# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

LINEAR LT1500 LT1501 Adaptive-Frequency Current Mode Switching Regulators Data Sheet User Manual

Summary

This manual provides comprehensive documentation for ultra-low quiescent current switching regulators designed for maximizing battery life in portable instrumentation and electronics. Featuring adaptive frequency control, these DC/DC converters deliver reliable power while minimizing noise and standby drain down to microampere levels. Essential reading for engineers designing high-efficiency, compact systems that require stable, low-noise output across varying voltages, especially those utilizing primary or secondary batteries.

📄 Preview PAGE OF 16

Page 1 Text Content

查询LT1500供应商

LT1500/LT1501

Adaptive-Frequency

Current Mode Switching Regulators

FEATURES DESCRIPTION

Low Noise Adaptive-Frequency Current Mode The LT®1500 is an adaptive-frequency current mode step- Operation Avoids Low Frequency Noise at up switching regulator with an internal power switch that Most Load Currents is rated up to 700m A. In contrast to pulse skipping Can Be Externally Synchronized (LT1500) switching regulators, the LT1500 uses a current mode Micropower Quiescent Current: 200µA topology that provides lower noise operation and im- Shutdown Current: 8µA Typ proved efficiency. Only at very light loads is Burst Mode TM Internal Loop Compensation activated to give high efficiency and micropower opera- Low-Battery Comparator Active in Shutdown tion. High switching frequency (up to 500k Hz) allows very Minimum Input Voltage: 1.8V Typ small inductors to be used, along with ceramic capacitors Additional Negative Voltage Feedback Pin (LT1500) if desired. Up to 500k Hz Switching Frequency

The LT1500 operates with input voltages from 1.8V to 15V

Uses Low Profile, Low Cost Surface Mount Inductors

and has only 200µA operating current dropping to 8µA in shutdown. A low-battery comparator is included which stays alive in shutdown. A second output feedback pin

APPLICATIONS

with negative polarity allows negative output voltages to Portable Instrumentation be regulated when the switcher is connected up as a Cuk Battery Operated Systems or a flyback converter.

PDA’s

Two package types are available. The LT1500 comes in a

Standby Power

14-pin SO package, with two options available for fixed output (3.3V or 5V) or adjustable operation. A reduced feature part, the LT1501, comes in the smaller 8-pin SO package with internal frequency compensation. It is also available in adjustable and fixed output voltage versions. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a trademark of Linear Technology Corporation.

TYPICAL APPLICATION

2-Cell to 5V Converter

D1 MBR0520L

VIN ISENSE

2 EACH SHDN SW

Ni Cd OR 33µF*

LT1501-5 10V

ALKALINE 6V

LBI OUT

CELLS

AVX, TPSC107M006R0150

1% LBO GND AVX, TPSD107M010 R0100

SUMIDA CD73-220, CD54-220

OR CD43-220. SELECT ACCORDING TO MAXIMUM LOAD CURRENT LT1500/01 • TA01

LOW-BATTERY FLAG (USE EXTERNAL PULL-UP)

Page Summary Contents For LINEAR LT1500 LT1501 Adaptive-Frequency Current Mode Switching Regulators Data Sheet User Manual

Page 1 查询LT1500供应商 LT1500/LT1501 Adaptive-Frequency Current Mode Switching Regulators FEATURES DESCRIPTION Low Noise Adaptive-Frequency Current Mode The LT®1500 is an adaptive-frequency current mode step- Op...
Page 2 LT1500/LT1501 ABSOLUTE MAXIMUM RATINGS Supply Voltage 20V Operating Ambient Temperature Range Switch Voltage (SW)................................................ 30V Commercial 0°C to 70°C Shutdown Vo...
Page 3 LT1500/LT1501 ELECTRICAL CHARACTERISTICS TJ = 25°C, VIN = 2.3V unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS Internal Divider Current LT1500-3.3/LT1501-3.3 µA LT1500-5/LT1501-5 µA Ope...
Page 4 EF FI CI EN CY FR EQ EN CY (k z) LT1500/LT1501 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating peak inductor current to increase and therefore switching fre...
Page 5 TP CU EN (m A) EF FI CI EN CY SS EF FI CI EN CY LT1500/LT1501 TYPICAL PERFORMANCE CHARACTERISTICS Efficiency (3.3V Output) Efficiency (5V Output) Efficiency (12V Output) ILOAD = 10m A ILOAD = 50m A IL...
Page 6 LO AD EN (m A) LT1500/LT1501 SU PP LY EN (µ A) TYPICAL PERFORMANCE CHARACTERISTICS CU EN (µ A) Peak-to-Peak Inductor Ripple Burst Mode Threshold Switch Saturation Voltage Current 1.0 TJ = 25°C TJ = 25...
Page 7 LT1500/LT1501 PIN FUNCTIONS SHDN: Logic Level Shutdown Pin. This pin must be held NFB/SELECT (LT1500 Only): NFB is a second feedback high (> 1.1V) for the regulator to run. SHDN can be tied node us...
Page 8 LT1500/LT1501 BLOCK DIAGRAM INSYNCLBO ISENSE OUTPUT RSENSE 0.28ΩRh 18m V UU WU 0.75V CURRENT COMPARATOR SHDN R1 BURST COMPARATOR FIXED HYSTERESIS 1.265V I1 REFERENCE VARIABLE ERROR AMP HYSTERESIS NEGA...
Page 9 LT1500/LT1501 APPLICATIONS INFORMATION value, the peak-to-peak inductor current (set internally) compensation capacitor filters out most the ripple voltage and the values for VIN and VOUT. The LT1500 ...
Page 10 LT1500/LT1501 APPLICATIONS INFORMATION mode. Normal operation resumes for one or more switch Input Capacitor cycles and the output voltage increases until the error Input capacitors for boost regulato...
Page 11 LT1500/LT1501 APPLICATIONS INFORMATION type TPS from AVX, or type 595D from Sprague. These have an ESR of 0.06Ω in a “E” case size. At lower output 118= k2 current levels, a 100µF unit in a “D” case s...
Page 12 LT1500/LT1501 APPLICATIONS INFORMATION with an external divider no switch exists and the divider Low-Battery Detector current remains. There may be additional current drawn The low-battery detector is...
Page 13 LT1500/LT1501 APPLICATIONS INFORMATION and it should be no more than 300k to keep bias current errors under 1%, giving: DIV BAT 272k (Use 274k 1%) The total divider resistance will be 274k + 301k = 57...
Page 14 LT1500/LT1501 APPLICATIONS INFORMATION capacitors may require the capacitor to be larger. To PTOTAL = total device power dissipation ensure proper reset of the soft start capacitor, an external RSW = ...
Page 15 LT1500/LT1501 Dimensions in inches (millimeters) unless otherwise noted.PACKAGE DESCRIPTION S Package 14-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0° – 8° TYP DIMENSION DOES NOT...
Page 16 LT1500/LT1501 TYPICAL APPLICATION Typical LT1500 (14-Pin) Application, 2-Cell to 5V Converter MBR0520L 249k IN ISENSE ON(HI) SHDN SW OFF (LO) LBI OUT 2 EACH Ni Cd OR LT1500-3.3/LT1501-5 ALKALINE CELLS...

Manual Details

Brand Current
Pages 16
File Size 194.99 KB
Published May 18, 2026
121 views

Enter the captcha to get the download link:

captcha

Frequently Asked Questions

What is the minimum input voltage for the LT1500 regulator?

The LT1500 operates with input voltages ranging from 1.8V to 15V.

How does the operational current of the LT1500 compare during light loads (shutdown)?

It has a low quiescent current of 200μA, dropping significantly down to just 8μA in shutdown mode.

What physical package options are available for the LT1500 and LT1501?

The LT1500 is available in a 14-pin SO package, while the smaller LT1501 option uses an 8-pin SO package.

Can the regulator output negative voltages?

Yes, it supports regulated negative output voltages when configured as a Cuk converter or flyback converter.