Impala Linear Corporation
1
(408) 574-3939
www.impalalinear.com
April 1999
ILC7082 1.3
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.
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 100
A 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
Cellular phones
Wireless communicators
PDAs / palmtops / organizers
Battery powered portable electronics
ILC7082
5
4
1
2
3
ON
OFF
SOT-23-5
V
OUT
V
IN
C
IN
C
OUT
C
NOISE
Ordering Information (TA = -40C to +85C)
ILC7082AIM5-xx
ILC7082AIM5-ADJ
ILC7082AIK-xx 150mA
150mA, fixed voltage
150mA, adjustable voltage
Fixed voltage (SOIC-8)
ILC7082
150mA SOT-23 Ultra Low Noise
CMOS RF-LDOTM Regulator
Impala Linear Corporation
General Description
Features
Applications
TYPICAL CIRCUIT
150mA SOT-23 Ultra Low Noise CMOS RF-LDOTM Regulator
Impala Linear Corporation
2
(408) 574-3939
www.impalalinear.com
April 1999
ILC7082 1.3
Pin Number Pin Name
Pin Description
1
V
IN
Connect Directly to Supply
2
GND
Ground pin
3
ON/OFF
By Applying less than 0.4V to this pin the device will be turned off
4
C
NOISE
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.
5
V
OUT
Output voltage. Connect C
OUT
between this pin and the GND (pin 2).
Pin Number Pin Name
Pin Description
1
V
IN
Connect Directly to Supply
2
GND
Ground pin. Local ground for C
NOISE
and C
OUT
.
3
ON/OFF
By Applying less than 0.4V to this pin the device will be turned off
4
V
ADJ
Voltage feedback pin to set the adjustable output voltage. Do not
connect a capacitor to this pin.
5
V
OUT
Output voltage. Connect C
OUT
between this pin and the GND (pin 2).
Pin Number Pin Name
Pin Description
1
GND
Connect Directly to Supply
2
ON/OFF
Ground pin. Local ground for C
NOISE
and C
OUT
.
3
V
IN
Connect directly to supply
4
N/C
No connection
5
N/C
No connection
6
V
OUT
Output Voltage. Connect C
OUT
between this pin and GND (pin 2)
7
N/C
No Connection
8
N/C
No Connection
Fixed Voltage option
Adjustable Voltage option
PIN DESCRIPTION ILC7082-XX (fixed voltage version)
PIN DESCRIPTION ILC7082-AIK-xx (SOIC fixed voltage version)
PIN DESCRIPTION ILC7082-ADJ (adjutable voltage version)
PIN PACKAGE CONFIGURATIONS
150mA SOT-23 Ultra Low Noise CMOS RF-LDOTM Regulator
Impala Linear Corporation
3
(408) 574-3939
www.impalalinear.com
April 1999
ILC7082 1.3
Parameter
Symbol
Ratings
Units
Input voltage
On/Off Input voltage
V
IN
V
ON/OFF
-0.3 to +13.5
-0.3 to VIN
V
Output Current
I
OUT
Short circuit protected MA
Output voltage
V
OUT
-0.3 to VIN+0.3
V
Package Power Dissipation
(SOT-23-5)
P
D
250 (Internally Limited)
MW
Maximum Junction Temp
Range
T
J(max)
-40~+150
O
C
Storage Temperature
T
STG
-40~+125
O
C
Operating Ambient
Temperature
T
A
-40 to +85
O
C
Package Thermal Resistance
JA
333
O
C/W
Parameter
Symbol
Conditions
Min
Typ
Max
Units
Input voltage
Range
V
IN
2
13
V
I
OUT
= 1mA
-1
V
OUT
(
NOM
)
+1
1mA
<
I
OUT
<
100mA
1mA
<
I
OUT
<
100mA
-1.5
-2.5
V
OUT
(
NOM
)
+1.5
+2.5
Output Voltage
V
OUT
1mA
<
I
OUT
<
150mA
1mA
<
I
OUT
<
150mA
-2.5
-3.5
V
OUT
(
NOM
)
+2.5
+3.5
%V
OUT
(
NOM
)
Feedback
Voltage
(ADJ Version)
V
ADJ
1.215
1.202
1.265
1.278
V
Line regulation
!
V
OUT
(V
OUT
*
!
V
OUT
)
V
OUT
(
NOM
)+1V
<
V
IN
<
12V
0.007
0.014
0.032
%/V
I
OUT
= 0mA (Note 4)
0.1
1
2
I
OUT
= 10mA
10
25
35
I
OUT
= 50mA
50
75
100
I
OUT
= 100mA
100
150
200
Dropout
Voltage
(Note 3)
"
"
V
IN
-
V
OUT
I
OUT
= 150mA
150
225
300
mV
Unless otherwise specified. all limits are at T
A
= 25C, V
IN
= V
OUT(NOM)
+1V, I
OUT
= 1mA, C
OUT
= 1
F, V
ON/OFF
= 2V
Boldface limits apply over the operating temperature range. (Note 2)
ABSOLUTE MAXIMUM RATINGS (NOTE 1)
ELECTRICAL CHARACTERISTICS ILC7082AIM5
150mA SOT-23 Ultra Low Noise CMOS RF-LDOTM Regulator
Impala Linear Corporation
4
(408) 574-3939
www.impalalinear.com
April 1999
ILC7082 1.3
Parameter
Symbol
Conditions
Min
Typ
Max Units
I
OUT
= 0mA
95
200
220
I
OUT
= 1mA
100
220
240
1mA
<
I
OUT
<
100mA
100
220
240
1mA
<
I
OUT
<
150mA
100
240
260
Ground Pin
Current
I
GND
1mA
<
I
OUT
<
150mA
115
260
280
A
Shutdown (OFF)
Current
I
ON/OFF
V
ON/OFF
= 0
V
0.1
2
A
ON/OFF Input
Voltage
V
ON/OFF
High = Regulator On
Low = Regulator Off
1.5
13
0.06
ON/OFF Pin
Input Current
(Note 5)
I
IN
(on/off)
V
ON/OFF
= 0.6V,
REGULATOR OFF
V
ON/OFF
= 2V,
REFULATOR ON
0.3
1
A
Peak Output
Current (Note 4)
I
OUT(peak)
V
OUT
>
0.95V
OUT
(
NOM
),
t
pw
=2ms
400
500
MA
Output Noise
Voltage (RMS)
e
N
BW = 300Hz to 50kHz, C
IN
= 1
F
C
NOISE
= 0.01
F,
C
OUT
= 2.2
F,
I
OUT
= 10
M
A
30
V
RMS
freq = 1kHz
85
freq = 10kHz
70
Ripple Rejection
"
!
V
OUT
/
!
V
IN
C
OUT
= 4.7
F,
I
OUT
= 100
M
A
freq = 1mHz
60
dB
Dynamic Line
Regulation
"
"
!
V
OUT
(line)
V
IN
: V
OUT
(
NOM
) + 1V to
V
OUT
(
NOM
) + 2V,
tr/tf = 2ms; I
OUT
= 150
M
A
14
mV
Dynamic Load
Regulation
!
V
OUT(load)
I
OUT
: 1mA to 150mA; tr < 5
S
40
mV
Short Circuit
Current
I
SC
V
OUT
= 0V
600
mA
Unless otherwise specified. all limits are at T
A
= 25C, V
IN
= V
OUT(NOM)
+1V, I
OUT
= 1mA, C
OUT
= 1
F, V
ON/OFF
= 2V
Boldface limits apply over the operating temperature range. (Note 2)
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 2M
internal pulldown resistor connected to ground.
ELECTRICAL CHARACTERISTICS ILC7082AIM5 (continued)
150mA SOT-23 Ultra Low Noise CMOS RF-LDOTM Regulator
Impala Linear Corporation
5
(408) 574-3939
www.impalalinear.com
April 1999
ILC7082 1.3
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.
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.
ELECTRICAL CHARACTERISTICS ILC7082AIM5 (continued)
Figure 1: ILC7082 RF LDO frequency response
ON/OFF
GND
V
OUT
V
IN
C
NOISE
FEEDBACK
BANDGAP
REFERENCE
V
REFD
ERROR
AMPLIFIER
TRANS-
CONDUCTANCE
AMPLIFIER
INTERNAL V
DD
Figure 2: ILC7082 RF LDO regulator block diagram
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