MICREL MIC5258

MIC5258
Micrel
MIC5258
150mA µCap CMOS LDO Regulator w/Power Good
Final Information
General Description
Features
The MIC5258 is an efficient, precise CMOS voltage regulator
with power good output. The MIC5258 offers better than 3%
initial accuracy, and constant ground current (typically
100µA)over load .
•
•
•
•
•
•
•
•
•
•
The MIC5258 also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in hand-held wireless devices.
Key features include current limit, thermal shutdown, a pushpull output for faster transient response, and an active clamp
to speed up device turnoff. Available in the IttyBitty™ SOT-23-5
package, the MIC5258 is a fixed 1.2V regulator.
Power Good indicator
Load independent, ultralow ground current: 100µA
150mA output current
Current limiting
Thermal shutdown
Tight load and line regulation
“Zero” off-mode current
Stability with low-ESR capacitors
Fast transient response
TTL-Logic-controlled enable input
Applications
• Processor power-up sequencing
• Laptop, notebook, and palmtop computers
• PCMCIA VCC and VPP regulation/switching
Ordering Information
Part Number
Marking
Voltage
Junction Temp. Range*
Package
LN12
1.2
–40°C to +125°C
SOT-23-5
MIC5258-1.2BM5
Other voltages available. Contact Micrel for details.
Typical Application
47k
VIN
MIC5258-x.xBM5
1
5
2
COUT
3
Enable
Shutdown
VOUT
4
PG
EN
EN (pin 3) may be
connected directly
to IN (pin 1).
Low-Noise Regulator Application
IttyBitty is a trademark of Micrel, Inc.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
September 2001
1
MIC5258
MIC5258
Micrel
Pin Configuration
EN GND IN
3
2
1
LNxx
4
5
PG
OUT
MIC5258-x.xBM5
Pin Description
Pin Number
Pin Name
Pin Function
1
IN
Supply Input
2
GND
3
EN
Enable/Shutdown (Input): CMOS compatible input. Logic high = enable;
logic low = shutdown. Do not leave open.
4
PG
Power Good Output
5
OUT
MIC5258
Ground
Regulator Output
2
September 2001
MIC5258
Micrel
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Supply Input Voltage (VIN) .................................. 0V to +7V
Enable Input Voltage (VEN) .................................. 0V to VIN
Flag Output Voltage (VPG) ................................... 0V to VIN
Junction Temperature (TJ) ...................................... +150°C
Storage Temperature ............................... –65°C to +150°C
Lead Temperature (soldering, 5 sec.) ....................... 260°C
ESD, Note 3
Input Voltage (VIN) ......................................... +2.7V to +6V
Enable Input Voltage (VEN) .................................. 0V to VIN
Flag Output Voltage (VPG) ................................... 0V to VIN
Junction Temperature (TJ) ....................... –40°C to +125°C
Thermal Resistance
SOT-23(θJA) ...................................................... 235°C/W
Electrical Characteristics
VIN = 2.7V, VEN = VIN; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.
Symbol
Parameter
Conditions
Min
VO
Output Voltage Accuracy
IOUT = 100µA
∆VLNR
Line Regulation
VIN = 2.7V to 6V
∆VLDR
Load Regulation
IOUT = 0.1mA to 150mA, Note 4
IQ
Quiescent Current
IGND
Ground Pin Current, Note 5
Typical
Max
Units
–3
–4
3
4
%
%
–0.3
0.3
%/V
3.5
4
%
VEN ≤ 0.4V (shutdown) PG = NC
0.45
1
µA
IOUT = 0mA; VIN = 6.0V
110
150
µA
IOUT = 150mA; VIN = 6.0V
110
150
µA
tbd
dB
350
mA
PSRR
Power Supply Rejection
f = 120Hz, COUT = 4.7µF, IOUT = 150mA
ILIM
Current Limit
VOUT = 0V
VIL
Enable Input Logic-Low Voltage
VIN = 5.5V, regulator shutdown
VIH
Enable Input Logic-High Voltage
VIN = 5.5V, regulator enabled
IEN
Enable Input Current
VIL ≤ 0.4V; VIN = 5.5V
0.01
µA
VIH ≥ 1.6V; VIN = 5.5V
0.01
µA
Thermal Shutdown Temperature
150
°C
Thermal Shutdown Hysteresis
10
°C
160
Enable Input
0.4
1.6
V
V
Thermal Protection
Power Good , Note 6
VPG
Low Threshold
High Threshold
% of VOUT (PG ON)
% of VOUT (PG OFF)
89
VOL
PG Output Logic-Low Voltage
IL = 100µA, fault condition
0.02
IPG
Power Good Leakage Current
power good off, VPG = 5.5V
0.01
VPG Delay
Delay time to Power Good
See Timing Diagram
1
97
%
%
0.1
V
µA
5
ms
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.
Devices are ESD sensitive. Handling precautions recommended.
Note 4.
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.
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.
The power good is a function of the output voltage being 5% low and the detection of one of the following: overcurrent, overtemperature or
dropout. See “Applications Information” section for additional information.
Note 5.
Note 6.
September 2001
3
MIC5258
MIC5258
Micrel
Block Diagrams
IN
EN
Reference
Voltage
Startup/
Shutdown
Control
Quickstart
PULL
UP
Thermal
Sensor
FAULT
Error
Amplifier
Undervoltage
Lockout
Current
Amplifier
ACTIVE SHUTDOWN
OUT
PULL
DOWN
Out of
Regulation
Detection
PG
Overcurrent
Dropout
Detection
Delay
GND
Timing Diagram
VOUT
97%
89%
97%
Fault Condition
VEN
Min - Max
1-5ms
1-5ms
VPG
MIC5258
4
September 2001
MIC5258
Micrel
Typical Characteristics
Ground Current vs.
Input Voltage
Ground Current vs.
Output Current
105
IOUT = 150mA
103
101
99
97
99
98.8
98.6
98.4
98.2
0
SHORT CIRCUIT CURRENT (mA)
340
330
320
310
300
290
280
270
260
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
INPUT VOLTAGE (V)
260
240
220
200
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
2.5
2
1.5
1
10000
1000
1
0.001
0
0.1
1.1
1
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
10
Power Fail
0.5
PULL-UP RESISTOR (kΩ)
Output Voltage vs.
Output Current
1.16
0
VIN = 3.3V
20 40 60 80 100 120 140 160
OUTPUT CURRENT (mA)
September 2001
1.2
1.195
1.19
1.185
IOUT = 100µA
1.18
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
5
IOUT = 100µA
1.18
1.175
IOUT = 150mA
1.17
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
INPUT VOLTAGE (V)
Enable Voltage vs.
Input Voltage
1.4
ENABLE VOLTAGE (V)
OUTPUT VOLTAGE (V)
1.165
1.2
1.1
1.185
1.205
1.19
1.17
1.4
1.3
1.19
Output Voltage vs.
Temperature
1.195
1.175
1.6
1.5
Output Voltage
vs. Input Voltage
OUTPUT VOLTAGE (V)
Power Good
100
1.4
1.3
1.2
IOUT = 100µA
1.8
1.7
1.195
3
1.6
1.5
1.18
2
1.9
Power Good Pull-up Resistor
vs. Power Good
1.8
1.7
1.185
90
1
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
INPUT VOLTAGE (V)
3.5
POWER GOOD (V)
POWER GOOD DELAY (ms)
VIN = 3.3V
300
280
VIN = 3.3V
IOUT = 150mA
Power Good Delay
vs. Input Voltage
340
320
Power Good Delay
vs. Temperature
2
1.9
95
85
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
400
380
360
IOUT = 100µA
100
20 40 60 80 100 120 140 160
OUTPUT CURRENT (mA)
0.01
SHORT CIRCUIT CURRENT (mA)
350
105
Short Circuit Current
vs. Temperature
Short Circuit Current
vs. Input Voltage
360
VIN = 3.3V
GROUND CURRENT (µA)
107
99.2
110
POWER GOOD DELAY (ms)
109
GROUND CURRENT (µA)
GROUND CURRENT (µA)
IOUT = 100µA
111
95
2.5 3 3.5 4 4.5 5 5.5 6 6.5
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
Ground Current vs.
Temperature
99.4
113
1.3
1.2
1.1
1
0.9
0.8
0.7
IOUT = 100µA
0.6
2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1
INPUT VOLTAGE (V)
MIC5258
MIC5258
Micrel
Enable Voltage vs.
Temperature
ENABLE VOLTAGE (V)
1.2
VIN = 3.3V
1.15
1.1
1.05
1
0.95
0.9
0.85
0.8
-40 -20 0 20 40 60 80 100120140
TEMPERATURE (°C)
Power Good
(2V/div)
Output
(1V/div)
Enable
(2V/div)
Power Good Characteristic
VIN = 12V
VOUT = 5V
TIME (250µs/div)
MIC5258
6
September 2001
MIC5258
Micrel
Applications Information
Transient Response
Enable/Shutdown
The MIC5258 implements a unique output stage to dramatically improve transient response recovery time. The output is
a totem-pole configuration with a P-channel MOSFET pass
device and an N-channel MOSFET clamp. The N-channel
clamp is a significantly smaller device that prevents the
output voltage from overshooting when a heavy load is
removed. This feature helps to speed up the transient response by significantly decreasing transient response recovery time during the transition from heavy load (100mA) to light
load (100µA).
The MIC5258 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-modecurrent 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.
Input Capacitor
Active Shutdown
An input capacitor is not required for stability. A 1µF input
capacitor is recommended when the bulk ac supply capacitance is more than 10 inches away from the device, or when
the supply is a battery.
The MIC5258 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.
Output Capacitor
The MIC5258 requires an output capacitor for stability. The
design requires 1µF or greater on the output to maintain
stability. The capacitor can be a low-ESR ceramic chip
capacitor. The MIC5258 has been designed to work specifically with the low-cost, small chip capacitors. Tantalum
capacitors can also be used for improved capacitance over
temperature. The value of the capacitor can be increased
without bound.
Thermal Considerations
The MIC5258 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:
 TJ(max) − TA 
PD(max) = 

θ JA


X7R dielectric 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 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 or a tantalum capacitor to ensure the same minimum
capacitance value over the operating temperature range.
Tantalum capacitors have a very stable dielectric (10% over
their operating temperature range) and can also be used with
this device.
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 MIC5258.
Package
SOT-23-5 (M5)
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:
Power Good
PD = (VIN – VOUT) IOUT + VIN IGND
The power good output is an open-drain output. It is designed
essentially to work as a power-on reset generator once the
regulated voltage was up and/or a fault condition. The output
of the power good drives low when a fault condition AND an
undervoltage detection occurs. The power good output comes
back up once the output has reached 97% of its nominal value
and a 1ms to 5ms delay has passed. See Timing Diagram.
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 MIC5258-1.2BM5 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 
The MIC5258’s internal circuit intelligently monitors
overcurrent, overtemperature and dropout conditions and
ORs thes outputs together ti indicate some fault condition.
this output is fed into an on-board delay circuitry that drives
the open drain transistor to indicate a fault.
September 2001
θJA Recommended
Minimum Footprint
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 1.2V 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
7
MIC5258
MIC5258
Micrel
ground current is < 1% and can be ignored for this calculation.
315mW = (VIN – 1.2V) 150mA
315mW = VIN ·150mA – 195mW
510mW = VIN ·150mA
VIN(max) = 3.4V
Therefore, a 1.2V application at 150mA of output current can
accept a maximum input voltage of 3.4V 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.
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.
MIC5258
8
September 2001
MIC5258
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 (M)
September 2001
9
MIC5258
MIC5258
MIC5258
Micrel
10
September 2001
MIC5258
September 2001
Micrel
11
MIC5258
MIC5258
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.
© 2001 Micrel Incorporated
MIC5258
12
September 2001