Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - LDO voltage regulator Negative, fixed or adjustable SOT 23 5

General Description

The MAX1735 negative-output, low-dropout linear regu-

lator operates from a -2.5V to -6.5V input and delivers a

guaranteed 200mA with a low 80mV dropout. The high-

accuracy (±1%) output voltage is preset or can be

adjusted from -1.25V to -5.5V with an external resistive

voltage-divider.

An internal N-channel MOSFET allows for a low 85µA

quiescent current virtually independent of the load,

making this device ideal for battery-powered portable

equipment, such as PDAs, mobile phones, cordless

phones, and wireless data modems.

The device is available in several preset output voltage

versions: -5.0V, -3.0V, and -2.5V. All versions offer a

1nA low-power shutdown mode, short-circuit protec-

tion, and thermal overload protection. The device is

offered in a tiny 5-pin SOT23 package.

Applications

Disk Drives

Modems

Instrumentation Amplifiers

Notebook Computers

Mobile and Cordless Telephones

PCMCIA Cards

GaAsFET Bias

Mobile Wireless Data Modems

PDAs and Palmtop Computers

Features

♦ Guaranteed 200mA Output Current

♦ Low 80mV Dropout Voltage at 200mA

♦ Low 85µA Quiescent Supply Current

♦ Low 1nA Current Shutdown Mode

♦ Stable with 1µF C

OUT

♦ PSRR >60dB at 100Hz

♦ Thermal Overload Protection

♦ Short-Circuit Protection

♦ -5.0V, -3.0V, or -2.5V Output Voltage

or Adjustable (-1.25V to -5.5V)

♦ Tiny SOT23-5 Package

MAX1735

200mA, Negative-Output, Low-Dropout

Linear Regulator in SOT23

________________________________________________________________ Maxim Integrated Products 1

SETSHDN

15OUTGND

MAX1735

SOT23-5

TOP VIEW

MAX1735

SHDN

-6.5V TO -2.5V

INPUT

-5V, -3V, OR -2.5V

OUTPUT

UP TO 200mA

OUT

SET

GND

OFF

Typical Operating Circuit

19-1783; Rev 1; 11/03

Pin Configuration

Ordering Information

PART TEMP RANGE

PIN-

PACKAGE

MAX1735EUK50-T -40°C to +85°C 5 SOT23-5

MAX1735EUK30-T -40°C to +85°C 5 SOT23-5

MAX1735EUK25-T -40°C to +85°C 5 SOT23-5

Output-Voltage Selector Guide

PART

PRESET OUTPUT

VOLTAGE

SOT TOP

MARK

MAX1735EUK50-T -5.0V or adj ADOZ

MAX1735EUK30-T -3.0V or adj ADOY

MAX1735EUK25-T -2.5V or adj ADOX

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Summary of content (10 pages)

PAGE 1
9-1783; Rev 1; 11/03 200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 The MAX1735 negative-output, low-dropout linear regulator operates from a -2.5V to -6.5V input and delivers a guaranteed 200mA with a low 80mV dropout. The highaccuracy (±1%) output voltage is preset or can be adjusted from -1.25V to -5.5V with an external resistive voltage-divider.
PAGE 2
MAX1735 200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 ABSOLUTE MAXIMUM RATINGS IN, SET to GND .................................................... -7.0V to +0.3V SHDN to GND ............................................ (VIN - 0.3)V to +7.0V OUT to GND ...............................................(VIN - 0.3)V to +0.3V Output Short-Circuit Duration ........................................Indefinite Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C)..........
PAGE 3
200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT vs. LOAD CURRENT 130 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 140 120 100 80 60 MAX1735 toc02 ILOAD = 200mA 160 140 MAX1735 toc01 180 120 110 100 90 40 80 20 0 70 -1 -2 -3 -4 -5 -6 20 40 60 80 100 120 140 160 180 200 LOAD CURRENT (mA) SUPPLY CURRENT vs. TEMPERATURE DROPOUT VOLTAGE vs. LOAD CURRENT 140 120 100 80 NO LOAD 60 100 MAX1735 toc03 ILOAD = 200mA VOUT = -2.
PAGE 4
Typical Operating Characteristics (continued) (Circuit of Figure 2, VIN = -4.0V, VOUT = -3.0V, TA = +25°C, unless otherwise specified.) 50 COUT = 10µF 40 30 COUT = 1.0µF MAX1735 toc09 MAX1735 toc08 60 10 OUTPUT NOISE (µVRMS/√Hz) MAX1735 toc07 70 20 OUTPUT NOISE (10Hz TO 1MHz) OUTPUT NOISE DENSITY vs. FREQUENCY POWER-SUPPLY REJECTION RATIO vs. FREQUENCY PSRR (dB) 500µV/div COUT = 1µF ILOAD = 50mA 1 0.1 10 0.
PAGE 5
200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 SHUTDOWN RESPONSE (DRIVEN BY A NEGATIVE VOLTAGE) SHUTDOWN-PIN BIAS CURRENT vs. SHUTDOWN-PIN VOLTAGE MAX1735 toc14b VSHDN 2V/div 0 0 VSHDN 2V/div 0 VOUT 2V/div 0 VOUT 2V/div 1.5 1.0 0.5 MAX1735 toc15 SHUTDOWN-PIN BIAS CURRENT (µA) 2.0 INVALID LOGIC VOLTAGE MAX1735 toc14a INVALID LOGIC VOLTAGE SHUTDOWN RESPONSE (DRIVEN FROM A POSITIVE VOLTAGE) 0 -0.5 TIME (200µs/div) TIME (200µs/div) -6.5 -5.0 -3.5 -2.0 -0.5 1.0 2.5 4.0 5.
PAGE 6
MAX1735 200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 IN THERMAL SENSOR CIN SHUTDOWN LOGIC NMOS PASS TRANSISTOR OUT ON GND SHDN OFF MAX1735 ON COUT ERROR AMPLIFIER R1 VREF -1.25V SET Dual Mode COMPARATOR R2 -270mV GND Figure 1. Functional Diagram Detailed Description The MAX1735 is a low-dropout negative linear voltage regulator. It features Dual Mode operation, allowing a fixed -5.0V, -3.0V, or -2.5V output voltage or an adjustable output from -1.25V to -5.5V.
PAGE 7
200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 OUT IN CIN 1µF CERAMIC COUT 1µF CERAMIC MAX1735 -6.5V TO -2.5V INPUT -5.5V TO -1.25V ADJUSTABLE OUTPUT -6.5V TO -2.5V INPUT -5.0V,-3.0V, OR -2.5V FIXED OUTPUT OUT IN CIN 1µF CERAMIC R1 COUT 1µF CERAMIC MAX1735 MAX1735 ON ON GND OFF ON GND SET SHDN OFF ON SET SHDN GND GND R2 VOUT = VSET Figure 2. Typical Application Circuit with Preset Output Voltage In adjustable mode, an output voltage between -5.5V and -1.
PAGE 8
MAX1735 200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 MAXIMUM OUTPUT CURRENT vs. INPUT-OUTPUT VOLTAGE DIFFERENTIAL MAX SUPPLY VOLTAGE – MIN OUTPUT VOLTAGE MAXIMUM CONTINUOUS CURRENT 200 DEVICE IN DROPOUT MAXIMUM OUTPUT CURRENT (mA) 250 150 100 TA AT MAXIMUM JUNCTION TEMP (TJ = +150°C) TA =+ 5 = + 0°C = + 70°C 85 °C TA 50 0 0 1 2 3 4 5 6 INPUT-OUTPUT VOLTAGE DIFFERENTIAL (V) Figure 4.
PAGE 9
200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 Dropout Voltage A regulator’s minimum input-to-output voltage differential dropout voltage determines the lowest usable supply voltage for an application. In battery-powered systems, this determines the useful end-of-life battery voltage. Since the MAX1735’s pass element is an N-channel MOSFET, dropout voltage is the product of R DS(ON) and the load current; see Electrical Characteristics and Dropout Voltage vs.
PAGE 10
Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) SOT-23 5L .EPS MAX1735 200mA, Negative-Output, Low-Dropout Linear Regulator in SOT23 PACKAGE OUTLINE, SOT-23, 5L 21-0057 E 1 1 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.