LTC3035
300mA VLDO Linear
Regulator with Charge Pump
Bias Generator
FEATURES
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DESCRIPTIO
Wide Input Voltage Range: 1.7V to 5.5V
Wide Adjustable Output Voltage Range:
0.4V to 3.6V
Built-In Charge Pump Generates High Side Bias
Very Low Dropout: 45mV at 300mA
±
2% Voltage Accuracy Over Temperature,
Supply, Load
Fast Transient Recovery
Low Operating Current: I
IN
= 100µA Typ
Low Shutdown Current: I
IN
= 1µA Typ
Stable with Ceramic Capacitor Down to 1µF
Output Current Limit
Thermal Overload Protected
Reverse Output Current Protected
Available in 8-Lead (3mm
×
2mm) DFN Package
APPLICATIO S
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The LTC
®
3035 is a micropower, VLDO™ (very low drop-
out) linear regulator which operates from input voltages as
low as 1.7V. The device is capable of supplying 300mA of
output current with a typical dropout voltage of only
45mV. To allow operation at low input voltages the LTC3035
includes a charge pump generator that provides the nec-
essary bias voltage for the internal LDO circuitry. Output
current comes directly from the input supply for high
efficiency regulation. The charge pump bias generator
requires only a 0.1µF flying capacitor and a 1µF bypass
capacitor for operation. The low 0.4V internal reference
voltage allows the LTC3035 to be programmed to much
lower output voltages than commonly available in LDOs.
The output voltage is programmed via two tiny SMD
resistors. The LTC3035’s low quiescent current makes it
an ideal choice for use in battery-powered systems.
Other features include high output voltage accuracy, ex-
cellent transient response, stability with ultralow ESR
ceramic capacitors as small as 1µF, short-circuit and
thermal overload protection, output current limiting and
reverse output current protection. The LTC3035 is avail-
able in a tiny, low profile (3mm
×
2mm
×
0.75mm) 8-lead
DFN package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
VLDO is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 6411531, others pending.
Li-Ion to 3.3V Low Dropout Supplies
2
×
AA to 1.8V Low Dropout Supplies
Low Power Handheld Devices
Low Voltage Logic Supplies
DSP Power Supplies
Cellular Phones
Portable Electronic Equipment
Handheld Medical Instruments
Post Regulator for Switching Supply Noise Rejection
TYPICAL APPLICATIO
0.1µF
Dropout Voltage vs Load Current
70
60
DROPOUT VOLTAGE (mV)
3.3V Output Voltage from Li-Ion Battery
T
A
= 25°C
50
40
30
20
10
0
0
50
100
200
150
I
OUT
(mA)
250
300
3035 TA01b
CP
IN
Li-Ion
BATTERY
3.4V TO 4.2V
1µF
0.4V
CM
BIAS
C
BIAS
1µF
OUT
V
OUT
3.3V
C
OUT
300mA
1µF
BIAS
GENERATOR
+
–
LTC3035
ADJ
294k
40.2k
3035 TA01a
OFF ON
SHDN
GND
U
3035f
U
U
1
LTC3035
ABSOLUTE
(Notes 1, 2)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
CP 1
CM 2
GND 3
IN 4
9
8
7
6
5
BIAS
SHDN
ADJ
OUT
V
IN
to GND .................................................. – 0.3V to 6V
SHDN to GND ............................................. – 0.3V to 6V
CP, CM, BIAS to GND ................................. – 0.3V to 6V
ADJ to GND ................................................ – 0.3V to 6V
V
OUT
to GND ............................................... – 0.3V to 6V
Operating Junction Temperature
(Note 3) ........................................... – 40°C to 125°C
Storage Temperature Range ................ – 65°C to 125°C
Output Short Circuit Duration .......................... Indefinite
DDB PACKAGE
8-LEAD (3mm
×
2mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 76°C/W
EXPOSED PAD (PIN 9) IS GND,MUST BE SOLDERED TO PCB
ORDER PART NUMBER
LTC3035EDDB
DDB PART MARKING
LBRM
Order Options
Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
PARAMETER
V
IN
Operating Voltage (Note 4)
V
BIAS
Output Voltage Range
V
OUT
Output Voltage Range
V
IN
Operating Current
V
IN
Shutdown Current
V
ADJ
Regulation Voltage (Note 5)
I
ADJ
ADJ Input Current
OUT Load Regulation (Referred to ADJ Pin)
Dropout Voltage (Note 6)
I
OUT
Continuous Output Current
I
OUT
Short Circuit Output Current
V
OUT
Output Noise Voltage
V
IH
SHDN Input High Voltage
V
IL
SHDN Input Low Voltage
I
IH
SHDN Input High Current
I
IL
SHDN Input Low Current
The
●
denotes specifications which apply over the full specified temperature
range, otherwise specifications are at T
A
= 25
°
C. V
IN
= 3.6V, V
OUT
= 3.3V, C
FLY
= 0.1
µ
F, C
OUT
= 1
µ
F, C
IN
= 1
µ
F, C
BIAS
= 1
µ
F (all
capacitors ceramic) unless otherwise noted.
CONDITIONS
●
2.63V < V
IN
< 5.5V
1.7V < V
IN
< 2.63V
I
OUT
= 10µA
V
SHDN
= 0V
1mA < I
OUT
< 300mA, 1.7V < V
IN
< 5.5V,
V
OUT
= 1.5V
V
ADJ
= 0.4V
I
OUT
= 1mA to 300mA
V
IN
= 1.7V, V
ADJ
= 0.37V, I
OUT
= 300mA
V
ADJ
= V
OUT
= 0
F = 10Hz to 100kHz, I
OUT
= 150mA
●
●
●
●
●
●
●
●
MIN
1.7
4.8
1.85 • V
IN
V
ADJ
TYP
5
1.90 • V
IN
100
1
0.4
0
–0.2
45
760
150
0.392
–50
MAX
5.5
5.3
1.95 • V
IN
3.6
200
5
0.408
50
100
UNITS
V
V
V
V
µA
µA
V
nA
mV
mV
mA
mA
µVrms
V
V
µA
µA
300
●
●
1.1
–1
–1
0.3
1
1
SHDN = V
IN
SHDN = 0V
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 3:
The LTC3035 regulator is tested and specified under pulse load
conditions such that T
J
≈
T
A
. The LTC3035 is 100% production tested at
25°C. Performance at –40°C and 125°C is assured by design,
characterization and correlation with statistical process control.
Note 4:
Min Operating Input Voltage required for regulation is:
V
IN
> V
OUT
+ V
DROPOUT
and V
IN
> 1.7V
3035f
2
U
W
U
U
W W
W
LTC3035
ELECTRICAL CHARACTERISTICS
Note 5:
Operating conditions are limited by maximum junction
temperature. The regulated output voltage specification will not apply for
all possible combinations of input voltage and output current. When
operating at maximum input voltage, the output current range must
be limited.
Note 6:
Dropout voltage is minimum input to output voltage differential
needed to maintain regulation at a specified output current. In dropout, the
output voltage will be equal to V
IN
– V
DROPOUT
.
TYPICAL PERFOR A CE CHARACTERISTICS
Dropout Voltage vs Load Current
70
60
DROPOUT VOLTAGE (mV)
5.0
4.5
4.0
50
T
A
= 125°C
I
IN
(µA)
T
A
= 25°C
30
20
T
A
= –40°C
10
0
0
50
100
200
150
I
OUT
(mA)
250
300
3035 G01
2.5
2.0
1.5
1.0
0.5
0
0
1
T
A
= –40°C
2
3
V
IN
(V)
4
5
6
T
A
= 85°C
T
A
= 25°C
I
IN
(µA)
40
V
IN
No Load Operating Current
120
110
100
V
OUT
= 1.5V
T
A
= 125°C
ADJUST VOLTAGE (mV)
T
A
= 85°C
404
403
402
401
400
399
398
397
0
1
2
3
V
IN
(V)
4
5
6
3035 G04
ADJ VOLTAGE (mV)
I
IN
(µA)
90
80
70
60
T
A
= 25°C
T
A
= –40°C
U W
V
IN
Shutdown Current
115
110
105
V
IN
No Load Operating Current
V
OUT
= 3.3V
T
A
= 125°C
T
A
= 85°C
100
95
90
T
A
= –40°C
85
80
3
3.5
4
4.5
V
IN
(V)
5
5.5
6
3035 G03
3.5
3.0
T
A
= 25°C
LT1108 • TPC12
ADJ Voltage vs Temperature
V
OUT
= 3.3V
ADJ Voltage vs Input Voltage
404
403
402
401
400
399
398
397
V
OUT
= 1.5V
396
–45 –25 –5
15 35 55 75
TEMPERATURE (°C)
95 115
3035 G05
396
0
1
2
3
V
IN
(V)
4
5
6
3035 G06
3035f
3
LTC3035
TYPICAL PERFOR A CE CHARACTERISTICS
BIAS Voltage vs Input Voltage
6
5
1000
900
SHDN THRESHOLD (mV)
SHDN THRESHOLD (mV)
BIAS VOLTAGE (V)
4
3
2
1
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
V
IN
(V)
3035 G07
Current Limit vs Input Voltage
900
800
700
CURRENT LIMIT (mA)
REJECTION (dB)
V
OUT
= 0V
600
500
400
300
200
100
0
1.5
2
2.5
3
3.5
V
IN
(V)
3035 G10
Transient Response
V
OUT
20mV/DIV
AC
I
OUT
300mA
10mA
V
IN
= 3.6V
V
OUT
= 3.3V
C
OUT
= 1µF
200µs/DIV
3035 G11
4
U W
SHDN Threshold (Rising)
vs Temperature
1000
900
V
IN
= 5.5V
800
V
IN
= 3.6V
700
V
IN
= 1.7V
600
500
400
–45
SHDN Threshold (Falling)
vs Temperature
V
IN
= 5.5V
800
V
IN
= 3.6V
700
600
500
400
–45
V
IN
= 1.7V
–20
55
30
5
80
TEMPERATURE (°C)
105
130
–20
55
30
5
80
TEMPERATURE (°C)
105
130
3035 G08
3035 G09
V
IN
Ripple Rejection vs Frequency
70
60
50
40
30
20
10
V
IN
= 3.6V
V
OUT
= 3.3V
I
OUT
= 100mA
1k
10k
100k
1M
10M
3035 G13
C
OUT
= 10µF
C
OUT
= 1µF
4
4.5
5
5.5
0
100
FREQUENCY (Hz)
BIAS Output Ripple
V
BIAS
50mV/DIV
AC
V
OUT
5mV/DIV
AC
V
IN
= 3.6V
V
OUT
= 3.3V
C
BST
= 1µF
C
FLY
= 0.1µF
C
OUT
= 1µF
I
OUT
= 1mA
500µs/DIV
3035 G12
3035f
LTC3035
PI FU CTIO S
CP (Pin 1):
Flying Capacitor Positive Terminal.
CM (Pin 2):
Flying Capacitor Negative Terminal.
GND (Pin 3):
Ground. Connect to a ground plane.
IN (Pin 4):
Input Supply Voltage. The output load current
is supplied directly from IN. The IN pin should be locally
bypassed to ground if the LTC3035 is more than a few
inches away from another source of bulk capacitance. In
general, the output impedance of a battery rises with
frequency, so it is usually adviseable to include an input
bypass capacitor when supplying IN from a battery. A
capacitor of 1µF is usually sufficient.
OUT (Pin 5):
Regulated Output Voltage. The OUT pin
supplies power to the load. A minimum ceramic output
capacitor of at least 1µF is required to ensure stability.
Larger output capacitors may be required for applications
with large transient loads to limit peak voltage transients.
See the Applications Information section for more infor-
mation on output capacitance.
ADJ (Pin 6):
Adjust Input Pin. This is the input to the error
amplifier. The ADJ pin reference voltage is 0.4V referenced
to ground. The output voltage range is 0.4V to 3.6V and is
set by connecting ADJ to a resistor divider from OUT to
GND.
SHDN (Pin 7):
Shutdown Input, Active Low. This pin is
used to put the LTC3035 into shutdown. The SHDN pin
current is typically less than 10nA. The SHDN pin cannot
be left floating and must be tied to a valid logic level if
not used.
BIAS (Pin 8):
BIAS Output Voltage Pin. BIAS is the output
of the charge pump and provides the high side supply for
the LTC3035 LDO circuitry. This pin should be locally
bypassed to ground by a 1µF or greater capacitor as close
as possible to the pin. Nothing else should be connected
to this pin.
Exposed Pad (Pin 9):
Ground and Heat Sink. Must be
soldered to PCB ground plane or large pad for optimal
thermal performance.
BLOCK DIAGRA
8
BIAS
1.9 • V
IN
V
IN
V
MIN
4
7
SHDN
0.400V
BIAS
UVLO
GND
PINS 3, 9
ADJ
+
SHDN
REFERENCE
–
+
5V
–
W
U
U
U
EN
800kHz
OSCILLATOR
CHARGE
PUMP
CP
1
CM
2
SOFT-START
BIAS
OUT
2.5k
5
6
3035 BD
3035f
5
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