LTC1844 Series
150mA, Micropower,
Low Noise, VLDO
Linear Regulator
FEATURES
DESCRIPTIO
TM
Very Low Dropout:
The LTC 1844 Series are low noise VLDO (very low
90mV at 150mA
dropout) linear regulators designed for low power/portable
30mV at 50mA (LTC1844-3.3)
applications. These regulators can operate from input
Wide Input Voltage Range: 1.6V to 6.5V
voltages as low as 1.6V. Typical output noise is only
Low 35A Supply Current, Even in Dropout
30V and typical dropout for the LTC1844-3.3 is just
RMS
Low Noise: 60V (10Hz to 100kHz)
90mV at the maximum load current of 150mA, reducing to
RMS
1.75% Voltage Accuracy Over Temperature,
30mV at 50mA.
Voltage and Current Ranges
The internal P-channel MOSFET pass transistor requires
Fast Transient Response
no base current, allowing the device to draw only 35A
10nA Supply Current in Shutdown
during normal operation, independent of the dropout
Fixed Output Voltages: 1.5V, 1.8V, 2.5V, 2.8V, 3.3V
voltage and load current. The quiescent current falls to a
Adjustable Output Voltage: 1.25V to 6V
negligible 10nA during shutdown.
Output Current Limit
Reverse-Battery and Reverse-Current Protection Other features include high output voltage accuracy,
excellent transient response, stability with ultralow ESR
No Protection Diodes Needed
Stable with 1F Output Capacitor ceramic capacitors as small as 1F, reverse-battery and
Stable with Ceramic Capacitors reverse-current protection, short-circuit and thermal
overload protection and output current limiting.
Short-Circuit and Thermal Overload Protection
Low Profile (1mm) SOT-23 Package
The LTC1844 regulators are available in a low profile
U TM
(1mm) SOT-23 (ThinSOT ) package.
APPLICATIO S
, LTC and LT are registered trademarks of Linear Technology Corporation.
VLDO and ThinSOT are trademarks of Linear Technology Corporation.
Portable Instruments and Battery-Powered Systems
All other trademarks are the property of their respective owners.
Bluetooth/802.11 Cards
Cellular Phones
PDAs and Notebook Computers
TYPICAL APPLICATIO
LTC1844-3.3 Dropout Voltage vs Load Current
120
Fixed Voltage Low Noise, VLDO Linear Regulator
100
V V
IN OUT
IN OUT
80
3.3V TO 6.5V 3.3V
1F 1F
LTC1844-3.3
60
OFF ON SHDN BYP
GND
40
0.1F
1844 TA01
20
0
0 25 50 75 100 125 150
I (mA)
OUT
1844 TA02
1844fa
1
DROPOUT VOLTAGE (mV)
U
ULTC1844 Series
ABSOLUTE AXI U RATI GS (Note 1)
Supply Voltage (IN) ....................................... 7V to 7V Output Short-Circuit Duration ......................... Indefinite
Input Voltage Operating Junction Temperature Range
SHDN, BYP, ADJ .................................... 0.3V to 7V (Notes 2, 10) .....................................40C to 125C
Output Voltage Storage Temperature Range ................. 65C to 150C
OUT ........................................................ 0.3V to 7V Lead Temperature (Soldering, 10 sec).................. 300C
OUT to IN .................................................. 7V to 7V
UUW
PACKAGE/ORDER I FOR ATIO
TOP VIEW
TOP VIEW
TOP VIEW
IN 1 5 OUT
IN 1 5 OUT IN 1 5 OUT
GND 2
GND 2
GND 2
SHDN 3 4 ADJ BYP 3 4 ADJ
SHDN 3 4 BYP
S5 PACKAGE S5 PACKAGE
S5 PACKAGE
5-LEAD PLASTIC TSOT-23 5-LEAD PLASTIC TSOT-23
5-LEAD PLASTIC TSOT-23
T = 125C, = 250C/ W, = 90C/ W T = 125C, = 250C/ W, = 90C/ W T = 125C, = 250C/ W, = 90C/ W
JMAX JA JC JMAX JA JC JMAX JA JC
SEE THE APPLICATIONS INFORMATION SECTION SEE THE APPLICATIONS INFORMATION SECTION SEE THE APPLICATIONS INFORMATION SECTION
S5 PART S5 PART S5 PART
ORDER PART ORDER PART ORDER PART
NUMBER MARKING NUMBER MARKING NUMBER MARKING
LTF1 LTE8 LTE9
LTC1844ES5-1.5 LTC1844ES5-SD LTC1844ES5-BYP
LTF2
LTC1844ES5-1.8
LTF3
LTC1844ES5-2.5
LTQK
LTC1844ES5-2.8
LTF4
LTC1844ES5-3.3
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: