1/4
June 2002
IP Library: Ultra Low Noise, Low power,
100mA Low Dropout Voltage Regulator
s
RF REGULATOR
s
VERY LOW DROPOUT VOLTAGE : 50mV
s
ULTRA LOW OUTPUT NOISE
s
HIGH OUTPUT CURRENT : 100mA
s
LOW QUIESCENT CURRENT : 110
A
s
HIGH PSRR : 65dB
s
NO CURRENT IN POWER DOWN MODE
s
SHORT CIRCUIT PROTECTION
TYPICAL APPLICATIONS
Cellular and Cordless phones supplied by 1 cell
Lithium-ion battery / 3 cells Ni-MH or Ni-Cd
battery.
PDA (Personal Digital Assistant), Smart phone.
Portable equipment.
Supply for RF devices for cellular phone.
APPLICATION NOTE
An external capacitor (C
OUT
= 1
F) with an
equivalent serial resistance (ESR) in the range
0.02 to 0.6
is used for regulator stability.
Figure 1 : Block Diagram
?
V
REF
?
?
?
LDO_58
OUT
IN
PWRDWN
STDBY
Figure 2 : Typical Application Circuit
1
F
ESR
V
OUT
C
OUT
?
?
OUT
GND
?
?
?
V
IN
IN
PWRDWN
Power Down Mode
OFF
ON
Stand-by Mode
STDBY
Active Mode
LDO_58
Stand-by Mode
LDO_58
This is advance information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
PRODUCT PREVIEW
LDO_58
2/4
ELECTRICAL CHARACTERISTICS
3V < V
IN
< 5.5V, -30C < T
A
< +85C, V
REF
= 2.8V, C
OUT
= 1
F 20%, 20m
< ESR < 0.6
,
I
LOAD
= 100mA.
Typical case : V
IN
= 4V, T = 25C, C
OUT
= 1
F.
Notes: 1. Above characteristics are given for 2.9V minimum input operating range voltage, but regulator
is operational with 2.7V minimum input voltage.
2. All parameters are guaranteed with 170mV min dropout voltage.
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Input Voltage Range (Note 1)
V
IN
3
5,5
V
Output Voltage
V
OUT
2,8
V
Output Voltage Accuracy
3
%
Output current
I
OUT
100
mA
Dropout Voltage
V
DO
V
OUT
= 50mV,
I
LOAD
= 100mA
50
mV
(Note 2)
170
Quiescent current
I
Q
I
LOAD
= 100
A
50
70
A
I
LOAD
= 100mA
110
250
Quiescent Current in stand-by
mode
I
STDBY
I
LOAD
= 100
A
20
40
Power down mode quiescent
current
I
QPDM
Power down active
100
nA
Power Supply Rejection Ratio
PSRR
DC
45
65
dB
f = 10KHz
45
60
f = 100KHz
35
45
Line Regulation
Lir
I
LOAD
= 100mA,
V
IN
= 3V to 5.5V
0,5
1
mV
Load Regulation
Ldr
I
LOAD
= 100
A - 100mA
25
40
mV
Line Transient
Lirt
V
IN
= 300mV
t
RISE
= t
FALL
=10
s
0,5
1,5
mV
Load Transient
Ldtr
I
LOAD
= 100
A - 100mA in 10
s
3
10
mV
Output Noise Voltage
en
100Hz
40
65
1KHz - 10KHz
30
40
en
RMS
BW : 10Hz to 100KHz
25
30
V
RMS
Output decoupling Capacitor
C
OUT
1
F
Settling time
From power down to active
mode
20
50
s
Short Circuit Current Limit
I
SHORT
200
mA
nV
Hz
------------
LDO_58
3/4
1
10
100
1000
10000
100000
1000000
-65
-55
-45
-35
FREQUENCY (Hz)
PS
R
R
(
d
B
)
150m V
170m V
200m V
2V
TYPCIAL CHARACTERISTICS
Figure 7 : PSRR vs Frequency for Various
Voltage Drop (I
LOAD
= 100mA)
LDO_58
4/4
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics
2002 STMicroelectronics - All Rights Reserved
STMicroelectronics GROUP OF COMPANIES
Australia - Brazil - Canada - China - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco
Singapore - Spain - Sweden - Switzerland - United Kingdom - United States
http://www.st.com
PDF 
ZIP