March 2003
1
MIC3775
MIC3775
Micrel
Ordering Information
Part Number
Voltage
Junction Temp. Range
Package
MIC3775-1.5BMM
1.5V
40
C to +125
C
MSOP-8
MIC3775-1.65BMM
1.65V
40
C to +125
C
MSOP-8
MIC3775-1.8BMM
1.8V
40
C to +125
C
MSOP-8
MIC3775-2.5BMM
2.5V
40
C to +125
C
MSOP-8
MIC3775-3.0BMM
3.0V
40
C to +125
C
MSOP-8
MIC3775-3.3BMM
3.3V
40
C to +125
C
MSOP-8
MIC3775BMM
Adj.
40
C to +125
C
MSOP-8
MIC3775
750mA
Cap Low-Voltage Low-Dropout Regulator
Final
General Description
The MIC3775 is a 750mA low-dropout linear voltage regula-
tors that provides low-voltage, high-current output from an
extremely small package. Utilizing Micrel's proprietary
Super
eta PNPTM pass element, the MIC3775 offers ex-
tremely low-dropout (typically 280mV at 750mA) and low
ground current (typically 7.5mA at 750mA).
The MIC3775 is ideal for PC add-in cards that need to convert
from standard 5V to 3.3V or 3.0V, 3.3V to 2.5V or 2.5V to 1.8V
or 1.65V. A guaranteed maximum dropout voltage of 500mV
over all operating conditions allows the MIC3775 to provide
2.5V from a supply as low as 3.0V and 1.8V or 1.5V from a
supply as low as 2.25V.
The MIC3775 is fully protected with overcurrent limiting,
thermal shutdown, and reversed-leakage protection. Fixed
and adjustable output voltage options are available with an
operating temperature range of 40
C to +125
C.
For other voltages, contact Micrel.
Typical Applications
Features
Fixed and adjustable output voltages to 1.24V
280mV typical dropout at 750mA
Ideal for 3.0V to 2.5V conversion
Ideal for 2.5V to 1.8V or 1.65V conversion
Stable with ceramic capacitor
750mA minimum guaranteed output current
1% initial accuracy
Low ground current
Current limiting and thermal shutdown
Reversed-leakage protection
Fast transient response
Low-profile power MSOP-8 package
Applications
Fiber optic modules
LDO linear regulator for PC add-in cards
PowerPCTM power supplies
High-efficiency linear power supplies
SMPS post regulator
Multimedia and PC processor supplies
Battery chargers
Low-voltage microcontrollers and digital logic
Super
eta PNP is a trademark of Micrel, Inc.
PowerPC is a trademark of Motorola
Micrel, Inc. 1849 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 944-0970 http://www.micrel.com
IN
R1
1.25V
V
IN
2.5V
10
F
ceramic
R2
EN
OUT
ADJ
GND
MIC3775BMM
ENABLE
SHUTDOWN
1.25V/750mA Adjustable Regulator
0
50
100
150
200
250
300
0
0.25
0.5
0.75
DROPOUT (mV)
OUTPUT CURRENT (A)
Dropout
vs. Output Current
1.8V
OUT
2.5V
OUT
3.3V
OUT
MIC3775
Micrel
MIC3775
2
March 2003
Pin Configuration
1
EN
IN
FLG
OUT
8
GND
GND
GND
GND
7
6
5
2
3
4
MIC3775-x.x
Fixed
MSOP-8 (MM)
1
EN
IN
ADJ
OUT
8
GND
GND
GND
GND
7
6
5
2
3
4
MIC3775
Adjustable
MSOP-8 (MM)
Pin Description
Pin No.
Pin No.
Fixed
Adjustable
Pin Name
Pin Function
1
1
EN
Enable (Input): CMOS-compatible control input. Logic high = enable, logic
low or open = shutdown.
2
2
IN
Supply (Input).
3
FLG
Flag (Output): Open-collector error flag output. Active low = output under-
voltage.
3
ADJ
Adjustment Input: Feedback input. Connect to resistive voltage-divider
network.
4
4
OUT
Regulator Output.
58
58
GND
Ground.
March 2003
3
MIC3775
MIC3775
Micrel
Electrical Characteristics
(Note 5)
V
IN
= V
OUT
+ 1V; V
EN
= 2.25V; T
J
= 25
C, bold values indicate 40
C
T
J
+125
C; unless noted
Symbol
Parameter
Condition
Min
Typ
Max
Units
V
OUT
Output Voltage
10mA
1
1
%
10mA
I
OUT
750mA, V
OUT
+ 1V
V
IN
6V
2
2
%
Line Regulation
I
OUT
= 10mA, V
OUT
+ 1V
V
IN
6V
0.06
0.5
%
Load Regulation
V
IN
= V
OUT
+ 1V, 10mA
I
OUT
750mA,
0.2
1
%
V
OUT
/
T
Output Voltage Temp. Coefficient,
40
ppm/
C
Note 6
V
DO
Dropout Voltage, Note 7
I
OUT
= 100mA,
V
OUT
= 1%
125
200
mV
250
mV
I
OUT
= 500mA,
V
OUT
= 1%
210
mV
I
OUT
= 750mA,
V
OUT
= 1%
280
500
mV
I
GND
Ground Current, Note 8
I
OUT
= 100mA, V
IN
= V
OUT
+ 1V
700
A
I
OUT
= 500mA, V
IN
= V
OUT
+ 1V
3.7
mA
I
OUT
= 750mA, V
IN
= V
OUT
+ 1V
7.5
15
mA
I
OUT(lim)
Current Limit
V
OUT
= 0V, V
IN
= V
OUT
+ 1V
1.6
2.5
A
Enable Input
V
EN
Enable Input Voltage
logic low (off)
0.8
V
logic high (on)
2.25
V
I
EN
Enable Input Current
V
EN
= 2.25V
1
10
30
A
V
EN
= 0.8V
2
A
4
A
Flag Output
I
FLG(leak)
Output Leakage Current
V
OH
= 6V
0.01
1
A
2
A
V
FLG(do)
Output Low Voltage
V
IN
= 2.250V, I
OL
, = 250
A
250
500
mV
V
FLG
Low Threshold
% of V
OUT
93
%
High Threshold
% of V
OUT
99.2
%
Hysteresis
1
%
Adjustable Output Only
Reference Voltage
1.227
1.240
1.252
V
1.215
1.265
V
Adjust Pin Bias Current
40
80
nA
120
nA
Note 1.
Exceeding the absolute maximum ratings 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.
P
D(max)
= (T
J(max)
T
A
)
JA
, where
JA
depends upon the printed circuit layout. See "Applications Information."
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
IN
) .................................................... 6.5V
Enable Voltage (V
EN
) ................................................. +6.5V
Storage Temperature (T
S
) ....................... 65
C to +150
C
Lead Temperature (soldering, 5 sec.) ....................... 260
C
ESD ......................................................................... Note 3
Operating Ratings
(Note 2)
Supply Voltage (V
IN
) .................................... +2.25V to +6V
Enable Voltage (V
EN
) ......................................... 0V to +6V
Maximum Power Dissipation (P
D(max)
) ..................... Note 4
Junction Temperature (T
J
) ....................... 40
C to +125
C
Package Thermal Resistance
MSOP-8
(
JA
) ...................................................... 80
C/W
MIC3775
Micrel
MIC3775
4
March 2003
Note 5.
Specification for packaged product only.
Note 6.
Output voltage temperature coefficient is
V
OUT(worst case)
(T
J(max)
T
J(min)
) where T
J(max)
is +125
C and T
J(min)
is 40
C.
Note 7.
V
DO
= V
IN
V
OUT
when V
OUT
decreases to 98% of its nominal output voltage with V
IN
= V
OUT
+ 1V. For output voltages below 1.75V, dropout
voltage is the input-to-output voltage differential with the minimum input voltage being 2.25V. Minimum input operating voltage is 2.25V.
Note 8.
I
GND
is the quiescent current. I
IN
= I
GND
+ I
OUT
.
March 2003
5
MIC3775
MIC3775
Micrel
Typical Characteristics
0
10
20
30
40
50
60
70
80
0.01
0.1
1
10
100
1000
PSRR (dB)
FREQUENCY (KHz)
Power Supply
Rejection Ratio
IOUT=750mA
COUT =10
F
CIN
=0
VIN
= 5V
VOUT
= 3.3V
0
10
20
30
40
50
60
70
80
0.01
0.1
1
10
100
1000
PSRR (dB)
FREQUENCY (KHz)
Power Supply
Rejection Ratio
IOUT=750mA
COUT =47
F
CIN
=0
VIN
=5V
VOUT
=3.3V
0
10
20
30
40
50
60
70
80
0.01
0.1
1
10
100
1000
PSRR (dB)
FREQUENCY (KHz)
Power Supply
Rejection Ratio
IOUT=750mA
COUT =10
F
CIN
=0
VIN
=3.3V
VOUT
=2.5V
0
10
20
30
40
50
60
70
80
0.01
0.1
1
10
100
1000
PSRR (dB)
FREQUENCY (KHz)
Power Supply
Rejection Ratio
IOUT=750mA
COUT =47
F
CIN
=0
VIN
=3.3V
VOUT
=2.5V
0
50
100
150
200
250
300
0
0.25
0.5
0.75
DROPOUT (mV)
OUTPUT CURRENT (A)
Dropout
vs. Output Current
1.8V
OUT
2.5V
OUT
3.3V
OUT
0
50
100
150
200
250
300
350
400
-40 -20 0
20 40 60 80 100 120
DROPOUT (mV)
TEMPERATURE (
C)
Dropout
vs. Temperature
2.5VOUT
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.5
1.7
1.9
2.1
2.3
2.5
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Dropout Characteristics
(1.5V)
10mA Load
750mA Load
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
1.5
2
2.5
3
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Dropout Characteristics
(1.8V)
10mA Load
750mA Load
0
0.5
1.0
1.5
2.0
2.5
3.0
1.5
2
2.5
3
3.5
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Dropout Characteristics
(2.5V)
10mA Load
750mA Load
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
1.5
2
2.5
3
3.5
4
4.5
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Dropout Characteristics
(3.3V)
10mA Load
750mA Load
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0
1
2
3
4
5
6
GROUND CURRENT (mA)
INPUT VOLTAGE (V)
Ground Current
vs. Supply Voltage (1.5V)
10mA
100mA
0
1
2
3
4
5
6
7
0
0.25
0.5
0.75
GROUND CURRENT (mA)
OUTPUT CURRENT (A)
Ground Current
vs. Output Current
3.3V
OUT
2.5V
OUT
PDF 
ZIP