Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - system monitor Dual voltage detector TQFN 16

General Description

The MAX6887/MAX6888 multivoltage supply supervi-

sors provide several voltage-detector inputs, one watch-

dog input, and three outputs. Each voltage-detector

input offers a factory-set undervoltage and overvoltage

threshold. Manual reset and margin disable inputs offer

additional flexibility.

The MAX6887 offers six voltage-detector inputs, while

the MAX6888 offers four inputs. Output RESET asserts

when any input voltage drops below its respective

undervoltage threshold or manual reset MR is asserted.

Output OV asserts when any input voltage exceeds its

respective overvoltage threshold. Monitor standard

supply voltages listed in the

Selector Guide

The MAX6887/MAX6888 offer a watchdog timer with an

initial and normal timeout periods of 102.4s and 1.6s,

respectively. Watchdog output WDO asserts when the

watchdog timer expires. Connect WDO to manual reset

input MR to generate resets when the watchdog timer

expires. RESET, OV, and WDO are active-low, open-

drain outputs.

The MAX6887/MAX6888 are available in a 5mm x 5mm

x 0.8mm, 16-pin thin QFN package and operate over

the extended -40°C to +85°C temperature range.

Applications

Multivoltage Systems

Telecom

Networking

Servers/Workstations/Storage Systems

Features

o Hex/Quad Voltage Detectors

o Undervoltage and Overvoltage Thresholds

o 1% Threshold Accuracy

o Margining Disable and Manual Reset Input

o Watchdog Timer

o Open-Drain RESET, OV, and WDO Outputs

o 180ms (min) Reset Timeout Period

o Few External Components

o Small 5mm x 5mm, 16-Pin Thin QFN Packages

MAX6887/MAX6888

Hex/Quad, Power-Supply Supervisory Circuits

________________________________________________________________

Maxim Integrated Products

PART TEMP RANGE PIN-PACKAGE

MAX6887_ETE+ -40°C to +85°C 16 Thin QFN-EP*

MAX6888_ETE+ -40°C to +85°C 16 Thin QFN-EP*

Ordering Information

Selector Guide

19-0291; Rev 2; 2/10

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

Pin Configurations and Typical Operating Circuit appear at

end of data sheet.

Note: Insert the desired letter from the Selector Guide into the

blank to complete the part number.

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

EP = Exposed pad.

NOMINAL INPUT VOLTAGE (V)*

PART

IN1 IN2 IN3 IN4 IN5 IN6

TOL

(%)

MAX6887AETE 5.0 3.3 2.5 1.8 Adj Adj 5

MAX6887BETE 5.0 3.3 2.5 Adj Adj Adj 5

MAX6887CETE 5.0 3.3 1.8 Adj Adj Adj 5

MAX6887DETE 3.3 2.5 1.8 1.5 Adj Adj 5

MAX6887EETE 3.3 2.5 1.8 Adj Adj Adj 5

MAX6887FETE 3.3 2.5 1.5 Adj Adj Adj 5

MAX6887GETE 3.3 2.5 Adj Adj Adj Adj 5

MAX6887HETE 3.3 1.8 Adj Adj Adj Adj 5

MAX6887QETE Adj Adj Adj Adj Adj Adj 5

NOMINAL INPUT VOLTAGE (V)*

PART

IN1 IN2 IN3 IN4 IN5 IN6

TOL

(%)

MAX6887IETE 5.0 3.3 2.5 1.8 Adj Adj 10

MAX6887JETE 5.0 3.3 2.5 Adj Adj Adj 10

MAX6887KETE 5.0 3.3 1.8 Adj Adj Adj 10

MAX6887LETE 3.3 2.5 1.8 1.5 Adj Adj 10

MAX6887METE 3.3 2.5 1.8 Adj Adj Adj 10

MAX6887NETE 3.3 2.5 1.5 Adj Adj Adj 10

MAX6887OETE 3.3 2.5 Adj Adj Adj Adj 10

MAX6887PETE 3.3 1.8 Adj Adj Adj Adj 10

MAX6887RETE Adj Adj Adj Adj Adj Adj 10

See thresholds options tables (Tables 1 and 2) for actual undervoltage and overvoltage thresholds.

Selector Guides continued at end of data sheet.

Summary of content (13 pages)

PAGE 1
9-0291; Rev 2; 2/10 Hex/Quad, Power-Supply Supervisory Circuits The MAX6887/MAX6888 multivoltage supply supervisors provide several voltage-detector inputs, one watchdog input, and three outputs. Each voltage-detector input offers a factory-set undervoltage and overvoltage threshold. Manual reset and margin disable inputs offer additional flexibility. The MAX6887 offers six voltage-detector inputs, while the MAX6888 offers four inputs.
PAGE 2
MAX6887/MAX6888 Hex/Quad, Power-Supply Supervisory Circuits ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) IN1–IN6, VCC, RESET, OV, WDO .............................-0.3V to +6V WDI, MR, MARGIN ...................................................-0.3V to +6V BP .............................................................................-0.3V to +3V Input/Output Current (all pins)..........................................
PAGE 3
Hex/Quad, Power-Supply Supervisory Circuits (VIN1–VIN4 or VCC = 2.7V to 5.8V, WDI = GND, MARGIN = MR = BP, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP VIL MR, MARGIN, WDI Input Voltage MR Input Pulse Width UNITS 0.6 VIH 1.
PAGE 4
Typical Operating Characteristics (continued) (VIN1–VIN4 or VCC = 5V, WDI = GND, MARGIN = MR = BP, TA = +25°C, unless otherwise noted.) 27 26 25 24 23 1.650 1.625 1.600 1.575 1.550 22 21 1.525 20 1.500 -40 -15 10 35 60 85 1.005 MAX6887 toc06 1.675 TIMEOUT PERIOD (s) 1.004 1.003 1.002 1.001 1.000 0.999 0.998 0.997 0.996 0.995 -40 -15 10 35 60 -40 85 -15 10 35 60 85 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) MAXIMUM IN_ TRANSIENT vs.
PAGE 5
Hex/Quad, Power-Supply Supervisory Circuits PIN MAX6887 MAX6888 5 5 NAME FUNCTION MR Manual Reset Input. Pull MR low to assert RESET. Connect MR to WDO to generate resets when the watchdog timer expires. Leave MR unconnected or connect to DBP if unused. MR is internally pulled up to BP through a 10µA current source. 6 6 MARGIN Margin Input.
PAGE 6
Hex/Quad, Power-Supply Supervisory Circuits MAX6887/MAX6888 Functional Diagram WDI *IN_ DETECTOR IN1 MARGIN MR IN2 IN2 DETECTOR IN3 IN3 DETECTOR IN4 IN4 DETECTOR IN5 (N.C.) IN6 (N.C.) IN5 DETECTOR RESET TIMING BLOCK OV OV TIMING BLOCK (VIRTUAL DIODES) IN6 DETECTOR LOGIC ARRAY RESET WDO WDO TIMING BLOCK VCC REFERENCE 1µF 2.55V LDO MAX6887 MAX6888 BP 1µF ( ) MAX6888 ONLY GND *FOR ADJUSTABLE INPUTS REFER TO THE ADJUSTABLE THRESHOLD INPUTS SECTION.
PAGE 7
Hex/Quad, Power-Supply Supervisory Circuits The MAX6887/MAX6888 provide several supply-detector inputs, one watchdog input, and three outputs for powersupply monitoring applications. The MAX6887 offers six voltage-detector inputs, while the MAX6888 offers four. Each voltage-detector input offers both an undervoltage and overvoltage threshold. The undervoltage and overvoltage thresholds are factory-set for monitoring standard supply voltages (see the Selector Guide).
PAGE 8
MAX6887/MAX6888 Hex/Quad, Power-Supply Supervisory Circuits detector input (IN1–IN6) to monitor a user-defined supply voltage: ⎛ R2 ⎞ 0.6V = VMON × ⎜ ⎟ ⎝ R1+ R2 ⎠ where VMON is the desired voltage to be monitored. Use the following procedure to design the proper voltage-divider and calculate thresholds: 1) Pick a value for R2. Use the equation above with the desired supply voltage to be monitored and solve for R1.
PAGE 9
Hex/Quad, Power-Supply Supervisory Circuits MAX6887/MAX6888 Table 2. MAX6888 Threshold Options PART UV THRESHOLDS (V) OV THRESHOLDS (V) IN1 IN2 IN3 IN4 IN1 IN2 IN3 IN4 MAX6888AETE 4.620 3.060 2.310 1.670 5.360 3.540 2.680 1.930 MAX6888BETE 4.620 3.060 2.310 0.557 5.360 3.540 2.680 0.643 MAX6888CETE 4.620 3.060 1.670 0.557 5.360 3.540 1.930 0.643 MAX6888DETE 3.060 2.310 1.670 1.390 3.540 2.680 1.930 1.610 MAX6888EETE 3.060 2.310 1.670 0.557 3.540 2.
PAGE 10
MAX6887/MAX6888 Hex/Quad, Power-Supply Supervisory Circuits OVERVOLTAGE THRESHOLD VIN PRIMARY THRESHOLD OV tOP RESET tRP Figure 2. Output Timing Diagram 2.5V . 2.5V VCC OR IN1–IN4 VCC OR IN1–IN4 WDO WDO RESET RESET WDI WDI tD-PO tRP *tWDI tWD *tWDI tD-PO tRP *tWDI WDO CONNECTED TO MR WDO NOT CONNECTED TO MR *tWDI IS THE INITIAL WATCHDOG TIMER PERIOD Figure 3.
PAGE 11
Hex/Quad, Power-Supply Supervisory Circuits Applications Information Selector Guide (continued) NOMINAL INPUT VOLTAGE (V)* PART TOLERANCE (%) IN1 IN2 IN3 IN4 MAX6888AETE 5.0 3.3 2.5 1.8 5 MAX6888BETE 5.0 3.3 2.5 Adj 5 MAX6888CETE 5.0 3.3 1.8 Adj 5 MAX6888DETE 3.3 2.5 1.8 1.5 5 MAX6888EETE 3.3 2.5 1.8 Adj 5 MAX6888FETE 3.3 2.5 1.5 Adj 5 MAX6888GETE 3.3 2.5 Adj Adj 5 5 MAX6888HETE 3.3 1.8 Adj Adj MAX6888QETE Adj Adj Adj Adj 5 MAX6888IETE 5.0 3.
PAGE 12
Hex/Quad, Power-Supply Supervisory Circuits IN6 BP VCC N.C. N.C. BP VCC 12 11 10 9 12 11 10 9 IN4 13 IN3 14 8 I.C. IN4 13 7 WDI IN3 14 IN1 16 *EXPOSED PAD 2 3 4 1 2 3 4 GND MR RESET 5 GND IN2 15 OV RESET 1 MARGIN WDO *EXPOSED PAD 6 OV IN2 15 IN1 16 8 I.C. 7 WDI 6 MARGIN 5 MR MAX6888 MAX6887 WDO TOP VIEW IN5 MAX6887/MAX6888 Pin Configurations THIN QFN THIN QFN *EXPOSED PAD CONNECTED TO GND. *EXPOSED PAD CONNECTED TO GND.
PAGE 13
Hex/Quad, Power-Supply Supervisory Circuits REVISION NUMBER REVISION DATE DESCRIPTION 0 5/05 Initial release 1 3/07 Revised Pin Description. 2 1/10 Revised Ordering Information to add lead-free information and revised Table 2. PAGES CHANGED — 1, 5, 14 1, 9 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.