IC DC/DC CONV ADJUSTBL OUT 8SOIC

LT1173CS8

Manufacturer Part NumberLT1173CS8
DescriptionIC DC/DC CONV ADJUSTBL OUT 8SOIC
ManufacturerLinear Technology
TypeStep-Down (Buck), Step-Up (Boost), Inverting
LT1173CS8 datasheet
 


Specifications of LT1173CS8

Internal Switch(s)YesSynchronous RectifierNo
Number Of Outputs1Voltage - Output1.25 ~ 50 V
Current - Output400mAFrequency - Switching23kHz
Voltage - Input2 ~ 30 VOperating Temperature0°C ~ 70°C
Mounting TypeSurface MountPackage / Case8-SOIC (3.9mm Width)
Power - Output500mWLead Free Status / RoHS StatusContains lead / RoHS non-compliant
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FEATURE
S
Operates at Supply Voltages From 2.0V to 30V
Consumes Only 110 A Supply Current
Works in Step-Up or Step-Down Mode
Only Three External Components Required
Low Battery Detector Comparator On-Chip
User-Adjustable Current Limit
Internal 1A Power Switch
Fixed or Adjustable Output Voltage Versions
Space Saving 8-Pin MiniDIP or SO8 Package
O
U
A
PPLICATI
S
Flash Memory Vpp Generators
3V to 5V, 5V to 12V Converters
9V to 5V, 12V to 5V Converters
LCD Bias Generators
Peripherals and Add-On Cards
Battery Backup Supplies
Laptop and Palmtop Computers
Cellular Telephones
Portable Instruments
U
O
TYPICAL
A
PPLICATI
Logic Controlled Flash Memory VPP Generator
L1*
1N5818
100 H
5V
IN
47
I
V
LIM
IN
SW1
+
LT1173
10 F
FB
GND
SW2
1N4148
PROGRAM
*L1 = GOWANDA GA20-103K
EFFICIENCY = 81%
COILTRONICS CTX100-4
= 1% METAL FILM
NO OVERSHOOT
Adjustable and Fixed 5V, 12V
D
ESCRIPTIO
The LT1173 is a versatile micropower DC-DC converter.
The device requires only three external components to
deliver a fixed output of 5V or 12V. Supply voltage ranges
from 2.0V to 12V in step-up mode and to 30V in step-down
mode. The LT1173 functions equally well in step-up, step-
down or inverting applications.
The LT1173 consumes just 110 A supply current at
standby, making it ideal for applications where low quies-
cent current is important. The device can deliver 5V at
80mA from a 3V input in step-up mode or 5V at 200mA
from a 12V input in step-down mode.
Switch current limit can be programmed with a single
resistor. An auxiliary gain block can be configured as a low
battery detector, linear post regulator, under voltage lock-
out circuit or error amplifier.
For input sources of less than 2V, use the LT1073.
and LTC are registered trademarks and LT is a trademark of Linear Technology Corporation.
S
12V
100mA
V
OUT
5V/DIV
1.07M
+
SANYO
OS-CON
100 F
PROGRAM
5V/DIV
124k
LT1173 • TA01
Micropower
DC/DC Converter
U
VPP Output
0V
5ms/DIV
1173 TA02
LT1173
1

LT1173CS8 Summary of contents

  • Page 1

    ... Switch current limit can be programmed with a single resistor. An auxiliary gain block can be configured as a low battery detector, linear post regulator, under voltage lock- out circuit or error amplifier. For input sources of less than 2V, use the LT1073. and LTC are registered trademarks and trademark of Linear Technology Corporation. S 12V 100mA V ...

  • Page 2

    ... TOP VIEW ORDER PART NUMBER FB (SENSE)* 8 SET 7 LT1173CN8 AO 6 LT1173CN8-5 GND 5 LT1173CN8-12 = 130 C/W JA TOP VIEW LT1173CS8 8 FB (SENSE)* LT1173CS8-5 7 SET LT1173CS8- PART MARKING GND 5 1173 11735 117312 = 150 C/W JA MIN TYP MAX 110 150 135 250 2.0 12.6 30 1.20 1.245 1 ...

  • Page 3

    ELECTRICAL C HARA TERISTICS C SYMBOL PARAMETER V SW Voltage, Step-Down Mode SAT SAT A Gain Block Gain V Current Limit Current Limit Temperature Coeff. Switch OFF Leakage Current V Maximum Excursion Below GND SW2 The denotes the specifications which ...

  • Page 4

    LT1 173 W U TYPICAL PERFOR A Quiescent Current vs Temperature 120 110 100 90 –50 – 100 125 TEMPERATURE (°C) LT1173 •TPC06 ...

  • Page 5

    O U LT1173 OPER ATI The LT1173 is a gated oscillator switcher. This type archi- tecture has very low supply current because the switch is cycled only when the feedback pin voltage drops below the reference voltage. Circuit operation can ...

  • Page 6

    LT1 173 PPLICATI S I FOR ATIO 1M +12V 1 F* – 100 LTC1050 1000 F V SET *NON-POLARIZED Figure 1. Test Circuit Measures No Load Quiescent Current of LT1073 Converter Inductor ...

  • Page 7

    PPLICATI S I FOR ATIO As an example, suppose 9V at 50mA generated from a 3V input. Recalling Equation 02 (9V + 0.5V – 3V) (50mA) = 325mW. L Energy required ...

  • Page 8

    LT1 173 PPLICATI S I FOR ATIO 5 s/DIV LT1173 • TA07 Figure 2. Aluminum In very low power applications where every microampere is important, leakage current of the capacitor must be considered. The OS-CON units ...

  • Page 9

    PPLICATI S I FOR ATIO keep V at the internal reference voltage of 1.245V and R2 set the output voltage according to the formula 245 . V . OUT ...

  • Page 10

    LT1 173 PPLICATI S I FOR ATIO LIM IN SW1 + LT1173 GND SW2 R2 –V IN Figure 8. Negative-to-Positive Converter Using the I Pin LIM The LT1173 switch can ...

  • Page 11

    PPLICATI FOR ATIO Using the Gain Block The gain block (GB) on the LT1173 can be used as an error amplifier, low battery detector or linear post regulator. The gain block itself is a ...

  • Page 12

    LT1 173 PPLICATI FOR ATIO Table 2. Inductor Manufacturers MANUFACTURER Gowanda Electronics Corporation 1 Industrial Place Gowanda, NY 14070 716-532-2234 Caddell-Burns 258 East Second Street Mineola, NY 11501 516-746-2310 Coiltronics International 984 S.W. 13th ...

  • Page 13

    U O TYPICAL A PPLICATI Step-Up Converter L1* 100 LIM IN SW1 2 X 1.5V LT1173-5 CELLS SENSE GND SW2 + * L1 = GOWANDA GA10-103K COILTRONICS CTX100-1 (SURFACE MOUNT) +5V to –5V Converter ...

  • Page 14

    LT1 173 U O TYPICAL A PPLICATI 4 X NICAD OR 470 F ALKALINE CELLS *L1 = COILTRONICS CTX100-4 GOWANDA GA20-103K 300mA Step-Up Converter with Under Voltage Lockout 47k 2N3906 2 X NICAD 100k *L1 = ...

  • Page 15

    ... GND *TOKO 262LYF-0100K 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. S Voltage Controlled Positive-to-Negative Converter ...

  • Page 16

    ... MIN (0.380) MIN 0.018 ± 0.003 (0.457 ± 0.076) N8 0694 0.150 – 0.157* (3.810 – 3.988 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSC SO8 0294 LT/GP 0894 2K REV B • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1994 ...