MIC5255-2.8YD5 [MICREL]
150mA Low Noise UCap CMOS LDO; 150毫安低噪声UCAP CMOS LDO
| 型号： | MIC5255-2.8YD5 |
| 厂家： | 
MICREL SEMICONDUCTOR |
| 描述： | 150mA Low Noise UCap CMOS LDO |
| 文件： | 总11页 (文件大小：131K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MIC5255
150mA Low Noise µCap CMOS LDO
General Description
Features
The MIC5255 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 MIC5255 pro-
vides a very-low-noise output, ideal for RF applications
where a clean voltage source is required. A noise bypass pin
is also available for further reduction of output noise.
• Input voltage range: 2.7V to 6.0V
• Thin SOT package: 1mm height SOT-23-5
• 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
Designed specifically for handheld and battery-powered de-
vices, the MIC5255 provides a TTL-logic-compatible enable
pin.Whendisabled,powerconsumptiondropsnearlytozero.
• Low quiescent current: 90µA
• Tight load and line regulation
• TTL-Logic-controlled enable input
• “Zero” off-mode current
The MIC5255 also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in handheld wireless devices.
• Thermal shutdown and current limit protection
Key features include current limit, thermal shutdown, faster
transient response, and an active clamp to speed up device
turn-off. Available in the 6-pin 2mm × 2mm MLF™ package,
the IttyBitty® SOT-23-5 package and the new Thin SOT-23-
5, which offers the same footprint as the standard IttyBitty®
SOT-23-5, but only 1mm tall. The MIC5255 offers a range of
output voltages.
Applications
• Cellular phones and pagers
• Cellular accessories
• Battery-powered equipment
• Laptop, notebook, and palmtop computers
• Consumer/personal electronics
All support documentation can be found on Micrel’s web
site at www.micrel.com.
Typical Application
MIC5255-x.xBM5
VOUT
VIN
VIN
VOUT
C
IN = 1.0µF
Ceramic
1
2
3
5
MIC5255-x.xBML
ENABLE
SHUTDOWN
COUT
6
5
4
1
2
3
EN
CBYP
(optional)
COUT = 1.0µF
Ceramic
4
Enable
Shutdown
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
C
BYP = 0.01µF
Ultra-Low-Noise Regulator Application
IttyBitty is a registered trademark of Micrel, Inc.
MicroLeadFrame and MLF are trademarks of Amkor Technology.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000• http://www.micrel.com
M0385-080204
August, 2004
1
MIC5255
Micrel
Ordering Information
Part Number
Marking
Voltage Temperature Range
Package
Standard
Pb-Free
Standard Pb-Free
MIC5255-2.5BM5 MIC5255-2.5YM5 LW25
MIC5255-2.6BM5 MIC5255-2.6YM5 LW26
MIC5255-2.7BM5 MIC5255-2.7YM5 LW27
MIC5255-2.8BM5 MIC5255-2.8YM5 LW28
MIC5255-2.8BML MIC5255-2.8YML W28
MIC5255-2.85BM5 MIC5255-2.85YM5 LW2J
MIC5255-2.9BM5 MIC5255-2.9YM5 LW29
LW25
LW26
LW27
LW28
W28
2.5V
2.6V
2.7V
2.8V
2.8V
2.85V
2.9V
3.0V
3.0V
3.1V
3.2V
3.3V
2.6V
2.7V
2.8V
2.85V
2.9V
3.0V
3.3V
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
SOT-23-5
SOT-23-5
SOT-23-5
SOT-23-5
6-Pin 2×2 MLF™
SOT-23-5
LW2J
LW29
LW30
W30
SOT-23-5
MIC5255-3.0BM5 MIC5255-3.0YM5
MIC5255-3.0BML MIC5255-3.0YML
LW30
W30
SOT-23-5
6-Pin 2×2 MLF™
SOT-23-5
MIC5255-3.1BM5 MIC5255-3.1YM5 LW31
MIC5255-3.2BM5 MIC5255-3.2YM5 LW32
MIC5255-3.3BM5 MIC5255-3.3YM5 LW33
MIC5255-2.6BD5 MIC5255-2.6YD5 NW26
LW31
LW32
LW33
NW26
NW27
NW28
NW2J
NW2J
NW2J
NW2J
SOT-23-5
SOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
TSOT-23-5
MIC5255-2.7BD5 MIC5255-2.7YD5
MIC5255-2.8BD5 MIC5255-2.8YD5
NW27
NW28
MIC5255-2.85BD5 MIC5255-2.85YD5 NW2J
MIC5255-2.9BD5 MIC5255-2.9YD5
MIC5255-3.0BD5 MIC5255-3.0YD5
MIC5255-3.3BD5 MIC5255-3.3YD5
NW29
NW30
NW33
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M0385-080204
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Micrel
Pin Configuration
EN GND IN
EN GND IN
EN GND IN
3
2
1
3
2
1
3
2
1
KWxx
LWxx
NWxx
4
5
4
5
4
5
BYP
OUT
BYP
OUT
BYP
OUT
MIC5255-x.xBM5
(SOT-23-5)
MIC5255-x.xYM5
(SOT-23-5)
MIC5255-x.xBD5
(TSOT-23-5)
6
5
4
BYP
NC
EN
GND
IN
1
2
3
OUT
MIC5255-x.xBML
6-Pin 2mm × 2mm MLF™ (ML)
(Top View)
Pin Description
Pin Number
SOT-23-5
Pin Number
6-MLF™
Pin Name
Pin Function
TSOT-23-5
1
2
3
3
2
1
IN
GND
EN
Supply Input.
Ground.
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
5
OUT
NC
Regulator Output
No internal connection.
EP
GND
Ground: Internally connected to the exposed pad. Connect externally to
GND pin.
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Micrel
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Input Voltage (V ) .................................. 0V to +7V
Input Voltage (V ) ......................................... +2.7V to +6V
IN
IN
Enable Input Voltage (V ) ................................. 0V to +7V
Enable Input Voltage (V ) .................................. 0V to V
EN
EN
IN
(3)
Power Dissipation (P ) ........................ Internally Limited
Junction Temperature (T ) ....................... –40°C to +125°C
D
J
Junction Temperature (T ) ....................... –40°C to +125°C
Thermal Resistance
J
SOT-23 (θ ) .....................................................235°C/W
Storage Temperature (T ) ....................... –65°C to +150°C
JA
S
2×2 MLF™ (θ ) ..................................................90°C/W
JA
Lead Temperature (soldering, 5 sec.) ....................... 260°C
(4)
ESD .............................................................................................. 2kV
Electrical Characteristics(5)
VIN = VOUT + 1V, VEN = VIN; OUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.
I
Symbol
Parameter
Conditions
Min Typical Max
Units
VO
Output Voltage Accuracy
IOUT = 100µA
–1
–2
1
2
%
%
∆VLNR
Line Regulation
Load Regulation
Dropout Voltage(7)
VIN = VOUT + 1V to 6V
IOUT = 0.1mA to 150mA(6)
IOUT = 100µA
0.02
1.5
0.1
90
0.05
2.5
5
%/V
%
∆VLDR
VIN – VOUT
mV
mV
IOUT = 100mA
150
IOUT = 150mA
135
200
250
mV
mV
IQ
Quiescent Current
V
EN ≤ 0.4V (shutdown)
0.2
90
1
µA
µA
IGND
Ground Pin Current(8)
IOUT = 0mA
150
IOUT = 150mA
117
60
µA
PSRR
Ripple Rejection
f = 10Hz, COUT = 1.0µF, CBYP = 0.01µF
f = 100Hz, VIN = VOUT +1
f = 10kHz, VIN = VOUT +1
VOUT = 0V
dB
60
dB
50
dB
ILIM
en
Current Limit
160
425
30
mA
Output Voltage Noise
COUT = 1.0µF, CBYP = 0.01µF,
µV(rms)
f = 10Hz to 100kHz
Enable Input
VIL
VIH
IEN
Enable Input Logic-Low Voltage
Enable Input Logic-High Voltage
Enable Input Current
VIN = 2.7V to 5.5V, regulator shutdown
VIN = 2.7V to 5.5V, regulator enabled
0.4
V
V
1.6
V
IL ≤ 0.4V, regulator shutdown
IH ≥ 1.6V, regulator enabled
0.01
0.01
500
µA
µA
Ω
V
Shutdown Resistance Discharge
Thermal Protection
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
150
10
°C
°C
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 T (ambient temperature) is P (max) = (T (max)–T )/θ . Exceeding the maximum allowable
A
D
J
A
JA
power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The θ of the MIC5255-x.xBM5 (all
JA
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 differen-
tial. 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.
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Typical Characteristics
Power Supply Rejection Ratio
70
Power Supply Rejection Ratio
70
Power Supply Rejection Ratio
70
60
50
60
50
40
30
20
60
50
40
30
20
10
0
0µF*
100µA*
100µA*
50mA*
0.01µF*
0.1µF*
1.0µF*
40
50mA*
30
20
10
0
100mA*
150mA*
*ILOAD
100mA*
150mA*
* ILOAD
* CBYP
ILOAD = 50mA
VIN = VOUT + 0.5V
COUT = 1µF Ceramic
10 COUT = 4.7µF Ceramic
COUT = 1µF Ceramic
0
FRQUENCY (Hz)
FRQUENCY (Hz)
FRQUENCY (Hz)
PSRR vs. Voltage Drop
PSRR vs. Voltage Drop
Ground Pin Current
70
60
50
40
30
20
10
0
80
130
125
120
115
110
105
100
ILOAD = 100µA
70
ILOAD = 100µA
60
50
40
ILOAD = 150mA
ILOAD = 150mA
30
20
COUT = 1µF
CBYP = 0.01µF
COUT = 1µF
CBYP = 0
VIN = VOUT + 1V
10
0
0
200 400 600 800 1000
VOLTAGE DROP (mV)
0
200 400 600 800 1000
VOLTAGE DROP (mV)
0.1
1
10
100
1000
OUTPUT CURRENT (mA)
Ground Pin Current
Ground Pin Current
Ground Pin Current
115
113
111
109
107
105
103
101
99
125
140
120
100
80
120
115
110
105
100
95
60
40
20
97
ILOAD = 100µA
ILOAD = 150mA
ILOAD = 100µA
95
0
-40 -20
0
20 40 60 80 100120140
-40 -20 0 20 40 60 80 100120140
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
INPUT VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
Ground Pin Current
Dropout Characteristics
Dropout Voltage
140
120
100
80
3.5
0.14
ILOAD = 100µA
3
2.5
2
0.12
0.1
ILOAD = 150mA
0.08
0.06
0.04
0.02
0
60
1.5
1
40
20
0.5
0
ILOAD = 150mA
ILOAD = 100µA
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
INPUT VOLTAGE (V)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
INPUT VOLTAGE (V)
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
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MIC5255
Micrel
Output Voltage vs.
Temperature
Enable Threshold
vs. Temperature
Short Circuit Current
500
3.05
3.04
3.03
3.02
3.01
3.00
2.99
2.98
2.97
2.96
2.95
1.3
1.25
1.2
VIN = VOUT + 1V
490
480
470
460
450
440
430
420
410
400
1.15
1.1
1.05
1
0.95
0.9
0.85
0.8
ILOAD = 100µA
ILOAD = 100µA
-40 -20
0
20 40 60 80 100120140
-40 -20
0
20 40 60 80 100120140
-40 -20
0
20 40 60 80 100120140
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
Turn-On Time vs.
Bypass Capacitance
500
450
400
350
300
250
200
150
100
50
CIN = 1µF Ceramic
COUT = 1µF Ceramic
ILOAD = 100µA
Rise Time
Prop Delay
0
100
1000 10000 1000001000000
BYPASS CAPACITANCE (pF)
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Functional Characteristics
Line Transient Response
Load Transient Response
5V
4V
CIN = 1µF Ceramic
CIN = 1µF Ceramic
COUT = 1µF Ceramic
CBYP = 0.01µF
COUT = 1µF Ceramic
CBYP = 0.01µF
VIN = 4V
IOUT = 100µA
150mA
100µA
TIME (400µs/div)
TIME (4µs/div)
Enable Pin Delay
Shutdown Delay
CIN = 1µF Ceramic
COUT = 1µF Ceramic
CBYP = 0.01µF
VIN = 4V
CIN = 1µF Ceramic
COUT = 1µF Ceramic
CBYP = 0.01µF
IOUT = 100µA
TIME (10µs/div)
TIME (400µs/div)
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Block Diagram
IN
Startup/
Shutdown
Control
Quickstart/
Noise
Cancellation
Reference
Voltage
EN
BYP
OUT
FAULT
Thermal
Sensor
Error
Amplifier
Current
Amplifier
Under-
voltage
Lockout
ACTIVE SHUTDOWN
GND
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No-Load Stability
Applications Information
TheMIC5255willremainstableandinregulationwithnoload
unlike many other voltage regulators. This is especially
important in CMOS RAM keep-alive applications.
Enable/Shutdown
The MIC5255 comes with an active-high enable pin that
allowstheregulatortobedisabled.Forcingtheenablepinlow
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 indetermi-
nate state on the output.
Thermal Considerations
The MIC5255 is designed to provide 150mA of continuous
current in a very small package. Maximum power dissipation
canbecalculatedbasedontheoutputcurrentandthevoltage
drop across the part. To determine the maximum power
dissipation of the package, use the junction-to-ambient ther-
malresistanceofthedeviceandthefollowingbasicequation:
Input Capacitor
The MIC5255 is a high performance, high bandwidth device.
Therefore, it requires a well-bypassed input supply for opti-
mal 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 practice in any RF-based circuit.
T (max)− T
J
A
P (max) =
D
θ
JA
T (max) is the maximum junction temperature of the die,
125°C, and T is the ambient operating temperature. θ is
layout dependent; Table 1 shows examples of junction-to-
ambient thermal resistance for the MIC5255.
J
A
JA
Package
θJA Recommended θJA 1" Square
Minimum Footprint
θJC
Output Capacitor
Copper Clad
The MIC5255 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.
SOT-23-5
(M5 or D5)
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:
P = (V – V
) I
+ V I
IN GND
D
IN
OUT OUT
Substituting P (max) for P and solving for the operating
D
D
conditions that are critical to the application will give the
maximum operating conditions for the regulator circuit. For
example, when operating the MIC5255-3.0BM5 at 50°C with
a minimum footprint layout, the maximum input voltage for a
set output current can be determined as follows:
X7R/X5R dielectric-type ceramic capacitors are recom-
mended because of their temperature performance. X7R-
type capacitors change capacitance by 15% over their oper-
ating temperature range and are the most stable type of
ceramiccapacitors.Z5UandY5Vdielectriccapacitorschange
value by as much as 50% and 60%, respectively, over their
operatingtemperatureranges. Touseaceramicchipcapaci-
torwithY5Vdielectric, thevaluemustbemuchhigherthanan
X7R ceramic capacitor to ensure the same minimum capaci-
tance over the equivalent operating temperature range.
125°C − 50°C
P (max) =
D
235°C/W
P (max) = 315mW
D
The junction-to-ambient thermal resistance for the minimum
footprint is 235°C/W, from Table 1. The maximum power
dissipationmustnotbeexceededforproperoperation. Using
the output voltage of 3.0V 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
groundcurrentis< 1%andcanbeignoredforthiscalculation:
Bypass Capacitor
A capacitor can be placed from the noise bypass pin to
ground to reduce output voltage noise. The capacitor by-
passes the internal reference. A 0.01µF capacitor is recom-
mended 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 MIC5255 to drive a large capacitor on the bypass
pin without significantly slowing turn-on time. Refer to the
“Typical Characteristics” section for performance with differ-
ent bypass capacitors.
315mW = (V – 3.0V) 150mA
IN
315mW = V × 150mA – 450mW
IN
810mW = V × 150mA
IN
V (max) = 5.4V
IN
Therefore, a 3.0V application at 150mA of output current can
accept a maximum input voltage of 5.4V in a SOT-23-5
package. For a full discussion of heat sinking and thermal
effectsonvoltageregulators,refertothe“RegulatorThermals”
sectionofMicrel’sDesigningwithLow-DropoutVoltageRegu-
lators handbook.
Active Shutdown
The MIC5255 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 dis-
charge, de-energizing the load.
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Micrel
Package Information
1.90 (0.075) REF
0.95 (0.037) REF
1.75 (0.069) 3.00 (0.118)
1.50 (0.059) 2.60 (0.102)
DIMENSIONS:
MM (INCH)
1.30 (0.051)
0.90 (0.035)
3.02 (0.119)
2.80 (0.110)
0.20 (0.008)
0.09 (0.004)
10°
0°
0.15 (0.006)
0.00 (0.000)
0.50 (0.020)
0.35 (0.014)
0.60 (0.024)
0.10 (0.004)
SOT-23-5 (M5)
TSOT-23-5 (D5)
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Micrel
Package Information (continued)
TOP VIEW
BOTTOM VIEW
DIMENSIONS IN
MILLIMETERS
Rev. 02
SIDE VIEW
6-Pin MLF™ (ML)
MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 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.
August, 2004
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M0385-080204
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