DA9123.005
31 March 2003
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MAS9123
80 mA
LDO Voltage Regulator IC
Very Low Noise: 9.5 Vrms
Very Short Start-up Time: 20 s
Excellent Ripple Rejection: 68 dB
Stable with Low-ESR Output
Capacitors
Low Minimum Output Capacitance
Requirement: 0.22 F
Regulator Enable/Disable Control
DESCRIPTION
MAS9123 is a low dropout voltage regulator with an
enable/disable pin, which allows device to be turned
off or on by pulling control to low or high.
Due to the very low noise level of only 9.5 Vrms
MAS9123 is highly suitable for very sensitive
circuits, e.g., in portable applications. In addition to
the noise level, MAS9123 excels in dropout voltage
(95 mV typical at 50 mA) and in start-up time
(typically 20 s from start-up to within 1% of
V
OUT(NOM)
). Also its ripple rejection ability of 68 dB at
10 kHz exceed that of competition.
The Equivalent Series Resistance (ESR) range of
output capacitors that can be used with MAS9123 is
very wide. This ESR range from a few m up to a
couple of Ohms combined with no minimum output
current requirement makes the usage of MAS9123
easier and low in cost. Also the minimum output
capacitance requirement is very low. This combined
with very short start-up time makes it possible to
switch the regulator off and on even in timing critical
and/or noise sensitive applications.
An internal thermal protection circuit prevents the
device from overheating. Also the maximum output
current is internally limited. In order to save power
the device goes into sleep mode when the regulator
is disabled.
FEATURES
APPLICATIONS
Optimized for Fast Start-up
Very Low Noise
Internal Thermal Shutdown
Short Circuit Protection
SOT23-5 Package (Pin Compatible with LP2982)
WL-CSP Package (Pin Compatible with LP3985)
Output Voltage Options: 2.8, 3.0 and 3.3 V,
see Ordering Information p. 12
RF Oscillators
Wireless Systems
Cellular Phones
Cordless Phones
Pagers
Battery Powered Systems
Portable Systems
Radio Control Systems
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31 March 2003
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PIN CONFIGURATION
SOT23-5
Top View
1
2
3
5
VIN
VOUT
CTRL
GND
BYPASS
23AX
4
For top marking information see
ordering information p. 12
WL-CSP
BOTTOM VIEW
A3
A1
C3
C1
B2
TOP VIEW
P
i
n A
1
D
e
s
i
gn
at
or
23XY
For top marking information see
ordering information p. 12
PIN DESCRIPTION
Pin Name
Pin
Number in
SOT23-5
Pin
Number in
WL-CSP
Type
Function
VIN
1
C3
P
Power Supply Voltage
GND
2
B2
G
Ground
CTRL
3
A1
I
Enable/Disable Pin for Regulator
BYPASS
4
A3
I
Pin for Bypass Capacitor
VOUT
5
C1
O
Output
G = Ground, I = Input, O = Output, P = Power
A1
A3
B2
C1
C3
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31 March 2003
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BLOCK DIAGRAM
ABSOLUTE MAXIMUM RATINGS
All voltages with respect to ground.
Parameter
Symbol
Conditions
Min
Max
Unit
Supply Voltage
V
IN
-0.3
6
V
Voltage Range for All Pins
-0.3
V
IN
+ 0.3
V
ESD Rating
HBM
2
kV
Junction Temperature
T
Jmax
+175
(limited)
C
Storage Temperature
T
S
-55
+150
C
Stresses beyond those listed may cause permanent damage to the device. The device may not operate under these conditions, but it will
not be destroyed.
RECOMMENDED OPERATING CONDITIONS
Parameter
Symbol
Conditions
Min
Max
Unit
Operating Junction
Temperature
T
J
- 40
+125
C
Operating Ambient
Temperature
T
A
-40
+85
C
Operating Supply Voltage
V
IN
2.5
5.3
V
CTRL
VIN
VOUT
GND
OVER CURRENT /
OVER TEMPERATURE
PROTECTION
VOLTAGE
REFERENCE
+
BYPASS
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31 March 2003
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ELECTRICAL CHARACTERISTICS
x
Thermal Protection
T
A
= -40C to +85C, typical values at T
A
= +27C, V
IN
= V
OUT(NOM)
+ 1.0 V, I
OUT
= 1.0 mA, C
IN
= 1.0 F, C
L
= 1.0 F, C
BYPASS
= 10 nF,
V
CTRL
= 2.0 V, unless otherwise specified.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Threshold High
T
H
145
160
175
C
Threshold Low
T
L
135
150
165
C
The hysteresis of 10C prevents the device from turning on too soon after thermal shut-down.
x
Control Terminal Specifications
T
A
= -40C to +85C, typical values at T
A
= +27C, V
IN
= V
OUT(NOM)
+ 1.0 V, I
OUT
= 1.0 mA, C
IN
= 1.0 F, C
L
= 1.0 F, C
BYPASS
= 10 nF,
V
CTRL
= 2.0 V, unless otherwise specified.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Control Voltage
OFF State
ON State
V
CTRL
-
0.3
1.6
0.55
V
IN
+ 0.3
V
Control Current
I
CTRL
V
CTRL
= V
IN
V
CTRL
= 0 V
5
0
15
A
If CTRL-pin is not connected, MAS9123 is in OFF state (900 k pull-down resistor to ground).
x
Voltage Parameters
T
A
= -40C to +85C, typical values at T
A
= +27C, V
IN
= V
OUT(NOM)
+ 1.0 V, I
OUT
= 1.0 mA, C
IN
= 1.0 F, C
L
= 1.0 F, C
BYPASS
= 10 nF,
V
CTRL
= 2.0 V, unless otherwise specified.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Output Voltage Tolerance
V
OUT
I
OUT
= 0 mA
I
OUT
= 50 mA
V
OUT(NOM)
-
0.05
V
OUT(NOM)
-
0.10
V
OUT(NOM)
+ 0.05
V
OUT(NOM)
+ 0.05
V
Dropout Voltage
V
DROP
I
OUT
= 1 mA
I
OUT
= 10 mA
I
OUT
= 50 mA
46
51
95
mV
x
Current Parameters
T
A
= -40C to +85C, typical values at T
A
= +27C, V
IN
= V
OUT(NOM)
+ 1.0 V, I
OUT
= 1.0 mA, C
IN
= 1.0 F, C
L
= 1.0 F, C
BYPASS
= 10 nF,
V
CTRL
= 2.0 V, unless otherwise specified.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Continuous Output Current
I
OUT
0
80
mA
Short Circuit Current
I
MAX
R
L
= 0
230
mA
Peak Output Current
I
PK
V
OUT
> 95% * V
OUT(NOM)
180
mA
Ground Pin Current
I
GND
I
OUT
= 0 mA
I
OUT
= 10 mA
I
OUT
= 50 mA
170
210
250
A
T
A
= 27C
0.02
0.5
Ground Pin Current, Sleep
mode
I
GND
V
CTRL
= 0 V
T
A
= 85C
0.2
2
A
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31 March 2003
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x
Power Dissipation
T
A
= -40C to +85C, typical values at T
A
= +27C, V
IN
= V
OUT(NOM)
+ 1.0 V, I
OUT
= 1.0 mA, C
IN
= 1.0 F, C
L
= 1.0 F, C
BYPASS
= 10 nF,
V
CTRL
= 2.0 V, unless otherwise specified.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
typical PC board mounting,
still air, SOT23-5 package
255.9
Thermal Resistance
(Junction-to-Air)
R
JA
mounted on MAS9123 CSP
evaluation board,
WL-CSP package
TBD
C/W
Maximum Power Dissipation
P
d
any ambient temperature,
SOT23-5 package
JA
A
(MAX)
J
MAX
d
R
T
T
P
-
=
W
Note 1
Note 1
: T
J(MAX)
denotes maximum operating junction temperature (+125C), T
A
ambient temperature, and R
JA
junction-to-air thermal
resistance (+255.9C/W).
x
Line and Load Regulation
T
A
= -40C to +85C, typical values at T
A
= +27C, V
IN
= V
OUT(NOM)
+ 1.0 V, I
OUT
= 1.0 mA, C
IN
= 1.0 F, C
L
= 1.0 F, C
BYPASS
= 10 nF,
V
CTRL
= 2.0 V, unless otherwise specified.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Line Regulation
V
OUT(NOM)
+ 1 V < V
IN
< 5.3 V,
I
OUT
= 50 mA
0.75
2
mV
Load Regulation
I
OUT
= 1.0 to 50 mA
13.5
25
mV
x
Noise and Ripple Rejection
T
A
= -40C to +85C, typical values at T
A
= +27C, V
IN
= V
OUT(NOM)
+ 1.0 V, I
OUT
= 1.0 mA, C
IN
= 1.0 F, C
L
= 1.0 F, C
BYPASS
= 10 nF,
V
CTRL
= 2.0 V, unless otherwise specified.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Output Noise Voltage
V
RMS
10 Hz < f < 100 kHz
9.5
Vrms
Noise Density
V
N
I
OUT
= 50 mA,
f = 10 kHz
24
nV
/
Hz
PSRR
f = 1 kHz
f = 10 kHz
f = 100 kHz
70
68
58
dB
x
Dynamic Parameters
T
A
= -40C to +85C, typical values at T
A
= +27C, V
IN
= V
OUT(NOM)
+ 1.0 V, I
OUT
= 1.0 mA, C
IN
= 1.0 F, C
L
= 1.0 F, C
BYPASS
= 10 nF,
V
CTRL
= 2.0 V, unless otherwise specified.
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Start-up Delay (from start-up
to 80% of V
OUT(NOM)
)
V
CTRL
= 0 to 2.4 V, I
OUT
= 50 mA,
C
L
1.0 F
7.5
s
Overshoot
V
CTRL
= 0 to 2.4 V
1.0
8.0
%
Start-up Time
(settling time of voltage
transient from start-up to
within
1% of V
OUT(NOM)
)
V
CTRL
= 0 to 2.4 V, I
OUT
= 50 mA
C
L
1.0 F
20
s
Figure1.
Definitions of
start-up delay, overshoot
and start-up time.
CTRL
VOUT
50%
start-up delay
80%
overshoot
start-up time
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