Impala Linear Corporation
ILC7082
150mA SOT-23 Ultra Low Noise
CMOS RF-LDO™ Regulator
General Description
The ILC7082 is a 150mA low dropout (LDO) voltage regu-
lator designed to provide a high performance solution to
low power systems. The device offers a typical combina-
tion of low dropout and low quiescent current expected
of CMOS parts, while uniquely providing the low noise and
high ripple rejection characteristics usually only associated
with bipolar LDO regulators.
The device has been optimized to meet the needs of mod-
ern wireless communications design; Low noise, low
dropout, small size, high peak current, high noise immunity.
The ILC7082 is designed to make use of low cost ceramic
capacitors while outperforming other devices that require
tantalum capacitors.
•
•
•
•
Features
Ultra low 1mV dropout per 1mA load
1% output voltage accuracy
Only 30mV
RMS
noise
Uses low ESR ceramic output capacitor to minimize
noise and output ripple
• Only 100µA ground current at 100mA load
• Ripple rejection up to 85dB at 1kHz, 60dB at 1MHz
• Excellent line and load transient response
• Over current / over temperature protection
• Guaranteed to 150mA output current
• Industry standard five lead SOT-23 package
• Fixed 2.8V, 3.0V, 3.3V, 3.6V, 4.7V, 5.0V and adjustable
output voltage options
• Metal mask option available for custom voltages between
2.5V and 10V
Applications
•
•
•
•
Cellular phones
Wireless communicators
PDAs / palmtops / organizers
Battery powered portable electronics
TYPICAL CIRCUIT
V
OUT
5
SOT-23-5
4
Ordering Information (TA = -40°C to +85°C)
C
NOISE
C
OUT
ILC7082
1
2
3
ILC7082AIM5-xx
ILC7082AIM5-ADJ
ILC7082AIK-xx 150mA
150mA, fixed voltage
150mA, adjustable voltage
Fixed voltage (SOIC-8)
V
IN
ON
C
IN
OFF
Impala Linear Corporation
ILC7082 1.3
(408) 574-3939
www.impalalinear.com
April 1999
1
150mA SOT-23 Ultra Low Noise CMOS RF-LDO™ Regulator
PIN DESCRIPTION ILC7082-XX (fixed voltage version)
Pin Number
1
2
3
4
Pin Name
V
IN
GND
ON/OFF
C
NOISE
Pin Description
Connect Directly to Supply
Ground pin
By Applying less than 0.4V to this pin the device will be turned off
Optional Noise bypass capacitor may be connected between this pin
and the GND (pin 2). Do not connect C
NOISE
directly to the main
power ground plane.
Output voltage. Connect C
OUT
between this pin and the GND (pin 2).
5
V
OUT
PIN DESCRIPTION ILC7082-AIK-xx (SOIC fixed voltage version)
Pin Number
1
2
3
4
5
6
7
8
Pin Name
GND
ON/OFF
V
IN
N/C
N/C
V
OUT
N/C
N/C
Pin Description
Connect Directly to Supply
Ground pin. Local ground for C
NOISE
and C
OUT
.
Connect directly to supply
No connection
No connection
Output Voltage. Connect C
OUT
between this pin and GND (pin 2)
No Connection
No Connection
PIN DESCRIPTION ILC7082-ADJ (adjutable voltage version)
Pin Number
1
2
3
4
5
Pin Name
V
IN
GND
ON/OFF
V
ADJ
V
OUT
Pin Description
Connect Directly to Supply
Ground pin. Local ground for C
NOISE
and C
OUT
.
By Applying less than 0.4V to this pin the device will be turned off
Voltage feedback pin to set the adjustable output voltage. Do not
connect a capacitor to this pin.
Output voltage. Connect C
OUT
between this pin and the GND (pin 2).
PIN PACKAGE CONFIGURATIONS
Fixed Voltage option
Adjustable Voltage option
Impala Linear Corporation
ILC7082 1.3
(408) 574-3939
www.impalalinear.com
April 1999
2
150mA SOT-23 Ultra Low Noise CMOS RF-LDO™ Regulator
ABSOLUTE MAXIMUM RATINGS (NOTE 1)
Parameter
Input voltage
On/Off Input voltage
Output Current
Output voltage
Package Power Dissipation
(SOT-23-5)
Maximum Junction Temp
Range
Storage Temperature
Operating Ambient
Temperature
Package Thermal Resistance
Symbol
V
IN
V
ON/OFF
I
OUT
V
OUT
P
D
T
J(max)
T
STG
T
A
θ
JA
Ratings
-0.3 to +13.5
-0.3 to VIN
Short circuit protected
-0.3 to VIN+0.3
250 (Internally Limited)
-40~+150
-40~+125
-40 to +85
333
Units
V
MA
V
MW
O
O
C
C
C
C/W
O
O
ELECTRICAL CHARACTERISTICS ILC7082AIM5
Unless otherwise specified. all limits are at T
A
= 25°C, V
IN
= V
OUT(NOM)
+1V, I
OUT
= 1mA, C
OUT
= 1µF, V
ON/OFF
= 2V
Boldface
limits apply over the operating temperature range.
(Note 2)
Parameter
Input voltage
Range
Output Voltage
Symbol
V
IN
V
OUT
Conditions
Min
2
-1
-1.5
-2.5
-2.5
-3.5
1.215
1.202
Typ
Max
13
+1
+1.5
+2.5
+2.5
+3.5
1.265
1.278
0.014
0.032
1
2
25
35
75
100
150
200
225
300
Units
V
%V
OUT
(
NOM
)
I
OUT
= 1mA
<
<
1mA I
OUT
100mA
<
<
1mA I
OUT
100mA
<
<
1mA I
OUT
150mA
<
<
1mA I
OUT
150mA
V
OUT
(
NOM
)
V
OUT
(
NOM
)
V
OUT
(
NOM
)
Feedback
Voltage
(ADJ Version)
Line regulation
V
ADJ
!
V
OUT
(V
OUT
*
!
V
OUT
)
<
<
V
%/V
mV
V
OUT
(
NOM
)+1V V
IN
12V
I
OUT
= 0mA
(Note 4)
0.007
0.1
10
50
100
150
Dropout
Voltage
"
(Note 3)"
V
IN
- V
OUT
I
OUT
= 10mA
I
OUT
= 50mA
I
OUT
= 100mA
I
OUT
= 150mA
Impala Linear Corporation
ILC7082 1.3
(408) 574-3939
www.impalalinear.com
April 1999
3
150mA SOT-23 Ultra Low Noise CMOS RF-LDO™ Regulator
ELECTRICAL CHARACTERISTICS ILC7082AIM5 (continued)
Unless otherwise specified. all limits are at T
A
= 25°C, V
IN
= V
OUT(NOM)
+1V, I
OUT
= 1mA, C
OUT
= 1µF, V
ON/OFF
= 2V
Boldface
limits apply over the operating temperature range.
(Note 2)
Parameter
Symbol
Conditions
I
OUT
= 0mA
I
OUT
= 1mA
Ground Pin
Current
I
GND
1mA I
OUT
100mA
1mA I
OUT
150mA
1mA I
OUT
150mA
Shutdown (OFF)
Current
ON/OFF Input
Voltage
ON/OFF Pin
Input Current
(Note 5)
Peak Output
Current
(Note 4)
Output Noise
Voltage (RMS)
I
ON/OFF
V
ON/OFF
V
ON/OFF
= 0
V
High = Regulator On
Low = Regulator Off
V
ON/OFF
= 0.6V,
REGULATOR OFF
V
ON/OFF
= 2V,
REFULATOR ON
V
OUT
> 0.95V
OUT
(
NOM
),
t
pw
=2ms
BW = 300Hz to 50kHz, C
IN
= 1µF
C
NOISE
= 0.01µF, C
OUT
= 2.2
µF,
I
OUT
= 10
M
A
C
OUT
= 4.7µF,
I
OUT
= 100
M
A
freq = 1kHz
freq = 10kHz
freq = 1mHz
1.5
0.3
1
400
500
<
<
<
<
<
<
Min
Typ
95
100
100
100
115
0.1
Max
200
220
220
240
220
240
240
260
260
280
2
13
0.06
Units
µA
µA
µA
MA
µV
RMS
I
IN (on/off)
I
OUT(peak)
e
N
30
Ripple Rejection
!V
OUT/
!
V
IN
"
"
!
V
OUT
(line)
"
Dynamic Line
Regulation
85
70
60
14
dB
mV
V
IN
: V
OUT
(
NOM
) + 1V to
V
OUT
(
NOM
) + 2V,
tr/tf = 2ms; I
OUT
= 150
M
A
40
I
OUT
: 1mA to 150mA; tr < 5µS
600
mA
mV
Dynamic Load
Regulation
Short Circuit
Current
!
V
OUT(load)
I
SC
V
OUT
= 0V
Note 1: Absolute maximum ratings indicate limits which when exceeded may result in damage to the component. Electrical specifications do not apply
when operating the device outside of its rated operating conditions.
Note 2: Specified Min/Max limits are production tested or guaranteed through correlation based on statistical control methods. Measurements are taken at
constant junction temperature as close to ambient as possible using low duty pulse testing.
Note 3: Dropout voltage is defined as the input to output differential voltage at which the output voltage drops 2% below the nominal value measured with
an IV differential.
Note 4: Guaranteed by design
Note5 : The device’s shutdown pin includes a 2MΩ internal pulldown resistor connected to ground.
Impala Linear Corporation
ILC7082 1.3
(408) 574-3939
www.impalalinear.com
April 1999
4
150mA SOT-23 Ultra Low Noise CMOS RF-LDO™ Regulator
ELECTRICAL CHARACTERISTICS ILC7082AIM5 (continued)
OPERATION
The ILC7082 LDO design is based on an advanced circuit
configuration for which patent protection has been applied.
Typically it is very difficult to drive a capacitive output with
an amplifier. The output capacitance produces a pole in the
feedback path, which upsets the carefully tailored dominant
pole of the internal amplifier. Traditionally the pole of the
output capacitor has been “eliminated” by reducing the out-
put impedance of the regulator such that the pole of the
output capacitor is moved well beyond the gain bandwidth
product of the regulator. In practice, this is difficult to do and
still maintain high frequency operation. Typically the output
impedance of the regulator is not simply resistive, such that
the reactive output impedance interacts with the reactive
impedance of the load resistance and capacitance. In addi-
tion, it is necessary to place the dominant pole of the circuit
at a sufficiently low frequency such that the gain of the reg-
ulator has fallen below unity before any of the complex
interactions between the output and the load occur. The
ILC7082 does not try to eliminate the output pole, but incor-
porates it into the stability scheme. The load and output
capacitor forms a pole, which rolls off the gain of the regu-
lator below unity. In order to do this the output impedance
of the regulator must be high, looking like a current source.
The output stage of the regulator becomes a transconduc-
tance amplifier, which converts a voltage to a current with a
substantial output impedance. The circuit which drives the
transconductance amplifier is the error amplifier, which
compares the regulator output to the band gap reference
and produces an error voltage as the input to the transcon-
ductance amplifier. The error amplifier has a dominant pole
at low frequency and a “zero” which cancels out the effects
of the pole. The zero allows the regulator to have gain out
to the frequency where the output pole continues to reduce
the gain to unity. The configuration of the poles and zero are
shown in figure 1. Instead of powering the critical circuits
from the unregulated input voltage, the CMOS RF LDO
powers the internal circuits such as the bandgap, the error
amplifier and most of the transconductance amplifier from
the boot strapped regulated output voltage of the regulator.
This technique offers extremely high ripple rejection and
excellent line transient response.
A block diagram of the regulator circuit used in the ILC7082
is shown in figure 2 (following page), which shows the input-
to-output isolation and the cascaded sequence of amplifiers
that implement the pole-zero scheme outlined above.
Figure 1: ILC7082 RF LDO frequency response
V
IN
C
NOISE
BANDGAP
REFERENCE
V
REFD
ERROR
AMPLIFIER
INTERNAL V
DD
TRANS-
CONDUCTANCE
AMPLIFIER
V
OUT
FEEDBACK
GND
ON/OFF
Figure 2: ILC7082 RF LDO regulator block diagram
The ILC7082 is designed in a CMOS process with some
minor additions, which allow the circuit to be used at input
voltages up to 13V. The resulting circuit exceeds the fre-
quency response of traditional bipolar circuits. The ILC7082
is very tolerant of output load conditions with the inclusion
of both short circuit and thermal overload protection. The
device has a very low dropout voltage, typically a linear
response of 1mV per milliamp of load current, and none of
the quasi-saturation characteristics of a bipolar output
devices. All the good features of the frequency response
and regulation are valid right to the point where the regula-
tor goes out of regulation in a 4 millivolt transition region.
Because there is no base drive, the regulator is capable of
providing high current surges while remaining in regulation.
This is shown in the high peak current of 500mA which
allows for the ILC7082 to be used in systems that require
short burst mode operation.
Impala Linear Corporation
ILC7082 1.3
(408) 574-3939
www.impalalinear.com
April 1999
5
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