Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - system monitor Dual voltage detector SOT 23 6

General Description

The MAX6715A–MAX6729A/MAX6797A are ultra-low-volt-

age microprocessor (μP) supervisory circuits designed to

monitor two or three system power-supply voltages. These

devices assert a system reset if any monitored supply falls

below its factory-trimmed or adjustable threshold and main-

tain reset for a minimum timeout period after all supplies rise

above their thresholds. The integrated dual/triple superviso-

ry circuits significantly improve system reliability and reduce

size compared to separate ICs or discrete components.

These devices monitor primary supply voltages (V

CC1

)

from 1.8V to 5.0V and secondary supply voltages (V

from 0.9V to 3.3V with factory-trimmed reset threshold

voltage options (see the Reset Voltage Threshold Suffix

Guide). An externally adjustable RSTIN input option

allows customers to monitor a third supply voltage down

to 0.62V. These devices are guaranteed to be in the cor-

rect reset output logic state when either V

CC1

or V

CC2

remains greater than 0.8V.

A variety of push-pull or open-drain reset outputs along

with watchdog input, manual-reset input, and power-fail

input/output features are available (see the Selector

Guide). Select reset timeout periods from 1.1ms to

1120ms (min) (see the Reset Timeout Period Suffix

Guide). The MAX6715A–MAX6729A/MAX6797A are

available in small 5-, 6-, and 8-pin SOT23 packages and

operate over the -40°C to +125°C temperature range.

Applications

● Multivoltage Systems

● Telecom/Networking

Equipment

● Computers/Servers

● Portable/Battery-

Operated Equipment

● Industrial Equipment

● Printers/Fax Machines

● Set-Top Boxes

Features

● V

CC1

(Primary Supply) Reset Threshold Voltages

from 1.58V to 4.63V

● V

CC2

(Secondary Supply) Reset Threshold Voltages

from 0.79V to 3.08V

● Externally Adjustable RSTIN Threshold for Auxiliary/

Triple-Voltage Monitoring (0.62V Internal Reference)

● Watchdog Timer Option

• 35s (min) Long Startup Period

• 1.12s (min) Normal Timeout Period

● Manual-Reset Input Option

● Power-Fail Input/Power-Fail Output Option

(Push-Pull and Open-Drain Active-Low)

● Guaranteed Reset Valid Down to V

CC1

CC2

= 0.8V

● Reset Output Logic Options

● Immune to Short V

Transients

● Low Supply Current 14μA (typ) at 3.6V

● Watchdog Disable Feature

● Small 5-, 6-, and 8-Pin SOT23 Packages

Ordering Information continued at end of data sheet.

Pin Configurations and Selector Guide appear at end of

data sheet.

19-0536; Rev 4; 3/14

Note: The first “_ _” are placeholders for the threshold voltage

levels of the devices. Desired threshold levels are set by the part

number suffix found in the Reset Voltage Threshold Suffix Guide.

The “_” after the D is a placeholder for the reset timeout delay

time. Desired delay time is set using the timeout period suffix

found in the Reset Timeout Period Suffix Guide. For example,

the MAX6716AUTLTD3-T is a dual-voltage supervisor V

TH1

4.625V, V

TH2

= 3.075V, and 210ms (typ) timeout period.

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

/V denotes an automotive qualified part.

*Future product—contact factory for availability.

PART TEMP RANGE

PIN-

PACKAGE

MAX6715AUT_ _D_+T -40°C to +125°C 6 SOT23

MAX6716AUT_ _D_+T -40°C to +125°C 6 SOT23

MAX6717AUK_ _D_+T -40°C to +125°C 5 SOT23

MAX6718AUK_ _D_+T -40°C to +125°C 5 SOT23

MAX6719AUT_ _D_+T -40°C to +125°C 6 SOT23

MAX6719AUT_ _D_/V+T* -40°C to +125°C 6 SOT23

OUT2

OUT1

DC-DC

CONVERTER

UNREGULATED

CC1

CC2

RSTIN/PFI

RST

WDI

PFO

MAX67_ _

PUSHBUTTON

SWITCH

I/O

SUPPLY

CORE

SUPPLY

RESET

I/O

NMI

µP

1.8V 0.9V

MAX6715A-

MAX6729A/

MAX6797A

MAX6715A–MAX6729A/

MAX6797A

Dual/Triple, Ultra-Low-Voltage, SOT23 μP

Supervisory Circuits

Typical Operating Circuit

Ordering Information

Summary of content (18 pages)

PAGE 1
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits General Description The MAX6715A–MAX6729A/MAX6797A are ultra-low-voltage microprocessor (μP) supervisory circuits designed to monitor two or three system power-supply voltages. These devices assert a system reset if any monitored supply falls below its factory-trimmed or adjustable threshold and maintain reset for a minimum timeout period after all supplies rise above their thresholds.
PAGE 2
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Absolute Maximum Ratings Terminal Voltage (with respect to GND) VCC1, VCC2..........................................................-0.3V to +6V Open-Drain RST, RST1, RST2, PFO, RST.............-0.3V to +6V Push-Pull RST, RST1, PFO, RST........... -0.3V to (VCC1 + 0.3V) Push-Pull RST2....................................... -0.3V to (VCC2 + 0.3V) RSTIN, PFI, MR, WDI..............................................-0.
PAGE 3
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Electrical Characteristics (continued) (VCC1 = 0.8V to 5.5V, VCC2 = 0.8V to 5.5V, GND = 0V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Reset Threshold Tempco Reset Threshold Hysteresis VCC to Reset Output Delay SYMBOL CONDITIONS TYP VHYST tRD tRP MAX UNITS 20 ppm/°C Referenced to VTH typical 0.
PAGE 4
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Electrical Characteristics (continued) (VCC1 = 0.8V to 5.5V, VCC2 = 0.8V to 5.5V, GND = 0V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 5
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Typical Operating Characteristics (VCC1 = 5V, VCC2 = 3.3V, TA = +25°C, unless otherwise noted.) 6 2 NORMALIZED/RESET WATCHDOG TIMEOUT PERIOD vs. TEMPERATURE 8 TOTAL ICC1 6 4 2 0 ICC2 1.008 MAX6715A-29A toc03 ICC2 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) MAXIMUM VCC TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVE 1.004 1.000 0.996 0.992 0.988 0.
PAGE 6
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Typical Operating Characteristics (continued) (VCC1 = 5V, VCC2 = 3.3V, TA = +25°C, unless otherwise noted.) 22 20 18 16 30mV OVERDRIVE 1.9 1.8 1.7 MR TO RESET OUTPUT DELAY MAX6715A-29A toc12 VMR 2V/div 0V 1.6 1.5 1.4 1.3 VRST 2V/div 1.2 14 12 2.0 MAX6715A-29A toc11 30mV OVERDRIVE POWER-FAIL INPUT TO POWER-FAIL OUTPUT DELAY vs.
PAGE 7
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Pin Description (continued) PIN MAX6728A/ NAME MAX6715A/ MAX6717A/ MAX6719A/ MAX6721A/ MAX6723A/ MAX6725A/ MAX6727A MAX6729A/ MAX6716A MAX6718A MAX6720A MAX6722A MAX6724A MAX6726A MAX6797A FUNCTION 5 — — — — — — — Active-Low Reset Output, Open-Drain or Push-Pull. RST2 changes from high to low when VCC1 or VCC2 drops below the selected reset thresholds or MR is pulled low.
PAGE 8
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Pin Description (continued) PIN MAX6728A/ NAME MAX6715A/ MAX6717A/ MAX6719A/ MAX6721A/ MAX6723A/ MAX6725A/ MAX6727A MAX6729A/ MAX6716A MAX6718A MAX6720A MAX6722A MAX6724A MAX6726A MAX6797A — — — — www.maximintegrated.com — 5 5 — 3 5 3 7 3 7 3 — WDI FUNCTION Watchdog Input.
PAGE 9
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Pin Description (continued) PIN MAX6728A/ NAME MAX6715A/ MAX6717A/ MAX6719A/ MAX6721A/ MAX6723A/ MAX6725A/ MAX6727A MAX6729A/ MAX6716A MAX6718A MAX6720A MAX6722A MAX6724A MAX6726A MAX6797A — — — — — — www.maximintegrated.com — — — — — — — — — — — 4 — — — 7 4 — FUNCTION PFI Power-Fail Voltage Monitor Input. Highimpedance input for internal power-fail monitor comparator.
PAGE 10
MAX6715A–MAX6729A/ MAX6797A Detailed Description Supply Voltages The MAX6715A–MAX6729A/MAX6797A μP supervisory circuits maintain system integrity by alerting the μP to fault conditions. These ICs are optimized for systems that monitor two or three supply voltages. The outputreset state is guaranteed to remain valid while either VCC1 or VCC2 is above 0.8V. Threshold Levels Input-voltage threshold level combinations are indicated by a two-letter code in the Reset Voltage Threshold Suffix Guide (Table 1).
PAGE 11
MAX6715A–MAX6729A/ MAX6797A The normal watchdog timeout period (1.12s min) begins after the first transition on WDI before the conclusion of the long initial watchdog period (Figure 2). During the normal operating mode, the supervisor will issue a reset pulse for the reset timeout period if the μP does not update the WDI with a valid transition (high-to-low or lowto-high) within the standard timeout period (1.12s min). Leave WDI unconnected to disable the watchdog timer.
PAGE 12
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Applications Information Interfacing to μPs with Bidirectional Reset Pins Most μPs with bidirectional reset pins can interface directly to open-drain RST output options. Systems simultaneously requiring a push-pull RST output and a bidirectional reset interface can be in logic contention. To prevent contention, connect a 4.7kΩ resistor between RST and the μP’s reset I/O port as shown in Figure 4.
PAGE 13
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits magnitude indicated (reset threshold overdrive). The graph shows the maximum pulse width that a negativegoing VCC transient may typically have without causing a reset pulse to be issued. As the amplitude of the transient increases (i.e., goes farther below the reset threshold), the maximum allowable pulse width decreases. A 0.1μF bypass capacitor mounted close to the VCC pin provides additional transient immunity.
PAGE 14
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Functional Diagram VCC1 VCC1 MR MR PULLUP VCC1 VCC1 VREF RESET TIMEOUT PERIOD VCC2 VCC2 RST RESET OUTPUT DRIVER RST RSTIN/PFI PFO VCC1 VREF VCC1 WATCHDOG TIMER WDI VREF/2 www.maximintegrated.
PAGE 15
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Selector Guide PART NUMBER NUMBER OF VOLTAGE MONITORS OPENDRAIN RESET OPENDRAIN RESET PUSHPULL RESET PUSHPULL RESET MANUAL RESET WATCHDOG INPUT POWER-FAIL INPUT/ OUTPUT MAX6715A MAX6716A 2 2 — — — √ — — 2 — — 2 — √ — — MAX6717A 2 1 — — — √ — — MAX6718A 2 — — 1 — √ — — MAX6719A 3 1 — — — √ — — MAX6720A 3 — — 1 — √ — — MAX6721A 2 1 — — — √ √ — MAX67
PAGE 16
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Table 1. Reset Voltage Threshold Suffix Guide** PART NUMBER SUFFIX (_ _) VCC1 NOMINAL VOLTAGE THRESHOLD (V) VCC2 NOMINAL VOLTAGE THRESHOLD (V) LT 4.625 3.075 MS 4.375 2.925 MR 4.375 2.625 TZ 3.075 2.313 SY 2.925 2.188 RY 2.625 2.188 TW 3.075 1.665 SV 2.925 1.575 RV 2.625 1.575 TI 3.075 1.388 SH 2.925 1.313 RH 2.625 1.313 TG 3.075 1.110 SF 2.925 1.050 RF 2.625 1.
PAGE 17
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Pin Configurations TOP VIEW + + RST1 1 GND 2 6 VCC1 RST 1 MAX6715A/ MAX6716A 5 RST2 GND 2 MR 3 4 VCC2 GND 2 VCC1 MAX6717A/ MAX6718A MR 3 + 6 VCC1 RST 1 MAX6721A/ MAX6722A 5 WDI 4 GND 2 VCC2 + VCC2 6 WDI 3 GND 2 WDI 3 + MAX6727A RST 4 VCC1 4 VCC2 MR 3 4 VCC2 + RST 1 GND 2 WDI MAX6725A/ MAX6726A 3 RST 4 8 VCC1 7 RSTIN 6 VCC2 5 MR SOT23 8 VCC1 RST 1 7 RSTIN GND 2
PAGE 18
MAX6715A–MAX6729A/ MAX6797A Dual/Triple, Ultra-Low-Voltage, SOT23 μP Supervisory Circuits Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 4/06 Initial release 1 7/06 Updated Ordering Information 2 6/08 Added the MAX6797A to Ordering Information, Electrical Characteristics, Pin Description, Detailed Description, Figures 4 and 5, Selector Guide, Table 2, Pin Configurations 3 9/08 Updated Selector Guide 15 4 3/14 Added automotive part to the Ordering Information table 1 DES