Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - system monitor Reserve capacity circuit SOIC 16

General Description

The MAX691A/MAX693A/MAX800L/MAX800M micro-

processor (μP) supervisory circuits are pin-compatible

upgrades to the MAX691, MAX693, and MAX695. They

improve performance with 30μA supply current, 200ms

typ reset active delay on power-up, and 6ns chip-enable

propagation delay. Features include write protection

of CMOS RAM or EEPROM, separate watchdog out-

puts, backup-battery switchover, and a RESET output

that is valid with V

down to 1V. The MAX691A/

MAX800L have a 4.65V typical reset-threshold voltage,

and the MAX693A/MAX800Ms’ reset threshold is 4.4V

typical. The MAX800L/MAX800M guarantee power-fail

accuracies to ±2%.

Applications

● Computers

● Controllers

● Intelligent Instruments

● Critical μP Power Monitoring

Features

● 200ms Power-OK/Reset Timeout Period

● 1μA Standby Current, 30μA Operating Current

● On-Board Gating of Chip-Enable Signals, 10ns max

Delay

● MaxCap

or SuperCap Compatible

● Guaranteed RESET Assertion to V

= +1V

● Voltage Monitor for Power-Fail or Low-Battery

Warning

● Power-Fail Accuracy Guaranteed to ±2%

(MAX800L/M)

● Available in 16-Pin Narrow SO, Plastic DIP, and

TSSOP Packages

Ordering Information continued at end of data sheet.

19-0094; Rev 12; 9/14

MaxCap is a registered trademark of Kanthal Globar, Inc.

*Dice are specified at T

= +25°C, DC parameters only.

Devices in PDIP, SO, and TSSOP packages are available in

both leaded and lead-free packaging. Specify lead free by add-

ing the + symbol at the end of the part number when ordering.

Lead free not available for CERDIP package.

PART TEMP RANGE

PIN-

PACKAGE

MAX691ACUE -0°C to +70°C 16 TSSOP

MAX691ACSE -0°C to +70°C 16 Narrow SO

MAX691ACWE -0°C to +70°C 16 Wide SO

MAX691ACPE -0°C to +70°C 16 Plastic DIP

MAX691AC/D -0°C to +70°C Dice*

MAX691AEUE -0°C to +70°C 16 TSSOP

MAX691AESE -40°C to +85°C 16 Narrow SO

MAX691AEWE -40°C to +85°C 16 Wide SO

MAX691AEPE -40°C to +85°C 16 Plastic DIP

MAX691A

MAX693A

MAX800L

MAX800M

OUT

BATT ON

CE OUT

CE IN

WDI

PFO

RESET

VBATT

PFI

GND

OSC IN

OSC SEL

ADDRESS

DECODE

AUDIBLE

ALARM

REGULATOR

+8V

0.1µF

CMOS RAM

A0-A15

I/O

NMI

RESET

µP

LOW LINE WDO

SYSTEM STATUS INDICATORS

CONNECTION

0.47F*

1N4148

*MaxCap

6 14

RESET

WDO

CE IN

GND

OUT

VBATT

TOP VIEW

MAX691A

MAX693A

MAX800L

MAX800M

CE OUT

WDI

PFO

PFI

OSC SEL

OSC IN

LOW LINE

BATT ON

DIP/SO/TSSOP

MAX691A/MAX693A/

MAX800L/MAX800M

Microprocessor Supervisory Circuits

Ordering Information

Typical Operating Circuit

Pin Conguration

Summary of content (17 pages)

PAGE 1
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits General Description Features Applications Ordering Information The MAX691A/MAX693A/MAX800L/MAX800M microprocessor (μP) supervisory circuits are pin-compatible upgrades to the MAX691, MAX693, and MAX695. They improve performance with 30μA supply current, 200ms typ reset active delay on power-up, and 6ns chip-enable propagation delay.
PAGE 2
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Absolute Maximum Ratings Terminal Voltage (with respect to GND) VCC......................................................................-0.3V to +6V VVBATT.................................................................-0.3V to +6V All Other Inputs....................................-0.3V to (VOUT + 0.3V) Input Current VCC Peak..........................................................................1.0A VCC Continuous.................
PAGE 3
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Electrical Characteristics (continued) (MAX691A, MAX800L: VCC = +4.75V to +5.5V; MAX693A, MAX800M: VCC = +4.5V to +5.5V; VVBATT = 2.8V, TA = TMIN to TMAX, unless otherwise noted. PARAMETER CONDITIONS MIN Battery Switchover Hysteresis TYP MAX 60 UNITS mV BATT ON Output Low Voltage ISINK = 3.2mA 0.1 0.4 0.7 1.5 BATT ON Output Short-Circuit Current Sink current 60 100 mA 1 15 100 µA MAX691A, MAX800L 4.50 4.65 4.
PAGE 4
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Electrical Characteristics (continued) (MAX691A, MAX800L: VCC = +4.75V to +5.5V; MAX693A, MAX800M: VCC = +4.5V to +5.5V; VVBATT = 2.8V, TA = TMIN to TMAX, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX 1.2 1.25 1.3 1.225 1.25 1.275 ±0.
PAGE 5
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) 28 -30 0 30 60 90 120 0 150 TEMPERATURE (°C) -60 VBATT to VOUT ON-RESISTANCE vs. TEMPERATURE VBATT = 2.8V 10 VBATT = 4.5V VCC = 0V -60 4.75 RESET THRESHOLD (V) 4.70 -30 0 30 60 90 120 -30 -60 -30 0 MAX691A toc03 60 30 120 150 180 TEMPERATURE (°C) VCC to VOUT ON-RESISTANCE vs. TEMPERATURE PFI THRESHOLD vs.
PAGE 6
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Typical Operating Characteristics (continued) 12 8 4 3 2 4 5 SHORT WATCHDOG TIMEOUT PERIOD 10 100 16 8 4 0 1000 0 50 100 150 200 VCC TO VOUT vs. OUTPUT CURRENT (NORMAL OPERATING MODE) VBATT TO VOUT vs. OUTPUT CURRENT (BATTERY-BACKUP MODE) VCC TO LOW LINE AND CE OUT DELAY SLOPE = 0.8Ω 1000 VCC = 0V VBATT = 4.5V 100 HI LOW LINE LO HI SLOPE = 8Ω 10 10 100 IOUT (mA) www.maximintegrated.
PAGE 7
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Pin Description PIN NAME 1 VBATT 2 VOUT 3 4 VCC GND FUNCTION Battery-Backup Input. Connect to external battery or capacitor and charging circuit. If backup battery is not used, connect to GND. Output Supply Voltage. When VCC is greater than VBATT and above the reset threshold, VOUT connects to VCC. When VCC falls below VBATT and is below the reset threshold, VOUT connects to VBATT. Connect a 0.1µF capacitor from VOUT to GND.
PAGE 8
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits WDI RESET 15 MAX691A MAX693A TO µP RESET WDO 1kΩ t2 RESET t1 t1 t3 t1 = RESET TIMEOUT PERIOD t2 = NORMAL WATCHDOG TIMEOUT PERIOD t3 = WATCHDOG TIMEOUT PERIOD IMMEDIATELY AFTER RESET Figure 1. Adding an external pulldown resistor ensures RESET is valid with VCC down to GND. Figure 2. Watchdog Timeout Period and Reset Active Time For battery voltages ≥ 2V connected to VBATT, RESET and RESET remain valid for VCC from 0V to 5.
PAGE 9
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Table 1. Reset Pulse Width and Watchdog Timeout Selections WATCHDOG TIMEOUT PERIOD NORMAL IMMEDIATELY AFTER RESET RESET TIMEOUT PERIOD External Clock Input 1024 clks 4096 clks 2048 clks OSC SEL OSC IN Low Low External Capacitor (600/47pF x C)ms (2.4/47pF x C)sec (1200/47pF x C)ms Floating Low 100ms 1.6s 200ms Floating Floating 1.6s 1.
PAGE 10
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits 5 BATT ON 4.65V* VCC 6 3 2 VBATT CE IN OSC IN OSC SEL WDI PFI LOW LINE CHIP-ENABLE OUTPUT CONTROL 1 13 12 16 MAX691A MAX693A MAX800L MAX800M 7 TIMEBASE FOR RESET AND WATCHDOG 8 WATCHDOG TRANSITION DETECTOR 11 9 RESET GENERATOR 15 WATCHDOG TIMER 14 10 VOUT CE OUT RESET RESET WDO PFO 1.25V 4 GND * 4.4V FOR THE MAX693A/MAX800M Figure 4. MAX691A/MAX693A/MAX800L/MAX800M Block Diagram 5.0V VCC RESET 4.
PAGE 11
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits +5V +5V VBATT VCC VBATT MAX691A MAX693A MAX800L MAX800M 2.8V CE OUT CE IN 50Ω OUTPUT IMPEDANCE 2.0V to 5.5V GND VCC MAX691A MAX693A MAX800L PFI MAX800M PFO GND CLOAD Figure 6. CE Propagation Delay Test Circuit Figure 7. Low-Battery Indicator Table 2. Input and Output Status in Battery-Backup Mode Power-Fail Input PIN NAME 1 VBATT 2 VOUT VOUT is connected to VBATT through an internal PMOS switch.
PAGE 12
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits load for currents less than 250mA. The parallel diode carries any current in excess of 250mA. Both the switch and the diode have impedances less than 1Ω each. The maximum continuous current is 250mA, but power-on transients may reach a maximum of 1A. Battery-Backup Input The Battery-Backup Input (VBATT) is similar to the VCC input except the PMOS switch and parallel diode are much smaller.
PAGE 13
MAX691A/MAX693A/ MAX800L/MAX800M VIN Rp* CE CE VOUT CE IN Microprocessor Supervisory Circuits RAM 1 +5V R1 C1* CE OUT CE MAX691A MAX693A MAX800L MAX800M CE RAM 2 R3 R2 CE CE CE MAX691A MAX693A MAX800L MAX800M PFO CE GND VCC PFI RAM 3 GND TO µP *OPTIONAL 5V RAM 4 PFO 0V VL VTRIP VH VIN 0V VTRIP = 1.25 *MAXIMUM Rp VALUE DEPENDS ON THE NUMBER OF RAMS. MINIMUM Rp VALUE IS 1kΩ. ACTIVE-HIGH CE LINES FROM LOGIC Figure10. Alternate CE Gating VH = 1.
PAGE 14
MAXIMUM TRANSIENT DURATION (µs) 100 Microprocessor Supervisory Circuits VCC = 5V TA = +25°C 0.1µF CAPACITOR FROM VOUT TO GND 80 MAX791-16 MAX691A/MAX693A/ MAX800L/MAX800M 60 Backup-Battery Replacement The backup battery may be disconnected while VCC is above the reset threshold. No precautions are necessary to avoid spurious reset pulses. Negative-Going VCC Transients 40 20 0 accuracy is affected by the PFI threshold tolerance, the VCC voltage, and resistors R1 and R2.
PAGE 15
MAX691A/MAX693A/ MAX800L/MAX800M lems, minimize external current leakage sources at this pin, and locate the capacitor as close to OSC IN as possible. The sum of PC-board leakage plus OSC capacitor leakage must be small compared to ±100nA. Microprocessor Supervisory Circuits START Maximum VCC Fall Time The VCC fall time is limited by the propagation delay of the battery switchover comparator and should not exceed 0.03V/μs.
PAGE 16
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Ordering Information (continued) PART TEMP RANGE MAX691AEJE MAX691AMJE MAX691AMSE/PR MAX691AMSE/PR-T MAX693ACUE MAX693ACSE MAX693ACWE MAX693ACPE MAX693AC/D MAX693AEUE MAX693AESE MAX693AEWE MAX693AEPE MAX693AEJE MAX693AMJE MAX800LCUE MAX800LCSE MAX800LCPE MAX800LEUE MAX800LESE MAX800LEPE MAX800MCUE MAX800MCSE MAX800MCPE MAX800MEUE MAX800MESE MAX800MEPE -40°C to +85°C -55°C to +125°C -55°C to +125°C -55°C to +125°C -0°C to +70°C -0°C to
PAGE 17
MAX691A/MAX693A/ MAX800L/MAX800M Microprocessor Supervisory Circuits Revision History REVISION NUMBER REVISION DATE 0 09/92 Initial release 1 12/92 Update Electrical Characteristics table. 2 5/93 Update Electrical Characteristics table, Tables 1 and 2. 3 12/93 Update Electrical Characteristics table. 2, 3, 4 4 3/94 Update Electrical Characteristics table. 2, 3, 4 5 8/94 Correction to Figure 4. 10 6 1/95 Update to new revision and correct errors.