Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - system monitor Reset/power-on reset SOIC 8

MAX709

Power-Supply Monitor with Reset

________________________________________________________________ Maxim Integrated Products 1

N.C.

RESET

N.C.

GND

N.C.

DIP/SO/µMAX

MAX709

__________________Pin Configuration

TOP VIEW

RESET

GND

µP

MAX709

RESET

__________Typical Operating Circuit

Call toll free 1-800-998-8800 for free samples or literature.

19-0136; Rev. 2; 12/05

_______________General Description

The MAX709 provides a system reset during power-up,

power-down, and brownout conditions. When V

falls

below the reset threshold, RESET goes low and holds

the µP in reset for 140ms min after V

rises above the

threshold.

The RESET output is guaranteed to be in the correct

state with V

down to 1V. The MAX709 provides

excellent circuit reliability and low cost by eliminating

external components and adjustments when used with

+5V, +3.3V, or +3V powered systems. The MAX709 is

available 8-pin DIP, µMAX, and SO packages.

_______________________Applications

Minimum Component Count,

Low-Cost Processor Systems

___________________________Features

♦ +5V, +3.3V, and +3V Versions

♦ No External Components

♦ Low Cost

♦ Precise Power-Down Reset Threshold

♦ 140ms Min Power-On Reset Delay

♦ Immune to Short Negative V

Transients

♦ 8-Pin DIP, µMAX, and SO Packages

♦ Low Supply Current: 35µA - MAX709R/S/T

65µA - MAX709L/M

______________Ordering Information

PART TEMP. RANGE PIN-PACKAGE

MAX709_CPA 0°C to +70°C

MAX709_CSA 0°C to +70°C 8 SO

MAX709_C/D 0°C to +70°C Dice

MAX709_EPA -40°C to +85°C 8 Plastic DIP

MAX709_ESA -40°C to +85°C 8 SO

8 Plastic DIP

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

Specify lead free by adding the + symbol at the end of the part

number when ordering.

*Dice are specified at T

= +25

°C

,DCparameters only.

Note: This part offers a choice of five different reset threshold

voltages. Select the letter corresponding to the desired

nominal reset threshold voltage, and insert it into the

blank to complete the part number.

RESET THRESHOLD

SUFFIX VOLTAGE (V)

L 4.65

M 4.40

T 3.08

S 2.93

R 2.63

MAX709_CUA 0°C to +70°C 8 µMAX

MAX709_EUA -40°C to +85°C 8 µMAX

Summary of content (8 pages)

PAGE 1
9-0136; Rev. 2; 12/05 Power-Supply Monitor with Reset The RESET output is guaranteed to be in the correct state with V CC down to 1V. The MAX709 provides excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, or +3V powered systems. The MAX709 is available 8-pin DIP, µMAX, and SO packages. ___________________________Features ♦ +5V, +3.
PAGE 2
MAX709 Power-Supply Monitor with Reset ABSOLUTE MAXIMUM RATINGS Terminal Voltage (with respect to GND) VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V RESET. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to (VCC + 0.3V) Input Current, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20mA Output Current, RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PAGE 3
Power-Supply Monitor with Reset POWER-UP RESET DELAY vs. TEMPERATURE POWER-DOWN RESET DELAY vs. TEMPERATURE 24 VCC = RESET THRESHOLD MAX, VCC RISING 250 POWER-DOWN RESET DELAY (µs) POWER-UP RESET DELAY (ms) 300 200 150 100 50 0 -20 20 60 8 4 VCC STEPPED FROM RESET THRESHOLD MAX TO RESET THRESHOLD MIN 100 -20 20 60 SUPPLY CURRENT vs. TEMPERATURE NORMALIZED RESET THRESHOLD vs. TEMPERATURE 100 1.
PAGE 4
MAX709 ____________________Pin Description PIN NAME 1, 4, 5, 6, 8 N.C. No Connect. There is no internal connection to this pin. 2 VCC +5V, +3.3V, or +3V Supply Voltage 3 GND Ground 7 RESET FUNCTION Reset Output remains low while VCC is below the reset threshold, and for 280ms after VCC rises above the reset threshold.
PAGE 5
Power-Supply Monitor with Reset MAX709 BUFFER BUFFERED RESET TO OTHER SYSTEM COMPONENTS VCC VCC VCC MAX709 RESET MAX709 RESET R1 µP 4.7k RESET GND GND Figure 2. RESET Valid to VCC = Ground Circuit GND Figure 3. Interfacing to µPs with Bidirectional Reset I/O Interfacing to µPs with Bidirectional Reset Pins Microprocessors with bidirectional reset pins (such as the Motorola 68HC11 series) can contend with the MAX709 reset output.
PAGE 6
MAX709 Power-Supply Monitor with Reset _____________________________________________________µP Supervisory Circuits Part Number Minimum Nominal Reset Reset Pulse Threshold Width (V) (ms) Nominal Watchdog Timeout Backup- CE Period Battery Write (sec) Switch Protect MAX690A/692A 4.65/4.40 140 1.6 ✔ MAX691A/693A 4.65/4.40 140/adj. 1.6/adj. ✔ MAX696 Adj. 35/adj. 1.6/adj. ✔ MAX697 Adj. 35/adj. 1.6/adj. MAX700 4.65/adj. 200 - MAX703/704 4.65/4.
PAGE 7
Power-Supply Monitor with Reset MAX709 ___________________Chip Topography V CC RESET 0.045" (1.143mm) GND 0.056" (1.
PAGE 8
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.) 4X S 8 E Ø0.50±0.1 8 INCHES DIM A A1 A2 b H c D e E H 0.6±0.1 1 L 1 α 0.6±0.1 S BOTTOM VIEW D MIN 0.002 0.030 MAX 0.043 0.006 0.037 0.014 0.010 0.007 0.005 0.120 0.116 0.0256 BSC 0.120 0.116 0.198 0.188 0.026 0.016 6° 0° 0.0207 BSC 8LUMAXD.