Ground Current
vs. Supply Voltage
4
0
GROUND CURRENT (mA)
VOUT = 2.5V
100
VOUT = 2.5V
100
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
3
3.2
3.4
3.6
VOUT = 1.8V
300
8
200
2.8
400
VOUT = 1.8V
300
Dropout Characteristics
500
0.0
400
0
1E+1
1k 1E+4
10k 1E+5
1M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
OUTPUT VOLTAGE (V)
DROPOUT VOLTAGE (mV)
VIN = 3.3V
VOUT = 2.5V
30
ILOAD = 1.5A
10 COUT = 10µF
CIN = 0
0
1E+1
1k 1E+4
10k 1E+5
1M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
600
Dropout Voltage
vs. Output Current
500
40
40
PSRR (dB)
PSRR (dB)
50
Power Supply
Rejection Ratio
50
DROPOUT VOLTAGE (mV)
Power Supply
Rejection Ratio
60
3.5
3.0
2.5
Short Circuit vs.
Temperature
typical 2.5V device
typical 1.8V device
2.0
1.5
1.0
0.5
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
MIC39150/39151
MIC39150/39151
Error Flag
Pull-Up Resistor
12
ENABLE CURRENT µA)
FLAG VOLTAGE (V)
VIN = 5V
5
4
FLAG HIGH
(OK)
3
2
FLAG LOW
(FAULT)
1
0
0.01 0.1
10
Enable Current
vs. Temperature
250
VIN = VOUT + 1V
VEN = 2.4V
FLAG VOLTAGE (mV)
6
Micrel
8
6
4
2
0
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
1
10 100 100010000
RESISTANCE (kΩ)
200
Flag-Low Voltage
vs. Temperature
FLAG-LOW
VOLTAGE
150
100
VIN = 2.25V
RPULL-UP = 22kΩ
50
0
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
Functional Characteristics
OUTPUT VOLTAGE
(500mV/div.)
Load Transient Response
VIN = 3.3V
VOUT = 2.5V
COUT = 10µF
VIN = 3.3V
VOUT = 2.5V
COUT = 47µF
1.5A
LOAD CURRENT
(500mA/div.)
1.5A
LOAD CURRENT
(500mA/div.)
OUTPUT VOLTAGE
(500mV/div.)
Load Transient Response
100mA
TIME (250µs/div.)
10mA
TIME (250µs/div.)
OUTPUT VOLTAGE
(50mV/div.)
Load Transient Response
VOUT = 2.5V
COUT = 10µF
ILOAD = 10mA
5V
INPUT VOLTAGE
(2V/div.)
3.3V
TIME (500µs/div.)
MIC39150/39151
6
May 2000
MIC39150/39151
Micrel
Functional Diagram
OUT
IN
O.V.
ILIMIT
1.180V
FLAG*
Ref.
18V
1.240V
EN*
Thermal
Shutdown
GND
* MIC39151 only
May 2000
7
MIC39150/39151
MIC39150/39151
Micrel
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.
Output Capacitor
The MIC39150/1 requires an output capacitor to maintain
stability and improve transient response. Proper capacitor
selection is important to ensure proper operation. The
MIC39150/1 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
2Ω. This will improve transient response as well as promote
stability. Ultralow ESR capacitors (<100mΩ), 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 < 2Ω.
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, surfacemount, 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 2.5V
or 2.5V to 1.8V Conversion
The MIC39150/1 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
Applications Information
The MIC39150/1 is a high-performance low-dropout voltage
regulator suitable for moderate to high-current voltage regulator applications. Its 500mV dropout voltage at full load and
overtemperature makes it especially valuable in batterypowered systems and as high-efficiency noise filters in postregulator 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 regulator is 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.
VIN
MIC39150-x.x
IN
VOUT
OUT
GND
CIN
COUT
Figure 1. Capacitor Requirements
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.
PD = (VIN – VOUT) IOUT + VIN IGND
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:
θSA =
TJ(max) − TA
PD
(
− θ JC + θCS
)
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
MIC39150/39151
8
May 2000
MIC39150/39151
Micrel
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.
May 2000
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.
Enable Input
The MIC39151 version features an enable input for on/off
control of the device. Its 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.
9
MIC39150/39151
MIC39150/39151
Micrel
Package Information
0.151 D ±0.005
(3.84 D ±0.13)
0.410 ±0.010
(10.41 ±0.25)
0.108 ±0.005
(2.74 ±0.13)
0.176 ±0.005
(4.47 ±0.13)
0.590 ±0.005
(14.99 ±0.13)
0.818 ±0.005
(20.78 ±0.13)
0.050 ±0.005
(1.27 ±0.13)
7°
0.356 ±0.005
(9.04 ±0.13)
3°
7°
1.140 ±0.010
(28.96 ±0.25)
0.050 ±0.003
(1.27 ±.08)
0.030 ±0.003
(0.76 ±0.08)
0.100 ±0.020
(2.54 ±0.51)
0.018 ±0.008
(0.46 ±0.020)
0.100 ±0.005
(2.54 ±0.13)
DIMENSIONS: INCH
(MM)
3-Lead TO-220 (T)
0.150 D ±0.005
(3.81 D ±0.13)
0.177 ±0.008
(4.50 ±0.20)
0.400 ±0.015
(10.16 ±0.38)
0.108 ±0.005
(2.74 ±0.13)
0.050 ±0.005
(1.27 ±0.13)
0.241 ±0.017
(6.12 ±0.43)
0.578 ±0.018
(14.68 ±0.46)
SEATING
PLANE
7°
Typ.
0.550 ±0.010
(13.97 ±0.25)
0.067 ±0.005
(1.70 ±0.127)
0.032 ±0.005
(0.81 ±0.13)
0.268 REF
(6.81 REF)
0.018 ±0.008
(0.46 ±0.20)
0.103 ±0.013
(2.62±0.33)
Dimensions: inch
(mm)
5-Lead TO-220-5 (T)
MIC39150/39151
10
May 2000
MIC39150/39151
Micrel
0.176 ±0.005
0.405±0.005
0.065 ±0.010
20°±2°
0.050 ±0.005
0.050±0.005
0.360±0.005
0.600±0.025
SEATING PLANE
0.004 +0.004
–0.008
0.100 BSC
8° MAX
0.050
0.100 ±0.01
0.015 ±0.002
DIM. = INCH
3-Lead TO-263 (U)
0.176 ±0.005
0.405±0.005
0.065 ±0.010
20°±2°
0.060 ±0.005
0.050±0.005
0.360±0.005
0.600±0.025
SEATING PLANE
0.004 +0.004
–0.008
0.067±0.005
0.032 ±0.003
8° MAX
0.100 ±0.01
0.015 ±0.002
DIM. = INCH
5-Lead TO-263-5 (U)
May 2000
11
MIC39150/39151
MIC39150/39151
Micrel
MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131
TEL
+ 1 (408) 944-0800
FAX
+ 1 (408) 944-0970
WEB
USA
http://www.micrel.com
This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or
other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.
© 2000 Micrel Incorporated
MIC39150/39151
12
May 2000