LTC1844-1.5 LINER [Linear Technology], LTC1844-1.5 Datasheet

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LTC1844-1.5

Manufacturer Part Number
LTC1844-1.5
Description
150mA, Micropower, Low Noise, VLDO Linear Regulator
Manufacturer
LINER [Linear Technology]
Datasheet
FEATURES
TYPICAL APPLICATIO
APPLICATIO S
Bluetooth/802.11 Cards
PDAs and Notebook Computers
Portable Instruments and Battery-Powered Systems
Cellular Phones
Very Low Dropout:
90mV at 150mA
30mV at 50mA (LTC1844-3.3)
Wide Input Voltage Range: 1.6V to 6.5V
Low 35 A Supply Current, Even in Dropout
Low Noise: 30 V
Voltage and Current Ranges
Fast Transient Response
10nA Supply Current in Shutdown
Fixed Output Voltages: 1.5V, 1.8V, 2.5V, 2.8V, 3.3V
Adjustable Output Voltage: 1.25V to 6V
Output Current Limit
Reverse-Battery and Reverse-Current Protection
No Protection Diodes Needed
Stable with 1 F Output Capacitor
Stable with Ceramic Capacitors
Short-Circuit and Thermal Overload Protection
Low Profile (1mm) SOT-23 Package
1.75% Voltage Accuracy Over Temperature,
Fixed Voltage Low Noise, VLDO Linear Regulator
3.3V TO 6.5V
OFF ON
V
IN
U
1 F
RMS
1
3
IN
SHDN
(10Hz to 100kHz)
LTC1844-3.3
GND
2
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
OUT
BYP
U
5
4
1844 TA01
1 F
0.1 F
V
3.3V
OUT
DESCRIPTIO
The LTC
dropout) linear regulators designed for low power/portable
applications. These regulators can operate from input
voltages as low as 1.6V. Typical output noise is only
30 V
90mV at the maximum load current of 150mA, reducing to
30mV at 50mA.
The internal P-channel MOSFET pass transistor requires
no base current, allowing the device to draw only 35 A
during normal operation, independent of the dropout
voltage and load current. The quiescent current falls to a
negligible 10nA during shutdown.
Other features include high output voltage accuracy,
excellent transient response, stablity with ultralow ESR
ceramic capacitors as small as 1 F, reverse-battery and
reverse-current protection, short-circuit and thermal
overload protection and output current limiting.
The LTC1844 regulators are available in a low profile
(1mm) SOT-23 (ThinSOT
VLDO and ThinSOT are trademarks of Linear Technology Corporation.
, LTC and LT are registered trademarks of Linear Technology Corporation.
RMS
LTC1844-3.3 Dropout Voltage vs Load Current
®
1844 Series are low noise VLDO
and typical dropout for the LTC1844-3.3 is just
120
100
80
60
40
20
150mA, Micropower,
0
0
25
U
Low Noise, VLDO
Linear Regulator
50
Final Electrical Specifications
I
TM
OUT
) package.
75
(mA)
LTC1844 Series
100
125
1844 TA02
150
May 2003
TM
(very low
1844ia
1

Related parts for LTC1844-1.5

LTC1844-1.5 Summary of contents

Page 1

... F, reverse-battery and reverse-current protection, short-circuit and thermal overload protection and output current limiting. The LTC1844 regulators are available in a low profile (1mm) SOT-23 (ThinSOT , LTC and LT are registered trademarks of Linear Technology Corporation. VLDO and ThinSOT are trademarks of Linear Technology Corporation. ...

Page 2

... LTC1844 Series ABSOLUTE AXI U RATI GS Supply Voltage (IN) ....................................... – Input Voltage SHDN, BYP, ADJ .................................... – 0. Output Voltage OUT ........................................................ – 0. OUT to IN .................................................. – PACKAGE/ORDER I FOR ATIO TOP VIEW OUT GND 2 SHDN 3 4 BYP S5 PACKAGE 5-LEAD PLASTIC TSOT-23 ...

Page 3

... L LTC1844-3 3.8V 0mA to 150mA IN OUT LTC1844-2 3.3V 0mA to 150mA IN OUT LTC1844-2 3.0V 0mA to 150mA IN OUT LTC1844-1 2.3V 0mA to 150mA IN OUT LTC1844-1 2.2V 0mA to 150mA IN OUT V = 2.0V 0mA to 150mA IN OUT LTC1844-BYP V = 2.2V 0mA to 150mA IN OUT V = 1.75V 0mA to 150mA IN OUT LTC1844- 2.2V 0mA to 150mA ...

Page 4

... OUT f = 10Hz to 100kHz 0 OUT load BP OUT load BP OUT (Notes 3, 8) LTC1844-3.3, LTC1844-2.8, LTC1844-2.5, LTC1844-1.8, LTC1844-1. –5V OUT LTC1844-BYP, LTC1844-SD –5V OUT OUT OUT(NOMINAL 0V OUT ...

Page 5

... GND (Pin 2): Ground and Heat Sink. Solder to a ground plane or large pad to maximize heat dissipation. SHDN (Pin 3, Fixed and SD Devices): Shutdown, Active Low. This pin is used to put the LTC1844 into shutdown. The SHDN pin current is typically less than 10nA. The SHDN pin cannot be left floating and must be tied to the input pin if not used ...

Page 6

... TIME ( s) Figure 1. LTC1844-2.5 Transient Response 1mA to 50mA to 1mA Adjustable Operation The adjustable version of the LTC1844 has an output voltage range of 1.25V to 6V. The output voltage is set by the ratio of two external resistors as shown in Figure 2. The device servos the output to maintain the ADJ pin voltage ...

Page 7

... Output Capacitance and Transient Response The LTC1844 regulators are designed to be stable with a wide range of output capacitors. The ESR of the output capacitor affects stability, most notably with small capaci- tors. A minimum output capacitor with an ESR of ...

Page 8

... OUT IN The LTC1844 series regulators have internal thermal lim- iting designed to protect the device during momentary overload conditions. For continuous normal conditions, the maximum junction temperature rating of 125 C must not be exceeded important to give careful consider- ...

Page 9

... Current flow into the device will be limited to less than 500 A (typically less than 200 A) and only a small negative voltage will appear at the output (~ –300mV with no load). The LTC1844 will protect both itself and the load against batteries plugged in backward. In circuits where a backup battery is required, several different input/output conditions can occur ...

Page 10

... U APPLICATIONS INFORMATION When V is held constant and V IN OUT will follow the curves shown in Figure 7. With V below V , the LTC1844 will be in current limit OUT(NOM) trying to pull V up. With V held between V OUT OUT and will be at the normal quiescent current level ...

Page 11

... MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 U S5 Package 5-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1635) 0.95 REF 1.22 REF 1.50 – 1.75 2.80 BSC 1.4 MIN (NOTE 4) PIN ONE 0.95 BSC 0.80 – 0.90 1.00 MAX 0.09 – 0.20 (NOTE 3) LTC1844 Series 2.90 BSC (NOTE 4) 0.30 – 0.45 TYP 5 PLCS (NOTE 3) 0.01 – 0.10 1.90 BSC S5 TSOT-23 0302 1844ia 11 ...

Page 12

... LTC1844 Series RELATED PARTS PART NUMBER DESCRIPTION LT1761 100mA, Low Noise LDO in ThinSOT LT1762 150mA, Low Noise LDO LT1763 500mA, Low Noise LDO LT1764A 3A, Fast Transient Response, Low Noise LDO LT1962 300mA, Low Noise LDO LT1963A 1.5A Low Noise, Fast Transient Response LDO ...

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