Micrel MIC5252-2.5BM5 150ma high psrr, low noise î¼cap cmos ldo Datasheet

MIC5252
Micrel, Inc.
MIC5252
150mA High PSRR, Low Noise µCap CMOS LDO
General Description
Features
The MIC5252 is an efficient, precise CMOS voltage regulator
optimized for ultra-low-noise applications. It offers 1% initial
accuracy, extremely-low dropout voltage (135mV at 150mA)
and low ground current (typically 90µA). The MIC5252
provides a very-low-noise output, ideal for RF applications
where a clean voltage source is required. The MIC5252 has
a high PSRR even at low supply voltages, critical for battery
operated electronics. A noise bypass pin is also available for
further reduction of output noise.
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Designed specifically for handheld and battery-powered
devices, the MIC5252 provides a TTL-logic-compatible enable pin. When disabled, power consumption drops nearly
to zero.
The MIC5252 also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in handheld wireless devices.
Input voltage range: 2.7V to 6.0V
PSRR = 50dB @ VO + 0.3V
Ultra-low output noise: 30µV(rms)
Stability with ceramic output capacitors
Ultra-low dropout: 135mV @ 150mA
High output accuracy:
1.0% initial accuracy
2.0% over temperature
Low quiescent current: 90µA
Tight load and line regulation
TTL-Logic-controlled enable input
“Zero” off-mode current
Thermal shutdown and current limit protection
Applications
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Key features include current limit, thermal shutdown, faster
transient response, and an active clamp to speed up device
turn-off. The MIC5252 is available in the 6-pin 2mm × 2mm
MLF™ package and the IttyBitty® SOT-23-5 package in a
wide range of output voltages.
Cellular phones and pagers
Cellular accessories
Battery-powered equipment
Laptop, notebook, and palmtop computers
Consumer/personal electronics
Typical Application
C IN = 1.0µF
Ceramic
Enable
Shutdown
V IN
MIC5252-x.xBM5
1
5
2
3
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
4
V OUT
VIN
ENABLE
SHUTDOWN
C OUT = 1.0µF
Ceramic
C BYP = 0.01µF
EN
VOUT
MIC5252-x.xBML
1
6
2
5
3
4
CBYP
COUT
(optional)
Ultra-Low-Noise Regulator Application
IttyBitty is a registered trademark of Micrel, Inc.
MicroLeadFrame and MLF are trademarks of Amkor Technology.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
February 2005
1
M9999-020305
MIC5252
Micrel, Inc.
Ordering Information
Part Number
Marking
Standard
Pb-Free
Voltage
Junction Temp. Range
Package
MIC5252-1.8YM5
L618
L618
1.8V
-40°C to +125°C
SOT-23-5
MIC5252-2.5BM5
MIC5252-2.5YM5
L625
L625
2.5V
-40°C to +125°C
SOT-23-5
MIC5252-2.8BM5
MIC5252-2.8YM5
L628
L628
2.8V
-40°C to +125°C
SOT-23-5
MIC5252-2.85BM5
MIC5252-2.85YM5
L62J
L62J
2.85V
-40°C to +125°C
SOT-23-5
MIC5252-3.0BM5
MIC5252-3.0YM5
L630
L630
3.0V
-40°C to +125°C
SOT-23-5
MIC5252-4.75BM5
MIC5252-4.75YM5
L64H
L64H
4.75V
-40°C to +125°C
SOT-23-5
MIC5252-2.8BML
MIC5252-2.8YML
628
628
2.8V
-40°C to +125°C
6-Pin 2x2 MLF™
MIC5252-2.85BML
MIC5252-2.85YML
62J
62J
2.85V
-40°C to +125°C
6-Pin 2x2 MLF™
MIC5252-3.0BML
MIC5252-3.0YML
630
630
3.0V
-40°C to +125°C
6-Pin 2x2 MLF™
Standard
Pb-Free
MIC5252-1.8BM5
Other voltages available. Contact Micrel for details.
Pin Configuration
EN GND
2
3
IN
1
EN 1
L6xx
4
BYP
GND 2
6 BYP
5 NC
5
IN 3
OUT
MIC5252-x.xBM5
SOT-23-5 (M5)
(Top View)
4 OUT
MIC5252-x.xBML
6-Pin 2mm × 2mm MLF™ (ML)
(Top View)
Pin Description
Pin Number
SOT-23-5
Pin Number
6-MLF™
1
3
IN
2
2
GND
3
1
EN
Enable/Shutdown (Input): CMOS compatible input. Logic high = enable;
logic low = shutdown. Do not leave open.
4
6
BYP
Reference Bypass: Connect external 0.01µF ≤ CBYP ≤ 1.0µF capacitor to
GND to reduce output noise. May be left open.
5
4
OUT
Regulator Output.
–
5
NC
–
EP
GND
M9999-020305
Pin Name
Pin Function
Supply Input.
Ground.
No internal connection.
Ground: Internally connected to the exposed pad. Connect externally to
GND pin.
2
February 2005
MIC5252
Micrel, Inc.
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Input Voltage (VIN) ....................................0V to +7V
Enable Input Voltage (VEN) ..................................0V to +7V
Power Dissipation (PD) ..........................Internally Limited(3)
Junction Temperature (TJ) ........................ –40°C to +125°C
Storage Temperature ................................ –65°C to +150°C
Lead Temperature (soldering, 5 sec.) ........................ 260°C
ESD(4)............................................................................ 2kV
Input Voltage (VIN) .......................................... +2.7V to +6V
Enable Input Voltage (VEN) ...................................0V to VIN
Junction Temperature (TJ) ........................ –40°C to +125°C
Thermal Resistance
SOT-23 (θJA) ......................................................235°C/W
2x2 MLF™ (θJA) ..................................................90°C/W
Electrical Characteristics(5)
VIN = VOUT + 1V, VEN = VIN; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.
Symbol
Parameter
Conditions
VO
Output Voltage Accuracy
IOUT = 100µA
ΔVLNR
Line Regulation
VIN = VOUT + 1V to 6V
VIN – VOUT
Dropout Voltage(7)
IOUT = 100µA
IOUT = 150mA
VEN ≤ 0.4V (shutdown)
0.2
1
µA
90
150
µA
IOUT = 150mA
117
200
63
dB
f = 10Hz, VIN = VOUT + 0.3V
48
dB
48
dB
425
mA
ΔVLDR
IQ
Load Regulation
Quiescent Current
Ground Pin Current(8)
PSRR
Ripple Rejection; IOUT = 150mA
en
µV(rms)
IOUT = 0.1mA to
Current Limit
Output Voltage Noise
Typical
Max
Units
1
3
%
%
0.02
0.2
%
0.6
1.5
%
0.1
5
mV
90
150
mV
135
200
250
mV
mV
–1
–3
150mA(6)
IOUT = 100mA
IGND
ILIM
Min
IOUT = 0mA
f = 10Hz, COUT = 1.0µF, CBYP = 0.01µF
f = 10kHz, VIN = VOUT + 0.3V
VOUT = 0V
250
COUT = 1.0µF, CBYP = 0.01µF,
µA
30
f = 10Hz to 100kHz
Enable Input
VIL
Enable Input Logic-Low Voltage
IEN
Enable Input Current
VIH
Enable Input Logic-High Voltage
Shutdown Resistance Discharge
VIN = 2.7V to 5.5V, regulator shutdown
VIN = 2.7V to 5.5V, regulator enabled
VIL ≤ 0.4V, regulator shutdown
VIH ≥ 1.6V, regulator enabled
0.4
1.6
V
V
0.01
1
µA
0.01
1
µA
500
Ω
Thermal Shutdown Temperature
150
°C
Thermal Shutdown Hysteresis
10
°C
Thermal Protection
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function 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 will go into thermal shutdown. The θJA of the MIC5252-x.xBM5 (all versions) is 235°C/W on a PC board. See ”Thermal Considerations” section for further details.
4. Devices are ESD sensitive. Handling precautions recommended.
5. Specification for packaged product only.
6. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range
from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
7. Dropout Voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal value measured at 1V differential. For outputs below 2.7V, dropout voltage is the input-to-output voltage differential with the minimum input voltage 2.7V. Minimum input operating
voltage is 2.7V.
8. 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 current.
February 2005
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M9999-020305
MIC5252
Micrel, Inc.
Typical Characteristics
P S R R with B ypas s V ariation
(V IN = V OUT + 0.3V )
90
90
80
80
70
70
20
10
0
10
C OUT = 1µF C eramic
10
10k 100k
1k
100
FREQUENCY (Hz)
PSRR (dB)
60
50
150mA
40
30
C OUT = 1µF
C B Y P = 10nF
V OUT 2.8V
20
10
OUTPUT VOLTAGE (V)
100µA
70
0
100
200
300
400
500
600
700
800
900
1000
0
50
10
10
1M
150mA
40
20
10k 100k
1k
100
FREQUENCY (Hz)
2.85
2.83
2.81
2.79
2.77
2.75
2.73
2.71
2.69
2.67
2.65
0
60
30
V IN = V OUT + 1V
V OUT = 2.8V
Load = 150mA
C OUT = 1µF C eramic
C B Y P = 10nF
V IN = V OUT + 1V
V OUT = 2.8V
10k 100k
1k
100
FREQUENCY (Hz)
1M
Output V oltage
vs . T emperature
Output V oltage
vs . L oad C urrent
PSR R
at 100Hz
90
80
C OUT = 1µF C eramic
0
10
1M
0nF
40
20
V IN = V OUT + 0.3V
V OUT = 2.8V
Load = 150mA
100nF
50
30
100µA
70
PSRR (dB)
0nF
10nF
30
80
1µF
60
1µF
50
40
90
10nF
2.84
2.82
OUTPUT VOLTAGE (V)
100nF
PSRR (dB)
PSRR (dB)
60
P S R R with L oad V ariation
P S R R with B ypas s C ap
V ariation (V IN = V OUT + 1V )
2.8V OUT
2.8
2.78
2.76
2.74
2.72
100µA
2.7
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
20 40 60 80 100 120 140
OUTPUT CURRENT (mA)
VOLTAGE DROP (mV)
G round C urrent
vs . T emperature
160
120
140
80
60
40
20
0
0
2.8V OUT
80 0mA Load
60
40
20
2.5
10mA Load
150mA Load
60
40
20
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
SUPPLY VOLTAGE (V)
M9999-020305
100
150mA
1.5
1
0.5
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
SUPPLY VOLTAGE (V)
4
0µA Load
60
40
20
Dropout
vs . T emperature
100 µA
2
80
1µA Load
100µA Load
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
SUPPLY VOLTAGE (V)
3
OUTPUT VOLTAGE (V)
GROUND CURRENT (µA)
80
150mA Load
Dropout C harac teris tic s
G round C urrent
vs . S uppl y V oltage
100
100
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
20 40 60 80 100 120 140 160
OUTPUT CURRENT (mA)
140
120
120
120
DROPOUT VOLTAGE (mV)
100
G round C urrent
vs . S uppl y V oltage
GROUND CURRENT (µA)
140
GROUND CURRENT (µA)
GROUND CURRENT (µA)
G round C urrent
vs . Output C urrent
200
180
160
140
120
100
80
60
40
2.8V OUT
20
I L = 150mA
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
February 2005
MIC5252
Micrel, Inc.
2.8V OUT
20 40 60 80 100 120 140 160
OUTPUT CURRENT (mA)
1.4
1.4
1.3
1.3
1.2
E nable On
1.1
1
E nable Off
0.9
0.8
0.7
0.6
2.7 3.2 3.7 4.2 4.7 5.2 5.7 6.2
SUPPLY VOLTAGE (V)
ENABLE THRESHOLD (V)
200
180
160
140
120
100
80
60
40
20
0
0
E nable T hres hold
vs . T emperature
E nable T hres hold
vs . S uppl y V oltage
ENABLE THRESHOLD (V)
DROPOUT (mV)
Dropout
vs . Output C urrent
V
IN
= 5V
1.2
1.1
1
0.9
V IN = 3.8V
0.8
0.7
0.6
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
SHORT CIRCUIT CURRENT (mA)
S hort C irc uit C urrent
vs . Input S uppl y V oltage
500
450
400
350
300
250
200
150
100
50
0
2.7
2.8V OUT
3.2 3.7 4.2 4.7
SUPPLY VOLTAGE (V)
February 2005
5.2
5
M9999-020305
MIC5252
Micrel, Inc.
Functional Characteristics
EnablePin Delay
OutputCurrent
(100mA/div)
OutputVoltage
(1V/div)
EnableVoltage
(1V/div)
OutputVoltage
(50mV/div)
Load Transient Response
VOUT = 2.85V
VIN = 3.6V
COUT = 1µF Ceramic
150mA
100µA
TIME (40µs/div)
TIME (10µs/div)
OutputVoltage
(200mV/div)
Line Transient Response
InputVoltage
(1V/div)
5V
3.3V
50mALoad
TIME (10µs/div)
M9999-020305
6
February 2005
MIC5252
Micrel, Inc.
Block Diagram
IN
Reference
Voltage
Startup/
Shutdown
Control
Quickstart/
Noise
Cancellation
EN
BYP
Thermal
Sensor
FAU LT
Error
Amplifier
Undervoltage
Lockout
Current
Amplifier
OU T
ACTIV E SHU TDO W N
GND
February 2005
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M9999-020305
MIC5252
Micrel, Inc.
Applications Information
No-Load Stability
The MIC5252 will remain stable and in regulation with no
load unlike many other voltage regulators. This is especially
important in CMOS RAM keep-alive applications.
Enable/Shutdown
The MIC5252 comes with an active-high enable pin that allows the regulator to be disabled. Forcing the enable pin low
disables 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. This part is CMOS and the enable pin
cannot be left floating; a floating enable pin may cause an
indeterminate state on the output.
Thermal Considerations
The MIC5252 is designed to provide 150mA of continuous
current in a very small package. Maximum power dissipation
can be calculated based on the output current and the voltage
drop across the part. To determine the maximum power dissipation of the package, use the junction-to-ambient thermal
resistance of the device and the following basic equation:
 T (max) − T A 
PD (max) =  J

θ JA


Input Capacitor
The MIC5252 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. 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.
TJ(max) is the maximum junction temperature of the die,
125°C, and TA is the ambient operating temperature. θJA is
layout dependent; Table 1 shows examples of junction-toambient thermal resistance for the MIC5252.
Package
Output Capacitor
SOT-23-5
(M5 or D5)
The MIC5252 requires an output capacitor for stability. The
design requires 1µF or greater on the output to maintain stability. The design is optimized for use with low-ESR ceramic chip
capacitors. High ESR capacitors may cause high frequency
oscillation. The maximum recommended ESR is 300mΩ.
The output capacitor can be increased, but performance has
been optimized for a 1µF ceramic output capacitor and does
not improve significantly with larger capacitance.
θJA 1” Square
Copper Clad
θJC
235°C/W
185°C/W
145°C/W
Table 1. SOT-23-5 Thermal Resistance
The actual power dissipation of the regulator circuit can be
determined using the equation:
PD = (VIN – VOUT) IOUT + VIN IGND
Substituting PD(max) for PD and solving for the operating
conditions that are critical to the application will give the
maximum operating conditions for the regulator circuit. For
example, when operating the MIC5252-2.8BM5 at 50°C with
a minimum footprint layout, the maximum input voltage for a
set output current can be determined as follows:
 125 °C − 50 °C 
PD (max) = 

 235 °C/W 
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.
PD(max) = 315mW
The junction-to-ambient thermal resistance for the minimum
footprint is 235°C/W, from Table 1. The maximum power dissipation must not be exceeded for proper operation. Using
the output voltage of 2.8V and an output current of 150mA,
the maximum input voltage can be determined. 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.
Bypass Capacitor
A capacitor is required from the noise bypass pin to ground
to reduce output voltage noise. The capacitor bypasses
the internal reference. A 0.01µF capacitor is recommended
for applications that require low-noise outputs. The bypass
capacitor can be increased, further reducing noise and improving PSRR. Turn-on time increases slightly with respect
to bypass capacitance. A unique quick-start circuit allows
the MIC5252 to drive a large capacitor on the bypass pin
without significantly slowing turn-on time. Refer to the “Typical Characteristics” section for performance with different
bypass capacitors.
315mW = (VIN – 2.8V) 150mA
315mW = VIN × 150mA – 420mW
735mW = VIN × 150mA
VIN(max) = 4.9V
Therefore, a 2.8V application at 150mA of output current
can accept a maximum input voltage of 4.9V in a SOT-23-5
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.
Active Shutdown
The MIC5252 also features an active shutdown clamp, which
is an N-Channel MOSFET that turns on when the device is
disabled. This allows the output capacitor and load to discharge, de-energizing the load.
M9999-020305
θJA Recommended
Minimum Footprint
8
February 2005
MIC5252
Micrel, Inc.
Package Information
SOT-23-5 (M5)
6-Pin MLF™ (ML)
MICREL INC.
TEL
2180 FORTUNE DRIVE
SAN JOSE, CA 95131
USA
+ 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com
This 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
February 2005
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M9999-020305
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