Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - system monitor Reset/power-on reset SOT 23 6

General Description

The MAX6342–MAX6345 family of microprocessor (µP)

supervisory circuits monitors power supplies in digital sys-

tems. These devices significantly improve system reliabili-

ty and accuracy compared to separate ICs or discrete

components.

The MAX6342–MAX6345 provide factory-trimmed V

reset threshold voltages from 2.33V to 4.63V and operate

with supply voltages between +1V and +5.5V. A +1.25V

threshold detector allows for a power-fail warning, for

low-battery detection, or for monitoring another power

supply. The MAX6342 contains an MR input and an

active-low push-pull reset. The MAX6343 and MAX6344

are identical to the MAX6342 except they provide an

active-low, open-drain reset and an active-high, push-

pull reset, respectively. The MAX6345 provides a second

reset output in place of the MR input to give it an active-

high push-pull reset and an active-low push-pull reset.

All of the devices are packaged in a miniature 6-pin

SOT23.

Applications

Portable Computers

Telecom Equipment

Networking Equipment

Portable/Battery-Powered Equipment

Multivoltage Systems

Embedded Control Systems

Features

♦ Small 6-Pin SOT23 Package

♦ Precision Factory-Set V

Reset Thresholds

Between 2.33V and 4.63V

♦ Guaranteed RESET Valid to V

= +1V

♦ 100ms min Reset Pulse Width

♦ Debounced CMOS-Compatible Manual-Reset

Input

♦ Voltage Monitor for Power-Fail or Low-Battery

Warning

MAX6342–MAX6345

6-Pin µP Reset Circuit with

Power-Fail Comparator

________________________________________________________________ Maxim Integrated Products 1

GND

PFI

( ) ARE FOR MAX6344 ONLY.

TOP VIEW

RESET (RESET)

PFO

MAX6342

MAX6343

MAX6344

SOT23-6

Selector Guide 1

Selector Guide 2

19-1568; Rev 2; 12/05

PART

MAX6342_UT-T

MAX6343_UT-T

MAX6344_UT-T

-40°C to +125°C

TEMP RANGE PIN-PACKAGE

6 SOT23-6

Note: The MAX6342–MAX6345 are available with factory-set

reset thresholds from 2.33V to 4.63V (see Selector Guides 1, 2).

Insert the letter corresponding to the desired nominal reset

threshold into the blank following the part number. There is a

2500 piece order increment required for the SOT package. SOT

Top Marks table appears at end of data sheet.

Devices are available in both leaded and lead-free packaging.

Specify lead-free by replacing “-T” with “+T” when ordering.

Pin Configurations

Ordering Information

MAX6345_UT-T

-40°C to +125°C 6 SOT23-6

PART

PUSH-PULL

RESET OUTPUT

OPEN-DRAIN

RESET OUTPUT

PUSH-PULL RESET

OUTPUT

MAX6342

✔

— —

MAX6343 —

✔

—

MAX6344 — —

✔

MAX6345

✔

—

✔

MANUAL-RESET

INPUT

✔

—

Typical Operating Circuit appears at end of data sheet.

Pin Configurations continued at end of data sheet.

SUFFIX

RESET THRESHOLD (V)

4.63

M 4.38

T 3.08

S 2.93

R 2.63

Z 2.33

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 (8 pages)

PAGE 1
9-1568; Rev 2; 12/05 6-Pin µP Reset Circuit with Power-Fail Comparator Features The MAX6342–MAX6345 family of microprocessor (µP) supervisory circuits monitors power supplies in digital systems. These devices significantly improve system reliability and accuracy compared to separate ICs or discrete components. The MAX6342–MAX6345 provide factory-trimmed VCC reset threshold voltages from 2.33V to 4.63V and operate with supply voltages between +1V and +5.5V. A +1.
PAGE 2
MAX6342–MAX6345 6-Pin µP Reset Circuit with Power-Fail Comparator ABSOLUTE MAXIMUM RATINGS VCC to GND ..............................................................-0.3V to +6V RESET, RESET (MAX6342/MAX6344/MAX6345) ......... -0.3V to (VCC + 0.3V) RESET (MAX6343)................................................... -0.3V to +6V MR, PFI, PFO ..............................................-0.3V to (VCC + 0.3V) Input Current, VCC ..............................................................
PAGE 3
6-Pin µP Reset Circuit with Power-Fail Comparator MAX6342–MAX6345 ELECTRICAL CHARACTERISTICS (continued) (VCC = +1.0V to +5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C and VCC = +3V.
PAGE 4
Typical Operating Characteristics (continued) (VPFI = VCC = +5V, TA = +25°C, unless otherwise noted.) PFO OUTPUT-VOLTAGE LOW vs. SUPPLY VOLTAGE PFO OUTPUT-VOLTAGE HIGH vs. SUPPLY VOLTAGE RL = 10kΩ 5 MAX6342-05 0.60 MAX6342-04 6 RL = 1kΩ 0.55 0.50 4 0.45 PFO (V) PFO (V) 3 0.40 0.35 2 0.30 1 0.25 0.
PAGE 5
6-Pin µP Reset Circuit with Power-Fail Comparator PIN MAX6342 MAX6343 MAX6344 NAME FUNCTION Manual-Reset Input. Pull low to force a reset. RESET or RESET remains active as long as MR is low and for the reset timeout period after MR goes high. Leave unconnected or connect to VCC if unused. MAX6345 5 5 5 — MR 6 6 — 5 RESET Active-Low Reset Output. Push-pull for MAX6342/MAX6345. Open-drain for MAX6343.
PAGE 6
160 +5.0V +3.3V VCC 10kΩ VCC µP RESET RESET MAX6343 MAXIMUM TRANSIENT DURATION (µs) MAX6342–MAX6345 6-Pin µP Reset Circuit with Power-Fail Comparator 140 120 100 80 MAX634_L/M 60 40 MAX634_T/S/R/Z 20 0 GND 1 10 100 1000 RESET COMPARATOR OVERDRIVE, VTH - VCC (mV) Figure 3. Open-Drain RESET Output Allows Use with Multiple Supplies VCC VCC VCC GND MAX6342 MAX6345 100kΩ RESET VCC RESET GND MAX6344 100kΩ Figure 5.
PAGE 7
6-Pin µP Reset Circuit with Power-Fail Comparator BUFFERED RESET TO OTHER SYSTEM COMPONENTS RESET (RESET) VCC R1 PFI R2 TO µP VCC MAX6342 MR MAX6343 MAX6344 VCC µP MAX6342 MAX6345 PFO GND 4.7kΩ RESET ( ) ARE FOR MAX6344 ONLY. RESET GND GND Figure 7. Monitoring Two Supplies VCC Figure 9. Interfacing to µPs with Bidirectional Reset I/O Monitoring a Negative Voltage R1 VCC 100kΩ MR MAX6342 MAX6343 PFO PFI MAX6344 100kΩ R2 GND V- RESET (RESET) VCC - 1.25V = 1.
PAGE 8
Typical Operating Circuit UNREGULATED DC Pin Configurations (continued) TOP VIEW LINEAR REGULATOR VCC 1 VCC PFI RESET MAX6342 MR PFO VCC GND 2 RESET µP PFI 3 INTERRUPT MAX6345 6 RESET 5 RESET 4 PFO SOT23-6 Chip Information PUSHBUTTON SWITCH TRANSISTOR COUNT: 403 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.) 6LSOT.