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MIC3975
Micrel
MIC3975
750mA µCap Low-Voltage Low-Dropout Regulator
General Description
The MIC3975 is a 750mA low-dropout linear voltage regula-
tors that provide low-voltage, high-current output from an
extremely small package. Utilizing Micrel’s proprietary Super
βeta
PNP™ pass element, the MIC3975 offers extremely low
dropout (typically 300mV at 750mA) and low ground current
(typically 6.5mA at 750mA).
The MIC3975 is ideal for PC add-in cards that need to con-
vert 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 MIC3975
to provide 2.5V from a supply as low as 3.0V and 1.8V or
1.65V from a supply as low as 2.25V.
The MIC3975 is fully protected with overcurrent limiting,
thermal shutdown, and reversed-battery protection. Fixed
voltages of 5.0V, 3.3V, 3.0, 2.5V, 1.8V, and 1.65V are avail-
able. An adjustable output voltage option is available for
voltages down to 1.24V.
For other voltages, contact Micrel.
Features
• Fixed and adjustable output voltages to 1.24V
• 300mV 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-battery protection
• Reversed-leakage protection
• Fast transient response
• Low-profile MSOP-8
Applications
•
•
•
•
•
•
•
•
Fiber optic modules
LDO linear regulator for PC add-in cards
PowerPC™ power supplies
High-efficiency linear power supplies
SMPS post regulator
Multimedia and PC processor supplies
Battery chargers
Low-voltage microcontrollers and digital logic
Ordering Information
Part Number
Standard
MIC3975-1.65BMM
MIC3975-1.8BMM
MIC3975-2.5BMM
MIC3975-3.0BMM
MIC3975-3.3BMM
MIC3975-5.0BMM
MIC3975BMM
Pb-Free
MIC3975-1.65YMM
MIC3975-1.8YMM
MIC3975-2.5YMM
MIC3975-3.0YMM
MIC3975-3.3YMM
MIC3975-5.0YMM
MIC3975YMM
Voltage
1.65V
1.8V
2.5V
3.0V
3.3V
5.0V
Adj.
Junction Temp. Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package
MSOP-8
MSOP-8
MSOP-8
MSOP-8
MSOP-8
MSOP-8
MSOP-8
Typical Applications
100k
V
IN
3.3V
ENABLE
SHUTDOWN
MIC3975-2.5BMM
OUT
IN
EN
FLG
GND
Error
Flag
Output
R1
2.5V
10F
ceramic
V
IN
2.5V
ENABLE
SHUTDOWN
MIC3975BMM
OUT
IN
EN
ADJ
GND
R1
R2
1.5V
10F
ceramic
2.5V/750mA Regulator with Error Flag
Super
βeta
PNP is a trademark of Micrel, Inc.
1.5V/750mA Adjustable Regulator
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
February 2005
1
MIC3975
MIC3975
Micrel
Pin Configuration
EN 1
IN 2
FLG 3
OUT 4
8 GND
7 GND
6 GND
5 GND
EN 1
IN 2
ADJ 3
OUT 4
8 GND
7 GND
6 GND
5 GND
MIC3975-x.x
Fixed
MSOP-8 (MM)
Adjustable
Pin Description
Pin No.
Fixed
1
2
3
3
4
5–8
4
5–8
Pin No.
Adjustable
1
2
EN
IN
FLG
ADJ
OUT
GND
Enable (Input): CMOS-compatible control input. Logic high = enable, logic
low or open = shutdown.
Supply (Input)
Flag (Output): Open-collector error flag output. Active low = output under-
voltage.
Adjustment Input: Feedback input. Connect to resistive voltage-divider net-
work.
Regulator Output
Ground
Pin Name
Pin Function
MIC3975
2
February 2005
MIC3975
Micrel
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
IN
) .......................................–20V to +20V
Enable Voltage (V
EN
) .................................................. +20V
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 +16V
Enable Voltage (V
EN
) .................................................. +16V
Maximum Power Dissipation (P
D(max)
) .....................
Note 4
Junction Temperature (T
J
) ........................ –40°C to +125°C
Package Thermal Resistance
MSOP-8
(θ
JA
) ...................................................... 80°C/W
Electrical Characteristics
(Note 12)
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
V
OUT
Parameter
Condition
Output Voltage
Line Regulation
Load Regulation
ΔV
OUT
/ΔT
ppm/°C
V
DO
Output Voltage Temp. Coefficient,
Note 5
Dropout Voltage,
Note 6
I
OUT
= 100mA, ΔV
OUT
= –1%
I
OUT
= 500mA, ΔV
OUT
= –1%
I
GND
Ground Current,
Note 7
I
OUT
= 100mA, V
IN
= V
OUT
+ 1V
I
OUT
= 500mA, V
IN
= V
OUT
+ 1V
I
OUT
= 750mA, V
IN
= V
OUT
+ 1V
I
OUT
= 750mA, ΔV
OUT
= –1%
140
225
300
400
4
7.5
1.8
15
2.5
0.8
2.25
1
15
30
75
2
4
0.01
210
93
99.2
1
1
2
300
400
500
200
250
mV
mV
mV
mV
µA
mA
mA
A
V
V
µA
µA
µA
µA
µA
µA
mV
mV
%
%
%
10mA
10mA ≤ I
OUT
≤ 750mA, V
OUT
+ 1V ≤ V
IN
≤ 8V
I
OUT
= 10mA, V
OUT
+ 1V ≤ V
IN
≤ 16V
V
IN
= V
OUT
+ 1V, 10mA ≤ I
OUT
≤ 750mA,
Min
–1
–2
0.06
0.2
40
Typ
Max
1
2
0.5
1
100
Units
%
%
%
%
I
OUT(lim)
V
EN
I
EN
Current Limit
Enable Input Voltage
Enable Input Current
Enable Input
V
OUT
= 0V, V
IN
= V
OUT
+ 1V
logic low (off)
logic high (on)
V
EN
= 2.25V
V
EN
= 0.8V
Flag Output
I
FLG(leak)
V
FLG(do)
V
FLG
Output Leakage Current
Output Low Voltage
Low Threshold
High Threshold
Hysteresis
V
OH
= 16V
V
IN
= 2.250V, I
OL
, = 250µA,
Note 9
% of V
OUT
% of V
OUT
February 2005
3
MIC3975
MIC3975
Symbol
Parameter
Reference Voltage
Note 10
Adjust Pin Bias Current
Reference Voltage
Temp. Coefficient
Adjust Pin Bias Current
Temp. Coefficient
Note 1.
Note 2.
Note 3.
Note 4.
Note 5.
Note 6.
Note 7.
Note 8.
Note 9.
Exceeding the absolute maximum ratings may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended.
P
D(max)
= (T
J(max)
– T
A
)
÷ θ
JA
, where
θ
JA
depends upon the printed circuit layout. See “Applications Information.”
Output voltage temperature coefficient is ΔV
OUT(worst case)
÷
(T
J(max)
– T
J(min)
) where T
J(max)
is +125°C and T
J(min)
is –40°C.
Micrel
Condition
Min
1.228
1.215
1.203
Typ
1.240
Max
1.252
1.265
1.277
80
120
Units
V
V
V
nA
nA
Adjustable Output Only
40
Note 11
20
ppm/°C
0.1
nA/°C
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 2.25V, dropout
voltage is the input-to-output voltage differential with the minimum input voltage being 2.25V. Minimum input operating voltage is 2.25V.
I
GND
is the quiescent current. I
IN
= I
GND
+ I
OUT
.
V
EN
≤ 0.8V, V
IN
≤ 8V, and V
OUT
= 0V.
For a 2.5V device, V
IN
= 2.250V (device is in dropout).
Note 10.
V
REF
≤ V
OUT
≤ (V
IN
– 1V), 2.25V ≤ V
IN
≤ 16V, 10mA ≤ I
L
≤ 750mA, T
J
= T
MAX
.
Note 11.
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 200mA load pulse at V
IN
= 16V for t = 10ms.
Note 12.
Specification for packaged product only.
MIC3975
4
February 2005
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