Rainbow Electronics MAX6871 User Manual

General Description

The MAX6870/MAX6871 EEPROM-configurable, multi­voltage supply sequencers/supervisors monitor several
voltage detector inputs, two auxiliary inputs, and four
general-purpose logic inputs. The MAX6870/MAX6871
feature programmable outputs for highly configurable
power-supply sequencing applications. The MAX6870
features six voltage detector inputs and eight program­mable outputs, while the MAX6871 features four voltage
detector inputs and five programmable outputs. Manual
reset and margin disable inputs offer additional flexibility.

All voltage detectors offer two configurable thresholds
for undervoltage/overvoltage or dual undervoltage
detection. One high voltage input (IN1) provides detec­tor threshold voltages from +2.5V to +13.2V in 50mV
increments, or from +1.25V to +7.625V in 25mV incre­ments. A bipolar input (IN2) provides detector threshold
voltages from ±2.5V to ±15.25V in 50mV increments, or
from ±1.25V to ±7.625V in 25mV increments. Positive
inputs (IN3–IN6) provide detector threshold voltages
from +1V to +5.5V in 20mV increments, or from +0.5V
to +3.05V in 10mV increments.

Programmable output stages control power-supply
sequencing or system resets/interrupts. Programmable
output options include: active-high, active-low, open­drain, weak pullup, push-pull, and charge pump.
Programmable timing delay blocks configure each output
to wait between 25µs and 1600ms before deasserting. A
fault register logs the condition that caused each output
to assert (undervoltage, overvoltage, manual reset, etc.).

An internal 10-bit ADC monitors the voltage detector
inputs, and two auxiliary inputs through a multiplexer
that automatically sequences through all inputs every
200ms. A SMBusTM-/I2CTM-compatible, serial data inter­face programs and communicates with the configuration
EEPROM, the configuration registers, the internal 4kb
user EEPROM, the ADC registers, and the fault registers
of the MAX6870/MAX6871.

The MAX6870/MAX6871 are available in a 7mm x 7mm
x 0.8mm 32-pin thin QFN package and operate over
the extended -40°C to +85°C temperature range.

Applications

Telecommunications/Central Office Systems
Networking Systems
Servers/Workstations
Basestations
Storage Equipment
Multimicroprocessor/Voltage Systems

Features

♦ Six (MAX6870) or Four (MAX6871) Configurable

Input Voltage Detectors

One High Voltage Input (+1.25V to +7.625V or

+2.5V to +13.2V Thresholds)

One Bipolar Voltage Input (±1.25V to ±7.625V

or ±2.5V to ±15.25V Thresholds)

Four (MAX6870) or Two (MAX6871) Positive

Voltage Inputs (+0.5V to +3.05V or +1V to
+5.5V Thresholds)

♦ Four General-Purpose Logic Inputs

♦ Two Configurable Watchdog Timers

♦ Eight (MAX6870) or Five (MAX6871)

Programmable Outputs

Active-High, Active-Low, Open-Drain, Weak

Pullup, Push-Pull, Charge-Pump

Timing Delays from 25µs to 1600ms

♦ 10-Bit Internal ADC Monitors the Input Voltage

Detectors and Two Auxiliary Inputs

♦ Margining Disable and Manual Reset Controls

♦ Internal 1.25V Reference or External Reference

Input

♦ 4kb Internal User EEPROM

Endurance: 100,000 Erase/Write Cycles
Data Retention: 10 Years

♦ I2C/SMBus-Compatible Serial

Configuration/Communication Interface

♦ ±1% Threshold Accuracy

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad

Power-Supply Sequencers/Supervisors with ADC

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-3384; Rev 1; 9/04

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.

EVALUATION KIT

AVAILABLE

Pin Configurations, Typical Operating Circuit, and Selector
Guide appear at end of data sheet.

PART

TEMP RANGE

PIN­PACKAGE

PKG

CODE

MAX6870ETJ

T3277-2

MAX6871ETJ

T3277-2

SMBus is a trademark of Intel Corp.

I

2

C is a trademark of Philips Corp.

Purchase of I

2

C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associated Companies, conveys
a license under the Philips I

2

C Patent Rights to use these com-

ponents in an I

2

C system, provided that the system conforms

to the I

2

C Standard Specification as defined by Philips.

-40°C to +85°C 32 Thin QFN

-40°C to +85°C 32 Thin QFN

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V

IN1

= +6.5V to +13.2V, V

IN2

= +10V, V

IN3

to V

IN6

= +2.7V to +5.5V, AUXIN_ = GPI_ = GND, MARGIN = MR = DBP, TA= -40°Cto

+85°C, unless otherwise noted. Typical values are at T

A

= +25°C.) (Notes 1 and 2)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

All Voltages referenced to GND
IN3–IN6, ABP, SDA, SCL, A0, A1,

GPI1–GPI4, MR, MARGIN, PO5–PO8

(MAX6870), PO3/PO4/PO5 (MAX6871)............-0.3V to +6V

IN1, PO1–PO4 (MAX6870), PO1/PO2 (MAX6871)....-0.3V to +14V

IN2 ...........................................................................-20V to +20V

DBP, AUXIN1, AUXIN2, REFIN.................................-0.3V to +3V

Input/Output Current (all pins)..........................................±20mA

Continuous Power Dissipation (T

A

= +70°C)
32-Pin 7mm x 7mm Thin QFN

(derate 33.3mW/°C above +70°C).............................2667mW

Operating Temperature Range ...........................-40°C to +85°C

Maximum Junction Temperature .....................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER

CONDITIONS MIN

UNITS

V

IN1

Voltage on IN1 to ensure the device is fully
operational, IN3 to IN6 = GND

4.0

Operating Voltage Range
(Note 3)

V

IN3

to

V

IN6

Voltage on any one of IN3 to IN6 to ensure
the device is fully operational, IN1 = GND

2.7 5.5

V

IN1 Supply Voltage
(Note 3)

V

IN1P

Minimum voltage on IN1 to guarantee that the
device is powered through IN1

6.5 V

Undervoltage Lockout

Minimum voltage on one of IN3 to IN6 to

2.5 V

V

IN1

= +13.2V, IN2 to IN6 = GND, no load 1.2 1.5

Supply Current I

CC

Writing to configuration registers or EEPROM,
no load

1.3 2

mA

V

IN1

(50mV increments) 2.5

V

IN1

(25mV increments)

V

IN2

(50mV increments)

V

IN2

(25mV increments)

V

IN3

to V

IN6

(20mV increments) 1.0 5.5

Threshold Range V

TH

V

IN3

to V

IN6

(10mV increments)

V

TA = +25°C-1.0

IN1 to IN6 positive,
V

IN_

falling

-1.5

TA = +25°C-1.5

-15.25V ≤ V

IN2

≤ -5V,

V

IN2

falling

-2 +2

%

TA = +25°C -75 +75

Threshold Accuracy

-5V ≤ V

IN2

≤ 0, V

IN2

falling

mV

Threshold Hysteresis

0.3

% V

TH

Reset Threshold Temperature
Coefficient

10

ppm/

°C

Threshold-Voltage Differential
Nonlinearity

-1 +1

LSB

SYM B O L

TYP MAX

13.2

V

UVLO

V

TH-HYST

∆VTH/°C

VTH DNL

guarantee the device is EEPROM configured.

13.2

1.250 7.625

±2.50 ±15.25

±1.250 ±7.625

0.50 3.05

TA = -40°C to +85°C

TA = -40°C to +85°C

TA = -40°C to +85°C -100 +100

+1.0

+1.5

+1.5

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad

Power-Supply Sequencers/Supervisors with ADC

_______________________________________________________________________________________ 3

PARAMETER

CONDITIONS MIN

UNITS

IN1 Input Leakage Current I

LIN1

For V

IN1

< the highest of V

IN3

to V

IN6

100 140 µA

IN2 Input Impedance R

IN2

160 230 320

kΩ

IN3 to IN6 Input Impedance

R

IN3

to

R

IN6

V

IN1

> 6.5V

70 100 145

kΩ

Power-Up Delay

t

PU

V

ABP

≥ V

UVLO

3.5

ms

IN_ to PO_ Delay t

DPO

V

IN_

falling or rising, 100mV overdrive 25 µs

000 25 µs

001

010

011

25

100 45 50 55

101 180 200 220

110 360 400 440

PO_ Timeout Period t

RP

Register contents
(Table 25)

111

ms

V

ABP

≥ +2.5V, I

SINK

= 500µA 0.3

PO1–PO4 (MAX6870), PO1/PO2
(MAX6871) Output Low (Note 3)

V

OL

V

ABP

≥ +4.0V, I

SINK

= 2mA 0.4

V

V

ABP

≥ +2.5V, I

SINK

= 1mA 0.3

P O5–P O8 ( M AX 6870) , P O 3/P O4/

P O5 ( M AX 6871) O utp ut Low ( N ote 3)

V

OL

V

ABP

≥ +4.0V, I

SINK

= 4mA 0.4

V

PO1–PO8 Output Initial Pulldown
Current

I

PD

V

ABP

≤ V

UVLO

, V

PO_

= 0.8V 10 40 µA

PO1–PO8 Output Open-Drain
Leakage Current

I

LKG

Output high impedance -1 +1 µA

PO1–PO8 Output Pullup

Resistance, Weak Pullup Selected

R

PU

V

PO_

= 2V 6.6 10

kΩ

PO1–PO4 (MAX6870), PO1/PO2
(MAX6871) Turn-On Time, Charge
Pump Selected (Note 4)

t

ON

C

PO_

= 1500pF, V

ABP

= +3.3V,

V

PO_

= +7.8V

0.5 1.5 3.0

ms

PO1–PO4 (MAX6870), PO1/PO2
(MAX6871) Turn-Off Time, Charge
Pump Selected

t

OFF

C

PO_

= 1500pF, V

ABP

= +3.3V,

V

PO_

= +0.5V

30 µs

With respect to V

ABP

, I

PO_

< 100nA 5.5

PO1–PO4 (MAX6870), PO1/PO2
(MAX6871) Output High,

Charge Pump Selected (Notes 3, 4)

With respect to V

ABP

, I

PO_

< 1µA 4.0 5.0 6.0

V

Any one of V

IN3

to V

IN6

≥ +2.7V, I

SOURCE

=

10mA, output pulled up to the same IN_

1.5

Any one of V

IN3

to V

IN6

≥ +2.7V, I

SOURCE

=

1mA, output pulled up to the same IN_

PO5–PO8 (MAX6870), PO3/PO4/
PO5 (MAX6871) Output High,
Push-Pull Selected (Note 3)

V

OH

Any one of V

IN3

to V

IN6

≥ +4.5V, I

SOURCE

=

2mA, output pulled up to the same IN_

V

ELECTRICAL CHARACTERISTICS (continued)

(V

IN1

= +6.5V to +13.2V, V

IN2

= +10V, V

IN3

to V

IN6

= +2.7V to +5.5V, AUXIN_ = GPI_ = GND, MARGIN = MR = DBP, TA= -40°Cto

+85°C, unless otherwise noted. Typical values are at T

A

= +25°C.) (Notes 1 and 2)

SYMBOL

TYP MAX

1.406 1.5625 1.719

5.625 6.25 6.875

22.5

1440 1600 1760

27.5

15.0

V

OHCP

0.8 x
V

IN_

0.8 x
V

IN_

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC

4 _______________________________________________________________________________________

PARAMETER

SYM B O L

CONDITIONS MIN

TYP

MAX

UNITS

V

IL

0.8

MR, MARGIN, GPI_ Input Voltage

V

IH

1.4

V

MR Input Pulse Width t

MR

1µs

MR Glitch Rejection 100 ns
MR to PO_ Delay t

DMR

2µs

MR to V

DBP

Pullup Current I

MR

V MR = +1.4V 5 10 15 µA

MARGIN to V

DBP

Pullup Current

V

MARGIN

= +1.4V 5 10 15 µA

GPI_ to PO_ Delay

200 ns

GPI_ Pulldown Current I

GPI_

V

GPI_

= +0.8V 5 10 15 µA

Watchdog Input Pulse Width t

WDI

GPI_ configured as a watchdog input 50 ns

000

001

25

010 90 100 110

011 360 400 440

ms

100

101

110

Watchdog Timeout Period t

WD

Register Contents
(Table 28)

111

s

Reference Input Voltage Range

V

Reference Input Resistance

V

REFIN

= +1.25V 500

kΩ

IN1, LSB = 18.3mV 0

IN1, LSB = 9.16mV 0

IN2, LSB = 18.3mV 0

IN2, LSB = 9.16mV 0

IN3 to IN6, LSB = 7.32mV 0

IN3 to IN6, LSB = 3.66mV 0

ADC Range

AUXIN_, LSB = 1.2mV 0

V

IN1 to IN6 positive

Internal Reference

IN2 negative

ADC Total Unadjusted Error
(Note 5)

TUE

E xter nal Refer ence, IN 1 to IN 6 p osi ti ve ( N ote 6)

%FSR

ADC Differential Nonlinearity DNL (Note 7) ±1

LSB

ADC Total Monitoring Cycle Time

t

C

Monitors all 8 inputs 200 266

ms

AUXIN_ Input Leakage Current

V

AUXIN_

= 1.25V -1 +1 µA

SERIAL INTERFACE LOGIC (SDA, SCL, A0, A1)

Logic Input Low Voltage V

IL

0.8 V

Logic Input High Voltage V

IH

2.0 V

Input Leakage Current I

LKG

-1 +1 µA

Output Voltage Low V

OL

I

SINK

= 3mA 0.4 V

Input/Output Capacitance C

I/O

10 pF

ELECTRICAL CHARACTERISTICS (continued)

(V

IN1

= +6.5V to +13.2V, V

IN2

= +10V, V

IN3

to V

IN6

= +2.7V to +5.5V, AUXIN_ = GPI_ = GND, MARGIN = MR = DBP, TA= -40°Cto

+85°C, unless otherwise noted. Typical values are at T

A

= +25°C.) (Notes 1 and 2)

I

MARGIN

t

DGPI_

V

REFIN

R

REFIN

I

LAUXIN_

5.625 6.25 6.875

22.5

1.44 1.60 1.76

5.76 6.40 7.04

23.04 25.60 28.16

92.16 102.40 112.64

1.225 1.25 1.275

±1.0

9.366

±15.25

±9.366

3.746

1.249

27.5

13.2

5.50

±1.0

±1.0

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad

Power-Supply Sequencers/Supervisors with ADC

_______________________________________________________________________________________ 5

Note 1: Specifications guaranteed for the stated global conditions. The device also meets the parameters specified when 0 < V

IN1

< +6.5V, and at least one of V

IN3

through V

IN6

is between +2.7V and +5.5V, while the remaining V

IN3

through V

IN6

are

between 0 and +5.5V.

Note 2: Device may be supplied from any one of IN_, except IN2.
Note 3: The internal supply voltage, measured at ABP, equals the maximum of IN3 to IN6 if V

IN1

= 0, or equals +5.4V if V

IN1

>

+6.5V. For +4V < V

IN1

< +6.5V and V

IN3

through V

IN6

> +2.7V, the input that powers the device cannot be determined.

Note 4: 100% production tested at T

A

= +25°C and TA= +125°C. Specifications at TA= -40°C are guaranteed by design.

Note 5: V

IN_

> 0.3 x ADC range.

Note 6: Does not include the inaccuracy of the external +1.25V voltage reference.
Note 7: DNL implicitly guaranteed by design in a sigma-delta converter.
Note 8: C

BUS

= total capacitance of one bus line in pF. Rise and fall times are measured between 0.1 x V

BUS

and 0.9 x V

BUS

.

Note 9: Input filters on SDA, SCL, A0, and A1 suppress noise spikes < 50ns.
Note 10: An additional cycle is required when writing to configuration memory for the first time.

TIMING CHARACTERISTICS

(IN1 = GND, V

IN2

= +10V, V

IN3

to V

IN6

= +2.7V to +5.5V, AUXIN_ = GPI_ = GND, MARGIN = MR = DBP, TA= -40°C to +85°C,

unless otherwise noted. Typical values are at T

A

= +25°C.) (Notes 1 and 2)

PARAMETER

SYM B O L

CONDITIONS

MIN

TYP

MAX

UNITS

TIMING CHARACTERISTICS (Figure 2)

Serial Clock Frequency f

SCL

kHz

Clock Low Period t

LOW

1.3 µs

Clock High Period

0.6 µs

Bus-Free Time t

BUF

1.3 µs

START Setup Time

0.6 µs

START Hold Time

0.6 µs

STOP Setup Time

0.6 µs

Data-In Setup Time

ns

Data-In Hold Time

0

ns

Receive SCL/SDA Minimum Rise Time t

R

(Note 8)

0.1 x

ns

Receive SCL/SDA Maximum Rise Time t

R

(Note 8)

ns

Receive SCL/SDA Minimum Fall Time t

F

(Note 8)

0.1 x

ns

Receive SCL/SDA Maximum Fall Time t

F

(Note 8)

ns

Transmit SDA Fall Time t

F

C

BUS

= 400pF

0.1 x

ns

Pulse Width of Spike Suppressed t

SP

(Note 9) 50 ns

EEPROM Byte Write Cycle Time t

WR

(Note 10) 11 ms

t

HIGH

t

SU:STA

t

HD:STA

t

SU:STO

t

SU:DAT

t

HD:DAT

100

20 +

C

BUS

20 +

C

BUS

300

20 +

C

BUS

300

400

900

300

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC

6 _______________________________________________________________________________________

Typical Operating Characteristics

(V

IN1

= +6.5V to +13.2V, V

IN2

= +10V, V

IN3–IN6

= +2.7V to +5.5V, AUXIN_ = GPI_ = GND, MARGIN = MR = DBP, TA= +25°C,

unless otherwise noted.)

SUPPLY CURRENT

vs. SUPPLY VOLTAGE (IN1)

MAX6870/71 toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

12.511.510.59.58.57.5

0.9

1.0

1.1

1.2

1.3

1.4

1.5

0.8

6.5 13.5

TA = +85°C

TA = +25°C

TA = -40°C

SUPPLY CURRENT

vs. SUPPLY VOLTAGE (IN3 TO IN6)

MAX6870/71 toc02

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

5.04.54.03.53.0

0.9

1.0

1.1

1.2

1.3

1.4

1.5

0.8

2.5 5.5

TA = +25°C

TA = +85°C

TA = -40°C

NORMALIZED PO_ TIMEOUT PERIOD

vs. TEMPERATURE

MAX6870/71 toc03

TEMPERATURE (°C)

NORMALIZED PO_ TIMEOUT PERIOD

6035-15 10

0.97

0.98

0.99

1.00

1.02

1.01

1.03

1.04

0.96

-40 85

IN_ TO PO_

PROPAGATION DELAY vs. TEMPERATURE

MAX6870/71 toc04

TEMPERATURE (°C)

IN_ TO PO_ OUTPUT PROPAGATION DELAY (µs)

603510-15

12

14

16

18

20

22

24

26

28

30

10

-40 85

100mV OVERDRIVE

NORMALIZED WATCHDOG TIMEOUT PERIOD

vs. TEMPERATURE

MAX6870/71 toc05

TEMPERATURE (°C)

NORMALIZED WATCHDOG TIMEOUT PERIOD

6035-15 10

0.985

0.990

0.995

1.000

1.010

1.005

1.015

1.020

0.980

-40 85

NORMALIZED IN_ THRESHOLD

vs. TEMPERATURE

MAX6870/71 toc06

TEMPERATURE (°C)

NORMALIZED IN_ THRESHOLD

603510-15

0.992

0.994

0.996

0.998

1.000

1.002

1.004

1.006

1.008

1.010

0.990

-40 85

IN3 THRESHOLD = 1V,
20mV/STEP RANGE

MAXIMUM IN_ TRANSIENT DURATION

vs. IN_ THRESHOLD OVERDRIVE

MAX6870/71 toc07

IN_ THRESHOLD OVERDRIVE (mV)

MAXIMUM_ TRANSIENT DURATION (µs)

10010

10

20

30

40

50

60

70

80

90

100

110

120

130

0

1 1000

PO_ ASSERTION
OCCURS ABOVE THIS LINE

OUTPUT VOLTAGE LOW

vs. SINK CURRENT

MAX6870/71 toc08

I

SINK

(mA)

V

OL

(mV)

131210

11

3456 789

1

2

50

100

150

200

250

300

350

400

450

0

014

15

OPEN-DRAIN, CHARGE
PUMP, OR WEAK PULLUP
PO1–PO4 (MAX6870)
PO1/PO2 (MAX6871)

PUSH-PULL
PO5–PO8 (MAX6870)
PO3/PO4/PO5 (MAX6871)

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad

Power-Supply Sequencers/Supervisors with ADC

_______________________________________________________________________________________ 7

OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT

(PUSH-PULL OUTPUT)

MAX6870/71 toc10

I

OUT

(mA)

V

OH

(V)

555040 4510 15 20 25 30 355

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

0

060

PUSH-PULL TO IN3
IN3 = 5V

PO5–PO8 (MAX6870)

PO3/PO4/PO5 (MAX6871)

OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT

(CHARGE-PUMP OUTPUT)

MAX6870/71 toc11

SOURCE CURRENT (µA)

OUTPUT VOLTAGE HIGH (V)

4321

3.5

4.0

4.5

5.0

5.5

6.0

3.0
05

MEASURED RELATIVE TO V

ABP

PO1–PO4 (MAX6870)

PO1/PO2 (MAX6871)

MR TO PO_ PROPAGATION DELAY

vs. TEMPERATURE

MAX6870/71 toc12

TEMPERATURE (°C)

MR TO PO_ PROPAGATION DELAY (µs)

6035-15 10

1.55

1.60

1.65

1.70

1.80

1.75

1.85

1.90

1.50

-40 85

MAXIMUM MR TRANSIENT DURATION

vs. MR THRESHOLD OVERDRIVE

MAX6870/71 toc13

MR THRESHOLD OVERDRIVE (mV)

MAXIMUM MR TRANSIENT DURATION (µs)

10010

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

0

1 1000

PO_ ASSERTION OCCURS
ABOVE THIS LINE

OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT

(WEAK PULLUP OUTPUT)

MAX6870/71 toc09

I

OUT

(mA)

V

OH

(V)

4.54.03.0 3.51.0 1.5 2.0 2.50.5

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

0

05.0

WEAK PULLUP
TO ABP

Typical Operating Characteristics (continued)

(V

IN1

= +6.5V to +13.2V, V

IN2

= +10V, V

IN3–IN6

= +2.7V to +5.5V, AUXIN_ = GPI_ = GND, MARGIN = MR = DBP, TA= +25°C,

unless otherwise noted.)

ADC ACCURACY

vs. TEMPERATURE

MAX6870/71 toc14

TEMPERATURE (°C)

TOTAL UNADJUSTED ERROR (%)

603510-15

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1.0

-1.0

-40 85

V

IN2

= -12V,

50mV/STEP RANGE

V

IN3

= 5V,

20mV/STEP RANGE

V

IN1

= 9V,

25mV/STEP RANGE

V

AUXIN1

= 1V

FET (IRF7811W)

TURN-ON WITH CHARGE PUMP

MAX6870/71 toc15

V

PO1

10V/div

V

SOURCE

2V/div

I

DRAIN

5A/div

SEE FIGURE 9

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC

8 _______________________________________________________________________________________

Pin Description

PIN

NAME

FUNCTION

1 3 PO2

Programmable Output 2. Configurable, active-high, active-low, open-drain, weak pullup, or
charge-pump output. PO2 pulls low with a 10µA internal current sink for +1V < V

ABP

< V

UVLO

.

PO2 assumes its programmed conditional output state when ABP exceeds UVLO.

2 5 PO3

Programmable Output 3. Configurable, active-high, active-low, open-drain, weak pullup
(MAX6870), push-pull (MAX6871), or charge-pump (MAX6870) output. PO3 pulls low with a
10µA internal current sink for +1V < V

ABP

< V

UVLO

. PO3 assumes its programmed conditional

output state when ABP exceeds UVLO.

3 6 PO4

Programmable Output 4. Configurable, active-high, active-low, open-drain, weak pullup
(MAX6870), push-pull (MAX6871), or charge-pump (MAX6870) output. PO4 pulls low with a
10µA internal current sink for +1V < V

ABP

< V

UVLO

. PO4 assumes its programmed conditional

output state when ABP exceeds UVLO.

4 4 GND Ground

5 7 PO5

Programmable Output 5. Configurable, active-high, active-low, open-drain, weak pullup, or
push-pull output. PO5 pulls low with a 10µA internal current sink for +1V < V

ABP

< V

UVLO

. PO5

assumes its programmed conditional output state when ABP exceeds UVLO.

6 — PO6

Programmable Output 6. Configurable, active-high, active-low, open-drain, weak pullup, or
push-pull output. PO6 pulls low with a 10µA internal current sink for +1V < V

ABP

< V

UVLO

. PO6

assumes its programmed conditional output state when ABP exceeds UVLO.

7 — PO7

Programmable Output 7. Configurable, active-high, active-low, open-drain, weak pullup, or
push-pull output. PO7 pulls low with a 10µA internal current sink for +1V < V

ABP

< V

UVLO

. PO7

assumes its programmed conditional output state when ABP exceeds UVLO.

8 — PO8

Programmable Output 8. Configurable, active-high, active-low, open-drain, weak pullup, or
push-pull output. PO8 pulls low with a 10µA internal current sink for +1V < V

ABP

< V

UVLO

.

PO8 assumes its programmed conditional output state when ABP exceeds UVLO.

9, 10

1, 8, 9, 10,

N.C. No Connection. Not internally connected.

11 11

Margin Input. Configure MARGIN to either assert PO_ into a programmed state or to hold PO_
in its existing state when driving MARGIN low. See Table 8. Leave MARGIN unconnected or
connect to DBP if unused. MARGIN overrides MR if both assert at the same time. MARGIN is
internally pulled up to DBP through a 10µA current source.

12 12 MR

Manual Reset Input. Configure MR to either assert PO_ into a programmed state or to have no
effect on PO_ when driving MR low. See Table 7. Leave MR unconnected or connect to DBP if
unused. MR is internally pulled up to DBP through a 10µA current source.

13 13 SDA Serial Data Input/Output (Open-Drain). SDA requires an external pullup resistor.

14 14 SCL Serial Clock Input. SCL requires an external pullup resistor.

15 15 A0

Address Input 0. Address inputs allow up to four MAX6870/MAX6871 connections on one
common bus. Connect A0 to GND or to the serial interface power supply.

16 16 A1

Address Input 1. Address inputs allow up to four MAX6870/MAX6871 connections on one
common bus. Connect A1 to GND or to the serial interface power supply.

MAX6870 MAX6871

25, 26, 32

MARGIN

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad

Power-Supply Sequencers/Supervisors with ADC

_______________________________________________________________________________________ 9

Pin Description (continued)

PIN

MAX6870

FUNCTION

17 17 GPI4

General-Purpose Logic Input 4. An internal 10µA current source pulls GPI4 to GND. Configure
GPI4 to control watchdog timer functions or the programmable outputs.

18 18 GPI3

General-Purpose Logic Input 3. An internal 10µA current source pulls GPI3 to GND. Configure
GPI3 to control watchdog timer functions or the programmable outputs.

19 19 GPI2

General-Purpose Logic Input 2. An internal 10µA current source pulls GPI2 to GND. Configure
GPI2 to control watchdog timer functions or the programmable outputs.

20 20 GPI1

General-Purpose Logic Input 1. An internal 10µA current source pulls GPI1 to GND. Configure
GPI1 to control watchdog timer functions or the programmable outputs.

21 21 ABP

Internal Power-Supply Output. Bypass ABP to GND with a 1µF ceramic capacitor. ABP powers
the internal circuitry of the MAX6870/MAX6871. ABP supplies the input voltage to the internal
charge pumps when the programmable outputs are configured as charge-pump outputs. Do
not use ABP to supply power to external circuitry.

22 22 DBP

Internal Digital Power-Supply Output. Bypass DBP to GND with a 1µF ceramic capacitor. DBP
supplies power to the EEPROM memory and the internal logic circuitry. Do not use DBP to
supply power to external circuitry.

23 23

Auxiliary Input 2. A 10-bit ADC monitors the input voltage at AUXIN2. The high-impedance
AUXIN2 input accepts input voltages up to V

REFIN

. AUXIN2 does not influence EEPROM-

configurable power-supply sequencing or reset detection functions.

24 24

Auxiliary Input 1. A 10-bit ADC monitors the input voltage at AUXIN1. The high-impedance
AUXIN1 input accepts input voltages up to V

REFIN

. AUXIN1 does not influence EEPROM-

configurable power-supply sequencing or reset detection functions.

25 — IN6

Voltage Input 6. Configure IN6 to detect voltage thresholds between +1V and +5.5V in 20mV
increments, or +0.5V to +3.05V in 10mV increments. For improved noise immunity, bypass IN6
to GND with a 0.1µF capacitor installed as close to the device as possible.

26 — IN5

Voltage Input 5. Configure IN5 to detect voltage thresholds between +1V and +5.5V in 20mV
increments, or +0.5V to +3.05V in 10mV increments. For improved noise immunity, bypass IN5
to GND with a 0.1µF capacitor installed as close to the device as possible.

27 27 IN4

Voltage Input 4. Configure IN4 to detect voltage thresholds between +1V and +5.5V in 20mV
increments, or +0.5V to +3.05V in 10mV increments. For improved noise immunity, bypass IN4
to GND with a 0.1µF capacitor installed as close to the device as possible.

28 28 IN3

Voltage Input 3. Configure IN3 to detect voltage thresholds between +1V and +5.5V in 20mV
increments, or +0.5V to +3.05V in 10mV increments. For improved noise immunity, bypass IN3
to GND with a 0.1µF capacitor installed as close to the device as possible.

29 29 IN2

Bipolar Voltage Input 2. Configure IN2 to detect negative voltage thresholds from -2.5V to

-15.25V in 50mV increments or -1.25V to -7.625V in 25mV increments. Alternatively, configure
IN2 to detect positive voltage thresholds from +2.5V to +15.25V in 50mV increments or +1.25V
to +7.625V in 25mV increments. For improved noise immunity, bypass IN2 to GND with a 0.1µF
capacitor installed as close to the device as possible.

MAX6871

NAME

AUXIN2

AUXIN1

MAX6870/MAX6871

Detailed Description

The MAX6870/MAX6871 EEPROM-configurable, multi­voltage supply sequencers/supervisors monitor several
voltage-detector inputs, two auxiliary inputs and four
general-purpose logic inputs, and feature programma­ble outputs for highly-configurable, power-supply
sequencing applications. The MAX6870 features six
voltage-detector inputs and eight programmable out­puts, while the MAX6871 features four voltage-detector
inputs and five programmable outputs. Manual reset
and margin disable inputs simplify board-level testing
during the manufacturing process. The MAX6870/
MAX6871 feature an accurate internal 1.25V reference.
For greater accuracy, connect an external +1.25V ref­erence to REFIN.

All voltage detectors provide two configurable thresh­olds for undervoltage/overvoltage or dual undervoltage
detection. One high-voltage input (IN1) provides detec­tor threshold voltages from +1.25V to +7.625V in 25mV
increments or +2.5V to +13.2V in 50mV increments.
A bipolar input (IN2) provides detector threshold volt­ages from ±1.25V to ±7.625V in 25mV increments, or
±2.5V to ±15.25V in 50mV increments. Positive inputs
(IN3–IN6) provide detector threshold voltages from
+0.5V to +3.05V in 10mV increments, or +1.0V to +5.5V
in 20mV increments.

An internal 10-bit ADC monitors the voltage-detector
inputs and two auxiliary inputs through a multiplexer
that automatically sequences through all inputs every
200ms. The host controller communicates with the
MAX6870/MAX6871s’ internal 4kb user EEPROM,
configuration EEPROM, configuration registers, ADC
registers, and fault registers through an SMBus/I

2

C-

compatible serial interface (see Figure 1).

Programmable output options include active-high,
active-low, open-drain, weak pullup, push-pull, and
charge pump. Select the charge-pump output feature
to drive n-channel FETs for power-supply sequencing
(see the Applications Information section). The outputs
swing between 0 and (V

ABP

+ 5V) when configured for

charge-pump operation.

Program each output to assert on any voltage-detector
input, general-purpose logic input, watchdog timer,
manual reset, or other output stages. Programmable
timing-delay blocks configure each output to wait
between 25µs and 1600ms before deasserting. A fault
register logs the conditions that caused each output to
assert (undervoltage, overvoltage, manual reset, etc.).

The MAX6870/MAX6871 feature two watchdog timers,
adding flexibility. Program each watchdog timer to assert
one or more programmable outputs. Program each

EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC

10 ______________________________________________________________________________________

Pin Description (continued)

PIN

MAX6870

NAME

FUNCTION

30 30 IN1

High Voltage Input 1. Configure IN1 to detect voltage thresholds from +2.5V to +13.2V in 50mV
increments or +1.25V to +7.625V in 25mV increments. For improved noise immunity, bypass
IN1 to GND with a 0.1µF capacitor installed as close to the device as possible.

31 31

Reference Voltage Input. Configure the MAX6870/MAX6871 to use either an internal reference
or external reference (see Table 9). When configured for an internal reference, leave REFIN
unconnected. When configured for an external reference, connect a +1.225V to +1.275V
reference to REFIN.

32 2 PO1

Programmable Output 1. Configurable active-high, active-low, open-drain, weak pullup, or
charge-pump output. PO1 pulls low with a weak 10µA internal current sink for +1V < V

ABP

< V

UVLO

. PO1 assumes its programmed conditional output state when ABP exceeds UVLO.

——EP Exposed Paddle. Exposed paddle is internally connected to GND.

MAX6871

REFIN

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad

Power-Supply Sequencers/Supervisors with ADC

______________________________________________________________________________________ 11

COMPARATORS

ADC
MUX

ADC

ADC REGISTERS

REGISTER BANK

CONTROLLER

EEPROM

(USER AND

CONFIG)

OUTPUT
STAGES

LOGIC NETWORK

FOR PO_

WATCHDOG

TIMERS

GPI_

GPI_, MR,

MARGIN

PO_

IN_

SDA,

SCL

ANALOG
BLOCK

DIGITAL
BLOCK

SERIAL

INTERFACE

AUXIN_

Figure 1. Top Level Block Diagram

watchdog timer to clear on a combination of one GPI_
input and one programmable output, one of the GPI_
inputs only, or one of the programmable outputs only.
The initial and normal watchdog timeout periods are
independently programmable from 6.25ms to 102.4s.

A virtual diode-ORing scheme selects the input that pow­ers the MAX6870/MAX6871. The MAX6870/MAX6871

derive power from IN1 if V

IN1

> +6.5V or from the highest

voltage on IN3–IN6 if V

IN1

< +2.7V. The power source

cannot be determined if +4V < V

IN1

< +6.5V and one

of V

IN3

through V

IN6

> +2.7V. The programmable out­puts maintain the correct programmed logic state for
V

ABP

> V

UVLO

. One of IN3 through IN6 must be
greater than +2.7V or IN1 must be greater than +4V for
device operation.

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC

12 ______________________________________________________________________________________

ADC

TIMING

SERIAL

INTERFACE

MAX6870
MAX6871

1.25V
V

REF

IN2 DETECTOR

IN_ DETECTOR

IN1

IN2

IN3

IN4

AUXIN1
AUXIN2

IN5

(N.C.)

IN6

(N.C.)

IN3 DETECTOR

IN4 DETECTOR

IN5 DETECTOR

IN6 DETECTOR

PROGRAMMABLE

ARRAY

TIMING BLOCK 2

TIMING BLOCK 3

TIMING BLOCK 4

TIMING BLOCK 5

TIMING BLOCK 6

TIMING BLOCK 7

TIMING BLOCK 8

PO2 OUTPUT

PO3 OUTPUT

PO4 OUTPUT

PO5 OUTPUT

PO6 OUTPUT

PO7 OUTPUT

PO8 OUTPUT

ADC

REGISTERS

TIMING BLOCK 1

V

ABP

+ 5V

CHARGE PUMP*

MUX

GPI1

GPI2

GPI3

GPI4

MARGIN

MR

IN3–IN6

(IN3–IN4)

PO_
OUTPUT

*PO1–PO4 ONLY
(PO1, PO2)

ABP

MUX

P1**

10kΩ

PO1

PO2

PO3

PO4

PO5

PO6
(N.C.)

PO7
(N.C.)

PO8
(N.C.)

SDA

SCL

A0

A1

OPEN­DRAIN

** PO5–PO8 ONLY
(PO3, PO4, PO5)

ADC

MUX

MAIN

OSCILLATOR

IN1
IN2
IN3
IN4
IN5

IN6
AUXIN1
AUXIN2

EEPROM

CHARGE PUMP

CONFIG

REGISTERS

CONFIG

EEPROM

USER

EEPROM

1µF

ABP

DBP

1µF

2.55V
LDO

5.4V
LDO

(VIRTUAL

DIODES)

REFIN

GND

( ) ARE FOR MAX6871 ONLY.

ADC

Functional Diagram

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad

Power-Supply Sequencers/Supervisors with ADC

______________________________________________________________________________________ 13

Powering the MAX6870/MAX6871

The MAX6870/MAX6871 derive power from the positive
voltage-detector inputs: IN1, or IN3–IN6. A virtual diode­ORing scheme selects the positive input that supplies
power to the device (see the Functional Diagram). IN1
must be at least +4V or one of IN3–IN6 (MAX6870)/
IN3/IN4 (MAX6871) must be at least +2.7V to ensure
device operation. An internal LDO regulates IN1 down
to +5.4V.

The highest input voltage on IN3–IN6 (MAX6870)/
IN3/IN4 (MAX6871) supplies power to the device, unless
V

IN1

≥ +6.5V, in which case IN1 supplies power to the

device. For +4V < V

IN1

< +6.5V and one of V

IN3

through

V

IN6

> +2.7V, the input power source cannot be deter­mined due to the dropout voltage of the LDO. Internal
hysteresis ensures that the supply input that initially pow­ered the device continues to power the device when
multiple input voltages are within 50mV of each other.

ABP powers the analog circuitry; bypass ABP to GND
with a 1µF ceramic capacitor installed as close to the
device as possible. The internal supply voltage, mea­sured at ABP, equals the maximum of IN3–IN6
(MAX6870)/IN3/IN4 (MAX6871) if V

IN1

= 0, or equals

+5.4V when V

IN1

> +6.5V. Do not use ABP to provide

power to external circuitry.

The MAX6870/MAX6871 also generate a digital supply
voltage (DBP) for the internal logic circuitry and the
EEPROM; bypass DBP to GND with a 1µF ceramic
capacitor installed as close to the device as possible.
The nominal DBP output voltage is +2.55V. Do not use
DBP to provide power to external circuitry.

ADC

The MAX6870/MAX6871 feature an internal 10-bit ADC
that monitors the voltage-detector inputs and auxiliary
inputs through an internal multiplexer that sequences
through all input voltages in 200ms. Registers 50h to
5Fh store the ADC data. Read the ADC data from the
MAX6870/MAX6871 with the serial interface. The ADC
strictly monitors input voltages and has no effect on
power-supply sequencing, reset detection, or the pro­grammable outputs.

Inputs

The MAX6870/MAX6871 contain multiple logic and volt­age-detector inputs. Each voltage-detector input is
simultaneously monitored for primary and secondary
thresholds. The primary threshold must be an under­voltage threshold. The secondary threshold may be an
undervoltage or overvoltage threshold. Table 1 summa­rizes these various inputs.

Table 1. Programmable Features

FEATURE DESCRIPTION

High Voltage Input

(IN1)

• Primary undervoltage threshold

• Secondary overvoltage or undervoltage threshold

• +2.5V to +13.2V threshold in 50mV increments

• +1.25V to +7.625V threshold in 25mV increments

Bipolar Voltage Input

(IN2)

• Primary undervoltage threshold

• Secondary overvoltage or undervoltage threshold

• ±2.5V to ±15.25V threshold in 50mV increments

• ±1.25V to ±7.625V threshold in 25mV increments

Positive Voltage Input

IN3–IN6 (MAX6870)
IN3, IN4 (MAX6871)

• Primary undervoltage threshold

• Secondary overvoltage or undervoltage threshold

• +1V to +5.5V threshold in 20mV increments

• +0.5V to +3.05V threshold in 10mV increments

Programmable Outputs

PO1–PO4 (MAX6870),

PO1, PO2 (MAX6871)

• Active high or active low

• Open-drain, weak pullup, or charge-pump output

• Weak pullup to IN3–IN6 (IN3 or IN4 for MAX6871) or ABP

• Dependent on MR, MARGIN, IN_, GPI1–GPI4 , WDI1 and WDI2, and/or PO_

• Programmable timeout periods of 25µs, 1.5625ms, 6.25ms, 25ms, 50ms, 200ms, 400ms, or 1.6s

Programmable Outputs

PO5–PO8 (MAX6870),

PO3, PO4, PO5

(MAX6871)

• Active high or active low

• Open-drain, weak pullup, or push-pull output

• Weak pullup to IN3–IN6 (IN3 or IN4 for MAX6871) or ABP

• Push-pull to IN3–IN6 (IN3 or IN4 for MAX6871)

• Dependent on MR, MARGIN, IN_, GPI1–GPI4 , WDI1 and WDI2 , and/or IN_

• Programmable timeout periods of 25µs, 1.5625ms, 6.25ms, 25ms, 50ms, 200ms, 400ms, or 1.6s

Set the primary and secondary threshold voltages for
each voltage-detector input with registers 00h–0Bh.
Each primary threshold voltage must be an undervolt­age threshold. Configure each secondary threshold
voltage as an undervoltage or overvoltage threshold
(see register 0Ch). Set the threshold range for each
voltage detector with register 0Dh.

High Voltage Input (IN1)

IN1 offers threshold voltages of +2.5V to +13.2V in
50mV increments, or +1.25V to +7.625V in 25mV incre­ments. Use the following equations to set the threshold
voltages for IN1:

where V

TH

is the desired threshold voltage and x is the
decimal code for the desired threshold (Table 2). For
the +2.5V to +13.2V range, x must equal 214 or less,
otherwise the threshold exceeds the maximum operat­ing voltage of IN1.

Bipolar Voltage Input (IN2)

IN2 offers negative thresholds from -2.5V to -15.25V in
50mV increments, or from -1.25V to -7.625V in 25mV
increments. Alternatively, IN2 offers positive thresholds
from +2.5V to +15.25V in 50mV increments, or +1.25V
to +7.625V in 25mV increments. Use the following
equations to set the threshold voltages for IN2:

x

VV

V

for V to V range

TH

=++

− .

.

. .

125

0 025

1 25 7 625

x

VV

V

for V to V range

TH

=++

− .

.

. .

25

005

2 5 13 2

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC

14 ______________________________________________________________________________________

Table 1. Programmable Features (continued)

FEATURE DESCRIPTION

General-Purpose Logic

Inputs (GPI1–GPI4)

• Active high or active low logic levels

• Configure GPI_ as inputs to watchdog timers or programmable output stages

Watchdog Timers

• Clear dependent on any combination of one GPI_ input and one programmable output, a GPI_ input

only, or a programmable output only

• Initial watchdog timeout period of 6.25ms, 25ms, 100ms, 400ms, 1.6s, 6.4s, 25.6s, or 102.4s

• Normal watchdog timeout period of 6.25ms, 25ms, 100ms, 400ms, 1.6s, 6.4s, 25.6s, or 102.4s

• Watchdog enable/disable

• Initial watchdog timeout period enable/disable

Auxiliary Inputs

(AUXIN1, AUXIN2)

• Monitored by the internal 10-bit ADC

Manual Reset Input

(MR)

• Forces PO_ into the active output state when MR = GND

• PO_ deassert after MR releases high and the PO_ timeout period expires

• PO_ cannot be a function of MR only

Margining Input

(MARGIN)

• Holds PO_ in existing state or asserts PO_ to a programmed output state, independent of changes in

monitored inputs or watchdog timers, when MARGIN = GND

• Overrides MR when both assert at the same time

Reference Input

(REFIN)

• Internal +1.25V reference voltage

• Goes high-impedance when internal reference selected

• External reference voltage input from +1.225V to +1.275V

• Sets ADC voltage range

10-Bit ADC*

• Monitors IN_, AUXIN1, and AUXIN2

• Completes conversion of all eight inputs in 200ms

• Reference voltage sets ADC range

• Read ADC data from SMBus/I

2

C interface

Write Disable • Locks user EEPROM based on PO_

Configuration Lock • Locks configuration EEPROM

*ADC does not control programmable outputs.

where VTHis the desired threshold voltage and x is the
decimal code for the desired threshold (Table 3).

IN3–IN6

IN3–IN6 offer positive voltage detectors monitor volt­ages from +1V to +5.5V in 20mV increments, or +0.5V
to +3.05V in 10mV increments. Use the following equa­tions to set the threshold voltages for IN_:

where VTHis the desired threshold voltage and x is the
decimal code for the desired threshold (Table 4). For
the +1V to +5.5V range, x must equal 225 or less, oth­erwise the threshold exceeds the maximum operating
voltage of IN3–IN6.

x

VV

V

for V to V range

TH

=++

− .

.

. .

05

001

05 305

x

VV

V

for V to V range

TH

=++

−

.

.

1

002

155

x

VV

V

for V to V range

TH

=++

− .

.

. .

125

0 025

1 25 7 625

x

VV

V

for V to V range

TH

=++

− .

.

. .

25

005

2 5 15 25

x

VV

V

for V to V range

TH

=

()

−−

−− .

.

. .

125

0 025

1 25 7 625

x

VV

V

for V to V range

TH

=

()

−

−−

−

.

.

. .

25

005

2 5 15 25

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad

Power-Supply Sequencers/Supervisors with ADC

______________________________________________________________________________________ 15

Table 2. IN1 Threshold Settings

REGISTER

ADDRESS

EEPROM

MEMORY

BIT

DESCRIPTION

00h 8000h [7:0]

IN1 primary undervoltage detector threshold (V1A) (see equations in the High Voltage Input
(IN1) section).

06h 8006h [7:0]

IN1 secondary undervoltage/overvoltage detector threshold (V1B) (see equations in the
High Voltage Input (IN1) section).

0Ch 800Ch [0]

IN1 secondary overvoltage/undervoltage selection.
0 = overvoltage threshold. 1 = undervoltage threshold.

0Dh 800Dh [0]

IN 1 r ang e sel ecti on.
0 = 2.5V to 13.2V r ang e i n 50m V i ncr em ents. 1 = 1.25V to 7.625V r ang e i n 25m V i ncr em ents.

Table 3. IN2 Threshold Settings

REGISTER

ADDRESS

EEPROM

MEMORY

BIT

DESCRIPTION

01h 8001h [7:0]

IN2 primary undervoltage detector threshold (V2A) (see equations in the Bipolar Voltage
Input (IN2) section).

07h 8007h [7:0]

IN2 secondary undervoltage/overvoltage detector threshold (V2B) (see equations in the
Bipolar Voltage Input (IN2) section).

0Ch 800Ch [1]

IN2 secondary overvoltage/undervoltage selection.
0 = overvoltage threshold. 1 = undervoltage threshold.

0Dh 800Dh [7:6]

IN2 range selection.
00 = -2.5V to -15.25V range in 50mV increments.
01 = -1.25V to -7.625V range in 25mV increments.
10 = +2.5V to +15.25V range in 50mV increments.
11 = +1.25V to +7.625V range in 25mV increments.

ADDRESS

RANGE

ADDRESS

RANGE

MAX6870/MAX6871

EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC

16 ______________________________________________________________________________________

Table 4. IN3–IN6 Threshold Settings

REGISTER

ADDRESS

EEPROM

MEMORY

BIT

DESCRIPTION

02h 8002h [7:0] IN3 primary undervoltage detector threshold (V3A) (see equations in the IN3–IN6 section).

03h 8003h [7:0] IN4 primary undervoltage detector threshold (V4A) (see equations in the IN3–IN6 section).

04h 8004h [7:0]

IN5 (MAX6870 only) primary undervoltage detector threshold (V5A)
(see equations in the IN3–IN6 section).

05h 8005h [7:0]

IN6 (MAX6870 only) primary undervoltage detector threshold (V6A)
(see equations in the IN3–IN6 section).

08h 8008h [7:0]

IN3 secondary undervoltage/overvoltage detector threshold (V3B)
(see equations in the IN3–IN6 section).

09h 8009h [7:0]

IN4 secondary undervoltage/overvoltage detector threshold (V4B)
(see equations in the IN3–IN6 section).

0Ah 800Ah [7:0]

IN5 (MAX6870 only) secondary undervoltage/overvoltage detector threshold (V5B)
(see equations in the IN3–IN6 section).

0Bh 800Bh [7:0]

IN6 (MAX6870 only) secondary undervoltage/overvoltage detector threshold (V6B)
(see equations in the IN3–IN6 section).

[2]

IN3 secondary overvoltage/undervoltage selection.
0 = overvoltage threshold. 1 = undervoltage threshold.

[3]

IN4 secondary overvoltage/undervoltage selection.
0 = overvoltage threshold. 1 = undervoltage threshold.

[4]

IN5 (MAX6870 only) secondary overvoltage/undervoltage selection.
0 = overvoltage threshold. 1 = undervoltage threshold.

[5]

IN6 (MAX6870 only) secondary overvoltage/undervoltage selection.
0 = overvoltage threshold. 1 = undervoltage threshold.

0Ch 800Ch

[7:6] Not used.

[1]

IN 3 r ang e sel ecti on.
0 = + 1V to + 5.5V r ang e i n 20m V i ncr em ents. 1 = + 0.5V to + 3.05V r ang e i n 10m V i ncr em ents.

[2]

IN 4 r ang e sel ecti on.
0 = + 1V to + 5.5V r ang e i n 20m V i ncr em ents. 1 = + 0.5V to + 3.05V r ang e i n 10m V i ncr em ents.

[3]

IN 5 ( M AX 6870 onl y) r ang e sel ecti on.
0 = + 1V to + 5.5V r ang e i n 20m V i ncr em ents. 1 = + 0.5V to + 3.05V r ang e i n 10m V i ncr em ents.

[4]

IN 6 ( M AX 6870 onl y) r ang e sel ecti on.
0 = + 1V to + 5.5V r ang e i n 20m V i ncr em ents. 1 = + 0.5V to + 3.05V r ang e i n 10m V i ncr em ents.

0Dh 800Dh

[5] Not used.

ADDRESS

RANGE