MICREL MIC5205

MIC5205
Micrel
MIC5205
150mA Low-Noise LDO Regulator
General Description
Features
The MIC5205 is an efficient linear voltage regulator with ultralow-noise output, very low dropout voltage (typically 17mV at
light loads and 165mV at 150mA), and very low ground
current (600µA at 100mA output). The MIC5205 offers better
than 1% initial accuracy.
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Designed especially for hand-held, battery-powered devices,
the MIC5205 includes a CMOS or TTL compatible enable/
shutdown control input. When shutdown, power consumption drops nearly to zero. Regulator ground current increases
only slightly in dropout, further prolonging battery life.
Key MIC5205 features include a reference bypass pin to
improve its already excellent low-noise performance, reversed-battery protection, current limiting, and
overtemperature shutdown.
The MIC5205 is available in fixed and adjustable output
voltage versions in a small SOT-23-5 package.
Ultra-low-noise output
High output voltage accuracy
Guaranteed 150mA output
Low quiescent current
Low dropout voltage
Extremely tight load and line regulation
Very low temperature coefficient
Current and thermal limiting
Reverse-battery protection
“Zero” off-mode current
Logic-controlled electronic enable
Applications
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For low-dropout regulators that are stable with ceramic
output capacitors, see the µCap MIC5245/6/7 family.
Cellular telephones
Laptop, notebook, and palmtop computers
Battery-powered equipment
PCMCIA VCC and VPP regulation/switching
Consumer/personal electronics
SMPS post-regulator/dc-to-dc modules
High-efficiency linear power supplies
Ordering Information
Part Number
Marking
Voltage
Accuracy
Junction Temp. Range*
Package
MIC5205BM5
MIC5205-2.5BM5
LBAA
Adj
1%
–40°C to +125°C
SOT-23-5
LB25
2.5V
1%
–40°C to +125°C
SOT-23-5
MIC5205-2.7BM5
LB27
2.7V
1%
–40°C to +125°C
SOT-23-5
MIC5205-2.8BM5
LB28
2.8V
1%
–40°C to +125°C
SOT-23-5
MIC5205-2.85BM5
LB2J
2.85V
1%
–40°C to +125°C
SOT-23-5
MIC5205-2.9BM5
LB29
2.9V
1%
–40°C to +125°C
SOT-23-5
MIC5205-3.0BM5
LB30
3.0V
1%
–40°C to +125°C
SOT-23-5
MIC5205-3.3BM5
LB33
3.3V
1%
–40°C to +125°C
SOT-23-5
MIC5205-3.6BM5
LB36
3.6V
1%
–40°C to +125°C
SOT-23-5
MIC5205-3.8BM5
LB38
3.8V
1%
–40°C to +125°C
SOT-23-5
MIC5205-4.0BM5
LB40
4.0V
1%
–40°C to +125°C
SOT-23-5
MIC5205-5.0BM5
LB50
5.0V
1%
–40°C to +125°C
SOT-23-5
Other voltages available. Contact Micrel for details.
Typical Application
VIN MIC5205-x.xBM5
1
5
2
3
Enable
Shutdown
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
4
VOUT
COUT = 2.2µF
tantalum
Low-Noise Operation:
CBYP
CBYP = 470pF, COUT ≥ 2.2µF
Basic Operation:
CBYP = not used, COUT ≥ 1µF
Ultra-Low-Noise Regulator Application
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
June 2000
1
MIC5205
MIC5205
Micrel
Pin Configuration
EN GND IN
3
2
EN GND IN
1
3
LBxx
2
1
Part
Identification
LBAA
4
5
4
5
BYP
OUT
ADJ
OUT
MIC5205-x.xBM5
Fixed Voltages
MIC5205BM5
Adjustable Voltage
Pin Description
MIC5205-x.x
(fixed)
MIC5205
(adjustable)
Pin Name
Pin Function
1
1
IN
Supply Input
2
2
GND
3
3
EN
Enable/Shutdown (Input): CMOS compatible input. Logic high = enable,
logic low or open = shutdown.
BYP
Reference Bypass: Connect external 470pF capacitor to GND to reduce
output noise. May be left open.
4
ADJ
Adjust (Input): Adjustable regulator feedback input. Connect to resistor
voltage divider.
5
OUT
Regulator Output
4
5
Ground
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Supply Input Voltage (VIN) ............................ –20V to +20V
Enable Input Voltage (VEN) ........................... –20V to +20V
Power Dissipation (PD) ............... Internally Limited, Note 3
Lead Temperature (soldering, 5 sec.) ....................... 260°C
Junction Temperature (TJ) ....................... –40°C to +125°C
Storage Temperature (TS) ....................... –65°C to +150°C
Input Voltage (VIN) ....................................... +2.5V to +16V
Enable Input Voltage (VEN) .................................. 0V to VIN
Junction Temperature (TJ) ....................... –40°C to +125°C
Thermal Resistance, SOT-23-5 (θJA) ....................... Note 3
MIC5205
2
June 2000
MIC5205
Micrel
Electrical Characteristics
VIN = VOUT + 1V; IL = 100µA; CL = 1.0µF; VEN ≥ 2.0V; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.
Symbol
Parameter
Conditions
Min
Typical
VO
Output Voltage Accuracy
variation from specified VOUT
∆VO/∆T
Output Voltage
Temperature Coefficient
Note 4
∆VO/VO
Line Regulation
VIN = VOUT + 1V to 16V
0.004
0.012
0.05
%/V
%/V
∆VO/VO
Load Regulation
IL = 0.1mA to 150mA, Note 5
0.02
0.2
0.5
%
%
VIN – VO
Dropout Voltage, Note 6
IL = 100µA
10
IL = 50mA
110
IL = 100mA
140
IL = 150mA
165
50
70
150
230
250
300
275
350
mV
mV
mV
mV
mV
mV
mV
mV
–1
–2
Max
Units
1
2
%
%
40
ppm/°C
IGND
Quiescent Current
VEN ≤ 0.4V (shutdown)
VEN ≤ 0.18V (shutdown)
0.01
1
5
µA
µA
IGND
Ground Pin Current, Note 7
VEN ≥ 2.0V, IL = 100µA
80
IL = 50mA
350
IL = 100mA
600
IL = 150mA
1300
125
150
600
800
1000
1500
1900
2500
µA
µA
µA
µA
µA
µA
µA
µA
PSRR
Ripple Rejection
frequency = 100Hz, IL = 100µA
75
dB
ILIMIT
Current Limit
VOUT = 0V
320
∆VO/∆PD
Thermal Regulation
Note 8
0.05
%/W
eno
Output Noise
IL = 50mA, CL = 2.2µF,
470pF from BYP to GND
260
nV/ Hz
500
mA
ENABLE Input
VIL
Enable Input Logic-Low Voltage
regulator shutdown
VIH
Enable Input Logic-High Voltage
regulator enabled
IIL
Enable Input Current
VIL ≤ 0.4V
VIL ≤ 0.18V
VIH ≥ 2.0V
VIH ≥ 2.0V
IIH
0.4
0.18
2.0
V
0.01
2
V
V
5
–1
–2
20
25
µA
µA
µA
µA
Note 1.
Exceeding the absolute maximum rating may damage the device.
Note 2.
The device is not guaranteed to function outside its operating rating.
Note 3:
The maximum allowable power dissipation at 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 MIC5205xxBM5 (all versions) is 220°C/W mounted on a PC board (see “Thermal Considerations” section for further details).
Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
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.
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.
Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of
the load current plus the ground pin current.
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 150mA load pulse at VIN = 16V for t = 10ms.
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
June 2000
3
MIC5205
MIC5205
Micrel
Typical Characteristics
PSRR (dB)
-20
-80
-20
PSRR (dB)
PSRR (dB)
0
VIN = 6V
VOUT = 5V
-40
-60
-80
-40
-60
-80
IOUT = 10mA
COUT = 1µF
Power Supply
Rejection Ratio
VIN = 6V
VOUT = 5V
-40
-60
-80
IOUT = 100mA
COUT = 1µF
-100
1E+1
1k 1E+4
10k 1E+5
1M 1E+7
10M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
MIC5205
IOUT = 100mA
20
COUT = 1µF
10
0
0.1
0.2
0.3
VOLTAGE DROP (V)
0.4
100
90
80
1mA
70
60
IOUT = 100mA
50
40
10mA
30
20
10
0
COUT = 2.2µF
CBYP = 0.01µF
0
0.1
0.2
0.3
VOLTAGE DROP (V)
0.4
Turn-On Time
vs. Bypass Capacitance
10000
-60
-20
10mA
VIN = 6V
VOUT = 5V
-40
0
30
Power Supply
Rejection Ratio
1000
100
IOUT = 10mA
COUT = 2.2µF
CBYP = 0.01µF
-100
1E+1
1k 1E+4
10k 1E+5
1M 1E+7
10M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
PSRR (dB)
PSRR (dB)
-20
IOUT = 1mA
COUT = 2.2µF
CBYP = 0.01µF
-80
-100
1E+1
1k 1E+4
10k 1E+5
1M 1E+7
10M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
0
-60
-20
PSRR (dB)
PSRR (dB)
-20
VIN = 6V
VOUT = 5V
-40
0
VIN = 6V
VOUT = 5V
1mA
40
Power Supply Ripple Rejection
vs. Voltage Drop
-100
1E+1
1k 1E+4
10k 1E+5
1M 1E+7
10M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
Power Supply
Rejection Ratio
50
0
Power Supply
Rejection Ratio
-80
IOUT = 1mA
COUT = 1µF
-100
1E+1
1k 1E+4
10k 1E+5
1M 1E+7
10M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
0
IOUT = 100µA
COUT = 2.2µF
CBYP = 0.01µF
-100
1E+1
1k 1E+4
10k 1E+5
1M 1E+7
10M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
Power Supply
Rejection Ratio
-20
-60
-80
IOUT = 100µA
COUT = 1µF
-100
1E+1
1k 1E+4
10k 1E+5
1M 1E+7
10M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
0
-40
RIPPLE REJECTION (dB)
-60
VIN = 6V
VOUT = 5V
TIME (µs)
-40
Power Supply Ripple Rejection
vs. Voltage Drop
60
RIPPLE REJECTION (dB)
VIN = 6V
VOUT = 5V
-20
PSRR (dB)
0
Power Supply
Rejection Ratio
10
10
Power Supply
Rejection Ratio
100
1000
CAPACITANCE (pF)
10000
Dropout Voltage
vs. Output Current
320
VIN = 6V
VOUT = 5V
-40
-60
IOUT = 100mA
COUT = 2.2µF
CBYP = 0.01µF
-80
-100
1E+1
1k 1E+4
10k 1E+5
1M 1E+7
10M
10 1E+2
100k 1E+6
100 1E+3
FREQUENCY (Hz)
4
DROPOUT VOLTAGE (mV)
0
Power Supply
Rejection Ratio
280
+125°C
240
200
+25°C
160
120
–40°C
80
40
0
0
40
80
120
160
OUTPUT CURRENT (mA)
June 2000
MIC5205
Micrel
Typical Characteristics
Noise Performance
Noise Performance
10
Noise Performance
10
10
10mA, COUT = 1µF
0.001
0.01
0.001
VOUT = 5V
0.0001
1E+1
10 1E+2
1k 1E+4
100 1E+3
10k 1E+5
100k 1E+6
1M 1E+7
10M
FREQUENCY (Hz)
Noise Performance
10mA
0.1
VOUT = 5V
COUT = 22µF
1mA
0.001
tantalum
CBYP = 10nF
0.0001
1k 1E+4
1E+1
10 1E+2
1M 1E+7
10k 1E+5
100k 1E+6
10M
100 1E+3
FREQUENCY (Hz)
Noise Performance
10
1
10mA
100mA
0.1
0.01
0.001
100mA
0.01
Noise Performance
NOISE (µV/√Hz)
NOISE (µV/√Hz)
100mA
1mA
VOUT = 5V
COUT = 10µF
0.001 electrolytic
10mA
CBYP = 100pF
0.0001
1k 1E+4
1E+1
10 1E+2
1M 1E+7
10k 1E+5
100k 1E+6
10M
100 1E+3
FREQUENCY (Hz)
June 2000
1mA
10
0.1
0.01
VOUT = 5V
COUT = 10µF
electrolytic
0.0001
1k 1E+4
1E+1
10 1E+2
1M 1E+7
10k 1E+5
100k 1E+6
10M
100 1E+3
FREQUENCY (Hz)
10
1
10mA
0.1
NOISE (µV/√Hz)
0.01
1mA
COUT = 1µF
CBYP = 10nF
1
100mA
VOUT = 5V
COUT = 10µF
electrolytic
CBYP = 1nF
1mA
0.0001
1k 1E+4
1E+1
10 1E+2
1M 1E+7
10k 1E+5
100k 1E+6
10M
100 1E+3
FREQUENCY (Hz)
5
1
NOISE (µV/√Hz)
0.1
1
NOISE (µV/√Hz)
NOISE (µV/√Hz)
1
100mA
0.1
0.01
0.001
1mA
VOUT = 5V
COUT = 10µF
electrolytic
CBYP = 10nF
10mA
0.0001
1E+1
10 1E+2
100 1E+3
1k 1E+4
10M
10k 1E+5
100k 1E+6
1M 1E+7
FREQUENCY (Hz)
MIC5205
MIC5205
Micrel
Block Diagrams
VIN
OUT
IN
VOUT
COUT
BYP
CBYP
(optional)
Bandgap
Ref.
V
REF
EN
Current Limit
Thermal Shutdown
MIC5205-x.xBM5
GND
Ultra-Low-Noise Fixed Regulator
VIN
OUT
IN
VOUT
COUT
ADJ
R1
R2
Bandgap
Ref.
V
REF
CBYP
(optional)
EN
VOUT = VREF (1 + R2/R1)
Current Limit
Thermal Shutdown
MIC5205BM5
GND
Ultra-Low-Noise Adjustable Regulator
MIC5205
6
June 2000
MIC5205
Micrel
Thermal Considerations
The MIC5205 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:
Applications Information
Enable/Shutdown
Forcing EN (enable/shutdown) high (> 2V) enables the regulator. EN is compatible with CMOS logic gates.
If the enable/shutdown feature is not required, connect EN
(pin 3) to IN (supply input, pin 1). See Figure 1.
Input Capacitor
A 1µF capacitor should be placed from IN to GND if there is
more than 10 inches of wire between the input and the ac filter
capacitor or if a battery is used as the input.
Reference Bypass Capacitor
PD(max) =
θ JA
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 MIC5205.
BYP (reference bypass) is connected to the internal voltage
reference. A 470pF capacitor (CBYP) connected from BYP to
GND quiets this reference, providing a significant reduction in
output noise. CBYP reduces the regulator phase margin;
when using CBYP, output capacitors of 2.2µF or greater are
generally required to maintain stability.
The start-up speed of the MIC5205 is inversely proportional
to the size of the reference bypass capacitor. Applications
requiring a slow ramp-up of output voltage should consider
larger values of CBYP. Likewise, if rapid turn-on is necessary,
consider omitting CBYP.
If output noise is not a major concern, omit CBYP and leave
BYP open.
Package
SOT-23-5 (M5)
θJA Recommended θJA 1" Square
Minimum Footprint Copper Clad
220°C/W
θJC
170°C/W
130°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 MIC5205-3.3BM5 at room
temperature with a minimum footprint layout, the maximum
input voltage for a set output current can be determined as
follows:
Output Capacitor
An output capacitor is required between OUT and GND to
prevent oscillation. The minimum size of the output capacitor
is dependent upon whether a reference bypass capacitor is
used. 1.0µF minimum is recommended when CBYP is not
used (see Figure 2). 2.2µF minimum is recommended when
CBYP is 470pF (see Figure 1). Larger values improve the
regulator’s transient response. The output capacitor value
may be increased without limit.
PD(max) =
(125°C
– 25°C)
220°C/W
PD(max) = 455mW
The junction-to-ambient thermal resistance for the minimum
footprint is 220°C/W, from Table 1. The maximum power
dissipation must not be exceeded for proper operation. Using
the output voltage of 3.3V and an output current of 150mA,
the maximum input voltage can be determined. From the
Electrical Characteristics table, the maximum ground current
for 150mA output current is 2500µA or 2.5mA.
455mW = (VIN – 3.3V) 150mA + VIN ·2.5mA
The output capacitor should have an ESR (effective series
resistance) of about 5Ω or less and a resonant frequency
above 1MHz. Ultra-low-ESR capacitors can cause a low
amplitude oscillation on the output and/or underdamped
transient response. Most tantalum or aluminum electrolytic
capacitors are adequate; film types will work, but are more
expensive. Since many aluminum electrolytics have electrolytes that freeze at about –30°C, solid tantalums are recommended for operation below –25°C.
At lower values of output current, less output capacitance is
required for output stability. The capacitor can be reduced to
0.47µF for current below 10mA or 0.33µF for currents below
1mA.
No-Load Stability
455mW = VIN ·150mA – 495mW + VIN ·2.5mA
950mW = VIN ·152.5mA
VIN(max) = 6.23V
Therefore, a 3.3V application at 150mA of output current can
accept a maximum input voltage of 6.2V 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.
The MIC5205 will remain stable and in regulation with no load
(other than the internal voltage divider) unlike many other
voltage regulators. This is especially important in CMOS
RAM keep-alive applications.
June 2000
(TJ(max) – TA )
7
MIC5205
MIC5205
Micrel
Fixed Regulator Applications
VIN
MIC5205-x.xBM5
1
5
2
3
 R2

VOUT = 1.242V × 
+ 1
 R1

VOUT
This equation is correct due to the configuration of the
bandgap reference. The bandgap voltage is relative to the
output, as seen in the block diagram. Traditional regulators
normally have the reference voltage relative to ground and
have a different VOUT equation.
2.2µF
4
470pF
Figure 1. Ultra-Low-Noise Fixed Voltage Application
Resistor values are not critical because ADJ (adjust) has a
high input impedance, but for best results use resistors of
470kΩ or less. A capacitor from ADJ to ground provides
greatly improved noise performance.
Figure 1 includes a 470pF capacitor for low-noise operation
and shows EN (pin 3) connected to IN (pin 1) for an application where enable/shutdown is not required. COUT = 2.2µF
minimum.
VIN
VIN MIC5205-x.xBM5 VOUT
1
5
2
3
Enable
Shutdown
1
R1
3
1.0µF
VOUT
5
2
2.2µF
4
4
470pF
EN
R2
Figure 3. Ultra-Low-Noise
Adjustable Voltage Application
Figure 2. Low-Noise Fixed Voltage Application
Figure 2 is an example of a low-noise configuration where
CBYP is not required. COUT = 1µF minimum.
Adjustable Regulator Applications
Figure 3 includes the optional 470pF noise bypass capacitor
from ADJ to GND to reduce output noise.
Dual-Supply Operation
When used in dual supply systems where the regulator load
is returned to a negative supply, the output voltage must be
diode clamped to ground.
The MIC5205BM5 can be adjusted to a specific output
voltage by using two external resistors (Figure 3). The resistors set the output voltage based on the following equation:
MIC5205
MIC5205BM5
8
June 2000
MIC5205
Micrel
Package Information
1.90 (0.075) REF
0.95 (0.037) REF
1.75 (0.069)
1.50 (0.059)
3.00 (0.118)
2.60 (0.102)
DIMENSIONS:
MM (INCH)
3.02 (0.119)
2.80 (0.110)
0.50 (0.020)
0.35 (0.014)
1.30 (0.051)
0.90 (0.035)
0.20 (0.008)
0.09 (0.004)
10°
0°
0.15 (0.006)
0.00 (0.000)
0.60 (0.024)
0.10 (0.004)
SOT-23-5 (M5)
June 2000
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MIC5205
MIC5205
MIC5205
Micrel
10
June 2000
MIC5205
June 2000
Micrel
11
MIC5205
MIC5205
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
MIC5205
12
June 2000