MIC5252
150 mA High PSRR, Low Noise μCap CMOS LDO
Features
General Description
•
•
•
•
•
•
The MIC5252 is an efficient, precise CMOS voltage
regulator optimized for ultra low-noise applications. It
offers 1% initial accuracy, extremely low dropout
voltage (135 mV at 150 mA) 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.
•
•
•
•
•
Input Voltage Range: 2.7V to 6.0V
PSRR = 50 dB @ VO + 0.3V
Ultra-Low Output Noise: 30 μVRMS
Stability with Ceramic Output Capacitors
Ultra-Low Dropout: 135 mV @ 150 mA
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
•
•
•
•
•
Cellular Phones and Pagers
Cellular Accessories
Battery-Powered Equipment
Laptop, Notebook, and Palmtop Computers
Consumer/Personal Electronics
Designed specifically for handheld and batterypowered 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, which is critical in
handheld wireless devices.
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-lead 2 mm × 2 mm VDFN package and the 5-Lead
SOT-23 package in a wide range of output voltages.
Package Types
MIC5252-x.xYM5
MIC5252-x.xYML
5-Lead SOT-23
(Top View)
6-Lead VDFN
(Top View)
2021 - 2022 Microchip Technology Inc.
DS20006579B-page 1
MIC5252
Typical Application Circuits
MIC5252-x.xYM5
Ultra-Low-Noise Regulator Application
Functional Block Diagram
DS20006579B-page 2
2021 - 2022 Microchip Technology Inc.
MIC5252
1.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings †
Supply Input Voltage (VIN) ............................................................................................. ...................................0V to +7V
Enable Input Voltage (VEN) ............................................................................................... ................................0V to +7V
Power Dissipation (PD) ..................................................................................... .......................Internally Limited (Note 1)
ESD Rating (Note 2) ......................................................................................... ........................................................ 2 kV
Operating Ratings ‡
Input Voltage (VIN) .................................................................................................... .................................. +2.7V to +6V
Enable Input Voltage (VEN) .................................................................................................................................0V to VIN
† Notice: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of the device at those or any other conditions above those indicated
in the operational sections of this specification is not intended. Exposure to maximum rating conditions for extended
periods may affect device reliability.
‡ Notice: The device is not guaranteed to function outside its operating ratings.
Note 1: 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.xYM5 (all versions) is 235°C/W on a PC
board. See Section 4.7 “Thermal Considerations” for further details.
2: Devices are ESD sensitive. Handling precautions recommended.
ELECTRICAL CHARACTERISTICS
VIN = VOUT + 1V, VEN = VIN; IOUT = 100 μA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.
(Note 1)
Parameter
Symbol
Output Voltage Accuracy
VO
Line Regulation
ΔVLNR
Load Regulation
Dropout Voltage (Note 3)
Ripple Rejection; IOUT = 150 mA
Current Limit
Output Voltage Noise
2021 - 2022 Microchip Technology Inc.
Max.
Units
Conditions
–1
—
1
%
–3
—
3
%
—
0.02
0.2
%
VIN = VOUT + 1V to 6V
1.5
%
IOUT = 0.1 mA to 150 mA
(Note 2)
IOUT = 100 μA
0.6
—
0.1
5
mV
IOUT = 100 μA
—
90
150
mV
IOUT = 100 mA
—
135
200
mV
—
250
IOUT = 150 mA
—
mV
—
0.2
1
IOUT = 150 mA
μA
90
150
VEN ≤ 0.4V (shutdown)
—
μA
—
117
200
IOUT = 0 mA
μA
IOUT = 150 mA
—
63
—
dB
f = 10 Hz, COUT = 1.0 μF,
CBYP = 0.01 μF
—
48
—
dB
f = 10 Hz, VIN = VOUT + 0.3V
—
48
—
dB
f = 10 kHz, VIN = VOUT +
0.3V
ILIM
250
425
—
mA
VOUT = 0V
en
—
30
—
μVRMS
VIN – VOUT
Ground Pin Current (Note 4)
Typ.
—
ΔVLDR
Quiescent Current
Min.
IQ
IGND
PSRR
COUT = 1.0 μF, CBYP =
0.01 μF, f = 10 Hz to
100 kHz
DS20006579B-page 3
MIC5252
ELECTRICAL CHARACTERISTICS (CONTINUED)
VIN = VOUT + 1V, VEN = VIN; IOUT = 100 μA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.
(Note 1)
Parameter
Symbol
Min.
Typ.
Max.
Units
Conditions
Enable Input Logic-Low Voltage
VIL
—
—
0.4
V
VIN = 2.7V to 5.5V, regulator
shutdown
Enable Input Logic-High Voltage
VIH
1.6
—
—
V
VIN = 2.7V to 5.5V, regulator
enabled
—
0.01
1
μA
VIL ≤ 0.4V, regulator
shutdown
—
0.01
1
μA
VIH ≥ 1.6V, regulator
enabled
—
—
500
—
Ω
—
Thermal Shutdown Temperature
—
—
150
—
°C
—
Thermal Shutdown Hysteresis
—
—
10
—
°C
—
Enable Input
Enable Input Current
IEN
Shutdown Resistance Discharge
Thermal Protection
Note 1:
2:
3:
4:
Specification for packaged product only.
Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are
tested for load regulation in the load range from 0.1 mA to 150 mA. 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. 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.
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.
TEMPERATURE SPECIFICATIONS (Note 1)
Parameters
Sym.
Min.
Typ.
Max.
Units
Conditions
TJ
–40
—
+125
°C
—
TJ(MAX)
–40
—
+125
°C
—
Temperature Ranges
Junction Temperature Range
Maximum Junction Temperature
Lead Temperature
—
—
—
+260
°C
Soldering, 5 seconds
Storage Temperature
TS
–65
—
+150
°C
—
Thermal Resistance, SOT-23
θJA
—
235
—
°C/W
—
Thermal Resistance, 2x2 VDFN
θJA
—
90
—
°C/W
—
Package Thermal Resistance
Note 1:
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable
junction temperature and the thermal resistance from junction to air (i.e., TA, TJ, JA). Exceeding the
maximum allowable power dissipation will cause the device operating junction temperature to exceed the
maximum rating. Sustained junction temperatures above that maximum can impact device reliability.
DS20006579B-page 4
2021 - 2022 Microchip Technology Inc.
MIC5252
2.0
Note:
TYPICAL PERFORMANCE CURVES
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
FIGURE 2-1:
PSRR with Bypass Variation
(VIN = VOUT + 0.3V ).
FIGURE 2-4:
PSRR at 100 Hz.
FIGURE 2-2:
PSRR with Bypass Cap
Variation (VIN = VOUT + 1V ).
FIGURE 2-5:
Current.
Output Voltage vs. Load
FIGURE 2-3:
FIGURE 2-6:
Temperature.
Output Voltage vs.
PSRR with Load Variation.
2021 - 2022 Microchip Technology Inc.
DS20006579B-page 5
MIC5252
FIGURE 2-7:
Current.
Ground Current vs. Output
FIGURE 2-10:
Voltage.
Ground Current vs. Supply
FIGURE 2-8:
Temperature.
Ground Current vs.
FIGURE 2-11:
Dropout Characteristics.
FIGURE 2-9:
Voltage.
Ground Current vs. Supply
FIGURE 2-12:
Dropout vs. Temperature.
DS20006579B-page 6
2021 - 2022 Microchip Technology Inc.
MIC5252
FIGURE 2-13:
Dropout vs. Output Current.
FIGURE 2-16:
Short Circuit Current vs.
Input Supply Voltage.
FIGURE 2-14:
Supply Voltage.
Enable Threshold vs.
FIGURE 2-17:
Enable Pin Delay.
FIGURE 2-15:
Temperature.
Enable Threshold vs.
FIGURE 2-18:
Load Transient Response.
2021 - 2022 Microchip Technology Inc.
DS20006579B-page 7
MIC5252
FIGURE 2-19:
DS20006579B-page 8
Line Transient Response.
2021 - 2022 Microchip Technology Inc.
MIC5252
3.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
PIN FUNCTION TABLE
5-Lead
SOT-23
Pin Number
6-Lead
VDFN Pin
Number
Pin Name
1
3
IN
2
2
GND
3
1
EN
4
6
BYP
Reference Bypass: Connect external 0.01 μF ≤ CBYP ≤ 1.0 μF capacitor to
GND to reduce output noise. May be left open.
Regulator Output.
5
4
OUT
—
5
NC
—
EP
GND
2021 - 2022 Microchip Technology Inc.
Description
Supply Input.
Ground.
Enable/Shutdown (Input): CMOS compatible input. Logic high = enable;
logic low = shutdown. Do not leave open.
No Internal Connection.
Ground: Internally connected to the exposed pad. Connect externally to
GND pin.
DS20006579B-page 9
MIC5252
4.0
APPLICATION INFORMATION
4.1
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.
4.2
Input Capacitor
The MIC5252 is a high performance, high bandwidth
device. Therefore, it requires a well-bypassed input
supply for optimal performance. A 1 μF 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.
4.3
Output Capacitor
The MIC5252 requires an output capacitor for stability.
The design requires 1 μF 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 300 mΩ. The output capacitor
can be increased, but performance has been optimized
for a 1 μF ceramic output capacitor and does not
improve significantly with larger capacitance.
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.
4.4
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 0.01 μF 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
DS20006579B-page 10
MIC5252 to drive a large capacitor on the bypass pin
without significantly slowing turn-on time. Refer to the
Typical Performance Curves section for performance
with different bypass capacitors.
4.5
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.
4.6
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.
4.7
Thermal Considerations
The MIC5252 is designed to provide 150 mA 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:
EQUATION 4-1:
T J MAX – T A
P D MAX = --------------------------------
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 4-1 shows
examples of junction-to-ambient thermal resistance for
the MIC5252.
TABLE 4-1:
SOT-23-5 THERMAL
RESISTANCE
θJA
Recommended
Package
Minimum
Footprint
θJA 1”
Square
Copper
Clad
θJC
SOT-23-5
(M5 or
D5)
185°C/W
145°C/W
235°C/W
The actual power dissipation of the regulator circuit can
be determined using the equation:
2021 - 2022 Microchip Technology Inc.
MIC5252
EQUATION 4-2:
P D = V IN – V OUT I OUT + V IN I GND
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
MIC5252-2.8YM5 at 50°C with a minimum footprint
layout, the maximum input voltage for a set output
current can be determined as follows:
EQUATION 4-3:
125C – 50C
P D MAX = -----------------------------------
235C/W
Where:
PD(MAX) = 315 mW
The junction-to-ambient thermal resistance for the
minimum footprint is 235°C/W, from Table 4-1. The
maximum power dissipation must not be exceeded for
proper operation. Using the output voltage of 2.8V and
an output current of 150 mA, the maximum input
voltage can be determined. Because this device is
CMOS and the ground current is typically 100 μA over
the load range, the power dissipation contributed by the
ground current is
工商网监
湘ICP备2023018690号
