Micrel MIC37150 1.5a, low voltage î¼cap ldo regulator Datasheet

MIC37150/51/52/53
1.5A, Low Voltage µCap LDO Regulator
General Description
Features
The Micrel MIC37150/51/52/53 is a 1.5A low-dropout
linear voltage regulator that provides a low voltage, high
current output with a minimum of external components. It
offers high precision, ultra-low dropout (500mV over
temperature), and low ground current.
The MIC37150/51/52/53 operates from an input of 2.25V
to 6.0V. It is designed to drive digital circuits requiring low
voltage at high currents (i.e., PLDs, DSPs, microcontrollers, etc.). It is available in fixed and adjustable
output voltages. Fixed voltages include 1.5V, 1.65V, 1.8V,
2.5V and 3.3V. The adjustable version is capable of
supplying output voltages from 1.24V to 5.5V.
Features of the MIC37150/51/52/53 LDO include thermal
and current limit protection, and reverse current and
reverse battery protection. Logic enable and error flag pins
are available.
Junction temperature range of the MIC37150/51/52/53 is
from –40°C to +125°C.
For applications requiring input voltage greater than 6.0V,
see MIC3910x, MIC3915x, MIC3930x, and MIC3950x
LDOs.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
• 1.5A minimum guaranteed output current
• 500mV maximum dropout voltage over temperature
– Ideal for 3.0V to 2.5V conversion
– Ideal for 2.5V to 1.8V, 1.65V, or 1.5V conversion
• Stable with ceramic or tantalum capacitor
• Wide input voltage range
– VIN: 2.25V to 6.0V
• ±1.0% initial output tolerance
• Fixed and adjustable output voltages
– MIC37150—3-pin fixed voltages
– MIC37151—5-pin S-Pak or 8-pin e-Pad SOIC
fixed voltages with flag
– MIC37152—5-pin adjustable voltage
– MIC37153—8-pin adjustable voltage with flag
• Excellent line and load regulation specifications
• Logic controlled shutdown
• Thermal shutdown and current limit protection
• Reverse-leakage protection
• Low profile 3 or 5-pin S-Pak packages or 8-pin e-Pad
SOIC
Applications
•
•
•
•
•
LDO linear regulator for low-voltage digital IC
PC add-in cards
High efficiency linear power supplies
SMPS post regulator
Battery charger
Typical Application
MIC37151
VIN = 3.0V
VIN
VOUT = 2.5V
VOUT
CIN
100k
VEN
FLG
GND
Fixed 2.5V Regulator with Error Flag
COUT
47µF, Ceramic
VIN
CIN
MIC37152
VIN
1.3V
VOUT
R1
VEN
ADJ
GND
COUT
47µF, Ceramic
R2
Adjustable Regulator
Super ßeta PNP 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 2007
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
Ordering Information
Part Number
Standard
RoHS Compliant* /
Pb-free
Output
Current
Voltage
Junction Temp. Range
Package
MIC37150-1.5BR
MIC37150-1.5WR*
1.5A
1.5V
–40° to +125°C
S-PAK-3
MIC37150-1.65BR
MIC37150-1.65WR*
1.5A
1.65V
–40° to +125°C
S-PAK-3
MIC37150-1.8BR
MIC37150-1.8WR*
1.5A
1.8V
–40° to +125°C
S-PAK-3
MIC37150-2.5BR
MIC37150-2.5WR*
1.5A
2.5V
–40° to +125°C
S-PAK-3
MIC37150-3.3BR
MIC37150-3.3WR*
1.5A
3.3V
–40° to +125°C
S-PAK-3
MIC37151-1.5BR
MIC37151-1.5WR*
1.5A
1.5V
–40° to +125°C
S-PAK-5
MIC37151-1.5YME*
1.5A
1.5V
–40° to +125°C
e-Pad SOIC-8
MIC37151-1.65WR*
1.5A
1.65V
–40° to +125°C
S-PAK-5
MIC37151-1.8YME*
1.5A
1.8V
–40° to +125°C
e- Pad SOIC-8
MIC37151-1.8WR*
1.5A
1.8V
–40° to +125°C
S-PAK-5
MIC37151-2.5YME**
1.5A
2.5V
–40° to +125°C
e-Pad SOIC-8
MIC37151-2.5BR
MIC37151-2.5WR*
1.5A
2.5V
–40° to +125°C
S-PAK-5
MIC37151-3.3BR
MIC37151-3.3WR*
1.5A
3.3V
–40° to +125°C
S-PAK-5
MIC37152BR
MIC37152WR*
1.5A
ADJ
–40° to +125°C
S-PAK-5
MIC37152YM
1.5A
ADJ
–40° to +125°C
SOIC-8
MIC37153YME**
1.5A
ADJ
–40° to +125°C
e-Pad SOIC-8
MIC37151-1.65BR
MIC37151-1.8BR
* RoHS compliant with ‘high-melting solder’ exemption.
** Contact factory for availablity.
October 2007
2
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
3
VOUT
2
GND
1
VIN
5
4
3
2
1
TAB
TAB
Pin Configuration
S-PAK-3 (R)
FLG/ADJ
VOUT
GND
VIN
EN
S-PAK-5 (R)
EN 1
8
GND
GND 1
VIN 2
7
GND
EN 2
7 VOUT/ADJ
VOUT 3
6
GND
VIN 3
6 VOUT
ADJ 4
5
GND
NC 4
5 NC
SOIC-8 (M)
8 FLG
e-Pad SOIC-8 (ME)
Pin Description
Pin Number
S-PAK-3
Pin Number
Pin Number
Pin Number
S-PAK-5
SOIC-8
e-Pad SOIC-8
–
1
1
2
EN
Enable (Input): CMOS compatible input.
Logic high = enable, logic low = shutdown.
1
2
2
3
VIN
Input voltage which supplies current to the output
power device.
2
3
5, 6, 7, 8
1
GND
Ground (TAB is connected to ground on S-Pak)
3
4
3
VOUT
Regulator Output
–
5
–
8
FLG
Error Flag (Output): Open collector output.
Active low indicates an output fault condition.
4
7
ADJ
Adjustable regulator feedback input.
Connect to resistor voltage divider.
–
4, 5
NC
Not internally connected.
–
October 2007
–
Pin Name
6, 7 (Fixed)
6 (Adj)
3
Pin Name
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VIN) ......................................................6.5V
Enable Input Voltage (VEN)............................................6.5V
Power Dissipation .....................................Internally Limited
Junction Temperature .........................–40°C ≤ TJ ≤ +125°C
Storage Temperature (Ts) ...................–65°C ≤ TJ ≤ +150°C
Lead Temperature (soldering, 5sec.)......................... 260°C
EDS Rating................................................................ Note 3
Supply voltage (VIN) ....................................... 2.25V to 6.0V
Enable Input Voltage (VEN).................................. 0V to 6.0V
Junction Temperature Range .............–40°C ≤ TJ ≤ +125°C
Maximum Power Dissipation..................................... Note 4
Package Thermal Resistance
S-Pak (θJC) ..........................................................2°C/W
Power SOIC-8 (θJA) ...........................................63°C/W
e-Pad SOIC-8 (θJC)............................................10°C/W
Electrical Characteristics(5)
TA = 25°C with VIN = VOUT + 1V; VEN = VIN; bold values indicate –40°C < TJ < +125°C, unless otherwise noted.
Parameter
Output Voltage Accuracy
Condition
Min
Typ
Max
Units
IL = 10mA
–1
+1
%
10mA < IOUT < IL(max), VOUT + 1 ≤ VIN ≤ 6V
–2
+2
%
0.5
%
Output Voltage Line Regulation
VIN = VOUT +1.0V to 6.0V
0.06
Output Voltage Load Regulation
IL = 10mA to 1.5A
0.2
VIN – VOUT; Dropout Voltage,
Note 6
Ground Pin Current, Note 7
IL = 1.5A
Ground Pin Current in Shutdown
VIL ≤ 0.5V, VIN = VOUT + 1V
1.0
Current Limit
VOUT = 0
2.25
4.0
A
Start-up Time
VEN = VIN, IOUT = 10mA, COUT = 22µF
170
500
µs
1
%
IL = 750mA
350
mV
IL = 1.5A
500
mV
30
mA
17
µA
Enable Input
Enable Input Threshold
Regulator enable
V
2.25
Regulator shutdown
Enable Pin Input Current
VIL ≤ 0.8V (regulator shutdown)
VIH ≥ 2.25V (regulator enabled)
1
15
0.8
V
2
4
µA
µA
30
75
µA
µA
1
2
µA
µA
300
400
mV
mV
Flag Output
IFLG(LEAK)
VOH = 6V
VFLG(LO)
VIN = 2.25V, IOL = 250µA, Note 8
VFLG
Low threshold, % of VOUT below nominal
210
93
Hysteresis
%
2
High threshold, % of VOUT below nominal
Reference Voltage
1.228
Note 9
Reference Voltage Temp.
Coefficient
1.240
1.215
Note 10
%
1.252
V
1.265
40
Adjust Pin Bias Current Temp.
Coefficient
0.1
4
V
ppm/°C
20
Adjust Pin Bias Current
October 2007
%
99.2
80
120
nA
nA
nA/°C
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
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.
VDO = VIN – VOUT when VOUT decreased to 98% of its nominal output voltage with VIN = VOUT +1V. For output voltages below 1.75V, dropout voltage
specification does not apply due to a minimum input operating voltage of 2.25V.
7.
IIN is the quiescent current. IIN = IIN + IOUT.
8.
For a 2.5V device, VIN = 2.250V (device is in dropout).
9.
VREF ≤ VOUT ≤ (VIN –1.0V), 2.25V ≤ VIN ≤ 6.0V, 10mA ≤ IL ≤ 1.5A, TJ = TMAX.
10. Thermal regulation is defined as the change in output voltage at a time t after a change in power dissipation is applied, excluding load or line
regulation effects. Specifications are for a 200mA load pulse at VIN = 6V for t = 10ms.
October 2007
5
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
Typical Characteristics
Power Supply
Rejection Ratio
80
VIN = 3.3V
VOUT = 2.5V
PSRR (dB)
60
40
20 IOUT = 1.5A
COUT = 10µF
CIN = 0
0
1E-2
1E+1
1
10 1E+2
1k
0.01 1E-1
100 1E+3
0.1 1E+0
FREQUENCY (Hz)
GROUND CURRENT (mA)
45
GROUND CURRENT (mA)
6
VOUT = 2.5V
40
35
30
25
20
15
1500mA
10
1000mA
5
0
0
7
Ground Current
vs. Supply Voltage
750mA
1
2
3
4
5
6
SUPPLY VOLTAGE (V)
Ground Current
vs. Temperature
GROUND CURRENT (mA)
DROPOUT VOLTAGE (mV)
Dropout Voltage vs.
Temperature
500
450
400
2.5VOUT
350
300
250
200
150
100
50
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE °C)
(
0.5
VOUT = 2.5V
0.445
ILOAD = 10mA
0.44
0.435
0.43
0.4
0.42
0.415
0.41
0.405
0.4
-40 -20 0 20 40 60 80 100 120
TEMPERATURE °C)
(
Ground Current
vs. Temperature
VOUT = 2.5V
ILOAD = 750mA
5.0
4
3
2
1
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE °C)
(
October 2007
6
M9999-101907
Micrel, Inc.
5
4
Error Flag
Pull-Up Resistor
250
VIN = 5V
FLAG HIGH
(OK)
3
2
FLAG LOW
(FAULT)
1
0
0.01 0.1
1
10 100 100010000
RESISTANCE (k )
October 2007
FLAG VOLTAGE (mV)
FLAG VOLTAGE (V)
6
MIC37150/51/52/53
Flag-Low Voltage
vs. Temperature
200
150
100
50 V = 2.25V
IN
RPULL-UP = 22k
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE °C)
(
7
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
Functional Characteristics
VOUT = 2.5V
COUT = 10µF
5V
INPUT VOLTAGE
(2V/div.)
OUTPUT VOLTAGE
(20mV/div.)
Line Transient Response
3.3V
TIME (250µs/div.)
October 2007
8
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
ßeta 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 1.0µF 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 applications.
Application Information
The MIC37150/51/52/53 is a high-performance lowdropout voltage regulator suitable for moderate to highcurrent regulator applications. Its 500mV dropout voltage
at full load and over-temperature makes it especially
valuable in battery-powered systems and as highefficiency noise filters in post-regulator applications.
Unlike older NPN-pass transistor designs, there the
minimum dropout voltage is limited by the based-toemitter 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 ßeta PNP™ process
reduces this drive requirement to only 2% to 5% of the
load current.
The MIC37150/51/52/53 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.
Output Capacitor
The MIC37150/51/52/53 requires an output capacitor for
stable
operation.
As
a
µCap
LDO,
the
MIC37150/51/52/53 can operate with ceramic output
capacitors as long as the amount of capacitance is 47µF
or greater. For values of output capacitance lower than
47µF, the recommended ESR range is 200mΩ to 2Ω.
The minimum value of output capacitance recommended
for the MIC37151 is 10µF.
For 47µF or greater, the ESR range recommended is
less than 1Ω. Ultra-low ESR ceramic capacitors are
recommended for output capacitance of 47µF or greater
to help improve transient response and noise reduction
at high frequency. 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
value by as much as 50% and 60% respectively over
their operating 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. The MIC37150/51/52/53
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 47µF
output capacitor, is all that is required. Larger values
help to improve performance even further.
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) – (θJC + θCS)
Where TJ(MAX) ≤ 125°C and θCS is between 0°C 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
October 2007
Input Capacitor
An input capacitor of 1.0µF or greater is recommended
when the device is more than 4 inches away from the
bulk and supply capacitance, or when the supply is a
battery. Small, surface-mount chip capacitors can be
used for the bypassing. The capacitor should be place
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, 2.5V to 1.8V or
1.65V, or 2.5V to 1.5V Conversions
The MIC37150/51/52/53 has excellent transient
response to variations in input voltage and load current.
The device has been designed to respond quickly to
9
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
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, 2.5V to
1.8V or 1.65V, or 2.5V to 1.5V, 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 MIC37150/51/52/53 regulator will provide
excellent performance with an input as low as 3.0V or
2.25V, respectively. This gives the PNP-based
regulators a distinct advantage over older, NPN-based
linear regulators.
Enable Input
The MIC37151/37152/37153 also 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 VIN. When
enabled, it draws approximately 15µA.
Adjustable Regulator Design
MIC37152
VIN
ENABLE
SHUTDOWN
OUT
R1
EN
ADJ
GND
R2
VOUT
COUT
VOUT = 1.240V (1 + R1)
R2
Minimum Load Current
The MIC37150/51/52/53 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 operation.
Figure 1. Adjustable Regulator with Resistors
The MIC37152 and MIC37153 allow programming the
output voltage anywhere between 1.24V and the 5.5V
maximum operating rating of the family. Two resistors
are used. Resistors can be quite large, up to 1MΩ,
because of the very high input impedance and low bias
current of the sense comparator: The resistor values are
calculated by:
Error Flag
The MIC37151 and MIC37153 feature an error flag
circuit that 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.
October 2007
IN
⎛V
⎞
R1 = R2⎜⎜ OUT − 1⎟⎟
1.240
⎝
⎠
Where VOUT is the desired output voltage. Figure 1
shows component definition. Applications with widely
varying load currents may scale the resistors to draw the
minimum load current required for proper operation (see
above).
10
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
Package Information
3-Pin S-PAK (R)
5-Pin S-PAK (R)
October 2007
11
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
8-Pin SOIC (M)
8-Pin SOIC (ME)
October 2007
12
M9999-101907
Micrel, Inc.
MIC37150/51/52/53
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 a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2003 Micrel, Incorporated.
October 2007
13
M9999-101907
Similar pages