MIC5255
150mA Low Noise µCap CMOS LDO
General Description
Features
The MIC5255 is an efficient, precise CMOS voltage
•
Input voltage range: 2.7V to 6.0V
regulator optimized for ultra-low-noise applications. It
•
Thin SOT package: 1mm height SOT-23-5
offers 1% initial accuracy, extremely-low dropout voltage
•
Ultra-low output noise: 30µV(rms)
(135mV at 150mA) and low ground current (typically
•
Stability with ceramic output capacitors
90µA). The MIC5255 provides a very-low-noise output,
•
Ultra-low dropout: 135mV @ 150mA
ideal for RF applications where a clean voltage source is
required. A noise bypass pin is also available for further
•
High output accuracy:
reduction of output noise.
– 1.0% initial accuracy
Designed specifically for handheld and battery-powered
– 2.0% over temperature
devices, the MIC5255 provides a TTL-logic-compatible en-
•
Low quiescent current: 90µA
able pin. When disabled, power consumption drops nearly
•
Tight load and line regulation
to zero.
•
TTL-Logic-controlled enable input
The MIC5255 also works with low-ESR ceramic
•
“Zero” off-mode current
capacitors, reducing the amount of board space necessary
for power applications, critical in handheld wireless
•
Thermal shutdown and current limit protection
devices.
Key features include current limit, thermal shutdown, faster
Applications
transient response, and an active clamp to speed up
device turn-off. Available in the 6-pin 2mm × 2mm MLF
®
•
Cellular phones and pagers
package, the IttyBitty
®
SOT-23-5 package and the new
•
Cellular accessories
Thin SOT-23-5, which offers the same footprint as the
•
Battery-powered equipment
standard IttyBitty
®
SOT-23-5, but only 1mm tall. The
•
Laptop, notebook, and palmtop computers
MIC5255 offers a range of output voltages.
•
Consumer/personal electronics
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
___________________________________________________________________________________________________________
Typical Application
V
IN
MIC5255-x.x_M5
1
2
3
4
5
C
IN
= 1.0µF
Ceramic
Enable
Shutdown
V
OUT
C
OUT
= 1.0µF
Ceramic
C
BYP
= 0.01µF
Ultra-Low-Noise Regulator Application
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
IttyBitty is a registered trademark of Micrel, Inc
MLF and
MicroLeadFrame
are registered trademarks of Amkor Technology, 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
November 2006
1
M9999-110906
Micrel, Inc.
MIC5255
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) ............................................. 0V to +7V
Enable Voltage (V
EN
)............................................ 0V to +7V
Power Dissipation (P
D
) ........................... Internally Limited
(3)
Junction Temperature (T
J
) ........................–40°C to +125°C
Storage Temperature (T
s
) .........................–60°C to +150°C
Lead Temperature (soldering, 5 sec.)........................ 260°C
EDS Rating
(4)
.................................................................. 2kV
Operating Ratings
(2)
Supply Voltage (V
IN
)........................................ +2.7V to +6V
Enable Voltage (V
EN
).............................................. 0V to V
IN
Junction Temperature (T
J
) ........................ –40°C to +125°C
Thermal Resistance
SOT23-5 (
θ
JA
) ..................................................235°C/W
2x2 MLF-6 (
θ
JA
) .................................................90°C/W
Electrical Characteristics
(5)
V
IN
= V
OUT
+ 1V, V
EN
= V
IN
; I
OUT
= 100µA; T
J
= 25°C,
bold
values indicate –40°C
≤
T
J
≤
+125°C; unless noted.
Symbol
V
O
∆V
LNR
∆V
LDR
V
IN
– V
OUT
Parameter
Output Voltage Accuracy
Line Regulation
Load Regulation
Dropout Voltage
(7)
Condition
I
OUT
= 100µA
V
IN
= V
OUT
+ 1V to 6V
I
OUT
= 0.1mA to 150mA
I
OUT
= 100µA
I
OUT
= 100mA
I
OUT
= 150mA
(6)
Min
–1
–2
Typ
Max
1
2
Units
%
%
%/V
%
mV
mV
mV
mV
µA
µA
µA
dB
dB
dB
mV
µV(rms)
0.02
1.5
0.1
90
135
0.2
90
117
60
60
50
160
425
30
0.05
2.5
5
150
200
250
1
150
I
Q
I
GND
PSRR
Quiescent Current
Ground Pin Current
Ripple Rejection
(8)
V
EN
≤
0.4V (shutdown)
I
OUT
= 0mA
I
OUT
= 150mA
f = 10Hz, C
OUT
= 1.0µF, C
BYP
= 0.01µF
f = 100Hz, V
IN
= V
OUT
+1
f = 10kHz, V
IN
= V
OUT
+1
I
LIM
e
n
Enable Input
V
IL
V
IH
I
EN
Current Limit
Output Voltage Noise
V
OUT
= 0V
C
OUT
= 1.0µF, C
BYP
= 0.01µF,
f = 10Hz to 100kHz
V
IN
= 2.7V to 5.5V, regulator shutdown
V
IN
= 2.7V to 5.5V, regulator enabled
V
IL
≤
0.4V, regulator shutdown
V
IH
≥
1.6V, regulator enabled
Enable Input Logic-Low Voltage
Enable Input Logic-High Voltage
Enable Input Current
Shutdown Resistance Discharge
0.4
1.6
0.01
0.01
500
150
10
V
V
µA
µA
Ω
°C
°C
Thermal Protection
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
November 2006
4
M9999-110906
Micrel, Inc.
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
MIC5255
3. The maximum allowable power dissipation of any T
A
(ambient temperature) is P
D(max)
= (T
J(max)
– T
A
) /
θ
JA
. Exceeding the maximum allowable power
dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The
θ
JA
of the MIC5255-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. Human body model, 1.5k in series with 100pF.
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 1.0mA 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.
November 2006
5
M9999-110906
嵌入式系统
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