MAX1735
19-1783; Rev 1; 11/03
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
The MAX1735 negative-output, low-dropout linear regulator operates from a -2.5V to -6.5V input and delivers a
guaranteed 200mA with a low 80mV dropout. The highaccuracy (±1%) output voltage is preset or can be
adjusted from -1.25V to -5.5V with an external resistive
voltage-divider.
An internal N-channel MOSFET allows for a low 85µA
quiescent current virtually independent of the load,
making this device ideal for battery-powered portable
equipment, such as PDAs, mobile phones, cordless
phones, and wireless data modems.
The device is available in several preset output voltage
versions: -5.0V, -3.0V, and -2.5V. All versions offer a
1nA low-power shutdown mode, short-circuit protection, and thermal overload protection. The device is
offered in a tiny 5-pin SOT23 package.
Features
♦ Guaranteed 200mA Output Current
♦ Low 80mV Dropout Voltage at 200mA
♦ Low 85µA Quiescent Supply Current
♦ Low 1nA Current Shutdown Mode
♦ Stable with 1µF COUT
♦ PSRR >60dB at 100Hz
♦ Thermal Overload Protection
♦ Short-Circuit Protection
♦ -5.0V, -3.0V, or -2.5V Output Voltage
or Adjustable (-1.25V to -5.5V)
♦ Tiny SOT23-5 Package
Applications
Ordering Information
Disk Drives
PART
Modems
PINPACKAGE
TEMP RANGE
Instrumentation Amplifiers
MAX1735EUK50-T
-40°C to +85°C
5 SOT23-5
Notebook Computers
MAX1735EUK30-T
-40°C to +85°C
5 SOT23-5
Mobile and Cordless Telephones
MAX1735EUK25-T
-40°C to +85°C
5 SOT23-5
PCMCIA Cards
Output-Voltage Selector Guide
GaAsFET Bias
Mobile Wireless Data Modems
PRESET OUTPUT
VOLTAGE
PART
PDAs and Palmtop Computers
MAX1735EUK50-T
-5.0V or adj
ADOZ
MAX1735EUK30-T
-3.0V or adj
ADOY
MAX1735EUK25-T
-2.5V or adj
ADOX
Pin Configuration
Typical Operating Circuit
-5V, -3V, OR -2.5V
OUTPUT
UP TO 200mA
-6.5V TO -2.5V
INPUT
OUT
IN
CIN
COUT
MAX1735
SOT TOP
MARK
TOP VIEW
GND 1
IN 2
5
OUT
4
SET
MAX1735
ON
GND
OFF
ON
SET
SHDN
SHDN 3
GND
SOT23-5
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX1735
General Description
MAX1735
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
ABSOLUTE MAXIMUM RATINGS
IN, SET to GND .................................................... -7.0V to +0.3V
SHDN to GND ............................................ (VIN - 0.3)V to +7.0V
OUT to GND ...............................................(VIN - 0.3)V to +0.3V
Output Short-Circuit Duration ........................................Indefinite
Continuous Power Dissipation (TA = +70°C)
5-Pin SOT23 (derate 7.1mW/°C above +70°C)........... 571mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range ............................ -65°C to +150°C
Lead Temperature (soldering, 10s) ................................ +300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 2, VIN = VOUT - 1V, V SHDN = VIN, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.)
(Note 1)
PARAMETER
Input Voltage
SYMBOL
CONDITIONS
VIN
Output Voltage Accuracy
MIN
Maximum Output Current
IOUT
Current Limit
ILIM
Ground-Pin Current
IQ
Dropout Voltage (Note 2)
+1
IOUT = -100µA, TA = 0°C to +85°C
-2
+2
ILOAD = -100µA to -200mA
-3
+2
-1.225
Circuit of Figure 3, ILOAD = -100µA to -200mA
-1.275
-1.2125
VOUT = 0
-1020
IOUT = -100µA
-180
-200
-85
40
IOUT = -200mA
80
240
0
+0.15
f = 100Hz
TA = +25°C
-1
Shutdown Supply Current
V SHDN = 0
SHDN Input High Threshold
(Note 3)
Negative voltage at SHDN
-1.6
Positive voltage at SHDN
+0.4
TA = +85°C
%/mA
µVRMS
60
dB
-0.001
TA = +25°C
Thermal Shutdown Junction
Temperature
Hysteresis = 15°C (typ)
-0.4
-15
V SHDN = +6.5V
V SHDN = 0, -6.5V
µA
+1.6
Negative voltage at SHDN
SHDN Input Bias Current
%/V
160
-1
-100
mV
0.004
Positive voltage at SHDN
VSET = -1.25V, TA = +25°C
mA
µA
IOUT = -100mA
10Hz to 1MHz, COUT = 1µF
ISET
-250
-125
IOUT from 0mA to -200mA
V
mA
-515
IOUT = -200mA
-0.15
%
-1.2375
-1.275
Output Voltage Noise
Set Input Bias Current
-1.25
Circuit of Figure 3, IOUT = -100µA,
TA = 0°C to +85°C
Load Regulation
SHDN Input Low Threshold
(Note 3)
V
-2.5
-1
Circuit of Figure 3,
VIN from -6.5V to -2.5V, VOUT = -1.25V
PSRR
UNITS
-6.5
Line Regulation
Power-Supply Rejection Ratio
MAX
TA = +25°C, IOUT = -100µA
Circuit of Figure 3, TA = +25°C, IOUT = -100µA -1.2625
SET Regulation Set Point
TYP
+0.5
160
V
nA
3.5
-0.5
V
µA
°C
Note 1: Limits are 100% production tested at TA = +25°C. Limits over operating temperature range are guaranteed by design.
Note 2: The dropout voltage is defined as VOUT - VIN, when VOUT is 100mV above the nominal value of VOUT.
Note 3: The SHDN logic input can be driven by either a positive voltage or a negative voltage. | V SHDN | < 0.4V puts the device in shutdown,
while | V SHDN | > 1.6V enables the device.
2
_______________________________________________________________________________________
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SUPPLY CURRENT
vs. LOAD CURRENT
130
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
140
120
100
80
60
MAX1735 toc02
ILOAD = 200mA
160
140
MAX1735 toc01
180
120
110
100
90
40
80
20
0
70
-1
-2
-3
-4
-5
-6
20 40 60 80 100 120 140 160 180 200
LOAD CURRENT (mA)
SUPPLY CURRENT
vs. TEMPERATURE
DROPOUT VOLTAGE
vs. LOAD CURRENT
140
120
100
80
NO LOAD
60
100
MAX1735 toc03
ILOAD = 200mA
VOUT = -2.9V
DROPOUT VOLTAGE (mV)
SUPPLY CURRENT (µA)
0
SUPPLY VOLTAGE (V)
180
160
-7
MAX1735 toc04
0
40
80
TA = +25°C
60
TA = +85°C
40
TA = -40°C
20
20
0
0
-15
10
35
60
0
50
75
100 125 150 175 200
LOAD CURRENT (mA)
OUTPUT VOLTAGE CHANGE
vs. LOAD CURRENT
OUTPUT VOLTAGE CHANGE
vs. TEMPERATURE
-0.4
TA = -40°C
TA = +85°C
-0.8
TA = +25°C
-1.0
MAX1735 toc06
-0.2
1.00
0.75
OUTPUT VOLTAGE CHANGE (%)
VOUT = -3V
-0.6
25
TEMPERATURE (°C)
0
OUTPUT VOLTAGE CHANGE (%)
85
MAX1735 toc05
-40
0.50
ILOAD = 200mA
0.25
0
-0.25
NO LOAD
-0.50
-0.75
-1.2
-1.00
0
25
50
75
100 125 150 175 200
LOAD CURRENT (mA)
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
3
MAX1735
Typical Operating Characteristics
(Circuit of Figure 2, VIN = -4.0V, VOUT = -3.0V, TA = +25°C, unless otherwise specified.)
Typical Operating Characteristics (continued)
(Circuit of Figure 2, VIN = -4.0V, VOUT = -3.0V, TA = +25°C, unless otherwise specified.)
50
COUT = 10µF
40
30
COUT = 1.0µF
MAX1735 toc09
MAX1735 toc08
60
10
OUTPUT NOISE (µVRMS/√Hz)
MAX1735 toc07
70
20
OUTPUT NOISE
(10Hz TO 1MHz)
OUTPUT NOISE DENSITY
vs. FREQUENCY
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
PSRR (dB)
500µV/div
COUT = 1µF
ILOAD = 50mA
1
0.1
10
0.01
0
1
10
100
1k
10k
100k
10
1M
1k
TIME (1ms/div)
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
REGION OF STABLE ESR
vs. LOAD CURRENT
LINE-TRANSIENT RESPONSE
MAX1735 toc11
MAX1735 toc10
100
COUT = 1µF
REGION OF STABLE ESR COUT (Ω)
MAX1735
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
10
VOUT
50mV/div
1
0.1
VIN
1V/div
REGION OF STABILITY
0.01
0.001
0
TIME (100µs/div)
20 40 60 80 100 120 140 160 180 200
LOAD CURRENT (mA)
LOAD-TRANSIENT RESPONSE
(NORMAL OPERATION)
LOAD-TRANSIENT RESPONSE
(NEAR DROPOUT)
MAX1735 toc12
TIME (100µs/div)
4
MAX1735 toc13
ILOAD STEP
0 to 50mA
ILOAD STEP
0 to 50mA
VOUT
10mV/div
VOUT
10mV/div
TIME (100µs/div)
_______________________________________________________________________________________
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
SHUTDOWN RESPONSE
(DRIVEN BY A NEGATIVE VOLTAGE)
SHUTDOWN-PIN BIAS CURRENT
vs. SHUTDOWN-PIN VOLTAGE
MAX1735 toc14b
VSHDN
2V/div
0
0
VSHDN
2V/div
0
VOUT
2V/div
0
VOUT
2V/div
1.5
1.0
0.5
MAX1735 toc15
SHUTDOWN-PIN BIAS CURRENT (µA)
2.0
INVALID LOGIC VOLTAGE
MAX1735 toc14a
INVALID LOGIC VOLTAGE
SHUTDOWN RESPONSE
(DRIVEN FROM A POSITIVE VOLTAGE)
0
-0.5
TIME (200µs/div)
TIME (200µs/div)
-6.5 -5.0 -3.5 -2.0 -0.5 1.0 2.5 4.0 5.5
SHUTDOWN-PIN VOLTAGE (V)
Pin Description
PIN
NAME
FUNCTION
1
GND
2
IN
Regulator Input. Supply voltage can range from -2.5V to -6.5V. Bypass with a 1µF capacitor to GND
(see Capacitor Selection and Regulator Stability). This pin also functions as a heatsink. Solder to a
large PC board pad or directly to the PC board power plane to maximize thermal dissipation.
3
SHDN
Shutdown Input. Drive SHDN to GND to turn the regulator off, reducing the input current to less than
1nA. Drive SHDN above +1.6V or below -1.6V to enable the regulator. Connect SHDN to IN for
always-on operation.
4
SET
Dual Mode™ Regulator Feedback Input. Connect SET to GND for the preset output voltage. Use a
resistive voltage-divider from OUT to SET to set the output voltage between -1.25V and -5.5V.
Regulation setpoint is -1.25V.
5
OUT
Regulator Output. OUT supplies up to 200mA in regulation. Bypass to GND with a 1µF ceramic
capacitor.
Ground
Dual Mode is a trademark of Maxim Integrated Products, Inc.
_______________________________________________________________________________________
5
MAX1735
Typical Operating Characteristics (continued)
(Circuit of Figure 2, VIN = -4.0V, VOUT = -3.0V, TA = +25°C, unless otherwise specified.)
MAX1735
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
IN
THERMAL
SENSOR
CIN
SHUTDOWN
LOGIC
NMOS
PASS
TRANSISTOR
OUT
ON
GND
SHDN
OFF
MAX1735
ON
COUT
ERROR
AMPLIFIER
R1
VREF
-1.25V
SET
Dual Mode
COMPARATOR
R2
-270mV
GND
Figure 1. Functional Diagram
Detailed Description
The MAX1735 is a low-dropout negative linear voltage
regulator. It features Dual Mode operation, allowing a
fixed -5.0V, -3.0V, or -2.5V output voltage or an
adjustable output from -1.25V to -5.5V. The regulator is
guaranteed to supply 200mA of output current. It features 60dB power-supply rejection for noise-sensitive
applications and a low 85µA operating current that optimizes it for battery-operated devices.
As Figure 1 illustrates, the device consists of an internal
-1.25V reference, an error amplifier, an N-channel
MOSFET, an internal precision-trimmed feedback voltage-divider, and a Dual Mode comparator.
The -1.25V reference is connected to the inverting input
of the error amplifier. The error amplifier compares the
reference voltage with the selected feedback voltage
and amplifies the difference. The error amplifier drives
the MOSFET to control the output voltage.
The feedback voltage for regulation is generated by
either an internal or external resistive voltage-divider
connected from OUT to SET. The internal Dual Mode
6
comparator selects the feedback path based on VSET.
Connect SET to GND to use the internal feedback path,
setting the output voltage to the preset value. If an
external voltage-divider is used, see Output Voltage
Selection.
Internal N-Channel MOSFET
The MAX1735 features an N-channel MOSFET pass
transistor. Unlike similar designs using NPN bipolar
pass transistors, N-channel MOSFETs require extremely low drive currents, reducing overall quiescent current. Also, NPN-based regulators consume still more
base current in dropout conditions when the pass transistor saturates. The MAX1735 does not suffer from
these problems, consuming only 125µA total current at
full load and in dropout.
Output Voltage Selection
The MAX1735 features Dual Mode operation, allowing for
a preset or adjustable output voltage. In preset voltage
mode, the output of the MAX1735 is set to -5.0V, -3.0V, or
-2.5V (see Ordering Information). Select this mode by
connecting SET to GND (Figure 2).
_______________________________________________________________________________________
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
OUT
IN
CIN
1µF CERAMIC
COUT
1µF CERAMIC
MAX1735
-6.5V TO -2.5V
INPUT
-5.5V TO -1.25V
ADJUSTABLE
OUTPUT
-6.5V TO -2.5V
INPUT
-5.0V,-3.0V, OR -2.5V
FIXED
OUTPUT
OUT
IN
CIN
1µF CERAMIC
R1
COUT
1µF
CERAMIC
MAX1735
MAX1735
ON
ON
GND
OFF
ON
GND
SET
SHDN
OFF
ON
SET
SHDN
GND
GND
R2
VOUT = VSET
Figure 2. Typical Application Circuit with Preset Output Voltage
In adjustable mode, an output voltage between -5.5V and
-1.25V is selected using two external resistors connected
as a voltage-divider from OUT to SET (Figure 3). The output voltage is determined by the following equation:
  R1  
VOUT = VSET 1 +   
  R2  
where VSET = VREFERENCE = -1.25V when in regulation.
Since the input bias current at SET is <100nA, use
large resistance values for R1 and R2 to minimize
power consumption in the feedback network. A typical
value of 100kΩ for R2 is acceptable for most applications. Higher values consume less current at the
expense of output voltage accuracy. The above equation solved for R1 is:
 V
 
R1 = R2  OUT  − 1
 VSET  
For preset output voltage mode, connect SET directly
to GND.
Shutdown
In shutdown, the N-channel MOSFET, control circuitry,
reference, and all internal circuits are turned off, reducing supply current to typically 1nA. SHDN can be driven by either a positive or negative voltage. Drive
SHDN above +1.6V or below -1.6V to turn the regulator
on. To turn the regulator off, drive SHDN to GND. For
always-on operation, connect SHDN to IN. By including
a positive threshold at SHDN, it can be driven by a
standard 5V TTL level without needing level-shifting circuitry.
(1 + R1R2)
Figure 3. Typical Application Circuit with Adjustable Output
Voltage
Current Limiting
The MAX1735 features a current limit that protects the
regulator. Short-circuit output current is typically
515mA. The output will withstand a short to ground
indefinitely; however, if the increased power dissipation
heats the die to +160°C, the thermal overload protection will shut off the regulator, preventing damage to the
IC.
Thermal Overload Protection
The thermal overload protection circuit protects the regulator against overheating due to prolonged overload
conditions. When the die temperature exceeds +160°C,
an on-chip thermal sensor disables the pass transistor,
allowing the IC to cool. The thermal sensor reenables
the pass MOSFET once the die temperature drops
15°C. A continuous short-circuit fault condition results in
a cyclical enabling and disabling of the output.
Thermal overload protection is designed to safeguard
the MAX1735 in the event of overload fault conditions.
For normal operation, do not exceed the absolute maximum junction temperature rating of +150°C. Junction
temperature is greater than ambient by an amount
depending on package heat dissipation and the thermal resistance from the junction to ambient (θJA):
TJUNCTION = TAMBIENT + (θJA)(PDISSIPATION)
where
θJA for the 5-pin SOT23 is about 0.140°C/mW.
_______________________________________________________________________________________
7
MAX1735
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
MAXIMUM OUTPUT CURRENT
vs. INPUT-OUTPUT VOLTAGE DIFFERENTIAL
MAX SUPPLY VOLTAGE – MIN OUTPUT VOLTAGE
MAXIMUM CONTINUOUS CURRENT
200
DEVICE IN DROPOUT
MAXIMUM OUTPUT CURRENT (mA)
250
150
100
TA
AT MAXIMUM
JUNCTION TEMP
(TJ = +150°C)
TA
=+
5
= + 0°C
= + 70°C
85
°C
TA
50
0
0
1
2
3
4
5
6
INPUT-OUTPUT VOLTAGE DIFFERENTIAL (V)
Figure 4. Output Current and In-Out Voltage Differential
Operating Region Bounded by Available Power Dissipation at
Selected Ambient Temperatures
Operating Region and Power Dissipation
Maximum power dissipation of the MAX1735 depends
on the thermal resistance of the case and the circuit
board, the temperature difference between the die
junction and ambient air, and the rate of air flow (see
also Thermal Overload Protection). The maximum
power that can be dissipated by the device is:
T
− TA TJMAX − TA
PMAX = JMAX
=
θJC + θCA
θJA
where the numerator expresses the temperature difference between the maximum allowed die junction
(+150°C) and the surrounding air, θJC (junction to case)
is the thermal resistance of the package, and θCA (case
to ambient) is the thermal resistance from the package
through the PC board, traces, and other material to the
surrounding air. The former is a characteristic solely of
the device in its package, and the latter is completely
defined by PC board layout and airflow. It is important to
note that the ability to dissipate power is as much a function of the PC board layout and air flow as the packaged
part itself. Hence, a manufacturer can reliably provide a
value for θJC, but not accurately provide a value for the
total thermal resistance θJA. θJA is the sum of θJC and
θCA, and the manufacturer can seldom reliably predict
the thermal characteristics of the application circuit.
Figure 4 shows the estimated allowable power dissipation for a MAX1735 mounted on a typical PC board at
ambient temperatures of +50°C, +70°C, and +85°C.
Figure 4 shows the maximum continuous output current
for a particular input-to-output voltage differential, for
8
selected ambient temperatures. The working principle is
that the SOT23-5 package is small enough that in a typical application circuit at room temperature, the package
cannot dissipate enough power to allow -6.5V to be regulated to -1.25V at -200mA output (more than 1200mW).
As ambient temperature falls, the available power dissipation increases to allow for a greater operating region.
The equation for the family of curves follows:
T − 70
PMAX − A
θJA
| IOUT | =
|VOUT − VIN |
where |IOUT| is in mA, |VOUT - VIN| in V, PMAX (571mW)
is the absolute maximum rated power dissipation at
+70°C for the SOT23-5, and θJA (0.140°C/mW) is the
approximate junction-to-ambient thermal resistance of
the SOT23-5 in a typical application.
A key to reducing θCA, thereby increasing thermal conductivity to the PC board, is to provide large PC board
pads and traces for IN.
__________Applications Information
Capacitor Selection and
Regulator Stability
Capacitors are required at the input and output of the
MAX1735. Connect a 1µF or greater capacitor between
IN and GND. This input capacitor serves only to lower
the source impedance of the input supply in transient
conditions; a smaller value can be used when the regulator is powered from a low-impedance source, such as
another regulated supply or low-impedance batteries.
For output voltages between -2.5V and -5.5V, connect
a 1µF or greater capacitor between OUT and GND. For
voltages between -1.25V and -2.5V, use a 2.2µF or
greater output capacitor. The maximum value of the
output capacitor to guarantee stability is 10µF.
The output capacitor’s value and equivalent series
resistance (ESR) affect stability and output noise. To
ensure stability and optimum transient response, output
capacitor ESR should be 0.1Ω or less for output voltages from -1.25V to -2.45V and 0.2Ω or less for output
voltages between -2.5V and -5.5V. Inexpensive surface-mount ceramic capacitors typically have very-low
ESR and are commonly available in values up to 10µF.
Other low-ESR capacitors, such as surface-mount tantalum, may also be used. Do not use low-cost aluminum electrolytic capacitors due to their large size
and relatively high ESR. Lastly, make sure the input and
output capacitors are as close to the IC as possible to
minimize the impact of PC board trace impedance.
_______________________________________________________________________________________
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
Dropout Voltage
A regulator’s minimum input-to-output voltage differential dropout voltage determines the lowest usable supply voltage for an application. In battery-powered
systems, this determines the useful end-of-life battery
voltage. Since the MAX1735’s pass element is an
N-channel MOSFET, dropout voltage is the product of
R DS(ON) and the load current; see Electrical
Characteristics and Dropout Voltage vs. Load Current
in the Typical Operating Characteristics for details. The
MAX1735 operating (ground pin) current typically
remains below 125µA at full load in dropout.
___________________Chip Information
TRANSISTOR COUNT: 293
_______________________________________________________________________________________
9
MAX1735
Noise, PSRR, and Transient Response
MAX1735 output noise is typically 160µVRMS. This is
suitably low for most applications. See the Output
Noise vs. Frequency plot in the Typical Operating
Characteristics.
The MAX1735 is optimized for battery-powered equipment, with low dropout voltage and low quiescent current. It maintains good transient response, AC rejection,
and noise characteristics even near dropout. See
Power-Supply Rejection Ratio vs. Frequency in the
Typical Operating Characteristics. When operating
from very noisy sources, supply noise rejection and
transient response can be improved by increasing the
input and output capacitance, and by employing passive postfiltering.
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
SOT-23 5L .EPS
MAX1735
200mA, Negative-Output, Low-Dropout
Linear Regulator in SOT23
PACKAGE OUTLINE, SOT-23, 5L
21-0057
E
1
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement